Arabidopsis Transcription Factors SPL1 and SPL12 Confer Plant Thermotolerance at Reproductive Stage
Arabidopsis Transcription Factors SPL1 and SPL12 Confer Plant Thermotolerance at Reproductive Stage
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DOI：
10.1016/j.molp.2017.03.010
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发表时间：
2017-05-01
期刊：
影响因子：
27.5
通讯作者：
Chen, Xiao-Ya
中科院分区：
文献类型：
--
作者：
Chao, Lu-Men;Liu, Yao-Qian;Chen, Xiao-Ya
植物生殖器官易受热的影响，但花序中热激反应的调节在很大程度上是不确定的。在这里，我们报告说，两个鳞状细胞启动子结合蛋白样（SPL）转录因子在拟南芥，SPL 1和SPL 12，在繁殖阶段的耐热性冗余行为。spl 1 -1和spl 12 -1花序对热胁迫表现出敏感性，而过表达SPL 1或SPL 12增强了拟南芥和烟草的耐热性。RNA测序结果显示，在热胁迫下野生型花序中有1939个基因上调，1479个基因下调，其中spl 1 -1 spl 12 -1中有1/4（1,040个）基因表达异常，表明SPL 1和SPL 12在热胁迫下花序转录重编程中起重要作用。值得注意的是，热胁迫诱导了大量的脱落酸（阿坝）响应基因，其中约39%的spl 1 -1 spl 12 -1花序中的热诱导受到干扰。阿坝预处理和SPL 1的过表达恢复了spl 1 -1 spl 12 -1和阿坝生物合成突变体aba 2 -1的花序耐热性，但在阿坝受体PYR 1/PYL 1/PYL 2/PYL 4/PYL 5/PYL 8缺陷的pyl六重突变体中没有恢复。因此，由SPL 1和SPL 2赋予的花序耐热性涉及PYL介导的阿坝信号传导。SPL 1和SPL 12组成的分子网络为植物生殖阶段耐热性的机制提供了新的线索。
Plant reproductive organs are vulnerable to heat, but regulation of heat-shock responses in inflorescence is largely uncharacterized. Here, we report that two of the SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) transcriptional factors in Arabidopsis, SPL1 and SPL12, act redundantly in thermotolerance at the reproductive stage. The spl1-1 spl12-1 inflorescences displayed hypersensitivity to heat stress, whereas overexpression of SPL1 or SPL12 enhanced the thermotolerance in both Arabidopsis and tobacco. RNA sequencing revealed 1939 upregulated and 1479 downregulated genes in wild-type inflorescence upon heat stress, among which one-quarter (1,040) was misregulated in spl1-1 spl12-1, indicating that SPL1 and SPL12 contribute greatly to the heat-triggered transcriptional reprogramming in inflorescence. Notably, heat stress induced a large number of abscisic acid (ABA) responsive genes, of which similar to 39% were disturbed in heat induction in spl1-1 spl12-1 inflorescence. Preapplication of ABA and overexpression of SPL1 restored the inflorescence thermotolerance in spl1-1 spl12-1 and in the ABA biosynthesis mutant aba2-1, but not in the pyl sextuple mutant defective in ABA receptors PYR1/PYL1/PYL2/PYL4/PYL5/ PYL8. Thus, inflorescence thermotolerance conferred by SPL1 and SPL2 involves PYL-mediated ABA signaling. The molecular network consisting of SPL1 and SPL12 illustrated here shed new light on the mechanisms of plant thermotolerance at the reproductive stage.