Department of Landscape and Horticulture, Ecology College, Lishui University, Lishui, Zhejiang, China.
National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China.
PLoS One. 2021 Feb 26;16(2):e0247783. doi: 10.1371/journal.pone.0247783. eCollection 2021.
Autophagy plays a critical role in plant heat tolerance in part by targeting heat-induced nonnative proteins for degradation. Autophagy also regulates metabolism, signaling and other processes and it is less understood how the broad function of autophagy affects plant heat stress responses. To address this issue, we performed transcriptome profiling of Arabidopsis wild-type and autophagy-deficient atg5 mutant in response to heat stress. A large number of differentially expressed genes (DEGs) were identified between wild-type and atg5 mutant even under normal conditions. These DEGs are involved not only in metabolism, hormone signaling, stress responses but also in regulation of nucleotide processing and DNA repair. Intriguingly, we found that heat treatment resulted in more robust changes in gene expression in wild-type than in the atg5 mutant plants. The dampening effect of autophagy deficiency on heat-regulated gene expression was associated with already altered expression of many heat-regulated DEGs prior to heat stress in the atg5 mutant. Altered expression of a large number of genes involved in metabolism and signaling in the autophagy mutant prior to heat stress may affect plant response to heat stress. Furthermore, autophagy played a positive role in the expression of defense- and stress-related genes during the early stage of heat stress responses but had little effect on heat-induced expression of heat shock genes. Taken together, these results indicate that the broad role of autophagy in metabolism, cellular homeostasis and other processes can also potentially affect plant heat stress responses and heat tolerance.
自噬在植物耐热性中起着关键作用，部分原因是通过靶向热诱导的非天然蛋白进行降解。自噬还调节代谢、信号转导和其他过程，而自噬的广泛功能如何影响植物热应激反应则知之甚少。为了解决这个问题，我们对拟南芥野生型和自噬缺陷型 atg5 突变体在热应激下的转录组进行了分析。即使在正常条件下，野生型和 atg5 突变体之间也鉴定出大量差异表达基因（DEGs）。这些 DEGs 不仅参与代谢、激素信号、应激反应，还参与核苷酸处理和 DNA 修复的调节。有趣的是，我们发现热处理导致野生型植物中基因表达的变化比 atg5 突变体更剧烈。自噬缺陷对热调节基因表达的抑制作用与 atg5 突变体在热胁迫前许多热调节 DEGs 的已经改变的表达有关。在热胁迫之前，自噬突变体中参与代谢和信号转导的大量基因的表达改变可能会影响植物对热胁迫的反应。此外，自噬在热应激反应早期防御和应激相关基因的表达中发挥了积极作用，但对热诱导的热休克基因表达几乎没有影响。综上所述，这些结果表明，自噬在代谢、细胞内稳态和其他过程中的广泛作用也可能影响植物的热应激反应和耐热性。
