**6. Emerging roles of Jasmonates**

*Plant Science - Structure, Anatomy and Physiology in Plants Cultured in Vivo and in Vitro*

A number of co-repressors also play their role simultaneously in signal transduction pathway. Corepressors in transcriptional regulators inhibit transcription initiation. TOPLESS (TPL) and TPL-related proteins (TPRs) are members of Groucho/ Tup1 co-repressor family that causes histone deacetylation and demethylation which resulted in chromatin modification, eventually mediated repression of genes. [10]. Interaction of TPL with JAZ proteins takes place via ethylene response factor (ERF)-associated amphiphilic repression (EAR) motif. Those JAZ proteins having absence of repression motif recruit TPL through an adapter protein called novel

MYC2 the master regulator of many biological processes is a bHLH transcription factor mediating the transcriptional regulation of JA. Other transcription factors that controls JA mediated signaling are MYC3, MYC4, MYB, GL3, EGL3

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downstream targets [29].

interactor of JAZ (NINJA) [28].

*Signal transduction pathway of jasmonic acid.*

**5.1 Role of MYC2 in JA mediating signal transduction**

• An activator of JA-induced root growth inhibition

• Anthocyanin biosynthesis, oxidative stress tolerance

• Biosynthesis of tryptophan and indole glucosinolates

• Mediating resistance to necrotrophic pathogens, insects

Various homologs of MYC2 like MYC3 and MYC4 binds with G-box (5′-CACGTG-3′) and G-box-related hexamers and regulate the transcription of

AP, GL1, etc.

**Figure 5.**
