棉花种子发育过程中脂肪及脂肪酸积累模式研究

The Oil and Fatty Acid Accumulation Patterns in Developing Cottonseeds of Xuzhou 142 and Its Fiberless and Fuzeeless Mutant

通过对徐州142及其无绒无絮突变体不同发育时期棉子脂肪和脂肪酸组成含量的测定,分析棉子发育过程中脂肪及脂肪酸组成的积累模式。发现2个材料的棉子从开花后20 d到成熟这一阶段脂肪积累呈上升趋势,其中成熟种子含油量达到最高,且无绒无絮突变体材料各时期棉子脂肪含量都高于野生型。2个材料棉子发育过程中先后有8种脂肪酸成分出现,其中成熟棉子中油酸(C18:1)与亚油酸(C18:2)含量占脂肪酸总含量的72%左右,是棉子脂肪酸的重要组分。对棉子发育过程中各脂肪酸组成含量做相关分析发现徐州142中C18:1与C18:2呈一定正相关但不显著,而突变体材料中则呈极显著正相关。棉花的溶血磷脂酸酰基转移酶基因(Gh LPAAT1和Gh LPAAT2)在不同发育时期棉子中的表达水平与棉子脂肪积累趋势基本一致,推测其参与了棉子脂肪的积累。

The cottonseeds oil is one of the main edible oils and also one of the main raw materials in studies of biodiesel. How- ever, there are few reports on the dynamic process of oil and fatty acids in developing cottonseeds. In this study, the accumula- tive process of oil and fatty acids were analyzed in developing cottonseeds（- 3, - 1,0,1、 3、5、7、10、15、20 、25、30、35 days post anthesis-DPA and maturation stage） from Xuzhou 142 and its fiberless and fuzzless mutant of Xuzhou 142. The results indicated that cottonseed oils of the two cotton lines from 20 DPA to the maturation stage were gradually increased; however, the cotton- seeds in the mutant had significantly higher oil content than that of its wild type in each sampling date. Eight fatty acids were de- tectable in the whole development stages of the two genotypes＇ cottonseeds. Furthermore, C18：1 and Cl8：2 accounted for 72 percent of the total fatty acids in matural cottonseeds. After relevant analysis on the composition and content of fatty acids during the development process of cotton seeds, we found that C18：1 and C18：2 in Xuzhou 142 performed positive correlation to some extent, while that in mutant material presented significant positive correlation. Expression analyses indicated that the expression level of GhLPAAT1 and GhLPAAT2 had almost the same trend with the process of fat accumulation in these two genotypes＇ cottonseeds, qRT-PCR data revealed that GhLPAAT1 and GhLPAAT2 genes may play a role in oil accumulation of cottonseeds.