The biological activities of palmitoleic acid: Opportunities for exploitation

The biological activities of palmitoleic acid (16:1 Δ9) were investigated in this study, by expressing a yeast Δ9 desaturase gene in eggplants and in vitro testing of unsaturated fatty acids on the fungal spore germination.; Introduction of the yeast Δ9 desaturase gene into eggplant changed its fatty acid composition. There was dramatic increase of palmitoleic acid in the transgenic plants. Two new fatty acid species were found in the transgenic plants, but not in control plants. These results suggest that plant fatty acid biosynthesis could be altered by diverting the normal fatty acid synthesis pathway through introducing a single gene controlling the earliest step of fatty aid desaturation.; The transgenic plants showed enhanced resistance to Verticillium wilt. It was found that fungus infection triggered increase in the activity of phospholipase A₂, release of free fatty acid, and subsequent increase in the activity of lipoxygenase. The transgenic plants had constitutively higher level of PLA₂ and higher increase when challenged with pathogens, resulting in higher level of free fatty acids. The elevated level of free fatty acids and their derivatives in transgenic plants contributed to the enhanced disease resistance.; The transgenic plants were female sterile. It's proposed that the female sterility was due to inhibitory effect of palmitoleic acid on growth of young fruit, rather than on fertilization process. The release of palmitoleic acid during florescence and inhibition of fruit development by application of palmitoleic acid confirmed this hypothesis.; An investigation of a series of fatty acids revealed some important structural features of the fatty acid molecule required for their inhibitory effects on Erysiphe polygoni spore germination. Monounsaturated fatty acids with Δ-7 or -7 double bond showed the highest inhibitory effect. The inhibition of spore germination was associated with disruption of cellular organization. K+ channels were involved in the event.; The study concludes that fatty acids play important roles in plant defense and development.