title: AtMyb7, a subgroup 4 R2R3 Myb, negatively regulates ABA-induced inhibition of seed germination by blocking the expression of the bZIP transcription factor ABI5.
abstract: Various Myb proteins have been shown to play crucial roles in plants, including primary and secondary metabolism, determination of cell fate and identity, regulation of development and involvement in responses to biotic and abiotic stresses. The 126 R2R3 Myb proteins (with two Myb repeats) have been found in Arabidopsis; however, the functions of most of these proteins remain to be fully elucidated. In the present study, we characterized the function of AtMyb7 using molecular biological and genetic analyses. We used qRT-PCR to determine the levels of stress-response gene transcripts in wild-type and atmyb7 plants. We showed that Arabidopsis AtMyb7 plays a critical role in seed germination. Under abscisic acid (ABA) and high-salt stress conditions, atmyb7 plants showed a lower germination rate than did wild-type plants. Furthermore, AtMyb7 promoter:GUS seeds exhibited different expression patterns in response to variations in the seed imbibition period. AtMyb7 negatively controls the expression of the gene encoding bZIP transcription factor, ABI5, which is a key transcription factor in ABA signalling and serves as a crucial regulator of germination inhibition in Arabidopsis.
authors: College of Life Sciences and Biotechnology, Korea University, Seoul, 136-713, Korea; Institute of Life Science and Natural Resources, Korea University, Seoul, 136-713, Korea.
authors: Jun Hyeok
authors: JH
authors: Kim
authors: Woo Young
authors: WY
authors: Hyun
authors: Hoai Nguyen
authors: HN
authors: Nguyen
authors: Chan Young
authors: CY
authors: Jeong
authors: Liming
authors: L
authors: Xiong
authors: Suk-Whan
authors: SW
authors: Hong
authors: Hojoung
authors: H
authors: Lee
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism / Q000494:pharmacology*; D017360:Arabidopsis / Q000235:genetics* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D017930:Genes, Reporter; D018525:Germination / Q000187:drug effects; D009154:Mutation; D010937:Plant Growth Regulators / Q000378:metabolism / Q000494:pharmacology*; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D012639:Seeds / Q000235:genetics / Q000502:physiology; D015398:Signal Transduction; D012965:Sodium Chloride / Q000494:pharmacology*; D013312:Stress, Physiological; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: C409743:ABI5 protein, Arabidopsis; D029681:Arabidopsis Proteins; D050976:Basic-Leucine Zipper Transcription Factors; C500589:Myb protein, Arabidopsis; C000602360:Myb7 protein, Arabidopsis; D010937:Plant Growth Regulators; D014157:Transcription Factors; D012965:Sodium Chloride; D000040:Abscisic Acid
keywords: Arabidopsis thaliana; MYB transcription factor