National Key Laboratory of Crop Genetic Improvement, National Plant Gene Center (Wuhan), Huazhong Agricultural University, 430070 Wuhan, Hubei, China.
Plant Cell Rep. 2010 Feb;29(2):193-202. doi: 10.1007/s00299-009-0812-1. Epub 2009 Dec 30.
Cotton fibers, important natural raw materials for the textile industry, are trichomes elongated from epidermal cells of cotton ovules. To date, a number of genes have been shown to be critical for fiber development. In this study, the roles of genes encoding fasciclin-like arabinoglactan proteins (FLAs) in cotton fiber were examined by transforming RNA interfering (RNAi) construct. The RNAi according to the sequence of GhAGP4 caused a significant reduction of its mRNA level, and the expression of other three FLAs (GhAGP2, GhAGP3, GhFLA1) were also partially suppressed. The fiber initiation and fiber elongation were inhibited in the transgenic plants. As for the mature fibers of transgenic cotton, the fiber length became significantly shorter and the fiber quality became worse. In addition, the RNAi of GhAGP4 also affected the cytoskeleton network and the cellulose deposition of fiber cells. Through ovule culture, it was found that the expression of cotton FLA genes were upregulated by GA(3), especially for GhAGP2 and GhAGP4. These results indicate that the FLAs are essential for the initiation and elongation of cotton fiber development.
棉花纤维是纺织工业的重要天然原料，是由棉花胚珠表皮细胞伸长而成的毛状体。迄今为止，已有许多基因被证明对纤维发育至关重要。在这项研究中，通过转化 RNA 干扰（RNAi）构建体，研究了编码纤维蛋白类似阿拉伯半乳聚糖蛋白（FLAs）的基因在棉花纤维中的作用。根据 GhAGP4 的序列设计的 RNAi 导致其 mRNA 水平显著降低，其他三个 FLA（GhAGP2、GhAGP3、GhFLA1）的表达也部分受到抑制。转基因植物中的纤维起始和纤维伸长受到抑制。对于转基因棉花的成熟纤维，纤维长度明显变短，纤维质量变差。此外，GhAGP4 的 RNAi 还影响纤维细胞的细胞骨架网络和纤维素沉积。通过胚珠培养发现，棉花 FLA 基因的表达被 GA（3）上调，尤其是 GhAGP2 和 GhAGP4。这些结果表明，FLAs 对棉花纤维发育的起始和伸长是必需的。
