The basic helix-loop-helix transcription factor bHLH95 affects fruit ripening and multiple metabolisms in tomato
The basic helix-loop-helix transcription factor bHLH95 affects fruit ripening and multiple metabolisms in tomato
复制标题
碱性螺旋-环-螺旋转录因子bHLH95影响番茄果实成熟和多种代谢
DOI：
10.1093/jxb/eraa363
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发表时间：
2020
影响因子：
6.9
通讯作者：
Zongli Hu
中科院分区：
文献类型：
--
作者：
Lincheng Zhang;Jing Kang;Qiaoli Xie;Jun Gong;Hui Shen;Yanan Chen;Guoping Chen;Zongli Hu
乙烯信号通路调节番茄果实成熟过程中发生的几种生理变化，如颜色和风味的变化。尽管MADS-box转录因子RIN的作用已被广泛报道，但这些途径中基因转录调控的机制尚不清楚。在这里，我们描述了一种bHLH转录因子SlbHLH95，与thrin（成熟抑制剂）和nr（未成熟）突变体相比，其转录物在breaker+4和breaker+7果实中积累丰富。此外，slbhlh95的启动子活性在体内受RIN调控。抑制slbhlh95可降低对乙烯的敏感性，减少总类胡萝卜素的积累，降低谷胱甘肽含量，抑制果实成熟和谷胱甘肽代谢相关基因的表达。相反，在野生型番茄中，slbhlh95的上调导致对乙烯的敏感性提高，总类胡萝卜素的积累增加，略微早熟，谷胱甘肽、可溶性糖和淀粉的积累增加。值得注意的是，slbhlh95的过表达与果实成熟相关基因（FUL1、FUL2、SAUR69、ERF4和cnr）和多个谷胱甘肽代谢相关基因（GSH1、GSH2、GSTF1和gstf5）的表达上调有关。这些结果表明，SlbHLH95参与了番茄果实成熟的调控，并影响了乙烯敏感性和RIN靶向的多种代谢。
Ethylene signaling pathways regulate several physiological alterations that occur during tomato fruit ripening, such as changes in colour and flavour. The mechanisms underlying the transcriptional regulation of genes in these pathways remain unclear, although the role of the MADS-box transcription factor RIN has been widely reported. Here, we describe a bHLH transcription factor, SlbHLH95, whose transcripts accumulated abundantly in breaker+4 and breaker+7 fruits compared withrin(ripening inhibitor) andNr(never ripe) mutants. Moreover, the promoter activity ofSlbHLH95was regulated by RIN invivo. Suppression ofSlbHLH95resulted in reduced sensitivity to ethylene, decreased accumulation of total carotenoids, and lowered glutathione content, and inhibited the expression of fruit ripening- and glutathione metabolism-related genes. Conversely, up-regulation ofSlbHLH95in wild-type tomato resulted in higher sensitivity to ethylene, increased accumulation of total carotenoids, slightly premature ripening, and elevated accumulation of glutathione, soluble sugar, and starch. Notably, overexpression ofSlbHLH95inrinled to the up-regulated expression of fruit ripening-related genes (FUL1,FUL2,SAUR69,ERF4, andCNR) and multiple glutathione metabolism-related genes (GSH1,GSH2,GSTF1, andGSTF5). These results clarified that SlbHLH95 participates in the regulation of fruit ripening and affects ethylene sensitivity and multiple metabolisms targeted by RIN in tomato.