Control of plant trichome development by a cotton fiber MYB gene.
Cotton (Gossypium spp) plants produce seed trichomes (cotton fibers) that are an important commodity worldwide; however, genes controlling cotton fiber development have not been characterized. In Arabidopsis thaliana the MYB gene GLABRA1 (GL1) is a central regulator of trichome development. Here, we show that promoter of a cotton fiber gene, RD22-like1 (RDL1), contains a homeodomain binding L1 box and a MYB binding motif that confer trichome-specific expression in Arabidopsis. A cotton MYB protein GaMYB2/Fiber Factor 1 transactivated the RDL1 promoter both in yeast and in planta. Real-time PCR and in situ analysis showed that GaMYB2 is predominantly expressed early in developing cotton fibers. After transferring into Arabidopsis, GL1::GaMYB2 rescued trichome formation of a gl1 mutant, and interestingly, 35S::GaMYB2 induced seed-trichome production. We further demonstrate that the first intron of both GL1 and GaMYB2 plays a role in patterning trichomes: it acts as an enhancer in trichome and a repressor in nontrichome cells, generating a trichome-specific pattern of MYB gene expression. Disruption of a MYB motif conserved in intron 1 of GL1, WEREWOLF, and GaMYB2 genes affected trichome production. These results suggest that cotton and Arabidopsis use similar transcription factors for regulating trichomes and that GaMYB2 may be a key regulator of cotton fiber development.
Wang
Shui
S
National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
Wang
Jia-Wei
JW
Yu
Nan
N
Li
Chun-Hong
CH
Luo
Bin
B
Gou
Jin-Ying
JY
Wang
Ling-Jian
LJ
Chen
Xiao-Ya
XY
D020816:Amino Acid Motifs / Q000235:genetics; D004742:Enhancer Elements, Genetic / Q000235:genetics; D019143:Evolution, Molecular; D018506:Gene Expression Regulation, Plant / Q000235:genetics*; D018014:Gene Transfer Techniques; D020570:Genes, myb / Q000235:genetics / Q000502:physiology*; D003368:Gossypium / Q000235:genetics* / Q000254:growth & development* / Q000648:ultrastructure; D007438:Introns / Q000235:genetics; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D010802:Phylogeny; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D017434:Protein Structure, Tertiary / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics; D012639:Seeds / Q000235:genetics* / Q000254:growth & development* / Q000648:ultrastructure; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
D012097:Repressor Proteins; D014157:Transcription Factors