Just Accepted

This article has been peer reviewed and accepted for publication. It is in production and has not been edited, so may differ from the final published form.

Brassinosteroid improves light stress tolerance in tomato (Lycopersicon esculentum) by regulating redox status, photosynthesis and Photosystem II

Waseem Yousuf, Sabeeha Bashir, Showkat Bhat, Rayees Rather, Kishore Panigrahi, Riffat John

Abstract

Plants often experience variations in light intensity, referred to as light stress, which negatively impacts various important aspects of plant growth and development, including photosynthesis and antioxidant system. The photosynthetic machinery is susceptible to these disturbances, especially photosystem II (PSII) and its reaction centers. The present study aimed to evaluate role of brassinosteriod (Br) in plant under both high and low light conditions by examining various physiological parameters such as photosynthetic efficiency, pigment levels and enzymatic activity of various antioxidant enzymes. We investigated various chlorophyll fluorescence parameters under low light (LL) and high light (HL) conditions and associated gene expression related to photosynthesis including Plastocyanin (PetE), Ferredoxin (PetF), Photosystem II oxygen-evolving enhancer protein 3 (PsbQ), etc,. Our results indicate that exogenous Br application considerably increase tolerance to both high and low light stress in four week old tomato as Br-treated plants displayed enhanced photosynthesis, reduced oxidative damage and increased antioxidant enzyme activity in comparison to control plants. Furthermore, Br treatment upregulated antioxidant pathway related genes that significantly facilitate the recovery of chlorophyll fluorescence parameters known for their role in plant growth and development. Our results provide valuable insights into how Br can diminish light-induced stress in tomato plants.

FP24170  Accepted 30 October 2024

© CSIRO 2024