Some physiological studies on the effect of the growth retardant [Pix] on vicia faba plant: morphological characteristics and metabolic activities during growth and development

The effect of MC on growth, photosynthetic pigments, carbohydrates, nitrogenous constituents, nucleic acids and the activity of certain enzymes of Vicia faba plants were studied. The results showed that the relatively low concentration [250 ppm] of the Pix caused significant increases in most of the growth parameters. Meanwhile the relatively higher concentration [1500 ppm] resulted in a reduction in these parameters. All used concentrations of mepiquat increased chlorophyll a, chlorophyll b, chlorophyll [a+b] and carotenoid contents in Vicia leaves. All concentrations of Pix also increased reducing sugars, sucrose, polysaccharides and total sugars. On the contrary, highly significant decreases in DNA and RNA contents were detected. On the other hand, high significant increases were observed in the total-N, protein-N, total soluble-N and amino-N contents at lower concentration, while induced highly significant decreases in the same contents with the higher concentrations were induced. Concerning alpha-amylase, Beta-amylase, protease and RN-ase activities the growth retardant [MC] induced high significant decreases. Contrary IAA-oxidase activity showed high significant increases

Effect of foliar treatment with boron and zinc on physiological responses of cow pea [vigna sinensis Cv. cream 7]: II Metabolic activities during growth and development

In the present study Vigna sinensis plants cv. Cream 7 were sprayed with 10, 50 and 250 mg/L of boron or zinc. The effect of boron and Zn nutrition on different constituents shoots and roots of Vigna sinensis plants were investigated. At all three concentrations of boron or zinc chlorophyll a, chlorophyll b and carotenoid contents of Vigna sinensis leaves were increased. The low concentrations applied of both boron or zinc mostly increased the reducing sugars, sucrose, polysaccharides, total carbohydrates, DNA and RNA contents concomitantly with increases in the number and activities of gibberellin compounds and decreases the total-N contents of shoots and roots of Vigna sinensis plants. The highest concentrations of boron or zinc induced a significant reduction in DNA and RNA contents in most stages of growth and development of Vigna sinensis plants. In general, all concentrations of boron or zinc induced mostly highly significant decreases in a and [3-amylase activities of shoots and roots of Vigna sinensis plants throughout the experimental period. At flowering and fruiting stages, the highest concentrations of boron or zinc mostly decreased the protease activity in shoots and roots of Vigna sinensis plants, while the lower concentrations of both elements increased this activity. Moreover, the high concentration of boron or zinc mostly induced highly significant increases in RNase activity of Vigna sinensis plants throughout the experimental stages

Some physiological effects of abscisic acid on vicia faba plants III- changes in gibberellins and cytokinins contents

The activity levels of the endogenous gibberellins and cytokinins were followed in the extracts of radicles and plumules of Vicia faba seedlings at different stages of germination and seedling growth. It has been observed that the changes in the activity levels of both gibberellins and cytokinins were detected after treatment with the concentration of ABA [10-6 M]. Low concentration of ABA [10-9 M] induced marked increase in the contents of the same hormone in the radicles and plumules extracts throughout the experimental period

Some physiological effects of abscisic acid on vicia faba plants I- morphological characteristics and metabolic activities during germination and seedling growth

The effect of ABA on germination, growth, carbohydrates, nitrogenous constituents, nucleic acids and the activity of certain enzymes of Vicia faba seedlings throughout an experimental period of 192 hours were studied. It was found that the highest concentration of ABA [10-3 M] delayed the start of germination, while the relatively low concentration [10-9 M] induced nonsignificant effect on this parameter. The high concentration of ABA induced highly significant decreases in radicle and plumule lengths, fresh and dry weights of the seedlings, while the lowest concentration [10-9 M] highly significantly increased these characters. 10-6 and 10-9 M ABA decreased the reducing sugars content whereas the polysaccharides and total sugars were increased. 10-9 M ABA induced significant increases in total soluble nitrogen, decreased nonsignificantly the protein nitrogen whereas 10-6 M decreased the protein-N content and increased the total N. The activities of protease, RN-ase were decreased at all test concentrations

Some physiological effects of abscisic acid on vicia faba plants II- changes in the endogenous auxins, growth inhibitors and certain oxidative enzymes

The activities of IAA-oxidase, peroxidase and catalase in the extract of radicles and plumules of Vicia faba seedlings throughout an experimental period of 192 hours germination are markers to get information about the effect of abscisic acid on the endogenous auxins and growth inhibitors. It was found that 10-6 M ABA markedly reduced the biological activities of auxins and markedly increased the growth inhibitors particularly the unsaturated lactone compounds and ABA. On the other hand, the low concentration of ABA [10-9 M] induced opposite changes. The activities of IAA-oxidase and peroxidase were increased while the activity of catalase was decreased at all concentrations of ABA used