Dewhirst Rebecca A, Lei Joseph, Afseth Cassandra A, Castanha Cristina, Wistrom Christina M, Mortimer Jenny C, Jardine Kolby J
Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
School of Integrative Biology, University of Illinois at Urbana-Champaign, Champaign, IL 61801, USA.
Plants (Basel). 2021 Feb 23;10(2):411. doi: 10.3390/plants10020411.
Upregulation of acetate fermentation in plants has recently been described as an evolutionarily conserved drought survival strategy, with the amount of acetate produced directly correlating to survival. However, destructive measurements are required to evaluate acetate-linked drought responses, limiting the temporal and spatial scales that can be studied. Here, C-labeling studies with poplar () branches confirmed that methyl acetate is produced in plants from the acetate-linked acetylation of methanol. Methyl acetate emissions from detached leaves were strongly stimulated during desiccation, with total emissions decreasing with the leaf developmental stage. In addition, diurnal methyl acetate emissions from whole physiologically active poplar branches increased as a function of temperature, and light-dark transitions resulted in significant emission bursts lasting several hours. During experimental drought treatments of potted poplar saplings, light-dark methyl acetate emission bursts were eliminated while strong enhancements in methyl acetate emissions lasting > 6 days were observed with their initiation coinciding with the suppression of transpiration and photosynthesis. The results suggest that methyl acetate emissions represent a novel non-invasive tracer of acetate-mediated temperature and drought survival response in plants. The findings may have important implications for the future understanding of acetate-mediated drought responses to transcription, cellular metabolism, and hormone signaling, as well as its associated changes in carbon cycling and water use from individual plants to whole ecosystems.
植物中乙酸发酵的上调最近被描述为一种进化上保守的干旱生存策略，产生的乙酸量与存活率直接相关。然而，需要进行破坏性测量来评估与乙酸相关的干旱反应，这限制了可研究的时间和空间尺度。在这里，对杨树（）枝条进行的碳标记研究证实，植物中乙酸甲酯是由甲醇的乙酸连接乙酰化产生的。离体叶片在干燥过程中乙酸甲酯排放量受到强烈刺激，总排放量随叶片发育阶段而减少。此外，整个生理活性杨树枝条的乙酸甲酯日排放量随温度升高而增加，光暗转换导致持续数小时的显著排放激增。在盆栽杨树幼苗的实验干旱处理期间，光暗乙酸甲酯排放激增被消除，同时观察到乙酸甲酯排放量持续>6天的强烈增加，其开始与蒸腾作用和光合作用的抑制同时发生。结果表明，乙酸甲酯排放代表了植物中乙酸介导的温度和干旱生存反应的一种新型非侵入性示踪剂。这些发现可能对未来理解乙酸介导的干旱对转录、细胞代谢和激素信号的反应，以及其在从个体植物到整个生态系统的碳循环和水分利用方面的相关变化具有重要意义。
