Jasmonate signal pathway involved in phytoalexin biosynthesis in Sorbus aucuparia cell elicited by Hpa1

Abstract

The Harpin protein Hpa1 can induce defense responses in plant. This study aimed at investigating the role of jasmonate (JA) signal pathway in the process of biosynthesis of secondary metabolite in Sorbus aucuparia cell eliciting by Hpa1 crude extract (Hpa1 CE). The results showed that Hpa1 crude extract (Hpa1 CE) could induce phytoalexin synthesis in S. aucuparia cell， most of which was noraucuparin and its glycosides. Meanwhile Hpa1 CE treatment resulted in methyl jasmonate (MeJA) production increased and noraucuparin was de novo synthesized in large quantities. Combination of Hpa1 CE and salicylhydroxamic acid (SHAM, JA signaling inhibitor) caused the decreased MeJA and noraucuparin in the S. aucuparia cell compared with that in Hpa1 CE group. Real-time PCR results indicated that Hpa1 CE treatment caused down-regulation of JAZ and up-regulation of mcy2 in transcription level. Therefore Hpa1 CE elicited defense mechanism and JA signaling pathway involved in phytoalexin biosynthesis in S. aucuparia cell. It presented information to elucidate the role of JA signal pathway in stress response in the perspective of secondary metabolism of plant.