Liu Feng, Zhao Yan-Peng, Zhu Hua-Guo, Zhu Qian-Hao, Sun Jie
College of Agriculture, Shihezi University, Shihezi 832003, Xinjiang, China.
CSIRO Agriculture Flagship, GPO Box 1600, Canberra 2601, Australia.
J Plant Physiol. 2017 Aug;215:132-139. doi: 10.1016/j.jplph.2017.06.001. Epub 2017 Jun 15.
Cottonseed oil has become an important source of edible oil due to its significant cost advantage. However, there is a growing concern over its fatty acid composition and nutritional value. In Gossypium hirsutum, GhFAD2-1 and GhFATB encoding the microsomal oleate desaturase and palmitoyl-acyl carrier protein thioesterase, respectively, play critical roles in regulating the proportions of saturated and polyunsaturated fatty acids in cottonseed lipids. In this study, RNAi technology was used to simultaneously inhibit the expression levels of GhFAD2-1 and GhFATB to improve the quality of cottonseed oil by increasing oleic acid content. Transgenic cotton plants with reduced levels of both target genes were successfully generated. In mature seed kernels of transgenic plants, the content of oleic acid was 38.25%, accordingly increasing by 156.96%, while the content of palmitic acid and linoleic acid was 19.15% and 36.68%, decreasing by 21.28% and 33.92%, respectively, compared with that of the control. The total oil content in transgenic and control kernels was 22.48% and 29.83%, respectively. The reduced oil level in transgenic seeds was accompanied by a reduction in seed index, thereby causing disadvantageous effects on seed germination potentiality and seed vigor, particularly under cool stress conditions. Our results demonstrated the feasibility of simultaneous manipulation of multiple genes using RNAi technology and showed the important role of oil content in seed development and vigor. Our findings provide insight into the physiological significance of the fatty acid composition in cottonseeds.
由于具有显著的成本优势，棉籽油已成为食用油的重要来源。然而，人们对其脂肪酸组成和营养价值的担忧日益增加。在陆地棉中，分别编码微粒体油酸去饱和酶和棕榈酰 - 酰基载体蛋白硫酯酶的GhFAD2 - 1和GhFATB在调节棉籽脂质中饱和脂肪酸和多不饱和脂肪酸的比例方面发挥着关键作用。在本研究中，利用RNA干扰技术同时抑制GhFAD2 - 1和GhFATB的表达水平，通过提高油酸含量来改善棉籽油品质。成功培育出了两个靶基因水平降低的转基因棉花植株。与对照相比，转基因植株成熟种子仁中油酸含量为38.25%，相应增加了156.96%，而棕榈酸和亚油酸含量分别为19.15%和36.68%，分别降低了21.28%和33.92%。转基因和对照种子仁中的总油含量分别为22.48%和29.83%。转基因种子中油含量的降低伴随着种子指数的降低，从而对种子发芽潜力和种子活力产生不利影响，特别是在低温胁迫条件下。我们的结果证明了使用RNA干扰技术同时操纵多个基因的可行性，并表明油含量在种子发育和活力中的重要作用。我们的研究结果为棉籽脂肪酸组成的生理意义提供了见解。
