Taken together, these results indicate that MYC5, probably together with other, redundant transcription factors, may be activated by JA signaling to induce the expression of MYB21 and components required for male fertility. Importantly, expression of MYB21 and other transcription factors required for stamen and pollen maturation was strongly reduced in stamens of MYC5‐SRDX plants relative to the wild type. In particular, MYC5‐SRDX plants were male‐sterile, with defects in stamen filament elongation, anther dehiscence and pollen viability. The dHax3.SRDX protein efficiently repressed the transcription of the RD29A::LUC transgene and endogenous RD29A gene in Arabidopsis. Two allelic myc5 mutants exhibited no overt phenotype however, transgenic lines expressing MYC5 fused to an SRDX (SUPERMAN repressive domain X) motif phenocopied mutants defective in JA signaling. The dHax3 TALE was used as a scaffold to provide a DNA-binding module fused to the EAR-repression domain (SRDX) to generate a chimeric repressor that targets the RD29A promoter. A G‐box sequence in the JAZ2 promoter was necessary and sufficient for induction by MYC5 (as it is for MYC2, MYC3 and MYC4), and induction of JAZ genes was repressed by co‐expression of a stabilized, JAZ1ΔJas repressor. These results indicate that the Arabidopsis-derived TCP3-SRDX induced morphological changes in transgenic torenia and chrysanthemum although the observed phenotypes partially differ from each other. We found that a closely related transcription factor, MYC5 (bHLH28), was able to induce JAZ promoters that control some of the early JA‐responsive genes in a Daucus carota (carrot) protoplast expression system. In TCP3-SRDX transgenic chrysanthemum plants, floral organ development was suppressed as compared with the wild type. MYC2, MYC3 and MYC4 are JAZ‐interacting bHLH transcription factors that play a major role in controlling JA responses in vegetative tissue, but are not likely to play a role in reproductive tissue. 35S:GATA4-SRDX seedlings were significantly larger than wild type under nitrogensufficient and -deficient conditions (10 and 0.5 mM NH 4 NO 3, respectively). Arabidopsis thaliana plants deficient in JA‐biosynthesis or ‐signaling are male‐sterile, with defects in stamen and pollen development. Here, we report that the expression of the chimeric repressor for the GATA4 transcription factor (35S:GATA4-SRDX) improved tolerance to nitrogen deficiency in Arabidopsis thaliana. Jasmonate hormone (JA) plays critical roles in both plant defense and reproductive development. Male sterility in Arabidopsis induced by overexpression of a MYC5‐SRDX chimeric repressor Male sterility in Arabidopsis induced by overexpression of a MYC5‐SRDX chimeric repressor

Srdx repressor