Ultra-high α-linolenic acid accumulating developmental defective embryo was rescued by lysophosphatidic acid acyltransferase 2
Ultra-high α-linolenic acid accumulating developmental defective embryo was rescued by lysophosphatidic acid acyltransferase 2
复制标题
溶血磷脂酸酰基转移酶2拯救了超高α-亚麻酸积累的发育缺陷胚胎
DOI：
10.1111/tpj.14889
复制
发表时间：
2020-07-29
期刊：
影响因子：
7.2
通讯作者：
Li, Maoteng
中科院分区：
文献类型：
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作者：
Yin, Yongtai;Guo, Zhenyi;Li, Maoteng
几十年来，在农作物中产生不寻常脂肪酸(UFAs)的基因工程方法已经达到了瓶颈，包括降低了种子油产量和种子活力。目前，该研究领域的植物模型主要用于研究油料生产和幼苗发育中的缺陷，而不饱和脂肪酸在胚胎发育缺陷中的作用尚不清楚。在本研究中，我们建立了一个转基因拟南芥植物模型，在该模型中，由于α-亚麻酸(ALA)的积累，胚胎表现出严重的皱纹外观。对缺陷胚的RNA测序分析表明，油菜素类固醇合成、FA合成和光合作用受到抑制，而FA降解、内质网胁迫和氧化胁迫被激活。脂质组学分析表明，超积累的ALA以游离FA的形式从卵磷脂释放到细胞内，导致严重的内质网和氧化应激。此外，我们还发现，溶血磷脂酸酰基转移酶2的过表达挽救了缺陷表型。在救援线上，肯尼迪途径的池容量增加，ALA间接酯化为三酰甘油的能力增强，以避免应激。这项研究提供了一个植物模型，有助于理解胚胎发育缺陷的分子机制，并产生产生更高水平不饱和脂肪酸的策略。
For decades, genetic engineering approaches to produce unusual fatty acids (UFAs) in crops has reached a bottleneck, including reduced seed oil production and seed vigor. Currently, plant models in the field of research are primarily used to investigate defects in oil production and seedling development, while the role of UFAs in embryonic developmental defects remains unknown. In this study, we developed a transgenic Arabidopsis plant model, in which the embryo exhibits severely wrinkled appearance owing to alpha-linolenic acid (ALA) accumulation. RNA-sequencing analysis in the defective embryo suggested that brassinosteroid synthesis, FA synthesis and photosynthesis were inhibited, while FA degradation, endoplasmic reticulum stress and oxidative stress were activated. Lipidomics analysis showed that ultra-accumulated ALA is released from phosphatidylcholine as a free FA in cells, inducing severe endoplasmic reticulum and oxidative stress. Furthermore, we identified that overexpression of lysophosphatidic acid acyltransferase 2 rescued the defective phenotype. In the rescue line, the pool capacity of the Kennedy pathway was increased, and the esterification of ALA indirectly to triacylglycerol was enhanced to avoid stress. This study provides a plant model that aids in understanding the molecular mechanism of embryonic developmental defects and generates strategies to produce higher levels of UFAs.