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.
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.
Shui
S
Wang
Jia-Wei
JW
Wang
Nan
N
Yu
Chun-Hong
CH
Li
Bin
B
Luo
Jin-Ying
JY
Gou
Ling-Jian
LJ
Wang
Xiao-Ya
XY
Chen
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