Li Lan, Chen Guangling, Yuan Mingzhu, Guo Shirong, Wang Yu, Sun Jin
College of Horticulture, Nanjing Agricultural University, Nanjing, China.
Front Plant Sci. 2022 Apr 28;13:883876. doi: 10.3389/fpls.2022.883876. eCollection 2022.
High temperature stress seriously affects the growth of cucumber seedlings, and even leads to a decline in yield and quality. miRNAs have been shown to be involved in regulating the response to stress in plants, but little is known about its effects on cucumber high temperature stress tolerance. Here, we found that high temperature stress induced the expression of miR9748 in cucumber. Overexpression of cucumber miR9748 in Arabidopsis improved high temperature tolerance. Transcriptome analysis revealed that miR9748 might mediate high temperature tolerance through plant hormone signal pathway. 5' RNA ligase-mediated rapid amplification of cDNA ends (5' RLM-RACE) and transient transformation technology demonstrated that was the target gene of miR9748. overexpression plants decreased high temperature tolerance accompanied by reducing the content of jasmonic acid (JA), but alleviated by foliar application of methyl jasmonate, indicating that negatively regulated high temperature stress tolerance through inhibition JA signal pathway. Furthermore, high temperature stress also increased the expression level of . Yeast one-hybrid and dual-luciferase assays showed that CsbZIP2 directly bound to the promoter of to induce its expression. Taken together, our results indicated that CsbZIP2 directly regulated miR9748 expression to cleave to mediate high temperature tolerance through JA pathway.
高温胁迫严重影响黄瓜幼苗的生长，甚至导致产量和品质下降。已有研究表明，miRNA参与调控植物对胁迫的响应，但其对黄瓜高温胁迫耐受性的影响尚不清楚。在此，我们发现高温胁迫诱导黄瓜中miR9748的表达。在拟南芥中过表达黄瓜miR9748可提高其高温耐受性。转录组分析表明，miR9748可能通过植物激素信号通路介导高温耐受性。5'RNA连接酶介导的cDNA末端快速扩增（5'RLM-RACE）和瞬时转化技术表明，[具体基因名称未给出]是miR9748的靶基因。[具体基因名称未给出]过表达植株降低了高温耐受性，同时茉莉酸（JA）含量降低，但通过叶面喷施茉莉酸甲酯可缓解，这表明[具体基因名称未给出]通过抑制JA信号通路负向调控高温胁迫耐受性。此外，高温胁迫还提高了[具体基因名称未给出]的表达水平。酵母单杂交和双荧光素酶试验表明，CsbZIP2直接结合[具体基因名称未给出]的启动子以诱导其表达。综上所述，我们的结果表明，CsbZIP2直接调控miR9748的表达以切割[具体基因名称未给出]，从而通过JA途径介导高温耐受性。
