Disease relevance of ATMYC2

• RNA gel blot analysis revealed that transcription of the rd22BP1 gene is induced by dehydration stress and ABA treatment, and its induction precedes that of rd22 [1].
• An Arabidopsis cDNA clone encoding a DNA-binding protein, RAP-1, was isolated by southwestern screening of an Escherichia coli cDNA expression library [2].
• The Arabidopsis thaliana JASMONATE INSENSITIVE 1 gene is required for suppression of salicylic acid-dependent defenses during infection by Pseudomonas syringae [3].

High impact information on ATMYC2

• Knockout mutants in the AtMYC2 homolog gene of Arabidopsis are insensitive to JA and exhibit a decreased activation of the JA-responsive genes AtVSP and JR1 [4].
• These results show that the JAMYC/AtMYC2 transcription factors function as members of a MYC-based regulatory system conserved in dicotyledonous plants with a key role in JA-induced defense gene activation [4].
• Taken together, these results demonstrate that AtMYC2 is a common transcription factor of light, ABA, and JA signaling pathways in Arabidopsis [5].
• Our results further demonstrate that atmyc2 mutants have compromised sensitivity to ABA- and JA-mediated responses [5].
• 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 [5].

Biological context of ATMYC2

• These results indicate that both AtMYC2 and AtMYB2 proteins function as transcriptional activators in ABA-inducible gene expression under drought stress in plants [6].
• A cDNA encoding a MYC-related DNA binding protein was isolated by DNA-ligand binding screening, using the 67-bp region as a probe, and designated rd22BP1 [1].
• In a transient transactivation experiment using Arabidopsis leaf protoplasts, we demonstrated that both the rd22BP1 and ATMYB2 proteins activate transcription of the rd22 promoter fused to the beta-glucuronidase reporter gene [1].
• Accordingly, the O(3)-exposed jasmonate-insensitive mutant jar1 displayed spreading cell death and a prolonged O(2)(*)- accumulation pattern [7].
• While the TATA-box binding motif was also previously reported by Xie and colleagues, the transcription factors AtMYC2, ARF, SORLREP3, and LFY are identified for the first time as overrepresented binding motifs in miRNA promoters [8].

Associations of ATMYC2 with chemical compounds

• Here, we show that transgenic plants overexpressing AtMYC2 and/or AtMYB2 cDNAs have higher sensitivity to ABA [6].
• Arabidopsis AtMYC2 (bHLH) and AtMYB2 (MYB) function as transcriptional activators in abscisic acid signaling [6].
• The rd22BP1 cDNA encodes a 68-kD protein that has a typical DNA binding domain of a basic region helix-loop-helix leucine zipper motif in MYC-related transcription factors [1].
• JA activation via this pathway was blocked in the A. thaliana JA-insensitive mutants jin1, jin4 and coi1, and by exogenous application of cycloheximide or auxins [9].
• JIN1 encodes AtMYC2, a nuclear-localized basic helix-loop-helix-leucine zipper transcription factor, whose expression is rapidly upregulated by JA, in a CORONATINE INSENSITIVE1-dependent manner [10].

Regulatory relationships of ATMYC2

• By contrast, a Ds insertion mutant of the AtMYC2 gene was less sensitive to ABA and showed significantly decreased ABA-induced gene expression of rd22 and AtADH1 [6].

Other interactions of ATMYC2

• With a jasmonate-insensitive mutant (jar1), the induction by the volatiles was mostly suppressed, however, that of LOX2 was unaltered [11].

Analytical, diagnostic and therapeutic context of ATMYC2

• Microarray analysis of the transgenic plants overexpressing both AtMYC2 and AtMYB2 cDNAs revealed that several ABA-inducible genes also are upregulated in the transgenic plants [6].

References