Functional characterization of a basic helix-loop-helix (bHLH) transcription factor GhDEL65 from cotton (Gossypium hirsutum)
Functional characterization of a basic helix-loop-helix (bHLH) transcription factor GhDEL65 from cotton (Gossypium hirsutum)
复制标题
棉花（Gossypium hirsutum）的碱性螺旋-环-螺旋 (bHLH) 转录因子 GhDEL65 的功能表征。
DOI：
10.1111/ppl.12450
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发表时间：
2016-10-01
影响因子：
6.4
通讯作者：
Wang, Ling-Jian
中科院分区：
文献类型：
--
作者：
Shangguan, Xiao-Xia;Yang, Chang-Qing;Wang, Ling-Jian
棉花纤维被认为与拟南芥叶毛状体有一些相似之处，这是由MYB-bHLH-WD 40转录复合体调控的。虽然棉花中的几种MYB转录因子和WD 40家族蛋白已被表征，但对bHLH家族蛋白在棉花中的作用知之甚少。在这里，我们报告，GhDEL 65，从棉花（陆地棉）的bHLH蛋白，是拟南芥GLABRA 3（GL 3）和增强GLABRA 3（EGL 3）在调节毛状体发育的功能同源物。GhDEL 65基因在花后0 ~ 1天的胚珠中表达，并在3-DPA纤维中大量表达，表明GhDEL 65可能参与了纤维的早期发育。GhDEL 65在拟南芥gl 3 egl 3双突变体中的异位表达部分挽救了毛状体的发育，而GhDEL 65在野生型植物中的组成型表达导致莲座叶和茎上毛状体密度的增加，主要通过激活毛状体发育的两个关键正调控因子GLABRA 1（GL 1）和GLABRA 2（GL 2）的转录，并抑制R3单重复MYB因子TRIPTYCHON（TRY）的表达。GhDEL 65与棉花R2 R3、MYB转录因子GhMYB 2和GhMYB 3以及WD 40蛋白GhTTG 3相互作用，表明MYB-bHLH-WD 40蛋白复合体也存在于棉纤维细胞中，但其在棉纤维发育中的作用有待进一步研究。
Cotton fiber is proposed to share some similarity with the Arabidopsis thaliana leaf trichome, which is regulated by the MYB-bHLH-WD40 transcription complex. Although several MYB transcription factors and WD40 family proteins in cotton have been characterized, little is known about the role of bHLH family proteins in cotton. Here, we report that GhDEL65, a bHLH protein from cotton (Gossypium hirsutum), is a functional homologue of Arabidopsis GLABRA3 (GL3) and ENHANCER OF GLABRA3 (EGL3) in regulating trichome development. Transcripts of GhDEL65 were detected in 0 ∼ 1 days post-anthesis (DPA) ovules and abundant in 3-DPA fibers, implying that GhDEL65 may act in early fiber development. Ectopic expression of GhDEL65 in Arabidopsis gl3 egl3 double mutant partly rescued the trichome development, and constitutive expression of GhDEL65 in wild-type plants led to increased trichome density on rosette leaves and stems, mainly by activating the transcription of two key positive regulators of trichome development, GLABRA1 (GL1) and GLABRA2 (GL2), and suppressed the expression of a R3 single-repeat MYB factor TRIPTYCHON (TRY). GhDEL65 could interact with cotton R2R3 MYB transcription factors GhMYB2 and GhMYB3, as well as the WD40 protein GhTTG3, suggesting that the MYB-bHLH-WD40 protein complex also exists in cotton fiber cell, though its function in cotton fiber development awaits further investigation.