Calcium channels and membrane disorders induced by drought stress in Vicia faba plants supplemented with calcium

Abstract

Wcia faba plants were grown under drought conditions and variously supplemented with calcium. Drought stress markedly inhibited the growth of Vicia faba plants. Ca 2+ ameliorated to a large extent this inhibition; fresh weight, dry mass, chlorophyll and water contents were variably improved. Membranes were, also, negatively affected by drought stress and percentage leakage was elevated, Concomitantly the efflux of + 2 + K and Ca was enhanced by drought but lowered by supplemental Ca 2+. In addition, membranes of droughted plants were sensitive to the Ca 2+ channel blockers lanthanum, nifedipine or verapamil more than those of control plants. These blockers + 2 + significantly increased the eft]ux of K and Ca as well as percentage leakage particularly in those of droughted plants. The above results indicated that the functioning of the calcium channels was negatively affected when Viciafaba was grown under drought conditions. However, much of the droughtinduced disorders including sensitivity towards the applied calcium channel blockers could be ameliorated by supplemental Ca 2+.tassium (Navari-Izzo et al. 1988, Palta et al. 1977 as well as leakage of cellular metabolites (NavariIzzo et al. 1993)which are frequently used to assess membrane integrity. On the other hand, calcium regulates an array of metabolic processes in plants including the stabilization of cell membranes under conditions of stress. In this respect, Kent and L~uchli (1985) reported that high calcium increases m e m b r a n e a s s o c i a t e d Ca 2+, t i g h t e n i n g plasmalemma and reducing K + efflux. Also, Ca 2+ was found to protect ChloreEa cells as well as reducing K + efflux in case of cell dehydration (Abdel-B asset and Issa 1994). Since calcium and membranes are important factors in determining drought tolerance, the aim of this work was to assess alterations that might take place in membranes and, particularly, in the calcium channels of Vicia faba in response to drought stress. How far these alterations could be ameliorated by supplemental calcium was also considered.

Chilling and Drought Stresses in Crop Plants: Implications, Cross Talk, and Potential Management Opportunities

“… Waraich et al (2012) reported that Ca is an essential nutrient for stomatal closure in chilling tolerant genotypes. Application of Ca in Vicia faba enhanced plant biomass, plant water relations, and chlorophyll content while reduced membrane leakage ( Abdel-Basset, 1998 ). Magnesium (Mg) also improve root morphological charcaters which helps to increase uptake of water and nutrients via roots, whlist boron nutrition enhances sugar transport in the plant body and improves seed germination and grain formation process ( Waraich et al, 2012 ).…”

Herbicidal Properties of Antihypertensive Drugs: Calcium Channel Blockers

“…In contrast to diuron, c was able to break down the membrane integrity since the ion leakage degree was parallel to the time increase at a low concentration of 200 mg/L. Likewise, the percentage of leakage by leaves of Vicia faba plants treated with calcium channel blockers of verapamil and nifedipine were greater than those of nontreated plants 15 . At a higher concentration of 300 mg/L, the properties of the light-dependent mechanism of action for c are more apparent.…”

Effects of CaCl2 solutions to alleviate drought stress effects in potted ornamentals Salvia splendens and Ageratum houstonianum

“…This element also plays an essential role in regulating the properties of cytoplasmic membranes which are the first to respond to stresses: membrane disorders induced by drought in Vicia faba L. were ameliorated by supplemental Ca 2+ [11]. Due to such effects, calcium is widely applied in fruit production with the aim to improve fruit quality [9][10][11]. This aspect of its action was decisive for including calcium chloride in our investigations on the response of bedding plants to water stress.…”

“…A complex description of the Ca-controlled cascades of events occurring in plant cells under water stress can be found in a review by Hong-Bo et al [10]. This element also plays an essential role in regulating the properties of cytoplasmic membranes which are the first to respond to stresses: membrane disorders induced by drought in Vicia faba L. were ameliorated by supplemental Ca 2+ [11]. Due to such effects, calcium is widely applied in fruit production with the aim to improve fruit quality [9][10][11].…”

“…In the periodically stressed S. splendens plants, the RWC values were higher before and after the re-watering cycle: 86% and 92%, respectively. For agricultural and horticultural practice, it is important to predict whether re-watering of crops being exposed to lasting drought is still worthy [11]. Efficient irrigation, beside conserving water, also affects plant quality in commercial greenhouse production.…”