In order to facilitate the development of cotton (Gossypium hirsutum L.) strains with colored fiber, the genetic and developmental control of flavonoids in fibers must be understood. The major goal of this study was to determine whether anthocyanidins accumulate in three different natural colored cotton fibers during their development, and to document the expression levels of flavonoid genes necessary for the production of anthocyanidins to determine if differences in expression levels reflect differences in anthocyanidin production. Most flavonoid structural genes were more highly expressed during fiber elongation than before the beginning of secondary cell wall formation. High performance liquid chromatography (HPLC) analyses showed that the abundance of anthocyanidins was higher in brown fibers than in green or white fibers. Anthocyanidins were present at high levels in fibers, starting at 20 d post‐anthesis of fiber development, which is almost at the end of the fiber elongation stage. Brown cotton contains higher delphinidin levels than of green and white cotton. This pattern is consistent with greater expression of anthocyanin pathway genes in brown fibers. In naturally colored cotton, the enzyme Lar (leucoanthocyanidin reductase) converted leucoanthocyanidins to catechin, which are proanthocyanins (PAs) precursor subunits. It is suggested that failure to produce anthocyanins is likely due to a combination of insufficient expression of Ufgt (UDP‐glucose: flavonoid 3‐O‐glucosyltransferase) and high expression of Lar and Anr (anthocyanidin reductase).

中文翻译：

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天然彩色棉中类黄酮生物合成相关结构基因的分子分析

为了促进棉花（陆地棉）的发展。L.）有色纤维的菌株，必须了解纤维中类黄酮的遗传和发育控制。这项研究的主要目的是确定花色苷在发育过程中是否在三种不同的天然彩色棉纤维中积累，并记录生产花色苷所需的类黄酮基因的表达水平，以确定表达水平的差异是否反映出花色苷生产的差异。 。大多数黄酮类结构基因在纤维伸长期间比在次要细胞壁形成开始之前更高的表达。高效液相色谱（HPLC）分析表明，花色苷的丰富度在棕色纤维中高于在绿色或白色纤维中。花青素在纤维中的含量很高，从花粉发育后的20 d开始，这几乎是在纤维伸长阶段的末期。棕色棉比绿色和白色棉含有更高的飞燕草素含量。这种模式与花色苷途径基因在棕色纤维中的更高表达是一致的。在天然彩色棉中，酶Lar（白花青素还原酶）将白花青素转化为儿茶素，后者是原花青素（PAs）前体亚基。提示不能产生花色苷可能是由于Ufgt（UDP-葡萄糖：类黄酮3-O-葡萄糖基转移酶）表达不足和Lar和Anr（花色素苷还原酶）高表达所致。