ERF109 of trifoliate orange (Poncirus trifoliata (L.) Raf.) contributes to cold tolerance by directly regulating expression of Prx1 involved in antioxidative process
ERF109 of trifoliate orange (Poncirus trifoliata (L.) Raf.) contributes to cold tolerance by directly regulating expression of Prx1 involved in antioxidative process
复制标题
三叶橙（Poncirus trifoliata (L.) Raf.）的ERF109通过直接调节参与抗氧化过程的Prx1的表达来促进耐冷性
DOI：
10.1111/pbi.13056
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发表时间：
2019-07-01
影响因子：
13.8
通讯作者：
Liu, Ji-Hong
中科院分区：
文献类型：
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作者：
Wang, Min;Dai, Wenshan;Liu, Ji-Hong
乙烯响应因子（ERFs）在高等植物的多种生理和生物过程中发挥着重要作用。然而，大多数erf在冷应激中的功能和调控途径仍不清楚。本研究鉴定了三叶橙（Poncirus trifoliata (L.)）的PtrERF109。)，并破译了它在耐寒性中的作用。PtrERF109在低温、乙烯和脱水条件下显著上调，但在盐条件下受到抑制。PtrERF109定位于细胞核中并表现出转录活性，而C端是激活的必要条件。PtrERF109的过表达增强了转基因烟草和柠檬植株的耐寒性，而VIGS（病毒诱导的基因沉默）介导的三叶橙PtrERF109的抑制导致对冷的敏感性增加。PtrERF109的过表达导致了一系列应激反应基因的广泛转录重编程。编码III类过氧化物酶（POD）的Prx1基因是诱导能力最强的抗氧化基因之一。PtrERF109直接结合PtrPrx1（三叶橙Prx1同源物）的启动子，并积极激活其表达。此外，与野生型相比，ptrerf109过表达植株POD活性显著提高，H2O2积累显著减少，对氧化胁迫的耐受性更强，而VIGS过表达植株表现出相反的趋势。综上所述，这些结果表明，PtrERF109作为一个正调节因子，至少部分地通过直接调节pod编码基因来维持有效清除活性氧的强大抗氧化能力，从而有助于提高耐寒性。我们的研究结果有助于更好地理解抗氧化基因在应对冷应激时的转录调控。
Ethylene-responsive factors (ERFs) have been revealed to play essential roles in a variety of physiological and biological processes in higher plants. However, functions and regulatory pathways of most ERFs in cold stress remain largely unclear. Here, we identified PtrERF109 of trifoliate orange (Poncirus trifoliata (L.) Raf.) and deciphered its role in cold tolerance. PtrERF109 was drastically up-regulated by cold, ethylene and dehydration, but repressed by salt. PtrERF109 was localized in the nucleus and displayed transcriptional activity, and the C terminus is required for the activation. Overexpression of PtrERF109 conferred enhanced cold tolerance in transgenic tobacco and lemon plants, whereas VIGS (virus-induced gene silencing)-mediated suppression of PtrERF109 in trifoliate orange led to increased cold susceptibility. PtrERF109 overexpression caused extensive transcriptional reprogramming of several suites of stress-responsive genes. Prx1 encoding class III peroxidase (POD) was one of the antioxidant genes exhibiting the greatest induction. PtrERF109 was shown to directly bind to the promoter of PtrPrx1 (trifoliate orange Prx1 homologue) and positively activated its expression. In addition, the PtrERF109-overexpressing plants exhibited significantly higher POD activity and accumulated dramatically less H2O2 and were more tolerant to oxidative stress, whereas the VIGS plants exhibited opposite trends, in comparison with wild type. Taken together, these results indicate that PtrERF109 as a positive regulator contributes to imparting cold tolerance by, at least partly, directly regulating the POD-encoding gene to maintain a robust antioxidant capacity for effectively scavenging the reactive oxygen species. Our findings gain insight into better understanding of transcriptional regulation of antioxidant genes in response to cold stress.