Effects of water deficit and rehydration on the polar lipid and membranes resistance leaves of Phaseolus vulgaris L. cv. Pérola

Abstract

Bean leaves (Phaseolus vulgaris L.) cv. Pérola were used to evaluate the water deficit effects in polar lipids composition and in the electric conductivity. The results showed that the water deficiency a effected in the electrolytes loss which increased gradually in response to water deficit. This suggested a compartimentalization loss, due to the structural cellular membranes elements degradation. Total lipids contents decreased by reason of the water stress action. The polyunsaturated fatty acid contents (linoleic and linolenic acids) suffered a decrease while saturated fatty acid (palmitic and stearic acids) increased. The imbalance in the fatty saturated/unsaturated acid relation led to a reduction in the unsaturation index. The electrolytes loss increase related whith the to polyunsaturated fatty acid contents reduction suggested a larger dehydrated plants vulnerability, leading to a consequent loss in the productivity.