Many polypetalous plants have a constriction at the base of the petal that leaves a small gap that can provide entry into the young flower bud before the reproductive organs are fully developed. In cotton (Gossypium hirsutum L.), this gap is occluded by tufts of short unicellular trichomes superficially resembling the fibers found on cotton seeds. We are just beginning to understand the developmental regulation of the seed fibers and have previously characterized several MIXTA-like MYB transcription factors (TFs) that are critical for correct seed fiber development but know little about the molecular regulation of other types of cotton trichomes. Here, using RNAi or dominant suppression transgenic cotton lines and natural fiber mutants, we investigated the development and regulation of the petal base trichomes. Petal base trichomes and seed trichomes were also examined across several different species within and outside of the Malvoideae. We found that the petal base trichomes are regulated by the same MYB TFs as cotton seed fibers and, since they are more widely distributed across different taxa than the seed fibers, could have preceded them in the evolution of these important textile fibers produced by some cotton species.

中文翻译：

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花瓣基部的毛状体受与棉籽纤维相同的转录因子调控。

许多多瓣植物的花瓣基部有一个收缩，留下一个小间隙，可以在生殖器官完全发育之前进入年轻的花蕾。在棉花（Gossypium hirsutumL.），这个间隙被一簇短的单细胞毛状体堵塞，表面上类似于棉花种子上的纤维。我们刚刚开始了解种子纤维的发育调控，并且之前已经对几种 MIXTA 样 MYB 转录因子 (TF) 进行了表征，这些转录因子对于正确的种子纤维发育至关重要，但对其他类型的棉花毛状体的分子调控知之甚少。在这里，我们使用 RNAi 或显性抑制转基因棉花品系和天然纤维突变体，研究了花瓣基础毛状体的发育和调控。还检查了锦葵科内外几个不同物种的花瓣基部毛状体和种子毛状体。我们发现花瓣基部的毛受与棉籽纤维相同的 MYB TF 调节，并且，