Enhancing seed quality and viability by suppressing phospholipase D in Arabidopsis

Seed aging decreases the quality of seed and grain and results in agricultural and economic losses. Alterations that impair cellular structures and metabolism are implicated in seed deterioration, but the molecular and biochemical bases for seed aging are not well understood. Ablation of the gene for a membrane lipid-hydrolyzing phospholipase D (PLD alpha 1) in Arabidopsis enhanced seed germination and oil stability after storage or exposure of seeds to adverse conditions. The PLD alpha 1-deficient seeds exhibited a smaller loss of unsaturated fatty acids and lower accumulation of lipid peroxides than did wild-type seeds. However, PLD alpha 1-knockdown seeds were more tolerant of aging than were PLD alpha 1-knockout seeds. The results demonstrate the PLD alpha 1 plays an important role in seed deterioration and aging in Arabidopsis. A high level of PLD alpha 1 is detrimental to seed quality, and attenuation of PLD alpha 1 expression has the potential to improve oil stability, seed quality and seed longevity.