转录组分析超表达MpICE1香蕉抗枯萎病机理

Molecular Mechanism of MpICE1 Overexpressing Banana Resistant to Fusarium oxysporum Based on Transcriptome Analysis

前期研究发现在香蕉中超表达大蕉(Musa spp.‘Lingchuan Dajiao’)MpICE1能显著提高香蕉抗枯萎病能力,为进一步揭示其分子机理,通过转录组对接种Foc TR4前0 d和接种后7、14 d的野生型和超表达MpICE1香蕉(Musa spp.‘Brazil’)的根部中差异表达基因进行分析。结果表明,在接种前超表达MpICE1香蕉可诱导一系列基因的高表达,且这些高表达的基因富集在苯丙烷合成、黄酮合成、ABC转运蛋白、MAPK信号传导和戊糖、葡萄糖醛酸转换等途径中,与细胞壁结构和功能相关。MpICE1的超表达可能会增强香蕉的基础免疫反应,从而对Foc TR4的抗性增强。另外,接种Foc TR4后,超表达MpICE1香蕉接种前0 d高表达的大部分基因表达量开始下降,到7 d时达到相对稳定的状态。对差异表达基因进一步分析发现,编码12–氧–植物二烯酸还原酶的基因(Ma06_g18840)可能是MpICE1的靶基因,且其表达量受MpICE1的抑制,与氧化脂质(JA和OPDA)代谢相关,可能通过JA或OPDA信号途径调节根部细胞壁结构。泛素碳端水解酶(Ubiquitin carboxyl-terminal hydrolase 36/42)也受MpICE1的影响,但具体的作用机制需进一步研究。

Based on previous studies,it was found that overexpression of MpICE1 transcription factor in bananas significantly improved the resistance to fusarium wilt.To further reveal the resistance mechanism of MpICE1 to fusarium wilt,the samples from the roots of wild-type and MpICE1 overexpressing bananas before(0 d)and after(7 d and 14 d)Foc TR4 inoculation were collected,and these samples were applied to RNA-sequencing for DEGs analysis.The results showed that the overexpression of MpICE1 could increase the expression of a series of genes before inoculation.These genes were enriched in phenylpropane synthesis,flavonoid synthesis,ABC transporters,MAPK signal transduction,pentose and glucuronic acid conversion pathway,which were related to the structure and function of cell wall.Combined with KEGG pathway analysis,we speculate that overexpression of MpICE1 may elevate the resistance to Foc TR4 by enhancing the basic immunity.In addition,genes higherly expressed in MpICE1 overexpressing bananas began to decline after inoculation,and the interaction between MpICE1 overexpressing bananas and pathogens reached a relatively stable state seven days after inoculation.Compared with the wild type,only a small amount of DEGs were found in MpICE1 overexpressing bananas 7 and 14 days after incolation.The expression dynamic of DEGs revealed that 12-oxophytodienoic acid reductase(Ma06_g18840),which is related to oxidation lipid metabolism(JA and OPDA),may be the target gene of MpICE1.Moreover,the expression of ubiquitin carboxyl-terminal hydrolase 36/42 was also affected by MpICE1 overexpression.However,the specific mechanism was still unknown,and need further study.