Responses of phospholipase D and lipoxygenase to mechanical wounding in postharvest cucumber fruits.
This study was to investigate the responses of phospholipase D (PLD) and lipoxygenase (LOX) to mechanical wounding in postharvest cucumber (Cucumis sativus L. cv. Biyu-2) fruits. Membrane-associated Ca2+ content, activities and gene expression of PLD and LOX, and contents of phosphatidylcholine (PC), phosphatidylinositol (PI), and phosphatidic acid (PA) were determined in cucumber fruits following mechanical wounding. Results show that PLD and LOX activities increased with the PLD and LOX mRNAs which are upregulated upon wounding, while membrane-associated Ca2+ content decreased. Accompanying with the increase of PLD and LOX activities, accumulation of PA and losses of PC and PI were observed in all fruits, but there were differences of degrees between wounded and control fruits. Results suggest that PLD and LOX might be the main hydrolytic enzymes of phospholipids in postharvest cucumber fruits participating in the mechanical wounding injury. The activation of PLD and LOX might be the result of gene expression, which could be stimulated by the Ca2+ flowing from the membrane to the cytoplasm upon receiving the wounding signals.
Zhao
Yu-ying
YY
Department of Food Science and Nutrition, College of Biosystem Engineering and Food Science, Zhejiang University, Hangzhou 310029, China.
Qian
Chun-lu
CL
Chen
Ji-cheng
JC
Peng
Yan
Y
Mao
Lin-chun
LC
D018553:Cucumis sativus / Q000201:enzymology*; D005638:Fruit / Q000201:enzymology*; D008084:Lipoxygenase / Q000378:metabolism*; D010739:Phospholipase D / Q000378:metabolism*; D010935:Plant Diseases; D013314:Stress, Mechanical
D008084:Lipoxygenase; D010739:Phospholipase D