Institute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Kirschallee 1, 53115 Bonn, Germany.
J Exp Bot. 2017 Jul 10;68(15):4295-4308. doi: 10.1093/jxb/erx194.
Aldehyde dehydrogenases (ALDH) are a family of enzymes that are involved in plant metabolism and contribute to aldehyde homeostasis to eliminate toxic aldehydes. The ALDH enzymes produce NADPH and NADH in their enzymatic reactions and thus contribute to balancing redox equivalents. Previous studies showed that Arabidopsis ALDH genes are expressed in response to high salinity, dehydration, oxidative stress, or heavy metals, suggesting important roles in environmental adaptation. However, the role of ALDH genes in high temperature and stress combinations (heat stress combined with dehydration, wounding, or salt stress) is unclear. Here, we analysed expression patterns of selected ALDH genes on the transcript and protein level at different time points of heat stress, basal and acquired thermotolerance, and stress combination treatments. Our results indicate that ALDH3I1 and ALDH7B4 are strongly induced by heat stress. Higher levels of ALDH7B4 accumulated in response to dehydration-heat, heat-salt and wounding-heat combination stress than in response to single stressors. The comparison of physiological and biological parameters in T-DNA double mutants of ALDH genes and wild-type plants demonstrated that mutant lines are more sensitive to heat stress and stress combinations than wild-type plants.
醛脱氢酶（ALDH）是一类参与植物代谢的酶，有助于醛稳态，以消除有毒醛。ALDH 酶在其酶促反应中产生 NADPH 和 NADH，因此有助于平衡氧化还原当量。先前的研究表明，拟南芥的 ALDH 基因在高盐度、脱水、氧化应激或重金属胁迫下表达，表明其在环境适应中具有重要作用。然而，ALDH 基因在高温和胁迫组合（热胁迫与脱水、创伤或盐胁迫结合）中的作用尚不清楚。在这里，我们在不同的热应激时间点、基础和获得的耐热性以及胁迫组合处理的转录和蛋白质水平上分析了选定的 ALDH 基因的表达模式。我们的结果表明，ALDH3I1 和 ALDH7B4 被热应激强烈诱导。与单一胁迫相比，脱水-热、热-盐和创伤-热组合胁迫下 ALDH7B4 的积累水平更高。ALDH 基因 T-DNA 双突变体和野生型植物的生理和生物学参数比较表明，突变体比野生型植物对热胁迫和胁迫组合更敏感。
