The affinitive capacities of quinoidal chalcones towards the flower tissues were compared by examining apparent differences in the recovery rate of the pigments from dyer's saffron C. tinctorius) florets. Precarthamin is less extractable by non-polar solvents, while acetic acid and ammonia water rose its yield a little. Upon trituration of flowers, the solubility of precarthamin was increased considerably, the amounts of safflor yellows, on the other hand, were rather reduced by this treatment. The data are outlined correlating with the compartmental locality of the pigments in the floral tissues of the herbal plant.
Biochemical changes in the leaves of mungbean yellow mosaic virus (MYMV) resistant (ML-267) and suceptible (ML-5) varieties have indicated that the MYMV infection results in malfunctioning of polyphenol metabolism by increasing total sugars, free amino acids, total phenols in both the varieties, whereas ortho-dihydroxy phenol and flavonols only in the resistant variety as compared to their respective healthy ones. Polyphenol oxidase activity increased in resistant variety wheras it decreased in susceptible one with infection. Phenylalanine ammonia-lyase, tyrosine ammonia-lyase, and peroxidase activity decreased with MYMV infection in both the varieties.
Plasma membrane K+,Mg2+-ATPase with high specific acitivity was purified from soybean (Glycine max L, cv. Williams) hypocotyls. Aqueous polymer two-phase partition-purified PM vesicles were solubilized by the non-ionic detergent, C12E8, and P-11 phosphocellulose fibers were used to bind the solubilized ATPase. ATP hydrolyzing enzymes bound to the phosphocellulose fibers were eluted at 0.6 M NaCl during the step gradient elution. The pH dependence of the Mg activation, as well as that of its K+ stimulation and orthovanadate inhibition of the desalted and concentrated ATP-hydrolyzing fractions was identical to those obtained with the purified PM vesicles. The specific activity, however, was about 20 times higher in the fractions containing the partially purified enzyme than with the phase partition purified PM vesicles. This value was proportional to the protein yield of purification.
Sixteen leaf and three seed isozymes were tested for their ability to identify alien chromosomes in Triticum aestivum — Aegilops markgrafii amphiploid and six descending disomic addition lines. Four leaf isozymes (NADP-dependent aromatic alcohol dehydrogenase, aspartate aminotransferase, esterase, leucine aminopeptidase) and three seed enzymes (alcohol dehydrogenase, (ß-amylase, esterase) from Ae. markgrafii were found to be informative in differentiating both the amphiploid and five of the six different addition lines from wheat. Leaf peroxidase, an eighth informative marker among the 19 isozyme systems tested was only in the amphiploid present, none of the six addition lines showed the Aegilops-specific band.
The toxic effect of Ni2+ ions on photosynthetic electron transport was investigated by monitoring Hill activity, fluorescence, oxygen evolution and thermoluminescence properties in the green algae Scenedesmus obliquus 276-1. Nickel strongly inhibited 2,6-dichlorophenolindophenol (DCPIP) photoreduction in the broken cells of Scenedesmus, and the activity lost could not be restored by adding 1,5-diphenyl carbazide (DPC). Oxygen evolution both measured polarographically and under flash light conditions decreased by increasing the nickel concentration. Fluorescence intensity measured at room temperature decreased upon addition of nickel chloride, both in the presence and absence of DCMU. The maximum fluorescence could not be restored by addition of artificial electron donors. Thermoluminescence studies revealed that the S2Q(A)- charge recombination, however, was inhibited with increasing concentrations of nickel chloride. The results suggest that Ni2+ does not block the electron flow between the primary and secondary quinone electron acceptor, but modify the Q(B) site or interact with the non-heme iron between the Q(A) and Q(B), leading to the impairment of photosystem II.
Effect of (2-chloroethyl) trimethyl ammonium chloride (CCC) on shoot growth, nodulation, nitrogenase activity, and contents of nitrogen, ureides, sugars and starch in mung bean (Vigna radiata L. Wilczek var. Guj-2) was studied. CCC application at 1000ppm and 1500ppm markedly reduced the extension growth of the shoot system. CCC at 1000ppm (1000 mg · dm-3) significantly increased the number as well as dry weight of root nodules and activity of nitrogenase (acetylene reduction). The contents of total nitrogen, ureides, sugars and starch in shoot and root systes were also increased considerably in response to CCC (1000ppm) treatment. The present study suggests that CCC application may lead to the availability of more photosynthate for nodule formation and nitrogen fixation in mung bean.
Treatments with alkane betaine sulfonate (ABS) markedly reduced the concentration of potato virus X (PVX) as well as of tobacco mosaic virus (TMV) in inoculated and systemically infected leaves of Ncotiana tabacum L. ‘Samsun’. A very similar inhibition of TMV was obtained, if the plants were infected via roots instead of inoculation of leaves. Likewise the number of local lesions of TMV on leaves of Nicotiana glutinosa L. is substantially reduced by one treatment with ABS. As concluded from the time-response course of inhibition of PVX, ABS influences a late event in the virus replication cycle. Besides, ABS inactivates free virions.
Experiments were performed to demonstrate that glucose oxidase from Aspergillus niger conduces towards the flower colour modification in the capitula of Carthamus tinctorius L. For inducing the catalytic reaction, glucose oxidase displayed the absolute requirement for precarthamin, (β-D-glucose and atmospheric oxygen. The enzyme alone could also react with precarthamin to produce carthamin, however, the magnitude is very weak. No activity appeared in the reaction medium containing heat-inactivated enzyme sample even after the addition of glucose. The evidence was further corroborated in an incubation model, in which hydrogen peroxide and precarthamin is co-existent, instead of being added the enzyme and its substrate. The experimental model system showed a quite similar reaction pattern to that of the enzymatic process, indicating that a concomitant weight of red carthamin is accumulated as a major product of the hydrogen peroxide catalysis. On the basis of these assays, it was postulated that glucose oxidase may participate indirectly in the carthamin formation via the process of generating its by-product, hydrogen peroxide, which could react directly with precarthamin. The data are discussed in relation to flower colour modification induced characteristically in C. tinctorius capitula.
Effect of Sclerospora graminicola (Sacc.) Schroet. (the causal agent of ‘Downy mildew’/ ‘Green ear’ disease) infection on amino acids and phenols content of pearl millet were estimated colorimetrically at different stages of plant growth. Diseased leaves, stem and root with their healthy counterparts were selected for this study. Due to downy mildew infection amino acid pool was sufficiently reduced while reverse trend was noted for phenol accumulation in all the selected infection types. However, the level of these compounds significantly decreased with the age of the plant in both the healthy and diseased tissues. Phytopathological implications of these observations have been discussed.
Cell-free extracts from cell suspension cultures of Lycopersicon peruvianum were found to catalyze the glucosylation of [U-3H]DJA and [2-14C]ABA in the presence of UDP-glucose. The products of enzymatic reactions were identified as glucosyl esters of DJA and ABA by means of TLC, HPLC and hydrolysis with cellulase. The two activities were not separated by ammonium sulfate fractionation and gel filtration, but the transferase activity of the enzyme was enriched toward radioactive DJA about 60-fold and toward radioactive ABA nearly 2-fold. A DJA metabolyzing enzyme was described for the first time and can be classified as UDP-glucose: DJA glucosyltransferase. In addition to the glucosyl esters of DJA and ABA the formation of further labelled products with still unknown structure were observed during the incubation.
Effect of Sclerospora graminicola (Sacc.) Schroet. (the causal agent of 'Downy mildew'/'Green ear' disease) infection on amino acids and phenols content of pearl millet were estimated colorimetrically at different stages of plant growth. Diseased leaves, stem and root with their healthy counterparts were selected for this study. Due to downy mildew infection amino acid pool was sufficiently reduced while reverse trend was noted for phenol accumulation in all the selected infection types. However, the level of these compounds significantly decreased with the age of the plant in both the healthy and diseased tissues. Phytopathological implications of these observations have been discussed.
