Comparative transcriptome analysis reveals defense responses against soft rot in Chinese cabbage
Comparative transcriptome analysis reveals defense responses against soft rot in Chinese cabbage
复制标题
比较转录组分析揭示大白菜对软腐病的防御反应
DOI：
10.1038/s41438-019-0149-z
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发表时间：
2019-06-01
影响因子：
8.7
通讯作者：
Shen, Shuxing
中科院分区：
文献类型：
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作者：
Liu, Mengyang;Wu, Fang;Shen, Shuxing
胡萝卜果胶杆菌亚种胡萝卜软腐菌（carotovorum，Pcc）是引起大白菜软腐病的一种坏死营养型细菌。在这项研究中，具有抗性突变体sr基因，赋予对PCC的抗性，从800个M2群体的甲基磺酸乙酯（EMS）的突变体筛选，并在体外和体内的病变大小进行评分。结果表明，接种后6 ~ 12 h（hpi）是大白菜抗Pcc的重要防御调控期，在此期间，有512个差异表达基因（DEG）存在于大白菜抗Pcc的基因组中。病原体模式触发免疫（PTI）的下游防御基因（CPK、CML、RBOH、MPK 3和MPK 4）在感染后12 h在抗性突变体sr中被强烈激活; PTI似乎通过三种假定的模式识别受体（PRRs; BrLYM 1-BrCERK 1、BrBKK 1/SERK 4-PEPR 1、BrWAKs）的识别而对植物防御Pcc起核心作用。PCC引发了茉莉酸（JA）和乙烯（ET）生物合成基因在突变体sr中的上调，但生长素和其他激素可能影响了一些负面信号。内源性激素（生长素、茉莉酸和水杨酸）以及外源性生长素（MEJA和BTH）也被证实在免疫系统中起作用。同时，抗性突变体sr中硫代葡萄糖苷和木质素合成基因的表达在12 hpi时增加，硫代葡萄糖苷和木质素的积累也表明这些基因对Pcc具有功能性防御作用。本研究为进一步阐明大白菜对Pcc侵染的抗性机制提供了有价值的信息。
Pectobacterium carotovorum ssp. carotovorum (Pcc) is a necrotrophic bacterial species that causes soft rot disease in Chinese cabbage. In this study, plants harboring the resistant mutant sr gene, which confers resistance against Pcc, were screened from an 800 M 2 population mutated by ethyl methane sulfonate (EMS) and scored in vitro and in vivo for lesion size. The transcript profiles showed~ 512 differentially expressed genes (DEGs) between sr and WT plants occurring between 6 and 12 h postinoculation (hpi), which corresponded to the important defense regulation period (resistance) to Pcc in Chinese cabbage. The downstream defense genes (CPK, CML, RBOH MPK3, and MPK4) of pathogen pattern-triggered immunity (PTI) were strongly activated during infection at 12 hpi in resistant mutant sr; PTI appears to be central to plant defense against Pcc via recognition by three putative pattern recognition receptors (PRRs; BrLYM1-BrCERK1, BrBKK1/SERK4-PEPR1, BrWAKs). Pcc triggered the upregulation of the jasmonic acid (JA) and ethylene (ET) biosynthesis genes in mutant sr, but auxins and other hormones may have affected some negative signals. Endogenous hormones (auxins, JAs, and SA), as well as exogenous auxins (MEJA and BTH), were also verified as functioning in the immune system. Concurrently, the expression of glucosinolate and lignin biosynthesis genes was increased at 12 hpi in resistant mutant sr, and the accumulation of glucosinolate and lignin also indicated that these genes have a functional defensive role against Pcc. Our study provides valuable information and elucidates the resistance mechanism of Chinese cabbage against Pcc infection.