The Protective Role of 28-Homobrassinolide and Glomus versiforme in Cucumber to Withstand Saline Stress

Abstract

The strategic role of phytohormones and arbuscular mycorrhizal fungi (AMF) to overcome various stress conditions is gaining popularity in sustainable agricultural practices. This current study aims to investigate and identify the protective roles of 28-homobrassinolide (HBL) and Glomus versiforme on two cucumber cultivars (salt sensitive Jinyou 1# and tolerant Chanchun mici (CCMC)) grown under saline conditions (100 mM NaCl). HBL and AMF were applied as individual and combined treatments on two cucumber cultivars and their effects were observed on the morphological growth and physiology under control and saline conditions. Findings revealed that the treated plants showed better performance under saline conditions through improved photosynthesis, leaf relative water content, and decreased electrolyte leakage in tolerant cultivar (CCMC) and to a lesser extent in sensitive (Jinyou 1#) cultivar. Comparable differences were noticed in the antioxidant enzymes activity such as superoxide dismutase, catalase, and peroxidase after every 10 days in both cultivars. Treating the plants with HBL and AMF also improved the mineral uptake regulation and lowered sodium concentration in roots compared to that in the non-treated plants. Current findings suggest that the protective role of HBL and AMF involves the regulation of antioxidants and lowers the risk of ion toxicity in the cucumber and hence enhance tolerance to salinity. These results are promising, but further studies are needed to verify the crop tolerance to stress and help in sustainable agricultural production, particularly vegetables that are prone to salinity.

Arbuscular mycorrhiza in combating abiotic stresses in vegetables: An eco-friendly approach

“…AM colonization in the tomato plants showed increased activity of antioxidant enzymes such as superoxide dismutase and peroxidase which makes the plants more productive ( Dudhane et al, 2013 ). Improved photosynthesis and relative water content of leaves along with reduced electrolyte leakage has been observed in AM inoculated plants ( Ahmad et al, 2019 ). In greenhouse conditions, the AMF inoculated tomato plants showed enhanced nutrient uptake under moderate salt stress ( Balliu et al, 2015 ).…”

Mechanisms Regulating the Dynamics of Photosynthesis Under Abiotic Stresses

“…Salt stress accounts for ~50% reduction in crop productivity (Gururani et al, 2015 ; Ahmad et al, 2018 ; Sharma et al, 2020 ). Moreover, salinity-induced osmotic stress reduces photosynthesis via the ionic effect on the structure of subcellular organelles and the inhibition of metabolic processes (Lawlor, 2009 ; Sade et al, 2010 ; Ahmad et al, 2020 ). The cellular membranes exhibit stress responses (Ashraf and Ali, 2008 ; Tayefi-Nasrabadi et al, 2011 ), high concentration of ions, such as sodium (Na + ) and chloride (Cl − ) ions, in chloroplasts causes significant damage to the thylakoid membrane (Wu and Zou, 2009 ; Omoto et al, 2010 ).…”

Impact of water deficit on the development and senescence of tomato roots grown under various soil textures of Shaanxi, China

“…Several antioxidant enzymes have different levels of affinity for ROS and convert O 2 −1 , O 2 − , OH − , etc. to oxygen and water [ 8 ]. In our results, antioxidant enzymatic activity was higher in Yulin soil as the water deficit conditions progressed.…”

“…Studies have proven that the balance of the redox status of the roots is important for cell division and multiplication in the root apical meristem or that it may interfere with the biosynthesis and transport of hormones, especially auxin. The redox balance is mainly dependent upon the activity of antioxidant enzymes [ 7 , 8 ], particularly the ascorbate–glutathione cycle [ 9 ]. Plant endogenous hormones also have a key role in plant defence by mediating growth and development and improving source sink relationships in varying environments [ 10 ].…”