ABA regulation of antioxidant activity during post-germination desiccation and subsequent rehydration in wheat

Abstract

ABA regulation of antioxidant activity during post-germination desiccation and subsequent rehydration was studied in two wheat cultivars PBW 644 (ABA-higher sensitive and drought tolerant) and PBW 343 (ABA-lesser sensitive and drought susceptible) where 1 d-germinated seeds were exposed to ABA/ PEG-6000 for next 1 d, desiccated for 4 d and subsequently rehydrated for 4 d. Ascorbate, dehydrascorbate to ascorbate ratio, malondialdehyde (MDA), hydroxyl radicals, and activities of monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), alcohol dehydrogenase (AlcDH) and aldehyde dehydrogenase (AldDH) were measured in seedlings just before desiccation (2 d old), desiccated (6 d old) and rehydrated (10 d old) stages. ROS/NO signaling was studied under CT and ABA supply by supplying ROS and NO scavengers. During desiccation, both cultivars showed increase of oxidative stress (dehydroascorbate to ascorbate ratio, MDA, hydroxyl radicals) and antioxidant activity in the form of ascorbate content and AldDH activity while other antioxidant enzymes were not increased. PBW 644 showed higher antioxidant activity thus produced less oxidative stress compared to PBW 343. During rehydration, activities of all antioxidant enzymes and levels of ROS (hydroxyl radicals) were increased in both cultivars and MDA was decreased in PBW 343. ABA supply improved desiccation as well as rehydration by improving all parameters of antioxidant activity tested in this study. PEG supply resembled to ABA-supply for its effects. ABA/PEG improvements were seen higher in PBW 644. ROS/ NO-signalling was involved under CT as well as under ABA for increasing antioxidant activity during desiccation as well as rehydration in both cultivars.

Transcriptomic and Functional Analyses Indicate Novel Anti-viral Mode of Actions on Tobacco Mosaic Virus of a Microbial Natural Product ε-Poly-l-lysine

“…38 The increase of ABA content in plants can reduce the damage of free radicals to membrane and change metabolism, thereby increasing plant resistance. 39 It was reported that the decreased expression of ABA receptor PYL4 can regulate the ubiquitination of ABArelated proteins and promote clathrin-mediated endocytosis, which plays an important role in plant growth and resistance to external adverse environments. 40 In this study, the expression of PYL4 was reduced by ε-PL, which suggested that the agent may induce stress resistance by affecting proteins related to the ABA pathway in plants.…”

“…As a stress hormone, ABA can regulate the adaptability of plants to adversity . The increase of ABA content in plants can reduce the damage of free radicals to membrane and change metabolism, thereby increasing plant resistance . It was reported that the decreased expression of ABA receptor PYL4 can regulate the ubiquitination of ABA-related proteins and promote clathrin-mediated endocytosis, which plays an important role in plant growth and resistance to external adverse environments .…”

Effect of gamma-aminobutyric acid on resistance against stripe rust (caused by Puccinia striiformis f. sp. tritici) in wheat cultivars

“…Regeneration of ascorbate by MDHAR and DHAR could be important for removal of ROS during late infection. DHAR is reported to increase under increased stress when ascorbate gets deficient or dehydroascorbate over accumulates (Pérez-López et al, 2009;Kour and Zhawar, 2018). MDHAR gene has been found to contribute to adult plant resistance against stripe rust through ROS metabolism in wheat (Feng et al, 2014).…”