title: The promoter structure differentiation of a MYB transcription factor RLC1 causes red leaf coloration in Empire Red Leaf Cotton under light.
abstract: The red leaf coloration of Empire Red Leaf Cotton (ERLC) (Gossypium hirsutum L.), resulted from anthocyanin accumulation in light, is a well known dominant agricultural trait. However, the underpin molecular mechanism remains elusive. To explore this, we compared the molecular biological basis of anthocyanin accumulation in both ERLC and the green leaf cotton variety CCRI 24 (Gossypium hirsutum L.). Introduction of R2R3-MYB transcription factor Rosea1, the master regulator anthocyanin biosynthesis in Antirrhinum majus, into CCRI 24 induced anthocyanin accumulation, indicating structural genes for anthocyanin biosynthesis are not defected and the leaf coloration might be caused by variation of regulatory genes expression. Expression analysis found that a transcription factor RLC1 (Red Leaf Cotton 1) which encodes the ortholog of PAP1/Rosea1 was highly expressed in leaves of ERLC but barely expressed in CCRI 24 in light. Ectopic expression of RLC1 from ERLC and CCRI 24 in hairy roots of Antirrhinum majus and CCRI 24 significantly enhanced anthocyanin accumulation. Comparison of RLC1 promoter sequences between ERLC and CCRI 24 revealed two 228-bp tandem repeats presented in ERLC with only one repeat in CCRI 24. Transient assays in cotton leave tissue evidenced that the tandem repeats in ERLC is responsible for light-induced RLC1 expression and therefore anthocyanin accumulation. Taken together, our results in this article strongly support an important step toward understanding the role of R2R3-MYB transcription factors in the regulatory menchanisms of anthocyanin accumulation in red leaf cotton under light.
authors.affiliation: Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China.
authors.forename: Zhenrui
authors.initials: Z
authors.lastname: Gao
authors.forename: Chuanliang
authors.initials: C
authors.lastname: Liu
authors.forename: Yanzhao
authors.initials: Y
authors.lastname: Zhang
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.forename: Keke
authors.initials: K
authors.lastname: Yi
authors.forename: Xinhua
authors.initials: X
authors.lastname: Zhao
authors.forename: Min-Long
authors.initials: ML
authors.lastname: Cui
mesh_terms: D000595:Amino Acid Sequence; D000872:Anthocyanins / Q000378:metabolism; D029681:Arabidopsis Proteins; D003116:Color; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects*; D003368:Gossypium / Q000235:genetics* / Q000254:growth & development / Q000528:radiation effects; D008027:Light; D008969:Molecular Sequence Data; D000073718:Pancreatitis-Associated Proteins; D010802:Phylogeny; D018515:Plant Leaves / Q000235:genetics* / Q000254:growth & development / Q000528:radiation effects; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D000872:Anthocyanins; D029681:Arabidopsis Proteins; C500589:Myb protein, Arabidopsis; D000073718:Pancreatitis-Associated Proteins; D010940:Plant Proteins; C000612141:REG3A protein, human; D014157:Transcription Factors