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Core cis ‐element variation confers subgenome‐biased expression of a transcription factor that functions in cotton fiber elongation
Author(s) -
Zhao Bo,
Cao JunFeng,
Hu GuanJing,
Chen ZhiWen,
Wang LuYao,
Shangguan XiaoXia,
Wang LingJian,
Mao YingBo,
Zhang TianZhen,
Wendel Jonathan F.,
Chen XiaoYa
Publication year - 2018
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.15063
Subject(s) - biology , gene , transcription factor , promoter , elongation , transgene , gene expression , tata box , regulation of gene expression , genetics , regulatory sequence , microbiology and biotechnology , ultimate tensile strength , materials science , metallurgy
Summary Cotton cultivars have evolved to produce extensive, long, seed‐born fibers important for the textile industry, but we know little about the molecular mechanism underlying spinnable fiber formation. Here, we report how PACLOBUTRAZOL RESISTANCE 1 ( PRE 1 ) in cotton, which encodes a basic helix‐loop‐helix ( bHLH ) transcription factor, is a target gene of spinnable fiber evolution. Differential expression of homoeologous genes in polyploids is thought to be important to plant adaptation and novel phenotypes. PRE 1 expression is specific to cotton fiber cells, upregulated during their rapid elongation stage and A‐homoeologous biased in allotetraploid cultivars. Transgenic studies demonstrated that PRE 1 is a positive regulator of fiber elongation. We determined that the natural variation of the canonical TATA ‐box, a regulatory element commonly found in many eukaryotic core promoters, is necessary for subgenome‐biased PRE 1 expression, representing a mechanism underlying the selection of homoeologous genes. Thus, variations in the promoter of the cell elongation regulator gene PRE 1 have contributed to spinnable fiber formation in cotton. Overexpression of Gh PRE 1 in transgenic cotton yields longer fibers with improved quality parameters, indicating that this bHLH gene is useful for improving cotton fiber quality.