AUTHOR=Li Shucheng , Xiao Liuhua , Chen Ming , Cao Qing , Luo Zhenyu , Kang Naihui , Jia Mingshu , Chen Jinyin , Xiang Miaolian 

TITLE=The involvement of the phenylpropanoid and jasmonate pathways in methyl jasmonate-induced soft rot resistance in kiwifruit (Actinidia chinensis)

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.1097733

DOI=10.3389/fpls.2022.1097733

ISSN=1664-462X

ABSTRACT=<p><italic>Botryosphaeria dothidea</italic> is a major postharvest causal agent of soft rot in kiwifruit. Methyl jasmonate (MeJA) is an important plant hormone that participates as a plant defense against pathogens from a signal molecule. However, the impact and regulatory mechanism of MeJA on the attenuation of kiwifruit fungal decay remains unknown. This work investigated the effects of exogenous MeJA on the enzyme activity, metabolite content and gene expression of the phenylpropanoid and jasmonate pathways in kiwifruit. The results revealed that MeJA inhibited the expansion of <italic>B. dothidea</italic> lesion diameter in kiwifruit (<italic>Actinidia chinensis</italic> cv. ‘Hongyang’), enhanced the activity of enzymes (phenylalanine ammonia lyase, cinnamate 4-hydroxylase, 4-coumarate: coenzyme A ligase, cinnamyl alcohol dehydrogenase, peroxidase and polyphenol oxidase), and upregulated the expression of related genes (<italic>AcPAL</italic>, <italic>AcC4H</italic>, <italic>Ac4CL</italic>, and <italic>AcCAD</italic>). The accumulation of metabolites (total phenolics, flavonoids, chlorogenic acid, caffeic acid and lignin) with inhibitory effects on pathogens was promoted. Moreover, MeJA enhanced the expression of <italic>AcLOX</italic>, <italic>AcAOS</italic>, <italic>AcAOC</italic>, <italic>AcOPR3</italic>, <italic>AcJAR1</italic>, <italic>AcCOI1</italic> and <italic>AcMYC2</italic> and reduced the expression of <italic>AcJAZ</italic>. These results suggest that MeJA could display a better performance in enhancing the resistance of disease in kiwifruit by regulating the phenylpropanoid pathway and jasmonate pathway.</p>