The MYB transcription factor GhMYB25 regulates early fibre and trichome development
The MYB transcription factor GhMYB25 regulates early fibre and trichome development
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DOI：
10.1111/j.1365-313x.2009.03847.x
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发表时间：
2009-07-01
期刊：
影响因子：
7.2
通讯作者：
Dennis, Elizabeth S.
中科院分区：
文献类型：
--
作者：
Machado, Adriane;Wu, Yingru;Dennis, Elizabeth S.
关于棉花长种皮毛状体的发育控制，目前还知之甚少。在拟南芥中，叶毛状体的起始是由一组明确定义的转录因子，包括MYB和同源结构域类型的调控。许多MYB在纤维中表达，但它们在纤维发育中的作用仍不清楚。我们分析了一个MYB转录因子，GhMYB 25，从野生型和无芒棉突变体之间的转录组比较确定的功能。转基因棉花中的GhMYB 25启动子-GUS构建体在胚珠的表皮、发育中的纤维起始物和纤维、包括叶、茎和花瓣的许多组织的毛状体以及花药、花粉和根和根起始物的表皮层中表达，但不在根毛中表达。棉花是具有两个非常相似的GhMYB 25基因的异源四倍体，所述基因被单个RNAi构建体沉默。GhMYB 25沉默的棉花表现出纤维快速伸长的时间改变，导致纤维变短，植物其他部位的毛状体急剧减少，种子产量减少。转基因和非转基因植物之间的相互杂交表明，花粉和胚珠的生活力本身没有被破坏。GhMYB 25的异位过表达有更微妙的影响，随着棉纤维起始和叶毛数量的增加。高表达似乎对生育力产生不利影响。我们的研究结果提供了令人信服的证据GhMYB 25的作用，像其他混合物一样MYBS，在调节表皮细胞，包括，在这种情况下，棉纤维的专门的产物。
P>Little is still known about the developmental control of the long seed coat trichomes of cotton (Gossypium hirsutum L.). In Arabidopsis, leaf trichome initiation is regulated by a group of well-defined transcription factors that includes MYB and homeodomain types. Many MYBs are expressed in fibres, but their roles in fibre development remain unclear. We analysed the function of one MYB transcription factor, GhMYB25, identified from transcriptome comparisons between wild-type and fibreless cotton mutants. A GhMYB25 promoter-GUS construct in transgenic cotton was expressed in the epidermis of ovules, developing fibre initials and fibres, in the trichomes of a number of tissues including leaves, stems and petals, as well as in the anthers, pollen and the epidermal layers of roots and root initials, but not in root hairs. Cotton is an allotetraploid with two very similar GhMYB25 genes that were silenced by a single RNAi construct. GhMYB25-silenced cotton showed alterations in the timing of rapid fibre elongation, resulting in short fibres, dramatic reductions in trichomes on other parts of the plant, and reductions in seed production. Reciprocal crosses between transgenic and non-transgenic plants indicated that pollen and ovule viability per se were not disrupted. Ectopic over-expression of GhMYB25 had more subtle impacts, with increases in cotton fibre initiation and leaf trichome number. High expression appeared to adversely affect fertility. Our results provide convincing evidence for a role of GhMYB25, like other MIXTA-like MYBS, in regulating specialized outgrowths of epidermal cells, including, in this case, cotton fibres.