Plant growth, metabolism and adaptation in relation to stress conditions. XX. comparative effects of salinity on growth, metabolism and yield of three different bean plants

The effects of increasing NaCl concentrations [up to 1.5 percent being equivalent to 255 mM] on growth, yield and chemical composition of three different bean plants [Glycine max var. Crowford, Phaseolus vulgaris var. Giza 3 and Phaseolus vulgaris var. Contender] have been studied. Thus, all growth, development and yield parameters appeared to remain unaltered, accelerated or, in most cases, suppressed with particular significance. These changes appeared to be dependent on [1] the concentration of NaCl, [2] the plant tested and 3 the stage of plant growth and development. Teatrnent of the three bean plants with various salinity levels led to marked changes in the total amounts and in the relative composition of carbohydrate and nitrogen pools in shoots and the yield of beans. Variable changes were also obtained for the contents of oil as well as for the constituent saturated and unsaturated fatty acids. Moreover, the results of seed protein fractionation showed marked changes in the composition of polypeptides with a wide range of molecular weights. In conclusion, the following sequence of plants: soybean > kidney bean > bush bean appears to be displayed with respect to the degree of tolerance to salinity

Plant growth, metabolism and adaptation of glycine max and phaseolus vulgaris subjected to anaerobic conditions and drought

The present study was to investigate further the effects of water stress whether induced by water regime or excessive water supply on growth, yield and metabolism of three, leguminous plants [Phaseolus vulgaris cv. Giza 3, Phaseolus vulgaris cv. Contender and Glycine max cv. Crowford] to observe differences, in growth and metabolism, if any among these three plants of commercial interest in Egypt. The induction of water stress was applied in the form of four different water treatments; two of them were drought treatments [water withholding] where the two other treatments were anaerobic water stress [excessive water supply]. Except for the stimulation effect which was elected in growth criteria of soybean plants [shoot length, number of leaves, fresh and dry weights and mean leaf area of the fully expanded leaves] at the flowering stage in response to the excessive water supply, water withholding [at two levels] and excessive water supply [at the higher level] treatments reduced these growth criteria of the three tested plants during the experimental stage. On the other hand, the low level of excessive water supply [wet treatment] stimulates the growth criteria of the tested plants. Treatment of the three bean plants with various water levels led to marked changes in the total amounts and in the relative composition of carbohydrate and nitrogen contents in shoots and in the yielded seeds. Furthermore, a highly significant decrease in oil content of soybean seeds under the dry treatment was obtained whereas a reversible situation was apparent in seeds of wet treated plants. In seeds of both P. vulgaris plants, a significant decrease in oil content was induced under wet treatment in relation to control values; both plants did not survive to the yield stage under dry treatment Marked changes were also obtained for the constituent saturated and unsaturated fatty acids in the yield of seeds. In soybean seeds, the dry treatment increased the saturated fatty acids and decreased the unsaturated fatty acids, whereas an opposite results were observed in seeds of wet-treated plants. Also in seeds of both cultivars of P. vulgaris, the increase in saturated fatty acids was accompanied by a decrease in unsaturated ones under wet treatment. In relation to control levels, water stress appeared to induce marked qualitative and quantitative changes in the types of protein produced by the legume plants. These changes appeared to substantiate the conclusion arrived at from the other results that soybean plants can be considered as being more tolerant to water stress than both cultivars of P. vulgaris used

combined effects of salinity and Ca [No3] 2 of KNO3 on growth and metabolism of phaseolus vulgaris

Additional Ca[NO3]2 or KNO3 to media salinized with NaCl appeared to improve growth and metabolism of Phaseolus vulgaris. Ca2+ and K+ concentrations increased in both shoots and roots with increasing their concentration in the medium whereas Na+ concentration was greatly decreased. With the decrease in internal Na+ concentration, the concentrations of reducing sugars, sucrose and in consequence total carbohydrates were increased. However, the increase in sugars at 60 mM K+ was greater than at 40 mM Ca2+ although the internal Na+ concentration was similar in shoots [0.2 mmol/g dry weight]. Also, protein concentration was greatly increased, whereas soluble nitrogenous compounds were decreased with increasing either Ca2+ or K+ in the salinized medium. This suggests that Ca2+ and/or K+ as nitrate salts could be added to NaCl salinized media to overcome the deleterious effects of salinity on growth and ameliorate the productivity of leguminous crop plants

Plant growth, metabolism and adaptation in relation to stress conditions. XIII comparative effects of salinity on the activity of certain enzymes in both french bean and maize plant

activity of certain enzymes in both french bean and maize plant Changes in the specific activity of 8 respiratory enzymes were measured in the extracts of seedlings, whole plants and of leaves during growth on Hoagland media supplemented or not with increaseing concertrations of Na2 SO4 The Different Enzymes Appeared to respond differently to salinity in seedlings, whole plants and leaves of both Phaseolus vulgaris and Zea mays. The present results may therefore be explained on the basis of differential effects of salinity on the different enzymes in the various tissues studied