Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia, Jagiellonska 28, 40-032 Katowice, Poland.
Department of Plant Breeding, Physiology and Seed Science, University of Agriculture in Krakow, 30-239 Krakow, Poland.
Int J Mol Sci. 2020 Jul 19;21(14):5096. doi: 10.3390/ijms21145096.
The roles of endogenous brassinosteroids (BRs) in the modulation of reaction to drought and genetic regulation of this process are still obscure. In this study, a multidirectional analysis was performed on semi-dwarf barley () Near-Isogenic Lines (NILs) and the reference cultivar "Bowman" to get insights into various aspects of metabolic reaction to drought. The NILs are defective in BR biosynthesis or signaling and displayed an enhanced tolerance to drought. The BR metabolism perturbations affected the glucose and fructose accumulation under the control and stress conditions. The BR metabolism abnormalities negatively affected the sucrose accumulation as well. However, during drought, the BR-deficient NILs accumulated higher contents of sucrose than the "Bowman" cultivar. Under the control conditions, accumulation of transcripts encoding antioxidant enzymes ascorbate peroxidase (HvAPX) and superoxide dismutase (HvSOD) was BR-dependent. However, during drought, the accumulation of transcript was BR-dependent, whereas accumulations of transcripts encoding catalase (HvCAT) and HvSOD were not affected by the BR metabolism perturbations. The obtained results reveal a significant role of BRs in regulation of the HvAPX and HvCAT enzymatic activities under control conditions and the HvAPX and HvSOD activities during physiological reactions to drought.
内源性油菜素内酯 (BRs) 在调节对干旱的反应以及该过程的遗传调控中的作用仍不清楚。在这项研究中，对半矮秆大麦 () 近等基因系 (NILs) 和参比品种“Bowman”进行了多方向分析，以深入了解代谢对干旱反应的各个方面。NILs 在 BR 生物合成或信号转导中存在缺陷，表现出对干旱更强的耐受性。BR 代谢扰动影响控制和胁迫条件下葡萄糖和果糖的积累。BR 代谢异常也会对蔗糖的积累产生负面影响。然而，在干旱条件下，BR 缺乏的 NILs 比“Bowman”品种积累了更多的蔗糖。在对照条件下，编码抗氧化酶抗坏血酸过氧化物酶 (HvAPX) 和超氧化物歧化酶 (HvSOD) 的转录本的积累依赖于 BR。然而，在干旱期间，转录本的积累依赖于 BR，而编码过氧化氢酶 (HvCAT) 和 HvSOD 的转录本的积累不受 BR 代谢扰动的影响。所得结果表明 BRs 在调节对照条件下 HvAPX 和 HvCAT 酶活性以及生理反应过程中 HvAPX 和 HvSOD 活性方面具有重要作用。
