响应辣椒疫霉菌诱导的CaWRKY转录因子筛选及其信号通路分析

CaWRKY Transcription Factors Induced by Phytophthora capsici:Screening and Signal Pathway Analysis

在辣椒基因组中全面鉴定WRKY转录因子并筛选出受辣椒疫霉菌诱导的CaWRKY基因,并分析关键CaWRKY基因参与的信号通路。以CM334和NMCA10399为材料,基于辣椒基因组和RNA-seq数据,并在水杨酸(SA)和茉莉酸甲酯(MeJA)处理下通过qRT-PCR技术检测基因表达并分析。全基因组共鉴定出69个CaWRKY基因。接菌后12 h,抗、感材料中分别鉴定出7个和3个差异表达基因;接菌后36 h,分别有13个和22个差异表达基因,表明抗病材料能更快速应答。在筛选出的8个关键CaWRKY基因中,CaWRKY19和CaWRKY65受SA诱导上调表达;CaWRKY50受MeJA诱导上调表达;CaWRKY25受SA诱导上调表达同时受到MeJA抑制下调表达,而CaWRKY49同时受SA和MeJA抑制下调表达,推测CaWRKY19和CaWRKY65通过SA,CaWRKY50通过JA,而CaWRKY25和CaWRKY49则通过SA和JA信号途径参与辣椒抗疫病防御反应。

The aims of this study are to identify WRKY transcription factors in the whole genome of pepper,select the CaWRKYs induced by Phytophthora capsici and analyze the signal pathways involved in the key CaWRKY genes.CM334 and NMCA10399 were used as experimental materials.Based on genome and RNAseq data,gene expressions were obtained by qRT-PCR under the treatment of salicylic acid(SA)and methyl jasmonate(MeJA).The results showed that 69 CaWRKYs were identified in the whole genome of pepper.At the time point of 12 hpi,there were 7 and 3 CaWRKYs significantly and differentially expressed in resistant and susceptible materials,respectively.At 36 hpi,13 and 22 genes were significantly and differentially expressed in resistant and susceptible materials,respectively.These results indicated that resistant material could respond more quickly to the pathogens.Among the 8 key CaWRKYs selected,CaWRKY19 and CaWRKY65were induced by SA and up-regulated expressed,while CaWRKY50 was induced by MeJA and up-regulated expressed.CaWRKY25 was up-regulated by SA and down-regulated by MeJA,while CaWRKY49 was downregulated by both SA and MeJA.Signal pathway analysis speculated that CaWRKY19 and CaWRKY65 were involved in pepper defense against Phytophthora through SA signal pathway,CaWRKY50 through JA signal pathway,while CaWRKY25 and CaWRKY49 through both SA and JA signal pathway.