GbPDF1 Is Involved in Cotton Fiber Initiation via the Core cis-Element HDZIP2ATATHB2
GbPDF1 Is Involved in Cotton Fiber Initiation via the Core cis-Element HDZIP2ATATHB2
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GbPDF1 通过核心顺式元件 HDZIP2ATATHB2 参与棉纤维引发
DOI：
10.1104/pp.111.186742
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发表时间：
2012-02-01
期刊：
影响因子：
7.4
通讯作者：
Zhang, Xianlong
中科院分区：
文献类型：
--
作者：
Deng, Fenglin;Tu, Lili;Zhang, Xianlong
棉花（棉属）纤维细胞是源自棉籽种皮表皮层的种皮毛。负责调控纤维细胞分化的分子成分尚未完全阐明。发现一个棉花原表皮因子1基因（GbPDF1）在纤维起始和早期伸长过程中优先表达，在开花后5天的纤维细胞中积累量最高。与野生型相比，PDF1沉默导致纤维起始延迟，产生较短的纤维和较低的皮棉率，表明该基因是棉花纤维发育所必需的。进一步分析表明，在RNA干扰转基因棉花品系中过氧化氢积累量更高。同时，发现棉花纤维生长过程中与乙烯和果胶合成或糖转运相关的几个基因的表达在PDF1受抑制的棉花中显著降低。在酵母和植物体内与GbPDF1相互作用的三种蛋白质可能涉及细胞信号传导或代谢。转基因棉花中的GbPDF1启动子::GUS构建体主要在胚珠表皮和发育中的纤维中表达。对GbPDF1启动子的逐步缺失表明，一个236 -bp的启动子片段足以使棉花中GbPDF1进行基础转录。对假定调控序列的突变表明，该片段内的一个元件HDZIP2ATATHB2对PGbPDF1 - 1的表达至关重要。在开花后5天，这个顺式元件与含纤维的棉花胚珠的核提取物之间的结合活性是特异性的。我们得出结论，GbPDF1通过核心顺式元件HDZIP2ATATHB2，在纤维发育过程中与相互作用的伙伴一起在过氧化氢稳态以及乙烯和果胶的稳定生物合成中发挥关键作用。
Cotton (Gossypium spp.) fiber cells are seed trichomes derived from the epidermal layer of the cotton seed coat. The molecular components responsible for regulating fiber cell differentiation have not been fully elucidated. A cotton PROTODERMAL FACTOR1 gene (GbPDF1) was found to be expressed preferentially during fiber initiation and early elongation, with highest accumulation in fiber cells 5 d post anthesis. PDF1 silencing caused retardation of fiber initiation and produced shorter fibers and lower lint percentage compared with the wild type, indicating that the gene is required for cotton fiber development. Further analysis showed that a higher accumulation of hydrogen peroxide occurred in the RNA interference transgenic cotton lines. Meanwhile, the expression of several genes related to ethylene and pectin synthesis or sugar transport during cotton fiber growth was found to be significantly reduced in the PDF1-suppressed cotton. Three proteins interacting with GbPDF1 in yeast and in planta might involve cellular signaling or metabolism. GbPDF1 promoter::GUS constructs in transgenic cotton were predominantly expressed in the epidermis of ovules and developing fibers. Progressive deletions of the GbPDF1 promoter showed that a 236-bp promoter fragment was sufficient for basal GbPDF1 transcription in cotton. Mutation of putative regulatory sequences showed that HDZIP2ATATHB2, an element within the fragment, was essential for PGbPDF1-1 expression. The binding activity between this cis-element and nuclear extracts from fiber-bearing cotton ovules at 5 d post anthesis was specific. We conclude that GbPDF1 plays a critical role together with interaction partners in hydrogen peroxide homeostasis and steady biosynthesis of ethylene and pectin during fiber development via the core cis-element HDZIP2ATATHB2.