CaWRKY40b in Pepper Acts as a Negative Regulator in Response to Ralstonia solanacearum by Directly Modulating Defense Genes Including CaWRKY40.
CaWRKY40b in Pepper Acts as a Negative Regulator in Response to Ralstonia solanacearum by Directly Modulating Defense Genes Including CaWRKY40.
复制标题
胡椒中的 CaWRKY40b 通过直接调节包括 CaWRKY40 在内的防御基因，充当响应青枯菌的负调节剂
DOI：
10.3390/ijms19051403
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发表时间：
2018-05-08
影响因子：
5.6
通讯作者：
He S
中科院分区：
文献类型：
--
作者：
Ifnan Khan M;Zhang Y;Liu Z;Hu J;Liu C;Yang S;Hussain A;Furqan Ashraf M;Noman A;Shen L;Xia X;Yang F;Guan D;He S
WRKY转录因子（TFs）参与植物的生长、发育和对环境信号的响应;然而，大多数辣椒WRKY TFs的功能仍不清楚。在本研究中，我们的功能特点CaWRKY 40 b，AtWRKY 40的同源物，辣椒免疫。接种青枯雷尔氏菌（Ralstonia solanacearum，RSI）后，CaWRKY 40 b转录水平下调，绿色荧光蛋白（GFP）标记的CaWRKY 40 b在本氏烟草（Nicotiana benthamiana）中瞬时过表达，定位于细胞核。病毒诱导的CaWRKY 40 b基因沉默（VIGS）显著降低了辣椒对RSI的敏感性。一致地，CaWRKY 40 b-SRDX（CaWRKY 40 b的嵌合阻遏物形式）的瞬时过表达触发细胞死亡，如通过较深的台盼蓝和DAB染色所指示的。CaWRKY 40 b靶向许多免疫相关基因，包括CaWRKY 40 β、RLK 1、EIN 3、FLS 2、CNGIC 8、CDPK 13和热休克同源蛋白70（HSC 70），这些基因通过ChIP-seq鉴定并使用ChIP-实时PCR确认。在这些靶基因中，负调节因子HSC 70通过CaWRKY 40 b的瞬时过表达而上调，通过CaWRKY 40 b的沉默而下调，而其他正调节因子以及两个非靶基因CaNPR 1和CaDEF 1通过CaWRKY 40 b的瞬时过表达而下调，通过CaWRKY 40 b的沉默或CaWRKY 40 b-SRDX的瞬时过表达而上调。此外，CaWRKY 40 b通过直接靶向自身启动子，在转录水平上表现出正反馈调控作用。本研究结果提示CaWRKY 40 b在辣椒抗赤霉病菌的免疫中起负调节作用。它通过转录调节免疫相关基因的子集来抑制青枯菌;它还在病原体不存在时抑制免疫，并且在病原体攻击时解除免疫抑制。
WRKY transcription factors (TFs) have been implicated in plant growth, development, and in response to environmental cues; however, the function of the majority of pepper WRKY TFs remains unclear. In the present study, we functionally characterized CaWRKY40b, a homolog of AtWRKY40, in pepper immunity. Ralstonia solanacearum inoculation (RSI) in pepper plants resulted in downregulation of CaWRKY40b transcript, and green fluorescent protein (GFP)-tagged CaWRKY40b was localized to the nuclei when transiently overexpressed in the leaves of Nicotiana benthamiana. Virus-induced gene silencing (VIGS) of CaWRKY40b significantly decreased pepper’ susceptibility to RSI. Consistently, the transient over-expression of CaWRKY40b-SRDX (chimeric repressor version of CaWRKY40b) triggered cell death, as indicated by darker trypan blue and DAB staining. CaWRKY40b targets a number of immunity-associated genes, including CaWRKY40 JAR, RLK1, EIN3, FLS2, CNGIC8, CDPK13, and heat shock cognate protein 70 (HSC70), which were identified by ChIP-seq and confirmed using ChIP-real time PCR. Among these target genes, the negative regulator HSC70 was upregulated by transient overexpression of CaWRKY40b and downregulated by silencing of CaWRKY40b, whereas other positive regulators as well as two non-target genes, CaNPR1 and CaDEF1, were downregulated by the transient overexpression of CaWRKY40b and upregulated by CaWRKY40b silencing or transient overexpression of CaWRKY40b-SRDX. In addition, CaWRKY40b exhibited a positive feedback regulation at transcriptional level by directly targeting the promoter of itself. In conclusion, the findings of the present study suggest that CaWRKY40b acts as a negative regulator in pepper immunity against R. solanacearum by transcriptional modulation of a subset of immunity-associated genes; it also represses immunity in the absence of a pathogen, and derepresses immunity upon pathogen challenge.
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影响因子：
7.2
作者：
Bohman, S;Staal, J;Dixelius, C
通讯作者：
Dixelius, C
影响因子：
6.9
作者：
Encinas-Villarejo, Sonia;Maldonado, Ana M.;Caballero, Jose L.
通讯作者：
Caballero, Jose L.
影响因子：
7.2
作者：
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通讯作者：
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作者：
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影响因子：
5.1
作者：
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