Insights into the defense mechanisms involved in the induction of resistance against black spot of cherry tomatoes by Pichia caribbica
Xiaoyun Zhang, You Zhou, Solairaj Dhanasekaran, Junyi Wang, Hongyao Zhou, Xiangyu Gu, Bo Li, Lina Zhao, Hongyin Zhang
Abstract
Our previous study showed that Pichia caribbica could alleviate black spot of cherry tomatoes. This study aimed to explore the comprehensive mechanisms involved in the induced disease resistance of cherry tomatoes by this yeast. The results indicated that P. caribbica increased the activities of defense-related enzymes and enzymes of phenylpropanoid pathway including polyphenol oxidase, chitinase, β-1,3-glucanase, phenylalanine ammonia-lyase and cinnamate-4-hydroxylase in the fruits. Considering together with transcriptome analysis results, it was suggested that P. caribbica triggered mitogen-activated protein kinase, Ca2+ and plant hormone signaling pathways, up-regulated genes related to reactive oxygen species scavenging, induced defense-related genes and enzyme activities, and stimulated genes and the activities of enzymes involved in secondary metabolite synthesis to accumulate total phenols, lignin and flavonoids, thus enhancing the resistance of cherry tomatoes against black spot. This study will provide new insights into the underlying mechanisms involved in induced disease resistance of cherry tomatoes by antagonistic yeast.