Details

Autor(en) / Beteiligte

• Thireault, Caitlin
• Shyu, Christine
• Yoshida, Yuki
• St. Aubin, Brian
• Campos, Marcelo L
• Howe, Gregg A

Titel

Repression of jasmonate signaling by a non‐TIFY JAZ protein in Arabidopsis

Ist Teil von

• The Plant journal : for cell and molecular biology, 2015-05, Vol.82 (4), p.669-679

Ort / Verlag

England: Blackwell Scientific Publishers and BIOS Scientific Publishers in association with the Society for Experimental Biology

Erscheinungsjahr

2015

Quelle

Wiley-Blackwell Journals

Beschreibungen/Notizen

• JAsmonate ZIM‐domain (JAZ) proteins repress the activity of transcription factors that execute responses to the plant hormone jasmonoyl‐L‐isoleucine (JA‐Ile). The ZIM protein domain recruits the co‐repressors NINJA and TOPLESS to JAZ‐bound transcription factors, and contains a highly conserved TIF[F/Y]XG motif that defines the larger family of TIFY proteins to which JAZs belong. Here, we report that diverse plant species contain genes encoding putative non‐TIFY JAZ proteins, including a previously unrecognized JAZ repressor in Arabidopsis (JAZ13, encoded by At3g22275). JAZ13 is most closely related to JAZ8 and includes divergent EAR, TIFY/ZIM, and Jas motifs. Unlike JAZ8, however, JAZ13 contains a Ser‐rich C‐terminal tail that is a site for phosphorylation. Overexpression of JAZ13 resulted in reduced sensitivity to JA, attenuation of wound‐induced expression of JA‐response genes, and decreased resistance to insect herbivory. JAZ13 interacts with the bHLH transcription factor MYC2 and the co‐repressor TOPLESS but, consistent with the absence of a TIFY motif, neither NINJA nor other JAZs. Analysis of single and higher‐order T‐DNA insertion jaz null mutants provided further evidence that JAZ13 is a repressor JA signaling. Our results demonstrate that proteins outside the TIFY family are functional JAZ repressors and further suggest that this expansion of the JAZ family allows fine‐tuning of JA‐mediated transcriptional responses.