PDF(Pubmed)
Abstract：
Three carbon-chain extension genes associated with fatty acid synthesis in upland cotton (Gossypium hirsutum), namely GhKAR, GhHAD, and GhENR, play important roles in oil accumulation in cotton seeds. In the present study, these three genes were cloned and characterized. The expression patterns of GhKAR, GhHAD, and GhENR in the high seed oil content cultivars 10H1014 and 10H1041 differed somewhat compared with those of 10H1007 and 2074B with low seed oil content at different stages of seed development. GhKAR showed all three cultivars showed higher transcript levels than that of 2074B at 10-, 40-, and 45-days post anthesis (DPA). The expression pattern of GhHAD showed a lower transcript level than that of 2074B at both 10 and 30 DPA but a higher transcript level than that of 2074B at 40 DPA. GhENR showed a lower transcript level than that of 2074B at both 15 and 30 DPA. The highest transcript levels of GhKAR and GhENR were detected at 15 DPA in 10H1007, 10H1014, and 10H1041 compared with 2074B. From 5 to 45 DPA cotton seed, the oil content accumulated continuously in the developing seed. Oil accumulation reached a peak between 40 DPA and 45 DPA and slightly decreased in mature seed. In addition, GhKAR and GhENR showed different expression patterns in fiber and ovule development processes, in which they showed high expression levels at 20 DPA during the fiber elongation stage, but their expression level peaked at 15 DPA during ovule development processes. These two genes showed the lowest expression levels at the late seed maturation stage, while GhHAD showed a peak of 10 DPA in fiber development. Compared to 2074B, the oil contents of GhKAR and GhENR overexpression lines increased 1.05~1.08 folds. These results indicated that GhHAD, GhENR, and GhKAR were involved in both seed oil synthesis and fiber elongation with dual biological functions in cotton.
摘要：
3个与陆地棉脂肪酸合成相关的碳链延伸基因,即GhKAR,GhHAD,和GhENR,在棉花种子的油脂积累中起重要作用。在本研究中,这三个基因被克隆和鉴定。GhKAR的表达模式，GhHAD,在种子发育的不同阶段，高种子油含量的品种10H1014和10H1041中的GhENR与低种子油含量的10H1007和2074B中的GhENR有些不同。GhKAR显示所有三个品种在10-时都显示出比2074B更高的转录水平，40-,和开花期后45天（DPA）。GhHAD的表达模式在10和30DPA下均显示出比2074B更低的转录水平，但在40DPA下比2074B更高的转录水平。GhENR在15和30DPA下显示出比2074B更低的转录水平。与2074B相比,在10H1007、10H1014和10H1041中在15DPA检测到最高的GhKAR和GhENR转录水平。从5到45DPA棉籽，在发育中的种子中不断积累的油含量。油脂积累在40DPA和45DPA之间达到峰值，成熟种子中略有下降。此外,GhKAR和GhENR在纤维和胚珠发育过程中表现出不同的表达模式，在纤维伸长阶段，它们在20DPA时显示出高表达水平，但在胚珠发育过程中，它们的表达水平在15DPA达到峰值。这两个基因在种子成熟后期表现出最低的表达水平,而GhHAD在纤维发展中显示出10个DPA的峰值。与2074B相比，GhKAR和GhENR过表达系的油含量增加了1.05〜1.08倍。这些结果表明GhHAD,GhENR,GhKAR和GhKAR参与棉花种子油合成和纤维伸长，具有双重生物学功能。
