Understanding Physiological Basis of Senescence in Ailanthus excelsa Leaves

By : Upma Bhatt , Manish Mali , Shubhangani Sharma , Vineet Soni

Page No: 497-502

Abstract :
Leaf senescence is a major developmental event, in which leaves turns yellowing and cells passes through a series of physiological and biochemical changes, including a large metabolic shift from anabolism to catabolism, resulting in nutrition redistribution. Since dynamic protein trafficking transforms massive macromolecular complexes into transportable products through which cellular structures such as chloroplasts, nucleus and cell membrane are disintegrated. The chlorophyll fluorescence measurement can detect the physiological changes in leaves during senescence. Therefore, the OJIP-transient, leaf model and membrane model were studied to understand the photosynthetic process during senescence. The depression OJIP-transient curve and Fm shows reduction in PIcs. The increase in antenna size of LHCs ABS/RC and TR/RC increased but the phenomenological fluxes reduced, which illustrates the inhibition of electron transport chain in S5 (last stage of senescence). Although the absorption increased, but electron transport ceased so that DI/CS and DI/RC enhanced which directly influence ?Po and the leaf ultimately die.

Authors :
Upma Bhatt, Manish Mali, Shubhangani Sharma and Vineet Soni
Plant Bioenergetics and Biotechnology Laboratory, Department of Botany, Mohanlal Sukhadia University, Udaipur, Rajasthan, India.
 

DOI: https://doi.org/10.32381/JPSR.2022.38.02.6