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Introduction to Plant Physiology

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Introduction to Plant Physiology Chapter 1: Introduction to Plant Physiology Plant is source of food, fodder, fibers, clothing, shelter fuel, medicine, and oxygen. This all resources are the products of plant physiology. The basic and main process in plant, photosynthesis is responsible for the supply of all the above-mentioned resources. Figure 1: Different plant science areas studied under plant physiology. Definition: Plant physiology deals with the various metabolic process and pathways in plant. Practically it is heart of the botany, which study different functions performed by the plant. It deals with the study of organization and operation of all the physiological, biochemical and enzymological processes in plant. Importance of plant physiology: Plant metabolism is mainly anabolism and catabolism. Breaking and joining different biomolecules. Studying this aspect of plant provides the explanation the several question about the plant. Example: How plants utilize solar energy? SACP Dept. of Botany BO232 Plant Physiology How they obtain and distribute water and nutrients? How plants grow and develop? How they respond to the environment? How they produce flowers and seed? How seed germinate and form new plants? Answers of above questions helps to understand different process and acquired knowledge helps to improve productivity and yield of the crop. Need for the Study of Plant Physiology: • It is important branch of botany, understanding the plant physiology helps interlink other branches of botany. Understanding different physiological process such as Seed germination, Growth and development, Photosynthesis, Absorption of water and minerals, Ascent of sap, Translocation of solutes, Transpiration, Photorespiration, Respiration, Photoperiodism, Vernalization, Flowering, Ripening of fruits, Senescence and Death of plant gives huge knowledge and this knowledge finds wide application in every branch of botany. The knowledge of plant physiology will help in replicating several advances in agriculture, horticulture, forestry, plant pathology and other disciplines of botany. In fact, researches in plant physiology have been and are likely to contribute immensely to crop improvement. Increase in crop production is based on exploiting maximal levels or plant metabolic processes. The production of new varieties and strains shall have to take into account the physiological attributes of basic material or genotypes. The control of soil fertility, overcoming presence of excessive salts in the soil through the knowledge of plant physiology has helped in increased crop production. A basic knowledge of plant metabolic processes can help in the increase of photosynthetic conversion of solar energy for the production of food materials that are utilized by human beings. Basic knowledge on nitrogen fixation will help in increased utilization of atmospheric nitrogen by different plant species. In the past few years several tissue culture techniques have been developed which have shortened the life cycle of several plant species, helped in raising plants from seeds with shrunken endosperm, and have increased our understanding of cell wall formation and mineral uptake. SACP Dept. of Botany BO232 Plant Physiology The detailed knowledge of plant hormones, their synthesis and mode of action, has considerably facilitated their application in checking water loss, manipulating growth and development of certain crops and improving the quality of food materials. The usage of certain hormonal weedicides has minimized the occurrence of weeds in the crop fields. Crop yields have increased by the judicial usage of auxins, cycocel, gibberellins, phenols and aliphatic alcohols, etc. The regulation of flowering, seed formation and fruit setting has been controlled through the application of different hormones at the appropriate time of plant height and age. In recent years most of the breeding projects also seek the help of the plant physiologists. Physiological processes play a significant role in several interactions between plant and animals. Man changes his environments deliberately or unintentionally and this change affects the physiological behaviour of plants. The physiological reactions of plants due to their introduction and cultivation are an admitted fact. Increased urbanization, development of industry and excessive utilization of land has led to the modifications of the environments. As a result of these modifications there is a drastic effect on the accompanying fauna. For successful agricultural practices a sound physiological base is a must. Plant cultivation or agriculture was a crude art or a native effort and plant physiological studies have developed into a regular science. Modern understanding of the physiological mechanisms of growth and development is being increasingly exploited for increased quality and quantity of crops. This insight has also increased the survival and or extending the range of desirable plants. Controlled fertilizer application and proper water management have been exploited to the best advantage of limited resources. Practices as crop rotation, green crop ploughing, usage of selective fertilizers, use of growth hormones, inhibitors, etc., are all based on our understanding of plant physiological concepts. Recently computer technology has been used in aiding plant growth and manipulating plant responses to varied environments. With the growing population there are greater demands on production of various food crops. Agriculture and agricultural produce are becoming industrialized and the role of plant physiologist is ever increasing. Environmental engineering in all aspects including usage of barren lands, SACP Dept. of Botany BO232 Plant Physiology growing increased number of crops, and exploitation of solar radiations by the existing and newly bred species shall involve plant physiologists. In the coming years, teaching and research in plant physiology will occupy a pivotal place in our institutions. The search for deeper understanding and insight of how plants absorb water and minerals, utilize and conserve them will continue with added scientific techniques. Scope and Applications of plant Physiology: SACP Dept. of Botany BO232 Plant Physiology .
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