The grapevine (Vitis vinifera L. cv. Riesling) plants subjected to water deficit were studied for changes in relative water content (RWC), leaf dry mass, contents of chlorophyll (Chl), total leaf proteins, free amino acids, and proline, and activities of ribulose-1,5-bisphosphate carboxylase (RuBPC), nitrate reductase (NR), and protease. In water-stressed plants RWC, leaf dry matter, Chl content, net photosynthetic rate (PN), and RuBPC and NR activities were significantly decreased. The total leaf protein content also declined with increase in the accumulation of free amino acids. Concurrently, the protease activity in the tissues was also increased. A significant two-fold increase in proline content was recorded. and M. Bertaminni ... [et al.].
Greenhouse experiments showed that the preemergence herbicide fluchloralin ušed at recommended level inhibited the activities of nitiite reductase, net photosynthetic rate and DCPIP photoreduction but did not cause appreciable reduction in nitráte reductase activity. Prolonged treatment of groundnut cv. TMV-2 with fluchloralin resulted in accumulation of nitrite in leaves whereas statistically significant changes were not found in leaf crude protein and chlorophyll contents and growth of plants during different stages of growth.
In leaves of four tomato (Lycopersicon esculentum Mill.) cultivars (Red Cloud, Floradade, Peto 95, and Scorpio) the contents of chlorophyll (Chl) (a+b), Chl a, and β-carotene decreased due to 100 mM NaCl treatment as compared with those of controls. The contents of soluble sugars and total saccharides were significantly increased in leaves of NaCl-treated plants, but the starch content was not significantly affected. Transmission electron microscopy indicated that in leaves of NaCl-treated plants, the chloroplasts were aggregated, the cell membranes were distorted and wrinkled, and there was no sign of grana and thylakoid structures in chloroplasts. and R. A. Khavari-Nejad, Y. Mostofi.
Quaternary ammonium salts, besides having an inhibitory effect which was studied by Králová eí al. (1992), exhibited at low concentrations a stimulating effect upon the oxygen evolution rate in spinách chloroplasts. The stimulation is caused by changes in arrangement of thylakoid membranes due to a detergent-like effect of the compoimds.