The phytochrome-interacting transcription factor CsPIF8 contributes to cold tolerance in citrus by regulating superoxide dismutase expression
The phytochrome-interacting transcription factor CsPIF8 contributes to cold tolerance in citrus by regulating superoxide dismutase expression
复制标题
光敏色素相互作用转录因子 CsPIF8 通过调节超氧化物歧化酶表达促进柑橘的耐冷性
DOI：
10.1016/j.plantsci.2020.110584
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发表时间：
2020-09-01
期刊：
影响因子：
5.2
通讯作者：
Xu, Juan
中科院分区：
文献类型：
--
作者：
He, Zhenyu;Zhao, Tiantian;Xu, Juan
柑桔是亚热带、热带果树之一，对低温胁迫比较敏感。然而，大多数调节柑橘耐冷性的转录因子（TF）尚未报道。柑橘光敏色素相互作用转录因子（PIF）基因（CsPIF 8）在低温胁迫下表达显著上调。CsPIF 8的过表达增加了转基因番茄植株和葡萄柚愈伤组织的耐冷性，而病毒诱导的基因沉默介导的PIF 8抑制增加了枳幼苗的冷敏感性。超氧化物歧化酶（SOD）通过降低超氧阴离子（O-2）水平来增强植物的耐寒性。染色质免疫沉淀结合高通量测序、酵母单杂交、电泳迁移率改变和双荧光素酶分析表明，CsPIF 8直接结合CsSOD启动子的E-box（CANNTG），激活CsSOD启动子。此外，在转基因株系中，CsSOD的表达水平和CsSOD活性显著增加，而O-2（中心点-）水平显著降低。VIGS介导的PIF 8抑制的枳壳幼苗表现出相反的效果。这些结果表明，CsPIF 8通过调节SOD的表达水平和SOD活性来提高柑橘的耐冷性。这些发现可能为PIF 8在柑橘冷胁迫反应中的调控提供新的见解。
As one of the subtropical and tropical fruit trees, Citrus sinensis is sensitive to cold stress. However, most transcription factors (TFs) that regulate cold tolerance in citrus have not yet been reported. A phytochrome-interacting transcription factor (PIF) gene (CsPIF8) in citrus was significantly upregulated under cold stress. Overexpression of CsPIF8 increased cold tolerance in transgenic tomato plants and grapefruit callus, whereas virus-induced gene silencing-mediated suppression of PIF8 increased cold sensitivity in seedlings of Poncirus trifoliata. Superoxide dismutase (SOD) reduces the superoxide anion (O-2(center dot-)) level to enhance cold tolerance in plants. Chromatin immunoprecipitation combined with high-throughput sequencing, yeast one hybrid, electrophoretic mobility shift and dual luciferase assays showed that CsPIF8 directly bound the E-box (CANNTG) of CsSOD promoter and activated the promoter of CsSOD. Furthermore, the expression level of CsSOD and CsSOD activity were significantly increased, whereas the level of O-2(center dot-) was significantly reduced in the transgenic lines. The Poncirus trifoliata seedlings with VIGS-mediated suppression of PIF8 exhibited the opposite effects. These results have shown that CsPIF8 improved cold tolerance in citrus through regulating the expression level of SOD and SOD activity. These findings may provide novel insights into the regulation of PIF8 in the response to cold stress in citrus.