DOCSLIB.ORG

Nodulation Studies in Legumes

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Nodulation Studies in Legumes NODULATION STUDIES IN LEGUMES 1. THE SYNOHRONIZATION OF HOST AND SYMBIOTIC DEVELOPMENT IN THE FIELD PEA, PISUM ARVENSE L. By J. S. PATE* [Manu8cript received December 20, 1957] Summary Symbiotic development of two varieties of field pea (Pi8um arven8e L.) was studied by periodic sampling from populations of field· grown material. Various features of effective symbiosis were found to be characteristically synchronized with host plant life cycles. Nodule initiation was complete at the 7·leaf stage of plant development. Peak values in total nodule numbers and nodule/plant weight ratio occurred at this stage. Later, the regular decline in nodule numbers was offset by large in· creases in the size and fixation efficiency of remaining nodules. Well-defined pigment changes occurred in nodule populations. Numbers of young (white) nodules developed during precocious root expansion in the 1-3-leaf stages. Haemoglobin formation was rapid in all nodules. The first-developed nodules on primary roots were pigmented (red) just before cotyledon nitrogen reserves were exhausted. Maxima in total red nodules in both varieties were attained in the 6-8-leaf stages. The subsequent active (red) life of nodules varied from 8 to 80 days. Senescent (green) nodules accumulated on roots following extensive haemo­ globin destruction in the nodules of maturing plants. Average nodule fresh weight increased some 30-50-fold during plant growth. Comparisons of the average sizes of green and red nodule-population samples revealed a progressive elimination of smaller nodules throughout plant development. Nodule nitrogen and haemoglobin concentrations increased together to peak values in mid-vegetative stages. The maximum in total red-nodule nitrogen which occurred just before flowering, and some 7 -leaf units before a maximum in total plant nitrogen, reflected a general increase in nodule fixation efficiency as host plants matured. Approximately 30 per cent. of the nitrogen in the red nodule was removed as nodules turned green in early senility. Nitrogen returns from this source were estimated at less than 3 per cent. of the fixation benefit from healthy (red) nodule activity. High nodule-plant nitrogen transfer rates were recorded from red nodules from the 5-leaf stage until plant flowering. 1. INTRODUOTION Early observations of symbiotic nitrogen fixation in the annual legume led to the conclusion that legumes were rich in nitrogen at maturity through concerted nodule utilization in flowering and fruiting stages of host plant development. It was tacitly assumed that fixed nitrogen was stored in nodules and later released in host digestion of aging bacterial tissues (see monograph by Fred, Baldwin, and McCoy 1932). * Botany School, University of Sydney. NODULATION STUDIES IN LEGUMES. I 367 G. Bond (1936) was prominent among the first authors to question any sub­ stantial host plant benefit through nodule emptying. In. the soybean plant he described a regular and immediate transfer of fixation products from nodule to host plant in stages of plant growth where there were no signs of any degenerative changes in nodule populations. Wilson and Umbreit (1937) recognized three important phases in soybean symbiosis. First, a short initial phase when a large proportion of fixed nitrogen was retained in the nodules. Then, a longer phase, extending over most of vegeta­ tive growth, when a large-scale transfer of fixation products took place giving logarithmic increases in plant growth and nitrogen content. Finally, a phase when fixation slowed down, nodule to plant transfer was highest, and nodule to plant weight ratios decreased. Further studies by the Wisconsin school established a close interdependence of symbiotic nitrogen fixation and carbon assimilation processes in legume develop­ ment (see Wilson 1940). The discovery of nodule haemoglobin as an integral part of the fixation mechanism has led to considerable expansion of earlier concepts of symbiosis. Virtanen and co-workers found a positive correlation between nitrogen fixation rates and nodule haemoglobin concentrations in a number of legume associations. For the pea plant Virtanen et al. (1947) and Virtanen, Erkama, and Linkola (1947) showed that nodule haemoglobin development paralleled the course of fixation; that the commencement of fixation was attendant upon pigment formation in young nodules; and that the cessation of nodule fixation activity in fruiting plants was associated with widespread pigment destruction in senescent nodules. This relation­ ship between pigment changes and nodule fixation activity has been noted for various legumes by other authors, e.g. Jordan and Garrard (1951), Nowotny­ Mieczynska (1952), and Heumann (1952). The aim of this series' of investigations is to provide further information on the general pattern of symbiotic development in legumes. The present paper on nodulation of the field pea outlines various aspects of the initiation and functional life of root nodule populations in an effort to determine the role of the individual nodule in plant nitrogen economy. Further papers will attempt to evaluate the much neglected topics of environment and host determination of legume nodule activity and longevity. II. MATERIALS AND METHODS (a) Plant Material Symbiotic development in the field pea was studied by periodic sampling from two series of sowings: 1954 Series.-Pisum arvense L., var. New ·Zealand maple pea-summer sowing, growing period June 11, 1954, to August 30, 1954. 1955 Series.-Pisum arvense L., var. Black-eyed Susan-summer sowing, growing period May 25, 1955, to August 28, 1955. Both varieties were grown in 60 by 40-ft plots of red subsoil sand at C~erry­ valley, Belfast, Northern Ireland. The ground was chosen for its light texture and 368 J. S. PATE low plant nutrient content. A balanced nitrogen-free mineral fertilizer applied to the plots before each sowing created conditions suitable for maximum symbiotic development. Row cultivation was practised to facilitate extraction of nodulated roots. Approximately 10,000 seeds were sown in each season to give plant popu­ lations well in excess of predicted numerical demands in sampling. A seed-applied rhizobial supplement was given to each series since the subsoil of the plots was found to be markedly deficient in indigenous Pisum-group rhizobia. Inoculants were derived from a stock culture originally isolated from an effective nodule of maple pea. A satisfactory set of effective nodules was obtained. in both seasons allowing for uniform symbiotic development in both varieties. (b) Sampling Procedure Fifty plant samples were randomly selected from the plots at 3-7-day intervals in the life cycles of the host plants. This rather large sample unit was necessary for the construction of reliable nodulation histories from soil-grown legume sowings, and involved a 0·5-5 per cent. standard error in host or symbiotic characters. Extreme care was exercised in the lifting and washing of plant root systems. Diseased, chlorotic, or otherwise atypical plants were rejected from samples. (c) Recordings from Samples The following quantities were recorded for each sample: (i) Age.-Age of the sample in days from sowing. (ii) Developmental Age (expressed as average number of expanded leaves per plant).-Leaf age is of special value in gauging progress towards maturity in different seasons of growth. (iii) Nodule Number.-All nodules visible to the naked eye were recorded in population counts on primary and secondary root systems of the plants of the sample. (iv) Nodule Oolour.-Three colour classes were recognized in nodule counts: White (W-type) Nodules.-Small young nodules with cream-coloured contents, marking sites of recent infections on root systems. Red (R-type) Nodules.-Bacteroid-filled nodules with haemoglobin­ pigmented bacterial tissues. Green (G-type) Nodules.-Senescent nodules showing haemoglobin decomposition into bile-type pigment. Nodules remain green for a short period before entry by foreign 'bacteria causes extensive necrosis of internal tissues. A nodule was classed as G-type once more than two-thirds of its proximal bacterial tissues had turned green. Brown, disintegrating nodules were ignored in all nodule counts. (v) Nodule Weight and Tissue Analyses.-Nodules were removed by a razor stroke parallel to and touching the root surface. Representatives of the W +R and the G colour classes were separated, and both of these colour samples were weigh~d and subjected to Kjeldahl digestion. Determination of total nitrogen from aliquots of nodule or host plant tissue followed the conventional semi-micro- NODULATION STUDIES IN LEGUMES. I 369 Kjeldahl method, using a Markham steam-distillation outfit for ammonia recovery from digests. Portions of the 1954 series W +R samples were analysed for nodule haemoglobin. Nodule haemoglobin was extracted as pyridine haemochromogen (see Virtanen et al. 1947; Virtanen, Erkama, and Linkola 1947) and the reduced haemo­ chromogen estimated spectrophotometrically at 555mf-t. The latter absorption maximum gives least interference from the green pigment (see Hartree 1955). (vi) Host Plant Weight and Analysis.-Average fresh weights of individual plant organs were determined for each sample. In the 1955 series, plant tops and roots, cotyledons, fruits, and flowers were subjected to Kjeldahl analysis for total nitrogen. Nitrogen analyses were confined to cotyledon and nodule tissues in the 1954 series. III. RESULTS Various aspects of the symbiotic development of the field pea are summarized in the figures
Load more

Recommended publications
  • Roles of Non-Frankia Bacteria in Root Nodule Formation and Function in Alnus Sp
    University of New Hampshire University of New Hampshire Scholars' Repository Honors Theses and Capstones Student Scholarship Spring 2021 Roles of Non-Frankia Bacteria in Root Nodule Formation and Function in Alnus sp. Kelsey Christine Mercurio University of New Hampshire, Durham Follow this and additional works at: https://scholars.unh.edu/honors Part of the Agriculture Commons, Biology Commons, Environmental Microbiology and Microbial Ecology Commons, Microbial Physiology Commons, and the Plant Biology Commons Recommended Citation Mercurio, Kelsey Christine, "Roles of Non-Frankia Bacteria in Root Nodule Formation and Function in Alnus sp." (2021). Honors Theses and Capstones. 603. https://scholars.unh.edu/honors/603 This Senior Honors Thesis is brought to you for free and open access by the Student Scholarship at University of New Hampshire Scholars' Repository. It has been accepted for inclusion in Honors Theses and Capstones by an authorized administrator of University of New Hampshire Scholars' Repository. For more information, please contact [email protected]. Roles of Non-Frankia Bacteria in Root Nodule Formation and Function in Alnus sp. Honors Senior Thesis, University of New Hampshire, Kelsey Mercurio Additional Contributors: Céline Pesce, Ian Davis, Erik Swanson, Lilly Friedman, & Louis S. Tisa Department of Molecular, Cellular, and Biomedical Sciences University of New Hampshire, Durham, NH, USA. Roles of non-Frankia bacteria in root nodule formation and function in Alnus sp. Abstract: Plant roots are home to a wide variety of beneficial microbes; understanding and optimizing plant- microbe interactions may be critical to enhance global food security in a sustainable, equitable way. With the help of their nitrogen-fixing bacterial partner, Frankia, actinorhizal plants form symbiotic root nodules and play important roles in agroforestry and land reclamation.
    [Show full text]
  • Nitrogen Fixation by Non-Leguminous Plants
    Nitrogen Fixation by Non-leguminousPlants CharleneVan Raalte ALL STUDENTS OF BIOLOGY learn about legumes, ation in the non-legumes, I could find little information. Downloaded from http://online.ucpress.edu/abt/article-pdf/44/4/229/339852/4447478.pdf by guest on 03 October 2021 including such agriculturally essential plants as peas, My interest in these plants subsequently led me to several beans, and alfalfa that form a symbiosis with nitrogen- teams of biologists actively researching many aspects of fixing root nodule bacteria. But most biology students the biology and ecology of the non-leguminous nitrogen never learn about another abundant, widespread, and fixers. These scientists have recently made some impor- perhaps equally important group of plants that have tant discoveries of theoretical as well as immediate prac- nitrogen-fixingroot nodules quite different from those of tical interest. Some of these findings will be described the legumes. This group of non-leguminous nitrogen- here. fixing plants includes alder trees and shrubs (Alnus sp.), bayberry and sweet gale (Myrica sp.), and sweet-fern (Comptonia peregrina). These plants are rarely men- TABLE1. The BiologicalCharacteristics of NitrogenFixation tioned in basic biology or ecology texts, despite the fact The initialreaction N2 + 6H+-2NFL that their nitrogen-enrichingability makes them important FinalProducts components of their ecosystems and potentially very Aminoacids and proteins useful to farmers and foresters. OrganismsResponsible Onlybacteria (many types) The so-called nitrogen-fixing plants are of special in- EnzymeInvolved Nitrogenase(common to all N terest to me because I study vegetation tolerant of fixers) nutrient-poor soils. These plants have an advantage in Energetics Energyrequired to breakthe tripleN2 bond such soils since they associate with bacteriathat can con- vert or "fix" nitrogenous gas to ammonium (table 1).
    [Show full text]
  • Nodulation and Growth of Shepherdia × Utahensis ‘Torrey’
    Utah State University DigitalCommons@USU All Graduate Theses and Dissertations Graduate Studies 12-2020 Nodulation and Growth of Shepherdia × utahensis ‘Torrey’ Ji-Jhong Chen Utah State University Follow this and additional works at: https://digitalcommons.usu.edu/etd Part of the Plant Sciences Commons Recommended Citation Chen, Ji-Jhong, "Nodulation and Growth of Shepherdia × utahensis ‘Torrey’" (2020). All Graduate Theses and Dissertations. 7946. https://digitalcommons.usu.edu/etd/7946 This Thesis is brought to you for free and open access by the Graduate Studies at DigitalCommons@USU. It has been accepted for inclusion in All Graduate Theses and Dissertations by an authorized administrator of DigitalCommons@USU. For more information, please contact [email protected]. NODULATION AND GROWTH OF SHEPHERDIA ×UTAHENSIS ‘TORREY’ By Ji-Jhong Chen A thesis submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE in Plant Science Approved: ______________________ ____________________ Youping Sun, Ph.D. Larry Rupp, Ph.D. Major Professor Committee Member ______________________ ____________________ Jeanette Norton, Ph.D. Heidi Kratsch, Ph.D. Committee Member Committee Member _______________________________________ Richard Cutler, Ph.D. Interim Vice Provost of Graduate Studies UTAH STATE UNIVERSITY Logan, Utah 2020 ii Copyright © Ji-Jhong Chen 2020 All Rights Reserved iii ABSTRACT Nodulation and Growth of Shepherdia × utahensis ‘Torrey’ by Ji-Jhong Chen, Master of Science Utah State University, 2020 Major Professor: Dr. Youping Sun Department: Plants, Soils, and Climate Shepherdia × utahensis ‘Torrey’ (hybrid buffaloberry) (Elaegnaceae) is presumable an actinorhizal plant that can form nodules with actinobacteria, Frankia (a genus of nitrogen-fixing bacteria), to fix atmospheric nitrogen. However, high environmental nitrogen content inhibits nodule development and growth.
    [Show full text]
  • Range-Legume Inoculation and Nitrogen Fixation by Root-Nodule Bacteria
    i^T'*. D i v i s i o Agricultural Sciences l\ \; UNIVERSITY OF CALIFORN "0 c I < •) L 14* A * * hili HI^BHBHIHHI^H HHHH^I HHBll CALIFORNIA AGRICULTURAL EXPERIMENT STATION BULLETIN 842 Xhe great importance of legumes in agriculture is that they add nitrogen to the soil and thereby save the costs of nitrogen fertilizer, both for the legume crop and for the associated nonlegume crop. Leg- umes obtain nitrogen from the air, which contains uncombined nitro- gen—nearly 80 per cent—along with oxygen and other gases. Very few plants can utilize atmospheric nitrogen in its free form. However, if root-nodule bacteria of an effective strain have formed nodules on the roots of a legume, atmospheric nitrogen may be fixed within the nodules and converted to a utilizable compound. The successful establishment of legumes, particularly in a pasture mix for grazing, depends on effective nodulation. This can be obtained by inoculating the seed with an appropriate strain of root-nodule bac- teria. Methods of inoculating seed and measures that help to avoid inoculation failure are given in boxes on the following pages. All of the recommendations given here are of critical importance. There is no economical way to inoculate a field after planting. Faulty inoculation usually results in failure or partial failure of the legume stand. From this cause alone, California growers waste many thousands of dollars' worth of range-legume seed every year and waste also the labor and the fertilizer used. The Authors A. A. Holland was Lecturer in Agronomy and Assistant Research Agronomist in the Experiment Station, Davis, at the time this work was done.
    [Show full text]
  • Root Nodule Studies of a Desert Browse Legume Guajilla (Calliandra Eriophylla Benth.)
    Root nodule studies of a desert browse legume guajilla (Calliandra eriophylla Benth.) Item Type text; Thesis-Reproduction (electronic) Authors Tapia Jasso, Carlos, 1923- Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 26/09/2021 09:41:37 Link to Item http://hdl.handle.net/10150/554008 ROOT NODULE STUDIES OF A DESERT BROWSE LEGUME GUAJILLA (Calliandra eriophylla Benth.) by CARLOS TAPIA JASSO A Thesis Submitted to the Faculty of the DEPARTMENT OF WATERSHED MANAGEMENT In Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE In the Graduate College THE UNIVERSITY OF ARIZONA 1 9 6 5 STATEMENT BY AUTHOR This thesis has been submitted in partial fulfillment of requirements for an advanced degree at the University of Arizona and is deposited in the University Library to be made available to borrowers under rules of the Library. Brief quotations from this thesis are allowable without special permission, provided that accurate acknowledg­ ment of source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or part may be granted by the head of the major department or the Dean of the Graduate College when in his judgment the proposed use of the material is in the interests of scholarship. In all other instances, however, permission must be obtained from the author.
    [Show full text]
  • The Rhizobium-Pea Symbiosis As Affected by High Temperatures
    635.656:581.138.1.036 576.851.155.095.38 THE RHIZOBIUM-PEA SYMBIOSIS AS AFFECTED BY HIGH TEMPERATURES J. F. J. FRINGS Laboratory of Microbiology, Agricultural University, Wageningen, The Netherlands (Received26-V-1976 ) H. VEENMAN & ZONEN B.V. - WAGENINGEN - 1976 O/ü 1'? )C^Co Mededelingen Landbouwhogeschool Wageningen 76-7(1976 ) (Communications Agricultural University) is also published as a thesis CONTENTS 1. GENERAL INTRODUCTION 1 2. MATERIAL AND GENERAL METHODS 3 2.1. Plant material 3 2.2. Bacteria 3 2.3. Nodulation time and nodule number 3 2.4. Temperatures 4 3. LOCALIZATION OF THE HIGH TEMPERATURE EFFECT ON NODULATION 5 3.1. The possibility of a transported compound 5 3.2. Estimation of optimum inoculation time 7 3.3. Determination of the nodulation sites in relation to root age 9 3.4. Summary 12 4. EFFECT OF TEMPERATURE AND THE PRESENCE OF RHIZOBIA ON MORPHOLOGICAL CHARACTERS OF THE ROOT SYSTEM 14 4.1. Introduction 14 4.2. The effect of temperature on number of nodules and nodulation time . 14 4.3. Effect of temperature and the presence of R. leguminosarum on root growth and root numbers 15 4.4. Summary 17 5. THE INFLUENCE OF HIGH TEMPERATURE PERIODS ON NODULATION OF PEA PLANTS 19 5.1. Temperature-sensitive stages in the formation of nodules 19 5.1.1. Introduction 19 5.1.2. Effect of transfer to 30°C on nodule number and nodule growth 19 5.1.3. Transfer of inoculated pea plants to 30°C, followed by return to 22°C . 23 5.2.
    [Show full text]
  • Molecular Identification of Root Nodule Bacteria from Edible Crops of Fabaceae Family, Kerala
    1063-1065 ISSN : 0974-9411 (Print), 2231-5209 (Online) journals.ansfoundation.org Molecular identification of root nodule bacteria from edible crops of Fabaceae family, Kerala S. Darsha Article Info Department of Sudies in Microbiology, Mangalore University, PG Centre, Jnana Kaveri DOI:10.31018/jans.v10i3.1864 Campus, Kodagu– 571232 (Karnataka), India Received: August 12, 2018 R.Arivukarasu Revised: August 23, 2018 Department of Pharmacognosy, KMCH College of Pharmacy, Coimbatore-641014 Accepted: August 26, 2018 (Tamil Nadu), India M. Jayashankar Department of studies in Microbiology, Mangalore University, PG Centre, Jnana Kaveri Campus, Kodagu– 571232 (Karnataka), India How to Cite Mohammed A. Saeed* Darsha, S. et al. (2018). Department of studies in Microbiology, Mangalore University, PG Centre, Jnana Kaveri Molecular identification of Campus, Kodagu– 571232 (Karnataka), India root nodule bacteria from edible crops of Fabaceae *Corresponding author. E-mail: [email protected] family, Kerala. Journal of Applied and Natural Sci- Abstract ence, 10(3): 1063-1065 The root nodule bacteria were isolated from three different leguminous plants belonging to the Fabaceae family such as Cajanus cajan, Lablab purpureus and Vigna unguiculata using YEMA medium and identified. The isolates were submitted to 16S rRNA and PCR– RFLP typing. A representative sample was further submitted to sequence analysis of 16S rRNA. Isolates were assigned to two genera and were related to Rhizobium spp. (75%) and Bacillus spp. (25%) respectively. This study opens the doors to researchers to do specific studies on this root nodule bacteria which are symbiotic with these legume plants in this area for their antibacterial activity, medicine and food application, and sustainable agriculture.
    [Show full text]
  • Pea Nodule Gradients Explain N Nutrition and Limited Symbiotic Fixation in Hypernodulating Mutants Anne-Sophie Voisin, Marion Prudent, Gérard Duc, Christophe Salon
    Pea nodule gradients explain N nutrition and limited symbiotic fixation in hypernodulating mutants Anne-Sophie Voisin, Marion Prudent, Gérard Duc, Christophe Salon To cite this version: Anne-Sophie Voisin, Marion Prudent, Gérard Duc, Christophe Salon. Pea nodule gradients explain N nutrition and limited symbiotic fixation in hypernodulating mutants. Agronomy for Sustainable Development, Springer Verlag/EDP Sciences/INRA, 2015, 35 (4), pp.0. 10.1007/s13593-015-0328-8. hal-01353750 HAL Id: hal-01353750 https://hal.archives-ouvertes.fr/hal-01353750 Submitted on 12 Aug 2016 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Copyright Agron. Sustain. Dev. (2015) 35:1529–1540 DOI 10.1007/s13593-015-0328-8 RESEARCH ARTICLE Pea nodule gradients explain N nutrition and limited symbiotic fixation in hypernodulating mutants Anne-Sophie Voisin1 & Marion Prudent1 & Gérard Duc1 & Christophe Salon1 Accepted: 17 July 2015 /Published online: 13 August 2015 # INRA and Springer-Verlag France 2015 Abstract Legumes fix atmospheric nitrogen by symbiosis which limits the plant capacity to accumulate N. Furthermore, with soil bacteria in root nodules. Legume yields are limited symbiotic efficiency decreased with increasing nodule num- by the low capacity of N2 fixation.
    [Show full text]
  • Symbiotic Regulatory Genes Controlling Nodule Development in Pisum Sativum L
    plants Review Symbiotic Regulatory Genes Controlling Nodule Development in Pisum sativum L. Viktor E. Tsyganov * and Anna V. Tsyganova Laboratory of Molecular and Cellular Biology, All-Russia Research Institute for Agricultural Microbiology, Podbelsky Chaussee 3, Pushkin 8, 196608 Saint Petersburg, Russia; [email protected] * Correspondence: [email protected]; Tel.: +7-812-470-5100 Received: 11 November 2020; Accepted: 7 December 2020; Published: 9 December 2020 Abstract: Analyses of natural variation and the use of mutagenesis and molecular-biological approaches have revealed 50 symbiotic regulatory genes in pea (Pisum sativum L.). Studies of genomic synteny using model legumes, such as Medicago truncatula Gaertn. and Lotus japonicus (Regel) K. Larsen, have identified the sequences of 15 symbiotic regulatory genes in pea. These genes encode receptor kinases, an ion channel, a calcium/calmodulin-dependent protein kinase, transcription factors, a metal transporter, and an enzyme. This review summarizes and describes mutant alleles, their phenotypic manifestations, and the functions of all identified symbiotic regulatory genes in pea. Some examples of gene interactions are also given. In the review, all mutant alleles in genes with identified sequences are designated and still-unidentified symbiotic regulatory genes of great interest are considered. The identification of these genes will help elucidate additional components involved in infection thread growth, nodule primordium development, bacteroid differentiation and maintenance, and the autoregulation of nodulation. The significance of symbiotic mutants of pea as extremely fruitful genetic models for studying nodule development and for comparative cell biology studies of legume nodules is clearly demonstrated. Finally, it is noted that many more sequences of symbiotic regulatory genes remain to be identified.
    [Show full text]
  • Soybean Nodule-Associated Non-Rhizobial Bacteria Inhibit Plant Pathogens and Induce Growth Promotion in Tomato
    plants Article Soybean Nodule-Associated Non-Rhizobial Bacteria Inhibit Plant Pathogens and Induce Growth Promotion in Tomato 1 2, 1, 1, Serkan Tokgöz , Dilip K. Lakshman *, Mahmoud H. Ghozlan y, Hasan Pinar z , Daniel P. Roberts 2 and Amitava Mitra 1,* 1 Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; [email protected] (S.T.); [email protected] (M.H.G.); [email protected] (H.P.) 2 Sustainable Agricultural Systems Laboratory, USDA-ARS, Beltsville, MD 20705, USA; [email protected] * Correspondence: [email protected] (D.K.L.); [email protected] (A.M.); Tel.: +1-402-472-7054 (A.M.) Current address: Plant Pathology Department, Faculty of Agriculture, Damanhour University, y Damanhour 22511, Egypt. Current address: Agriculture Faculty, Department of Horticulture, Erciyes University, 38039 Kayseri, Turkey. z Received: 28 September 2020; Accepted: 2 November 2020; Published: 5 November 2020 Abstract: The root nodules are a unique environment formed on legume roots through a highly specific symbiotic relationship between leguminous plants and nodule-inducing bacteria. Previously, Rhizobia were presumed to be the only group of bacteria residing within nodules. However, recent studies discovered diverse groups of bacteria within the legume nodules. In this report soybean nodule-associated bacteria were studied in an effort to identify beneficial bacteria for plant disease control and growth promotion. Analysis of surface-sterilized single nodules showed bacterial diversity of the nodule microbiome. Five hundred non-rhizobial colonies from 10 nodules, 50 colonies per nodule, were tested individually against the tomato wilt causing bacterial pathogen Clavibacter michiganensis subsp. michiganensis (Cmm) for inhibition of pathogen growth.
    [Show full text]
  • Evolution of Root Nodule Symbiosis & Engineering of Symbiotic Nitrogen
    Evolution of root nodule symbiosis & engineering of symbiotic nitrogen fixation in Populus sp. Thomas B. Irving1* ([email protected]), Sanhita Chakraborty1, Sara Knaack1, Daniel Conde2, Matias Kirst2, Sushmita Roy1, and Jean-Michel Ané1 1University of Wisconsin-Madison, Madison, WI; 2Univeristy of Florida, Gainesville, FL https://nitfix.org/ Project Goal: Transfer the root nodule symbiosis from legumes to the bioenergy crops Populus sp. Legumes (Fabales) and close relatives of the Fagales, Cucurbitales, and Rosales can associate efficiently with nitrogen-fixing bacteria, in symbioses that lead to the development of root nodules. Legumes, in particular, host bacteria called rhizobia in their root nodules. Studies in model legumes such as Medicago truncatula and Lotus japonicus identified that (1) rhizobia colonize legume roots intracellularly following the recruitment of the arbuscular mycorrhizal (AM) signaling pathway known as the common symbiosis pathway (CSP), and (2) nodule formation (organogenesis) evolved from the lateral root developmental pathway, and is distinguished from it by the local cytokinin accumulation that requires the transcription factor Nodule Inception (NIN). Comparative phylogenomics suggest that the root nodule symbiosis appeared once in the last common ancestor of the Fabales, Fagales, Cucurbitales, and Rosales, and lost multiple times within this “nitrogen-fixing clade”1. Populus sp. are bioenergy crops and close relatives to the “nitrogen- fixing clade”. They retain several key genes known to be required for nodule symbiosis, including NIN2. Populus sp. is easily transformable and represents an excellent model for synthetic biology approaches. We demonstrated that certain species of rhizobia can activate the AM signaling pathway in Populus sp. We studied Populus sp.
    [Show full text]
  • Rhizobium Galegae, a New Species of Legume Root Nodule Bacteria KRISTINA LINDSTROM Department of Microbiology, University Qf Helsinki, SF-00710 Helsinki, Finland
    INTERNATIONALJOURNAL OF SYSTEMATICBACTERIOLOGY, July 1989, p. 365-367 Vol. 39, No. 3 0020-7713/89/030365-03$02.OO/O Copyright 0 1989, International Union of Microbiological Societies Rhizobium galegae, a New Species of Legume Root Nodule Bacteria KRISTINA LINDSTROM Department of Microbiology, University qf Helsinki, SF-00710 Helsinki, Finland Studies of root nodule bacteria isolated from Galega orientalis and Galega oficinalis are reviewed, and as a result a new species, Rhizobium galegae, is proposed. The type strain of the species is R. galegae HAMBI 540 (= ATCC 43677), which forms nitrogen-fixing root nodules on G. orientalis. Deoxyribonucleic acid homology distinguishes R. galegae from other rhizobia, whereas nodulation of Galega sp. and sensitivity to phage gal l/R phenotypically separate the strains currently included in the species from other members of the genus Rhizobium. Other criteria supporting the formation of a new species include ribosomal ribonucleic acid- deoxyribonucleic acid homology data, protein and lipopolysaccharide patterns, serological properties, and numerical taxonomy data. Root nodule bacteria are able to penetrate the roots of agar (14) are more than 1.0 mm in diameter after 7 days at primarily leguminous plants. As a result of the infection, a 28°C. The maximum growth temperature is 33 to 37°C. The specific structure, the root nodule, is formed. Once estab- cells grow in the presence of 0.5% NaCl but not in the lished within a nodule, the bacteria reduce atmospheric presence of 2.0% NaC1. A majority of the strains studied nitrogen to ammonia, which is transported to the plant. The form a serum zone and give an alkaline reaction in litmus present classification of root nodule bacteria, as described in milk.
    [Show full text]