光对油菜胚中蛋白质和脂肪酸生物合成的影响

为探究光对油菜胚中蛋白质和脂肪酸生物合成中的影响,本研究于油菜开花后25 d(25 d)起,对油菜角果用锡箔进行遮光处理,分别收集遮光处理后3 d(28 d)和10 d(35 d)角果种子中的胚,以未遮光处理的油菜种子胚为对照。结果表明,与对照相比,经遮光处理的胚中叶绿素和蛋白质含量显著降低;脂肪酸组分发生明显变化,其中棕榈酸(C16:0)、硬脂酸(C18:0)和油酸(C18:1)含量显著增加,而不饱和脂肪酸中的亚油酸(C18:2)和亚麻酸(C18:3)含量却大幅下降。进一步将开花后25 d油菜胚在加入电子传递抑制剂DCC培养基中进行体外培养,发现胚中不饱和脂肪酸的生物合成以及叶绿素含量均受到ATP的调节。综上,油菜胚发育过程中光照可以影响质体中氨基酸和脂肪酸的生物合成,从而调控油菜营养物的积累。本研究揭示了质体光合作用在油菜种子油脂积累过程中的作用,为今后培育高含油量、高品质油菜品种提供了理论依据。

Effects of Light on Biosynthesis of Protein and Fatty Acid in the Embryos of Brassica napus L.

To dissect the effect of light on the biosynthesis of protein and fatty acid components in Brassica napus L. embryos, this study was carried out by masked the developing silique with tinfoil on the 25 days after the flowering of B. napus(25 d). After 3 days(28 d) and 10 days(35 d), the embryos were collected from seeds in the masked silique, and the embryos from unmasked silique were used as the control. And analysis of chlorophll content、protein content and fatty acid composition was performed. The results showed that the contents of chlorophyll and protein in the masking-treated embryos significantly reduced compared with that in the control. The fatty acid components have differential changed. In which, the content of palmitic acid (C16:0), stearic acid (C18:0) and oleic acid (C18:1) showed significantly increase, while the unsaturated fatty acid linoleic acid (C18:2) and linolenic acid (C18:3) slumped. Furthermore, when the the embryos 25 d after flowering were cultured in medium with electron transport inhibitor N,N’-dicyclohexylcarbodiimide (DCC), the biosynthesis of unsaturated fatty acids and the content chlorophyll in the embryos significantly reduced. These results indicated that the light transmitted into embryo greatly affected the biosynthesis of fatty acids in plastids during the development of B.napus embryos, thereby regulating the accumulation of storage reserve in seed.