Proline Metabolism in Two High Yielding Groundnut Cultivars that Differ in their Drought Tolerance

By : K.V. Madhusudhan , C. Sudhakar

Page No: 21-29

Abstract
In this study, we compared the effects of drought stress on proline metabolism, glycine betaine and lipid peroxidation in two groundnut (Arachis hypogaea L.) cultivars, K-6 and JL-24, that are droughttolerant and drought-susceptible, respectively. As RWC decreased over time, leaf dry weight values also decreased across all stress regimes and cultivars. In the leaves of both cultivars, pyrroline-5- carboxylate reductase (P5CR) was upregulated in response to water stress, while proline oxidase (POX) and pyrroline-5-carboxylate dehydrogenase (P5CDH) were downregulated. These results imply that the induction of proline levels during groundnut development is associated with the elevation of proline synthesis enzyme (P5CR) and the downregulation of proline degrading enzymes (POX and P5CDH) that contribute to the plant’s decreased sensitivity to drought. Proline levels are greater in cultivar K-6 than in cultivar JL-24, which may be attributed to increased P5CR rates and less inhibition of POX and P5CDH. At all stress levels, the groundnut cv. K-6 accumulated more glycine betaine than the cv. JL-24. Malondialdehyde (MDA) is an indicator of lipid peroxidation, and in cultivar JL-24 it was found in significantly higher concentrations than in cultivar K-6. Dry mass buildup and physio-biochemical responses differed across cultivars and were based on the intensity of the stress. Tolerance levels of these two cultivars were compared.

Authors :
K.V. Madhusudhan : Government College for Men, Cluster University, Kurnool, AP, India.
C. Sudhakar : Department of Botany, S.K. University, Anatapuramu, AP, India.
 

DOI: https://doi.org/10.32381/JPSR.2023.39.03.3