Department of Plant Pathology, Kansas State University, Manhattan, KS, USA.
Plant Biotechnol J. 2012 Feb;10(2):164-73. doi: 10.1111/j.1467-7652.2011.00650.x. Epub 2011 Sep 5.
Changes in phospholipid composition and consequent loss of membrane integrity are correlated with loss of seed viability. Furthermore, phospholipid compositional changes affect the composition of the triacylglycerols (TAG), i.e. the storage lipids. Phospholipase D (PLD) catalyses the hydrolysis of phospholipids to phosphatidic acid, and PLDα is an abundant PLD isoform. Although wild-type (WT) seeds stored for 33 months were non-viable, 30%-50% of PLDα-knockdown (PLD-KD) soybean seeds stored for 33 months germinated. WT and PLD-KD seeds increased in lysophospholipid levels and in TAG fatty acid unsaturation during ageing, but the levels of lysophospholipids increased more in WT than in PLD-KD seeds. The loss of viability of WT seeds was correlated with alterations in ultrastructure, including detachment of the plasma membrane from the cell wall complex and disorganization of oil bodies. The data demonstrate that, during natural ageing, PLDα affects the soybean phospholipid profile and the TAG profile. Suppression of PLD activity in soybean seed has potential for improving seed quality during long-term storage.
磷脂组成的变化和随之而来的膜完整性的丧失与种子活力的丧失有关。此外，磷脂组成的变化影响三酰基甘油（TAG）的组成，即储存脂质。磷脂酶 D（PLD）催化磷脂水解生成磷酸脂，PLDα 是一种丰富的 PLD 同工型。尽管储存 33 个月的野生型（WT）种子失去了活力，但储存 33 个月的 30%-50%的 PLDα 敲低（PLD-KD）大豆种子发芽。WT 和 PLD-KD 种子在老化过程中游离态磷脂水平和 TAG 脂肪酸不饱和程度增加，但 WT 种子中游离态磷脂水平的增加高于 PLD-KD 种子。WT 种子活力的丧失与超微结构的改变有关，包括质膜从细胞壁复合体上的脱离和油体的紊乱。数据表明，在自然老化过程中，PLDα 影响大豆磷脂谱和 TAG 谱。抑制大豆种子中 PLD 的活性有可能在长期储存过程中提高种子质量。
