Comparison of TRY and the closely related At1g01380 gene in controlling Arabidopsis trichome patterning.
A screen of activation-tagged Arabidopsis lines resulted in the identification of At1g01380, which encodes a small R3 single repeat MYB gene, as a negative regulator of trichome initiation. Plants that overexpress this gene have fewer trichomes. The gene is closely related to the previously identified negative regulator TRY, and has a similar pattern of expression as TRY in developing leaves. As previously shown for TRY, At1g01380 protein can inhibit the interaction between the positive trichome regulators GL1 and GL3, and likely limits trichome initiation via this inhibition. While TRY and At1g01380 are closely related, they are not completely functionally equivalent. When placed under the transcriptional control of the TRY promoter, At1g01380 can only partially rescue the try mutant. Interestingly, Atg01380 is highly expressed in gl3-sst trichomes, while TRY expression is greatly reduced. The mutation in gl3-sst causes a reduced interaction between the GL1 and GL3 proteins and results in fewer leaf trichomes that develop in clusters. The differential expression of TRY and At1g01380 in this mutant can be used to explain how its altered trichome pattern in gl3-sst [corrected] is generated.
Esch
Jeffrey J
JJ
Department of Plant Biology, University of Minnesota, St Paul, MN 55108, USA.
Chen
Margaret A
MA
Hillestad
Matthew
M
Marks
M David
MD
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D002454:Cell Differentiation; D018506:Gene Expression Regulation, Plant; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D010802:Phylogeny; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development* / Q000648:ultrastructure; D011993:Recombinant Fusion Proteins / Q000235:genetics; D016415:Sequence Alignment; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins
D029681:Arabidopsis Proteins; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; C468526:TRIPTYCHON protein, Arabidopsis; C485326:ETC1 protein, Arabidopsis; D004268:DNA-Binding Proteins