MYC genes with differential responses to tapping, mechanical wounding, ethrel and @entity19086 in laticifers of rubber tree ( XXXX Muell. Arg.).

@entity1522 @entity7214 @entity2271 @entity3785 @entity958 @entity26866 @entity19086 @entity8230 @entity15020 @entity15543
@entity15020 transcription factor is a key component of the core module @entity26866 -JAZ- @entity15020 of jasmonate signaling in @entity958 , but the MYC transcription factor (s) associated with @entity7214 signaling in jasmonate-responsive laticifer cells remains to be identified. Two full-length cDNAs, designated HblMYC1 and HblMYC2, were isolated from laticifer cells in @entity15543 by the method of RACE. HblMYC1 contained 1431bp ORF encoding a putative protein of 476 @entity1522 while HblMYC2 contained 1428bp ORF encoding a putative protein of 475 @entity1522 . Bioinformatic analysis showed that the putative proteins, HblMYC1 and HblMYC2, possessed a bHLH domain and were most related to the @entity15020 among the selected 27 MYC members with identified functions in @entity958 . In addition to the presence of cis-regulatory elements involving jasmonate responsiveness in the promoter regions of HblMYC1 and HblMYC2, the @entity2271 -, @entity3785 - and gibberellin-responsive elements were found in the promoter region of HblMYC1. Transcripts of HblMYC1 and HblMYC2 were most abundant in latex, relatively low in male flowers and nearly undetected in bark tissues and roots by real-time RT-PCR analysis. Regular tapping, mechanical wounding, and @entity8230 remarkably up-regulated HblMYC1 expression, but had little effect on the expression of HblMYC2 in laticifer cells. Successive tapping, however, significantly down-regulated the expression of HblMYC2 while up-regulating the expression of HblMYC1. The HblMYC2 expression took a mutual ebb and flow relationship with the HblMYC1 expression upon treatment with @entity19086 . Characterization of HblMYC1 and HblMYC2 will contribute to the understanding of jasmonate signaling in laticifiers, a kind of specialized tissue for natural rubber biosynthesis in @entity15543 .
