本论文于2017年12月4日在线发表于Plant Physiology，原文题目如下：

SEIPIN proteins mediate lipid droplet biogenesis to promote pollen transmission and reduce seed dormancy

脂滴是植物细胞中普遍存在的细胞器，但其生理作用大部分是未知的。为了深入了解脂滴在植物中的功能，我们已经表征了SEIPIN蛋白的拟南芥同源物，其是酵母和动物中脂滴生物合成的关键因子。SEIPIN1几乎只在胚胎中表达，而SEIPIN2和SEIPIN3在胚胎和花粉中具有最大水平的表达谱，也是脂滴积累最丰富的位置。遗传分析表明，所有三个SEIPINs有助于脂滴在胚胎中正确的生物发生，而在花粉中，只有SEIPIN2和SEIPIN3发挥重要作用。双突变体seipin2 seipin3和seipin三突变体在种子和花粉中累积极度增大的脂滴，这阻碍了它们随后在萌发过程中的动员。有趣的是，电子显微镜分析揭示了在seipin三突变体胚胎中，存在附着于I型核质网的核脂滴，这支持了SEIPINs对于维持在核膜上脂滴出芽的正确极性，将其限制在外膜上是必需的。在花粉中，脂滴生物合成和周转的扰动与体外发芽减少以及体内受精效率较低有关。在种子中，seipin2seipin3和seipin三突变体中的发芽本身不受影响，但是种子休眠水平显着增加。我们的研究结果揭示了SEIPIN依赖的脂滴生物合成在花粉传播和调整种子萌发时间的相关性，是农业中两个重要的适应性特征

Lipid droplets (LDs) are ubiquitous organelles in plant cells, but their physiological roles are largely unknown. To gain insight into the function of LDs in plants, we have characterized the Arabidopsis homologues of SEIPIN proteins, which are crucial factors for LD biogenesis in yeast and animals. SEIPIN1 is expressed almost exclusively in embryos, while SEIPIN2 and SEIPIN3 have broader expression profiles with maximal levels in embryos and pollen, where LDs accumulate most abundantly. Genetic analysis demonstrates that all three SEIPINs contribute to proper LD biogenesis in embryos, whereas in pollen, only SEIPIN2 and SEIPIN3 play a significant role. The double seipin2 seipin3 and triple seipin mutants accumulate extremely enlarged LDs in seeds and pollen, which hinders their subsequent mobilization during germination. Interestingly, electron microscopy analysis reveals the presence of nuclear LDs attached to type I nucleoplasmic reticulum in triple seipin mutant embryos, supporting that SEIPINs are essential for maintaining the correct polarity of LD budding at the nuclear envelope, restricting it to the outer membrane. In pollen, the perturbations in LD biogenesis and turnover are coupled to reduced germination in vitro and with lower fertilization efficiency in vivo. In seeds, germination per se is not affected in seipin2 seipin3 and triple seipin mutants but there is a striking increase in seed dormancy levels. Our findings reveal the relevance of SEIPIN-dependent LD biogenesis in pollen transmission and in adjusting the timing of seed germination, two key adaptive traits of great importance in agriculture

每日一词

hinder 英[ˈhɪndə(r)]

美[ˈhɪndɚ]

vt. 阻碍，妨碍; 成为阻碍;

adj. 后面的，后方的;

[例句]Does the fact that your players are part-timers help or hinder you?

队员们都是兼职的，这对你有利还是不利？

[其他] 第三人称单数：hinders 现在分词：hindering 过去式：hindered 过去分词：hindered