ABSTRACT

‘Sushuai’ is a disease-resistant apple variety. Transcriptome sequencing revealed differentially expressed genes mainly in the metabolism, biosynthesis of secondary metabolites, plant–pathogen interactions, and plant signaling transduction pathways. The jasmonate/ethylene signaling pathway and WRKY transcription factors (especially WRKY75 genes) played important roles in improving Alternaria alternata resistance in ‘Sushuai’. An investigation of the effect of biotic and abiotic stresses on the expression of MdWRKY75s revealed that MdWRKY75d and MdWRKY75e expression was upregulated by A. alternata and methyl jasmonate treatments, while their expression was downregulated by salicylic acid treatment. Transient MdWRKY75d and MdWRKY75e expression improved apple resistance to A. alternata. The analysis, prediction, and validation of the transcriptome data revealed that MdLAC7, MdRFK1, and MdWFK1 are the most likely target genes of MdWRKY75d and MdWRKY75e. Our study provides a basis for investigating mechanisms of resistance to A. alternata.

摘要

'速帅'是抗病苹果品种。转录组测序揭示了主要在代谢、次级代谢产物的生物合成、植物-病原体相互作用和植物信号转导途径中差异表达的基因。茉莉酸/乙烯信号通路和WRKY转录因子（尤其是WRKY75基因）在提高'素帅'链格孢抗性方面发挥了重要作用。生物和非生物胁迫对MdWRKY75s表达影响的研究表明，MdWRKY75d和MdWRKY75e表达被互生花和茉莉酸甲酯处理上调，而它们的表达被水杨酸处理下调。短暂的MdWRKY75d和MdWRKY75e表达提高到苹果电阻链格孢。转录组数据的分析、预测和验证表明MdLAC7、MdRFK1和MdWFK1是MdWRKY75d和MdWRKY75e最有可能的靶基因。我们的研究提供了研究性的机制的基础A.病菌。