157 Journal of Applied Sciences Research, 8(1): 157-167, 2012 ISSN 1819-544X This is a refereed journal and all articles are professionally screened and reviewed

ORIGINAL ARTICLES

Effect of irrigation intervals and exogenous proline application in improving tolerance of garden cress plant (Lepidium sativum L.) to water stress.

Soha E. Khalil and A.A. El-Noemani

Department of Water Relations and Field Irrigation, National Research Centre, Dokki, Cairo, Egypt

ABSTRACT

The present work has been performed to study the growth, yield and some metabolic activities of garden cress plant (Lepidium sativum L.) grown under different irrigation intervals (5, 10 and 15 days) and sprayed with different exogenous proline concentrations (1, 5 and 10 mM) and to study the role of exogenous proline in increasing the drought tolerance of this plant. Growth and yield attributes of L. sativum plant decreased with increasing water stress duration. These changes were accompanied with significant increments in proline content and total carbohydrates %. While, oil % revealed increment under moderate stress and decreased with increasing severity of drought. When plants were sprayed with low and moderate proline concentrations opposite trend was detected, indicating significant increases in all studied growth, yield and oil % under all irrigation intervals which were accompanied with decrease in proline and total carbohydrates % compared with control values. The highest proline concentration was ineffective in improving plant tolerance under different irrigation intervals.

Key words: Lepidium sativum L., irrigation intervals, exogenous proline, growth characters, yield, carbohydrates, oil %.

Introduction

Limited water supply is the major environmental constraint in productivity of crop and medicinal plants (Razmjoo et al., 2008). Moisture deficiency induces various physiological and metabolic responses like stomatal closure, decline in growth rate and photosynthesis (Flexas and Medrano, 2002). Colom and Vazzana (2002) also showed that the number of stems per plants and plants dry weights were negatively related to water stress in Eragrostis curvula. Water stress may also change the mineral elements absorption from soil, therefore we can control accessibility of water and minerals in roots medium in order to increase the quality of medicinal plants produced in these soils (Ahmadian et al., 2011). Although a high soil water potential throughout the growing season is necessary to maintain unimpaired crop growth and high economic yield, the imposition of some stress by longer irrigation intervals, higher moisture depletion or skipping irrigation during the early vegetative or during maturation could still attain similar economic yields as well as saving irrigation water and improving water use efficiency (Tayel and Sabreen, 2011). Moussavi et al. (2011) revealed on Trachyspermum Ammi that number of umbels per m2, number of umbels per plant and subsidiary branches, number of umbellate per umbel and 1000-seeds weight were decreased significantly by increasing irrigation intervals. Several strategies have been proposed to alleviate the degree of cellular damage caused by abiotic stress and to improve crop tolerance. Among them, exogenous application of compatible osmolytes such as proline, glycinebetaine, trehalose, etc., had gained considerable attention in mitigating the effect of stress (Ashraf and Foolad, 2007). Under stress condition, exogenous proline application improved tolerance of stressed plants (Deivanai et al., 2011). Proline has been proposed to act as a compatible solute that adjusts the osmotic potential in the cytoplasm, it is considered to play an important role in defense mechanisms of stressed cells (Arshi et al., 2005). In view of Serraj and Sinclair (2002) osmotic adjustment is one of the major physiological phenomena vital for sustaining growth of plants under osmotic stress. Proline degradation can provide carbon, nitrogen and energy source (Gerdakaneh et al., 2010). Exogenously supplied proline is facilitating growth in highly stressed environments (Yancey, 1994); accumulation of proline in the cytoplasm is accompanied by a reduction in the concentrations of less compatible solutes and an increase in cyptosoic water volume (Cayley et al., 1992). On the other hand, there are some reports that showed that high concentrations of proline may be harmful to plants, including inhibitory effects on growth or deleterious effects on cellular metabolisms (Nanjo et al., 2003). Garden cress (Lepidium sativum L.) locally known as Haloon belonging to family Brassicaceae which is native to Southwest Asia and spread to Western Europe. Garden cress is a fast-growing, edible plant botanically related to watercress and mustard and sharing their peppery, tangy flavor and aroma. Garden cress is found to contain significant amounts of iron, calcium and folic acid, in addition to vitamins A and C. The young leaves

Corresponding Author: Soha E. Khalil, Department of Water Relations and Field Irrigation, National Research Centre, Dokki, Cairo, Egypt.

158 J. Appl. Sci. Res., 8(1): 157-167, 2012 were used for salads; the seeds are used as aphrodisiac, edible oil was also obtained from the seeds. It has medicinal properties as an antiscorbutic, incites coitus and stimulates the appetite. Some Arab scholars have attributed garden cress reputation among Muslims to the fact that it was directly recommended by the Prophet (Shehzad et al., 2011). Cress is considered as one of the most important medicinal plants in North Africa (Boulos, 1995). It is an annual herb, common in Nile, Oases and Sinai regions, the seeds are tonic have expectorant activity and contain high concentrations of iodine beneficial to peoples suffering from simple goiter. Moreover, the fresh plant (in the seedling stage) may be eaten as antscorbutic (Kobasi, 1993). The importance of modern herbal medicine has encouraged many farmers to start growing this medicinal plant, the production of this new crop to meet the heavy market demand has not been easy, and attempts at cultivation have brought their own problems (Chiej, 1984). Seed germination, seedling growth and physiological activities of some cultivated plants are strongly affected by soil type and stress conditions (Zidan, 1991; Hajar et al., 1996 and EL-Darier and Youssef, 2000). Therefore, the main target of the present study was to improve growth, tolerance and productivity of Lepidium sativum L. plant grown under limited water and to detect the effect of different exogenous proline doses on some morphological and biochemical compositions of the stressed plants.

Materials And Methods

Studied factors:

Irrigation intervals:

The following three irrigation intervals were applied throughout the entire growth period of the crop: IR1=Irrigation every 5 days. IR2= Irrigation every 10 days. IR3= Irrigation every 15 days. These irrigation intervals were applied 30 days after planting.

Proline treatments:

The following proline concentrations were used during the experiment: P0= sprayed with distilled water (control treatment). P1=sprayed with 1 mM proline. P2=sprayed with 5 mM proline. P3=sprayed with 10 mM proline.

Planting and growth conditions:

In the present investigation, exogenous application of proline was used to minimize the crop yield losses caused by water stress. Hence, the present study provides important information on physiological and biochemical roles of exogenously applied proline in drought tolerance of garden cress. Two pot experiments were carried out at the greenhouse of the National Research Center, Dokki, Egypt during two successive winter seasons of 2009/2010 and 2010/2011. Seeds were provided from the Agricultural Research Center, Giza, Cairo and directly sown on the 1st of October in earthenware pots of 30 cm diameter filled with 10 kg of clay loam soil. Plants were then thinned to five plants /pot. The mechanical and chemical analyses of the soil were determined according to the standard method described by Klute (1986) and results are shown in Table 1. All pots received a recommended dose of NPK fertilizers, namely 2 g calcium super phosphate (15.5% P2O5), which was added immediately after sowing, 1.5 g potassium sulphate (48% K2O), which was added immediately after thinning, and 2 g ammonium nitrate (33.5% N), which was divided into three equal portions: the first immediately after sowing, the second after thinning and the third 2 weeks after the second dose. Seeds were regularly irrigated with tap water for 30 days; then the different irrigation intervals were then established every 5, 10 and 15 days. All pots were weighted on a beam balance before and during the irrigation, to determine the degree of depletion in the soil moisture content and the calculating amount of water was added. The general principal stated by Boutraa and Sanders (2001) was used for the water treatments application. The four exogenous proline treatments and all possible combinations between them were tested. Each of these treatments was sprayed twice during the plant’s life: the first after 40 days from sowing and the second time two weeks later. Foliar sprays were applied always early in the morning.

Experimental design:

This experiment included 12 treatments which included all combinations between three irrigations intervals

159 J. Appl. Sci. Res., 8(1): 157-167, 2012

(IR1, IR2, and IR3) and four exogenous proline treatments (P0, P1, P2 and P3). Treatments were arranged in a split plot design with six replicates each, and different irrigations intervals were assigned at random in the main plots, while sub-plots were devoted to the different exogenous proline treatments. However, the statical analysis of the experiment was done as described in the randomized complete plot design.

Table 1: Mechanical and chemical analyses of the soil used during the experiment. Season 1st season 2nd season sand % 26 25.7 silt % 36 35.4 clay % 38 37 Texture clay loam clay loam F.C.% 30.9 31.2 W.P.% 16.2 14.3 CaCO3 % 4.5 4.3 OM % 1.3 1.1 PH 7.7 7.7 EC 0.6 0.6 Na+ 2.2 2.00 Mg++ 0.88 0.84 Ca++ 1.11 1.00 K+ 1.48 1.32 HCO3 – 1.14 1.02 Cl – 0.75 0.64 CO3 - - 2.14 2.09 SO4 - - 1.65 1.44

Samples collection:

After 120 days the plants were sampled at random to estimate the following characters: plant height (cm), number of leaves/plant, main root length (cm), number of branches, fresh weight (FW; g) and dry weight (DW; g) of the whole plant. Samples were then collected and dried for 48 h at 70°C to determine proline content (μmole/g DW) in dry leaves according to Troll (1995). Total soluble carbohydrates were also determined in dry leaves according to Dubois et al. (1956). Fixed oil percent in the seeds was determined according to A.O.A.C. method (1980). On 15th of February when plants reached suitable maturity, the following data were taken: plant height (cm), number of siliquae/plant, number of seeds/plant, 1000 seeds weight.

Statistical analyses:

The collected data of two seasons were summed together and means were calculated and were subjected to statistical analysis of variance using the normal (F) test and means were evaluated by using Least Significant Difference (LSD) test at the 5% level according to Snedecor and Cochran (1980).

Results And Discussions

Growth characters:

Results in Table 2 indicated that all studied growth characters were significantly affected by the duration of irrigation intervals in both growing seasons. By increasing the severity and duration of drought from IR1 to IR3, shoot length showed significant reduction. Such reduction in shoot length in response to drought may be due to blocking up of xylem and phloem vessels thus hindering any translocation through them (Lovisolo and Schuber, 1998). Similar results were obtained by Sahid and Juraimi, 1998; Ayodele, 2001; Singh et al., 2006 and Khalil et al., 2010. Data obtained in Table 2 indicated also that there was an inverse relationship between increasing the length of irrigation intervals and the number of leaves formed on plants. The significant reduction in leaf number in response to stress can be attributed to enhancement of leaf abscission due to hormonal imbalance which arose from increased ABA and decreased IAA levels in stressed plants (Wu et al., 2005). Confirmed results were obtained by Masinde et al., 2005; Luvaha et al., 2008 and Kharadi et al., 2011. Data on hand, illustrated also that number of branches/plant increased significantly with decreasing the lenght of irrigation, this may be due to that drought reduced cyclin-dependent kinase activity results in slower cell division as well as inhibition of growth (Schuppler et al., 1998). This supported by the results of Balasubramaniyan and Dharmatingam, 1996 and Ahmed and Mahmoud, 2010. Moreover, the main root length showed direct proportional relationship with increasing the lenght of irrigation intervals. Such significant increases in root growth in stressed plants were attributed to the ability of

160 J. Appl. Sci. Res., 8(1): 157-167, 2012 roots to branch and elongate quickly in an attempt to reach deeper levels in soil to absorb more water (Abdalla and El Khoshiban, 2007). These results were comparable to those obtained formerly by Sharp et al., 1990; Boutraa and Sanders, 2001; Liu and Stutzel, 2004 and Kharadi et al., 2011. Increasing irrigation intervals showed significant reduction in both fresh and dry weights of L. sativum plants (Table 2). The decline in fresh weight may be due to the decrease in water content of stressed plant cells and tissues which loose their turgor and thus shrink (Boyer, 1988). Abdalla and El Khoshiban (2007) reported that the decrease in both fresh and dry weights of stressed plants revealed the influence of water on stimulating and regulating the photosynthetic enzymes which thus influenced both the dry matter production and the fresh weights. These results were consistent with those of Singh- Sangwan et al., 2001; Fatima et al., 2002 and Kharadi et al., 2011.

Table 2: Growth characters of Lepidium sativum L. grown under different irrigation intervals, different exogenous proline concentrations and their interactions (combined analysis of two seasons). Characters Plant height No of leaves/ No of Root length FW DW (cm) plant branches/ (cm) (g) (g) Treatments plant Irrigation intervals IR1 44.33 13.58 8.00 10.58 4.11 1.07 IR2 39.67 11.83 6.33 13.75 3.92 0.70 IR3 33.67 10.17 3.83 15.33 2.39 0.60 LSD0.05 1.20 1.40 1.12 0.40 0.18 0.07 Proline concentrations P0 34.56 10.67 5.11 10.56 2.84 0.60 P1 48.00 14.67 8.44 18.11 5.09 1.24 P2 42.44 12.11 6.00 15.22 3.29 0.81 P3 31.89 10.00 4.67 9.00 2.67 0.51 LSD0.05 0.81 0.95 0.83 1.16 0.12 0.06 Irrigation intervals X Proline concentrations IR1 P0 36.67 12.00 7.00 9.00 3.16 0.80 P1 59.67 17.00 11.00 13.33 6.40 1.73 P2 47.33 13.67 8.00 11.33 3.83 1.09 P3 33.67 11.67 6.00 8.67 3.04 0.66 IR2 P0 34.33 11.00 5.33 10.00 3.09 0.56 P1 47.33 14.00 9.00 20.00 6.07 1.07 P2 45.00 12.00 6.00 16.33 3.60 0.73 P3 32.00 10.33 5.00 8.67 2.92 0.43 IR3 P0 32.67 9.00 3.00 12.67 2.27 0.44 P1 37.00 13.00 5.33 21.00 2.80 0.91 P2 35.00 10.67 4.00 18.00 2.43 0.59 P3 30.00 8.00 3.00 9.67 2.04 0.44

LSD0.05 1.41 1.65 1.43 2.02 0.21 0.11 IR1=irrigation every 5 days P0=control P3=10mM proline IR2=irrigation every 10 days IR3=irrigation every 15 days P1=1mM proline P2=5mM proline

It has been found also that the growth responses of Lepidium sativum plant, due to treatment with different exogenous proline concentrations (1, 5 and 10 mM) varied considerably ranging from stimulation to severe reduction (Table 2). Low proline concentration (P1) was promoting on inducing significant increases in shoot length, number of leaves, number of branches, root length, fresh and dry weights of whole plant as compared with control values. The values of growth parameters were significantly lowered by increasing proline concentration, compared with P1 (1 mM), and were more pronounced using the highest proline concentration P3 (10 mM) compared with untreated plants and P1 treatment. The increases in growth characters caused by low and moderate proline concentrations (P1 & P2) compared with control plants might be due to increase in proline accumulation, which not only protects enzymes, 3D structures of proteins and organelle membranes, but it also supplies energy for growth and survival thereby helping the plant to tolerate stress (Chandrashekar and Sandhyarani 1996; Hoque et al., 2007; Ashraf and Foolad, 2007). On the other hand, the reduction in growth characters under the highest proline concentration (P3) may be attributed to that high concentrations of proline were harmful to plants, including inhibitory effects on growth or deleterious effects on cellular metabolisms (Nanjo et al., 2003 and Deivanai, et al. 2011). The analysis of variance clearly indicated that the highest significant increases in growth characters of L. sativum plants were obtained under the combined effect of IR1XP1, and with significant difference compared with the other treatments. Furthermore, the highest significant means of the main root length were observed under the combined effect of IR3XP1 compared with the other values. These findings of the present study are similar to some studies in which it has been shown that exogenous application of proline alleviates the adverse effects of water stress on the growth of halophyte Allenrolfea occidentalis (Chrominski et al., 1989), rice (Kavi- Kishore et al., 1995), and Zea maize (Qasim and Habib-Ur-Rehman, 2007).

161 J. Appl. Sci. Res., 8(1): 157-167, 2012

Yield Attributes:

Irrigation L. sativum plants with the three studied irrigation intervals showed significant effect on all studied yield attributes (Table 3). Plant height decreased significantly and progressively in different plants of both seasons with increasing the length of irrigation intervals. These results were fortified by those of Sharifi et al., 2005 on Achillea millefolium; Abbaszadeh et al., 2008 on mint; Rahmani et al., 2008 on Calendula officinalis L. and Taheri et al., 2008 on Cichorium intybus L., whom indicated that water deficit during the vegetative period could result in shorter plants and smaller leaf areas. Significant higher number of siliquae/plant, number of seeds/plant and 1000 seeds weight were recorded with the shortest irrigation intervals (IR1) followed by IR2. The decrease in yield attributes under the longest irrigation interval (IR3) may be due to that water stress changing the hormonal balance of mature leaves, thus enhancing leaf senescence and hence the number of active leaves decreased, in addition leaf area was reduced by water shortage, which was attributed to its effect on cell division and lamina expansion, when the leaf level decreased the light attraction and CO2 diffusion inside the leaf decreased and the total capacity of photosynthesis decreased therefore the photosynthetic materials that transferred to seeds will decrease (Ahmed and Mahmoud, 2010 and Moussavi et al., 2011). This was supports the results of Tantawy et al., 2007 and Ahmed and Mahmoud, 2010 on Sesamum indicum. Hossein et al. (2009) illustrated that drought stress reduces yield of medicinal and aromatic plants by three main mechanisms: First, whole canopy absorption of incident photosynthetically active radiation may be reduced, either by drought- induced limitation of leaf area expansion, by temporary leaf wilting or rolling during periods of severe stress, or by early leaf senescence. Second, drought stress decreased the efficiency with which absorbed photosynthetically active radiation was used by the crop to produce new dry matter (the radiation use efficiency), this could be detected as a decrease in the amount of crop dry matter accumulated per unit of photosynthetically active radiation absorbed over a given period of time, or as a reduction in the instantaneous whole-canopy net CO2 exchange rate per unit absorbed photosynthetically active radiation. Third, drought stress may limit grain yield of medicinal and aromatic plants by reducing the harvest index (HI). This could occur even in the absence of a strong reduction in total medicinal and aromatic plants dry matter accumulation. Numerous studies were indicated that seed yield can be drastically reduced as a result of water deficit during the reproductive period of Vitis vinifera L. (Scalabrelli et al., 2007) and Coriandrum sativum L. (Aliabadi et al., 2008).

Table 3: Yield attributes of Lepidium sativum L. grown under different irrigation intervals, different exogenous proline concentrations and their interactions (combined analysis of two seasons). Characters Plant height No of siliquae/plant No of seeds/plant 1000 seeds weight Treatments (cm) (g) Irrigation intervals IR1 51.75 58.58 440.92 2.09 IR2 47.83 50.58 315.75 1.63 IR3 37.08 27.58 215.67 0.96 LSD0.05 1.74 1.18 7.15 0.05 Proline concentrations P0 41.44 30.78 257.22 1.20 P1 52.00 70.00 411.11 2.09 P2 50.56 54.89 399.56 1.94 P3 38.22 26.67 228.56 1.01 LSD0.05 0.89 1.68 4.83 0.06 Irrigation intervals X Proline concentrations IR1 P0 46.00 37.00 385.00 1.53 P1 60.00 100.33 515.00 2.90 P2 59.33 66.00 500.33 2.79 P3 41.67 31.00 363.33 1.12 IR2 P0 45.00 34.00 254.00 1.11 P1 54.00 74.67 410.00 2.35 P2 52.00 64.00 395.00 2.02 P3 40.33 29.67 204.00 1.05 IR3 P0 33.33 21.33 132.67 0.95 P1 42.00 35.00 308.33 1.02 P2 40.33 34.67 303.33 0.99 P3 32.67 19.33 118.33 0.86

LSD0.05 1.55 2.90 8.36 0.11 IR1=irrigation every 5 days P0=control P3=10mM proline IR2=irrigation every 10 days IR3=irrigation every 15 days P1=1mMproline P2=5mM proline

The obtained values of plant height, number of siliquae/plant, number of seeds/plant and thousand-seeds weight showed that both P1 and P2 treatments caused significant increases in all previously mentioned yield attributes, the more pronounced effect on these yield attributes were obtained under the lowest proline

162 J. Appl. Sci. Res., 8(1): 157-167, 2012 concentration P1 (1mM). A sharp reduction in all yield attributes obtained under the highest proline concentration P3 (10 mM) compared with control values. Foliar application of proline to water stressed plants caused an increase in stomatal conductance and sub-stomatal CO2 with an increase in net CO2 assimilation rate, these results suggest that the increase in photosynthesis was primarily due to the increase in stomatal conductance which caused higher CO2 diffusion inside the leaf thus favoring higher photosynthetic rate (Sharkey et al., 2007). These results were in agreement with those obtained by Raven, 2002 and Qasim and Habib-Ur-Rehman, 2007. The present investigation revealed also that the higher concentration of proline (P3) had a drastic reduction on all studied yield parameters compared with control treatments, this reduction may be due to the inhibitory effect on root growth which caused by greater accumulation of proline that may interfere with osmotic adjustment (Amzallag, 2002). This result was in confirmation with the findings of Qayyum et al 2007 and Deivanai, et al. 2011. Concerning the effect of interaction between the two studied factors the data on hand showed that low and moderate proline concentrations (P1 and P2) revealed significant increases in all studied yield parameters under different irrigation intervals compared with the other treatments, where the maximum significant records of yield attributes obtained under the effect of IR1XP1, while the minimum significant values were obtained under the effect of IR3XP3 compared with the other treatments. Similar results were recorded by Qasim and Habib- Ur-Rehman (2007) whom reported that exogenous proline counteracted the adverse effects of water stress on growth and yield of two maize cultivars.

Total carbohydrates percent:

Carbohydrates are a major category of compatible solutes which accumulated during stress. Table 4 showed the effect of water stress at different irrigation levels (5, 10 and 15 days) on the total carbohydrates of L. sativum leaves. From the obtained results it was clear that the total carbohydrates percent increased significantly by increasing irrigation intervals. These conditions, in the mean time, enhances some plants to increase their respiration rates as a prerequisite to produce both ATP to activate stressed cells and osmotic soluble substances which reduce cell osmotic potential thus increasing cell water uptake (Khalil et al., 2012). The results obtained here were in agreement with those obtained by Carvalho et al. (2005) whom reported that water stress caused an increase in sugar and total carbohydrates concentrations in seed's dry weight as compared with non stressed control plants of two Lupinus species. Also, Khalid (2006) pointed out that total carbohydrate of Ocimum spp. increased under water stress. Similar results were obtained by El-Sayed et al., 2008 on two Tribulus species and Khalil et al., 2012 on Jatropha curcas L. Treated plants with low and moderate proline concentrations (P1and P2) exhibited significant decrease in total carbohydrates percent, while P3 treatment revealed insignificant decrease compared with control treatment. Comparable results were obtained by El-Sherbiny and Hassan (1987) on Datura stramonium L., Gamal El-Din et al. (1997) on lemon-grass, and Tarraf (1999) who reported that application of proline decreased soluble sugar and carbohydrate contents of lupine plant. Also, Gamal El-Din and Abd El-Wahed (2005) reported a decrease in total carbohydrates % of chamomile (Matricaria chamomilla L.) plant under low proline concentrations followed by an increase under the highest concentrations. Data of interaction between the two studied factors showed that the highest significant percent of carbohydrate obtained under the interaction of IR3XP0, while the lowest significant values were obtained under the combined effect of IR1XP1 compared with the other treatments.

Proline accumulation:

It has been noticed from the data in Table 4 that, proline accumulation in L. sativum leaves increased progressively by increasing the thirsty period. Such increases in proline values with increasing stress was attributed to one of the defense mechanisms in which stressed plants used to reduce cell osmotic potential, which resulted in increasing cell water uptake with concomitant increases in both cell turgidity and its activity. These results were documented by many researches done in this field e.g., Al-Khayri and Al-Bahrany, 2004; Yamada et al., 2005; Zhao et al., 2007; Hossein et al., 2009 and Khalil et al., 2012. Increasing exogenous proline concentrations caused significant and progressive increases in proline content of L. sativum leaves, the data also showed that both P1and P2 treatments revealed significant decline in proline content compared with that of control plants, this decline in proline concentration may be due to that untreated control plants suffered and showed pronounced accumulation of organic solutes (proline, saccharides, protein and total amino acids) for osmotic adjustment (Abd El-Samad et al., 2011). This confirms the view of many authors such Silveira et al., 2003; Yamada et al., 2005 and Abd El-Samad et al., 2011. Further increase in proline concentration caused significant increase in proline accumulation of L. sativum leaves above that of control plants, this may attribute to the greater proline accumulation which may interfere with osmotic adjustment (Amzallag, 2002).

163 J. Appl. Sci. Res., 8(1): 157-167, 2012

Regarding the effect of interaction, it was found that the lowest significant proline accumulation was obtained under the combined effect of IR1XP1, while the highest significant accumulation was obtained under the combined effect of IR3XP3 compared with the other treatments. This was in accordance with the results obtained by Abd El-Samad et al. (2011) that indicated that proline treatment increased tolerance of maize and broad bean plants through osmo-regulation using the organic solutes. This confirms the view of many authors e.g. Yamada et al., 2005 and Cuin and Shabala 2005.

Table 4: Total carbohydrates %, proline conten and oil % of Lepidium sativum L. grown under different irrigation intervals, different exogenous proline concentrations and their interactions (combined analysis of two seasons). Treatments Total carbohydrates Proline Oil (%) (μmole/g DW) ( %) Irrigation intervals IR1 25.06 2.92 30.82 IR2 27.36 3.43 44.30 IR3 32.30 5.10 23.58 LSD0.05 1.89 0.17 2.79 Proline concentrations P0 32.71 3.58 28.47 P1 22.89 2.91 39.41 P2 25.20 3.08 36.89 P3 32.16 5.68 26.83 LSD0.05 1.12 0.10 2.14 Irrigation intervals X Proline concentrations IR1 P0 28.53 2.81 28.24 P1 20.46 2.05 36.24 P2 22.36 2.25 34.11 P3 28.90 4.55 24.70 IR2 P0 30.70 3.38 35.01 P1 22.53 2.95 55.62 P2 25.56 2.46 52.47 P3 30.63 4.91 34.10 IR3 P0 38.90 4.55 22.15 P1 25.67 3.73 26.37 P2 27.67 4.54 24.10 P3 36.95 7.58 21.70

LSD0.05 2.07 0.92 3.72 IR1=irrigation every 5 days P0=control P3=10mM proline IR2=irrigation every 10 days IR3=irrigation every 15 days P1=1mMproline P2=5mM proline

Oil percent:

By increasing the irrigation interval, the oil percent of L. sativum seeds increased till reached its maximum significant values under the moderate irrigation interval IR2 in both growing seasons, followed by significant decrease under the longest irrigation interval IR3 compared with the other treatments (Table 4). The present increase in oil % were conflicted with that of Hossein et al. (2009) who indicated that drought stress increased the oil percent of more medicinal and aromatic plants because in case of stress, more metabolites are produced in the plants and substances prevented from oxidization in these stressed cells. Fatima et al. (2006) mentioned also that under water stress conditions the oil percentage of palmarosa was increased and oil content was decreased. Moreover, Rahmani et al. (2008) showed that drought stress had significant effect on oil yield and oil percentage of calendula (Calendula officinalis L.), their results showed that the highest oil yield was achieved under non-drought condition and the highest oil percentage was achieved under drought condition. Furthermore, Aliabadi et al., (2009) illustrated that the oil yield of balm (Melissa officinalis L.) was reduced under water deficit stress but oil percentage was increased. On the other hand, the decrease in oil % under the highest irrigation interval IR3 was explained by Chanirar et al. (1989) whom illustrated that increasing severity of drought above certain limits caused reduction in oil % because there was a relationship between the amount of oil percentage and shoot yield, so when the shoot yield decreases by the drought stress therefore oil percentage is reduced. These results were fortified by those of El- Sabbagh, 2003 and Elham and Ibrahim, 2009 on sunflower. It has been found also that the maximum oil % value obtained under P1 concentration followed by significant and progressive decrease with increasing proline concentration till it reached its minimum values under P3 concentration compared with control values. In this respect, Gamal El-Din et al. (1997) reported that foliar application of proline significantly increased oil percent and yield on lemongrass plant. Talaat and Youssef (2002) and Gamal El-Din and Abd El-Wahed (2005) obtained similar results on basil and chamomile plants respectively. The decrease in oil % under the highest concentration (P3) may be due to the reduction in growth and yield parameters under this concentration.

164 J. Appl. Sci. Res., 8(1): 157-167, 2012

The obtained data in the same table showed that the greatest increase in oil percent of L. sativum seeds was obtained under the interaction effect of IR2XP1 and with significant difference compared with the other treatments, while the lowest values obtained under the effect of interaction between IR3XP3 compared with the other treatments.

Conclusions:

From the above mentioned data it could be concluded that: - Water stress negatively affected all growth and yield parameters as well as some metabolic activities of garden cress plants and the higher the level of water stress the greater the negative effect. - low and moderate proline concentrations enhancing the tolerance of garden cress against the water stress, while the highest proline concentration was ineffective in improving plant tolerance under different irrigation intervals. - The interaction between the IR1XP1 revealed the greatest effect on growth and yield parameters as well as of some metabolic activities of garden cress under different irrigation intervals as compared with the other treatments.

References

A.O.A.C., 1980. Association Official Agricultural Chemists (1970). "Official Methods of Analysis", 13th Ed., Washington, D. G., U.S.A. Abbaszadeh, B., A.E. Sharifi, M.R. Ardakani and F.H. Aliabadi, 2008. Effect of drought stress on quantitative and qualitative of mint.Abstracts Book of 5th International Crop Science Congress & Exhibition, Korea, pp: 23. Abd El-Samad, H.M., M.A.K. Shaddad and N. Barakat, 2011. Improvement of plants salt tolerance by exogenous application of amino acids. Journal of Medicinal Plants Research, 5(24): 5692-5699. Abdalla, M.M. and N.H. El-Khoshiban, 2007. The influence of water stress on growth, relative water content, photosynthetic pigments, some metabolic and hormonal contents of two Triticium aestivum cultuivars. Journal of Applied Sciences Research, 3(12): 2062-2074. Ahmadian, A., A. Tavassoli and A.E. Ebrahim, 2011. The interaction effect of water stress and manure on yield components, essential oil and chemical compositions of cumin (Cuminum cyminum). African Journal of Agricultural Research, 6(10): 2309-2315. Ahmed, M.E. and F.A. Mahmoud, 2010. Effect of irrigation on vegetative growth, oil yield and protein content of two sesame (Sesamum indicum L.) cultivars. Research Journal of Agriculture and Biological Sciences, 6(5): 630-636. Aliabadi, F.H., M.H. Lebaschi, A.H. Shiranirad, A.R. Valadabadi and J. Daneshian, 2008. Effects of arbuscular mycorrhizal fungi, different levels of phosphorus and drought stress on water use efficiency, relative water content and proline accumulation rate of coriander (Coriandrum sativum L.). J. Med. Plant. Res., 2(6): 125- 131. Aliabadi, F.H., S.A.R. Valadabadi, J. Daneshian and M.A. Khalvati, 2009. Evaluation changing of essential oil of balm (Melissa officinalis L.) under water deficit stress conditions. J. Med. Plant. Res., 3(5): 329-33. Al-Khayri, J.M. and A.M. Al-Bahrany, 2004. Growth, water content, and proline accumulation in drought- stressed callus of date palm. Bio. Planta, 48(1): 105-108. Amzallag, G.N., 2002. The adaptive potential of plant development: evidence from the response to salinity. In: Lauchli, A., Luttage, U. (Eds.), Salinity: Environment-Plant-Molecules, Kluwer, The Netherlands, 291-312. Arshi, A., M.Z. Abdin and M. Igbal, 2005. Ameliorative effects of CaCl2 on growth, ionic relations and proline content of senna under salinity stress, J. Plant Nutr., 28: 101-25. Ashraf, M. and M.R. Foolad, 2007. Roles of glycinebetaine and proline in improving plant abiotic stress tolerance. Environ. Exp. Bot., 59: 206-216. Ayodele, V.I., 2001. Influence of soil water stress at different physiological stages on growth and seed yield of Amaranthus species. Acta Hort., 537: 767-772. Balasubramaniyan, P. and V. Dharmalingam, 1996. Influence of irrigation and N levels on summer sesame. Sesame and Safflower Newsletter, 11: 45-49. Boulos, L., 1995. Flora of Egypt Checklist. Cairo: Al-Hadara Publishing, pp: 287. Boutraa, A. and F.E., Sanders, 2001. Influence of water stress on grain yield and vegetative growth of two cultivars of bean (Phaseolus vulgaris L.). Journal of Agronomy and Crop Science, 186: 229-237. Boyer, J.S., 1988. Cell enlargement and growth – induced water potentials. Physiol. Plant, 73: 311-316. Carvalho, I.S., M. Chaves and C.P. Ricardo, 2005. Influence of water stress on the chemical composition of seeds of two lupins Lupinus albus and Lupinus mutabilis. J. Agronomy & Crop Sci., 191: 95-98.

165 J. Appl. Sci. Res., 8(1): 157-167, 2012

Cayley, S., B.A. Lewis and M.T.J.R. Record, 1992. Origins of the osmoprotective properties of betaine and proline in Escherichia coli K-12. J. Bacteriol., 174: 1586-1595. Chandrashekar, K.R. and S. Sandhyarani, 1996. Salinity induced chemical changes in Crotalaria striata Dc. Plants. Indian J. Plant Physiol., 1: 44-48. Chanirar, N.J., D.D. Malavia and N.M. Baldha, 1989. Effect of irrigation, nitrogen and phosphorus on the productivity of sunflower. Indian J. Agron., 34(4): 399-401. Chiej, R., 1984. The Macdonald Encyclopedia of Medicinal Plants. London, UK: Macdonald Co. (Publishers) Ltd., pp: 447. Chrominski, A., S. Halls, D.J. Weber and B.N. Smith, 1989. Proline affects ACC to ethylene conversion under salt and water stresses in the halophyte Allenrolfea occidentalis. Environ. Exp. Bot., 29: 359-363. Colom, M.R. and C. Vazzana, 2002. Water stress effects on three cultivars of Eragrostis curvula. Italy J. Agron., 6: 127-32. Cuin, T.A. and S. Shabala, 2005. Exogenously supplied compatible rapidly ameliorate NaCl-induced potassium efflux from barley roots. Pant and Cell Physiol., 46: 1924-1933. Deivanai S, R. Xavier, V. Vinod, K. Timalata and O.F. Lim, 2011. Role of exogenous proline in ameliorating salt stress at early stage in two rice cultivars. Journal of Stress Physiology & Biochemistry, 7(4): 157-174. Dubois, M., K.A. Cilles, J. Hamilton, R. Rebers, F. Smith, 1956. Colorimetric method for the determination of sugars and related substances. Annals of Chemistry, 28: 350-356. EL-Darier, S.M. and R.S. Youssef, 2000. Effect of soil type, salinity, and allelochemicals on germination and seedling growth of a medicinal plant Lepidium sativum L. African Journal of Agricultural Research, 6(3): 608-617. Elham, A.B. and O.M. Ibrahim, 2009. Effect of irrigation intervals, biological, organic and mineral fertilization on the yield and yield components of sunflower plants. Egypt. J. Agron., 31(1): 29-37. El-Sabbagh, A.A., 2003. Influence of irrigation intervals on certain water relations and productivity of two sunflower cultivars. Miufiya J. Agric. Res., 28(4): 1113-1130. El-Sayed, 1A.A., A.M. Razin, 1H.M.F. Swaefy, S.M. Mohamed and K.E.A. Abou-Aitah, 2008. Effect of water stress on yield and bioactive chemical constituents of Tribulus Species. Journal of Applied Sciences Research, 4(12): 2134-2144. El-Sherbiny, E.S. and A.E. Hassan, 1987. Physiological studies on Datura stramanium L., The effect of some alkaloid precursors on growth, chemical composition and leaf alkaloid. Bull. Nat. Res. Cent. (Egypt), 12: 101-10. Fatima, S., A.H.A. Farooqi and R.S. Sangwan, 2006. Water stress mediated modulation in essential oil, proline and polypeptide profile in palmarosa and citronella java. Physiology and Molecular Biology of Plants. Central Institue of Medicinal and Aromatic Plants, P.O. CIMAP, Lucknow - 226 015, India. Fatima, S., A.H.A. Farooqi and S. Sharma, 2002. Physiological and metabolic responses of different genotypes of Cymbopogan martini and C. winterianus to water stress. Plant Growth Regl., 37: 143-149. Flexas, J. and H. Medrano, 2002. Drought-inhibition of photosynthesis in C3 plants: stomatal and non-stomatal limitations revisited. Ann. Bot., 89: 183-189. Gamal EL-Din, K.M. and M.S.A. Abd EL-Wahed, 2005. Effect of some amino acids on growth and essential oil content of chamomile plant. International Journal of. Agriculture and Bioogy, 7(3): 376-380. Gamal, El-Din, K.M., A.S.H. Tarraf and L. Balbaa, 1997. Physiological studies on the effect of some amino acids and micronutrients on growth and essential oil content in lemon grass. J. Agric. Sci. (Mansoura Univ.), 22: 4229-41. Gerdakaneh, M., A.A. Mozafari, Khalighi and A. Sioseh-Mardah, 2010. The effects of exogenous proline and osmotic stress on morpho-biochemical parameters of strawberry callus. African Journal of Biotechnology, 9(25): 3775-3779. Hajar, A.S., M.A. Zidan and M. Al-Zahrani, 1996. Effect of salinity stress on the germination, growth and some physiological activities of black cumin (Nigella sativa L.). Arabian Gulf Journal of ScientiJc Research, 14: 445-454. Hoque, M.A., E. Okuma, M.N.A. Banu, Y. Nakamura, Y. Shimoishi and N. Murata, 2007. Exogenous proline mitigates the detrimental effects of salt stress more than exogenous betaine by increasing antioxidant enzyme activities. J. Plant Physiol., 164: 553-561. Hossein, A.F., A.V. Sayed, D. Jahanfar, H.S. Amir and A.K. Mohammad, 2009. Medicinal and aromatic plants farming under drought conditions. Journal of Horticulture and Forestry, 1(6): 086-092. Kavi-Kishor, P.B., Z. Hong, G.H. Miao, C.A.A. Hu and D.P.S. Verma, 1995. Over expression of D1-pyrroline- 5-carboxylate synthetase increases proline production and confers osmotolerance in transgenic plants. Plant Physiol., 108: 1387-1394. Khalid, A.K., 2006. Influnce of water stress on growth, essential oil and chemical compostion of herbs Ocimum spp. Int. Agrophysics, 20: 289-296.

166 J. Appl. Sci. Res., 8(1): 157-167, 2012

Khalil, S.E, M.M. Hussein and J.T. da Silva, 2012. Roles of antitranspirants in improving growth and water relations of Jatropha curcas L. grown under water stress conditions. Plant Stress, 6(1): 49-54. Khalil, S.E., N.G. Abd El- Aziz and B.H. Abou-Leila, 2010. Effect of water stress and ascorbic acid on some morphologicaland biochemical composition of Ocimum basilicum plant. Journal of American Science, 6(12): 33-44. Kharadi, R., S.D. Upadhyaya, A. Upadhyay and P.S. Nayak, 2011. Differential responses of plumbagin content in Plumbago zeylanica L. (Chitrak) under controlled water stress treatments. Journal of Stress Physiology & Biochemistry, 7(4): 113-121 ISSN 1997-0838. Klute, A., 1986. "Method of solid Analysis", 2nded. Part 1. Physical and Mineralogical Methods. Part 2. Chemical and Microbiological methods. Properties. Modifon, Wiscon fin. U.S.A. Kobasi, H., 1993. Dictionary of Herbs and Medicinal Plants. Bierut, Lebanon: Scientific Books House, pp: 566. (In Arabic). Liu, F. and H. Stutzel, 2004. Biomass partitioning, specific leaf area and water use efficiency of vegetable amaranth (Amaranthus spp.) in response to drought stress. Scientia Horticulturae, 102: 15- 27. Lovisolo, C. and A. Schuber, 1998. Effects of water stress on vessel size xylem hydraulic conductivity in Vitis vinifera L. Journal of Exp. Botany, 49(321): 693-700. Luvaha, E., G.W. Netondo and G. Ouma, 2008. Effect of water deficit on the physiological and morphological characteristics of mango (mangifera indica) rootstock seedlings. American Journal of Plant Physiology, 3: 1-15. Masinde, P.W., H. Stutzel, S.G. Agong and A. Frickle, 2005. Plant growth, water relations and transpiration of spider plant (Gynandropsis gynandra) under water limited conditions. J. Amer. Soc. Hort. Sci., 130: 469- 477. Mohamed, M.A.H., P.J.C. Harris, J. Henderson and F. Senatore, 2002. Effect of drought stress on the yield and composition of volatile oils of drought tolerant and non-drought-tolerant clones of Tagetes minuta. Planta medica., 68(5): 472-474. Moussavi, S.M., M. Salari, H.R. Mobasser and K.M.H. Bijeh, 2011. The effect of different irrigation intervals and mineral nutrition on seed yield of Ajowan (Trachyspermum Ammi). Annals of Biological Research, 2(6): 692-698. Nanjo, T., M. Fujita, M. Seki, M. Kato, S. Tabata and K. Shinozaki, 2003. Toxicity of free proline revealed in an Arabidopsis TDNA- tagged mutant deficient in proline dehydrogenase. Plant Cell Physiol., 44: 541-548. Qasim, A.M.A. and A. Habib-Ur-Rehman, 2007. Exogenously applied proline at different growth stages enhances growth of two maize cultivars grown under water deficit conditions, Pak. J. Bot., 39(4): 1133- 1144. Qayyum, B., M. Shahbaz, and N.A. Akram, 2007. Effect of 24-epibrassinolide on salt tolerance of wheat. International Journal of Agriculture and Biology, 9: 584-589. Rahmani, N., H. Aliabadi Farahani and S.A.R. Valadabadi, 2008. Effects of nitrogen on oil yield and its component of Calendula (Calendula officinalis L.) in drought stress conditions. Abstracts Book of The worldcongress on medicinal and aromatic plants, South Africa, pp: 364. Raven, J.A., 2002. Selection pressures on stomatal evolution. New Phytol., 153: 371-386. Razmjoo, K., P. Heydarizadeh and R. Mohammad, 2008. Effect of salinity and drought stresses on growth parameters and essential oil content of Matricaria chamomile. International Journal of Agriculture and Biology, 10(4): 451-554. Sahid, I.B. and A.S. Juraimi, 1998. Effects of water stress, shading and clipping on growth and development of Asytasia gangetica. Plant Protection Quarterly, 13(3): 140-142. Scalabrelli, G., E. Saracini, D. Remorini, R. Massai and M. Tattini, 2007. Changes in leaf phenolic compounds in two grapevine varieties (Vitis vinifera L.) grown in different water conditions. Acta Hort., 754: 295-300. Schuppler, U., P.C.L. John and R. Munns, 1998. Effects of water stress on cell division and cell-divisioncycle- 2-like cell-cycle kinase activity in wheat leaves, Plant Physiol., 117: 667-678. Serraj, R. and T.R. Sinclair, 2002. Osmolyte accumulation: can it really help increase crop yield under drought conditions. Plant Cell Environ., 25: 333-341. Sharifi, A.E., M. Matin, H. Lebaschi, B. Abbaszadeh and B. Naderi, 2005. Effects of water stress on quantity yield in Achillea millefolium. Abstracts Book of The First International Conference on the Theory and Practices in Biological Water Saving, pp: 211. Sharkey, T.D., J.B. Carl, D.F. Graham and E.L. Singsaas, 2007. Fitting photosynthetic carbondioxide response curves for C3 leaves. Plant Cell Environ., 30: 1035-1040. Sharp, R.E., T.C. Hsiao and W.K. Silk, 1990. Growth of the maize primary root at low water potentials. Plant Physiology, 93: 1337-1346. Shehzad, M., A. Tanveer, M. Ayub, K. Mubeen, N. Sarwar, M. Ibrahim and I. Qadir, 2011. Effect of weed-crop competition on growth and yield of garden cress (Lepidium sativum L.). Journal of Medicinal Plants Research, 5(26): 6169-6172.

167 J. Appl. Sci. Res., 8(1): 157-167, 2012

Silveira, J.A., R.A. Viegas, I.M. da Rocha, A.C. Moreira, A. Moreira Rde, J.T. Oliveira, 2003. Proline accumulation and glutamine synthetase activity and increased by salt-induced proeolysis in cashew leaves. J. Plant Physiol., 160: 115-123. Singh, V., C.K. Pallaghy and D. Singh, 2006. Phosphorus nutrition and tolerance of cotton to water stress. I. Seed cotton yield and leaf morphology. Field Crops Research, 96: 191-198. Singh-Sangwan, N., A.H.A. Farooqi, F. Shibin and R.S. Sangwan, 2001. Regulation of essential oil production in plants. Plant Growth Regul., 34: 3-21. Snedecor, G.W. and W.G. Cochran, 1980. "Statistical Methods" 7th ed. Iowa State Univ., Iowa, USA. Taheri, A.M., J. Daneshian, S.A.R. Valadabadi and F.H. Aliabadi, 2008. Effects of water deficit and plant density on morphological characteristics of chicory (Cichorium intybus L.). Abstracts Book of 5th International Crop Science Congress & Exhibition, pp: 26. Talaat, I.M. and A.A. Youssef, 2002. The role of the amino acids lysine and ornithine in growth and chemical constituents of Basil plants. Egyptian J. Appl. Sci., 17: 83-95. Tarraf, S., 1999. Biochemical and physiological aspects of lupine plant under the effect of kinetin and some amino acids. Egyptian J. Appl. Sci., 14: 59-73. Tantawy, M.M., S.A. Ouda and F.A. Khalil, 2007. Irrigation optimization for different sesame varieties grown under water stress conditions. Journal of Applied Sciences Research, 3(1): 7-12. Tayel, M.Y. and Sabreen, K.H. P., 2011. Effect of Irrigation Regimes, Phosphorous Level and Two Vica faba Varities on II-Yield, Water and Phosphorous Use Efficiency. Journal of Applied Sciences Research, 7(11): 1518-1526. Troll, W.J.L., 1995. Aphotometric method for defermination of proline. Journal of Biological Chemistry, 215: 655-660. Wu, Q., R. Xia and Y. Zou, 2005. Reactive oxygen metabolism in mycorrhizal and nonmycorrhizal citrus (Poncirus trifoliate) seedlings subjected to water stress. Journal of Plant Physiology, 163: 417-425. Yamada, M., H. Morishita, K. Urano, N. Shiozaki, K. Yamaguchi-Shinozaki, K. Shinozaki and Y. Yoshiba, 2005. Effects of free proline accumulation in petunias under drought stress. J. Exp. Bot. 56(417):1975-1981. Yamada, M., H. Morishita and K. Urano, 2005. Effects of free proline accumulation in petunias under drought stress. J. Exp. Bot., 417: 1975-1981. Yancey, P.H., 1994. Compatible and counteracting solutes. In K. Strange (ed): Cellular and MolecularPhysiology of Cell Volume Regulation. CRC Press, Boca Raton, FL., pp: 81-109. Zhao, H., J. Tan and C. Qi, 2007. Photosynthesis of Rehmannia glutinosa subjected to drought stress is enhanced by choline chloride through alleviating lipid peroxidation and increasing proline accumulation. Plant Growth Reg., 51(3): 255-262. Zidan, M.A., 1991. Alleviation of salinity stress on growth and related parameters in wheat sprayed with thiamine, nicotinic acid or pyridoxine. Arabian Gulf Journal of Scientflic Research, 9: 103-117.