A basic helix-loop-helix transcription factor in Arabidopsis, MYC2, acts as a repressor of blue light-mediated photomorphogenic growth.
The crosstalk of light signaling pathways with other signaling cascades has just started to be revealed. Here, we report the identification and functional characterization of a Z-box binding factor (ZBF1) in light signaling pathways. Arabidopsis thaliana ZBF1 encodes AtMYC2/JIN1, a basic helix-loop-helix transcription factor, which has recently been shown to be involved in abscisic acid (ABA), jasmonic acid (JA), and jasmonate-ethylene signaling pathways. We demonstrate that AtMYC2 interacts with the Z- and G-box light-responsive elements of minimal light-regulated promoters. AtMYC2 is expressed in various light-grown seedlings, including in red, far red, and blue light. Genetic analyses suggest that AtMYC2 acts as a negative regulator of blue light-mediated photomorphogenic growth and blue and far-red-light-regulated gene expression; however, it functions as a positive regulator of lateral root formation. Our results further demonstrate that atmyc2 mutants have compromised sensitivity to ABA- and JA-mediated responses. Taken together, these results demonstrate that AtMYC2 is a common transcription factor of light, ABA, and JA signaling pathways in Arabidopsis.
Yadav
Vandana
V
National Centre for Plant Genome Research, New Delhi 110067, India.
Mallappa
Chandrashekara
C
Gangappa
Sreeramaiah N
SN
Bhatia
Shikha
S
Chattopadhyay
Sudip
S
D000040:Abscisic Acid / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000235:genetics* / Q000378:metabolism; D003517:Cyclopentanes / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000528:radiation effects*; D018257:Helix-Loop-Helix Motifs / Q000235:genetics; D008027:Light; D008969:Molecular Sequence Data; D054883:Oxylipins; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development; D011401:Promoter Regions, Genetic / Q000235:genetics / Q000528:radiation effects; D050436:Regulatory Elements, Transcriptional / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D036226:Seedlings / Q000235:genetics* / Q000254:growth & development / Q000528:radiation effects; D015398:Signal Transduction / Q000235:genetics / Q000528:radiation effects; D015533:Transcriptional Activation / Q000235:genetics
D029681:Arabidopsis Proteins; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D003517:Cyclopentanes; C473611:MYC2 protein, Arabidopsis; D054883:Oxylipins; D012097:Repressor Proteins; C011006:jasmonic acid; D000040:Abscisic Acid