PJB-2020-38
PHYSIOLOGICAL AND BIOCHEMICAL CHARACTERISTICS OF COTTON (GOSSYPIUM HIRSUTUM L.) IN RESPONSE TO EXOGENOUSLY APPLIED GLYCINE BETAINE UNDER HIGH SALINITY STRESS
MOUNKAILA HAMANI ABDOUL KADER
Abstract
Glycine betaine (GB) plays a key function in plant responding to environmental stresses. The purpose of the current research is to examine the impacts of foliar applied GB on plant growth indicators, photosynthesis and chlorophyll fluorescence characteristics, antioxidant and the key photosynthetic enzymes (Rubisco and phosphoenolpyruvate carboxylase) activities, leaf, stem and root total nitrogen (N) content of Gossypium hirsutum L. under high NaCl stress condition. Under the salinity of 150mM, the four levels of GB are 0, 2.5, 5 and 7.5mM, and the control (CK) was GB-untreated non saline. Salt stress did not only decrease plant growth parameters, but also affected the gas exchange and chlorophyll florescence parameters and the key photosynthetic enzyme activities of cotton. The foliar-applied GB was effective to alleviate the adverse impact of salinity in cotton plants. The treatment with 5mM GB significantly increased the photosynthetic rate (Pn), transpiration rate (Tr), intracellular CO2 concentration (Ci) and stomatal conductance (gs) compared to the GB-untreated saline treatment. Activities of glutathione reductase (GR), Ascorbate peroxidase (APX), superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) as well as malondialdehyde (MDA) content were elevated under 150mM salt stress without exogenous GB treatment, foliar supplementation with 5mM GB significantly increased the antioxidant activities, whereas it significantly decreased MDA content. The foliar-applied GB sustainably increased Rubisco and PEPC activities under salt stress. The 5mM GB also lead a high significant rise in leaf, stem and root total nitrogen content. The results suggested that foliar supplementation with 5mM GB is the optional choice for protecting cotton plants from high salinity through promoting the antioxidant and the key photosynthetic enzyme activities.
To Cite this article:
Download
