Biochemie und Physiologie der Pflanzen最新文献

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.

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.

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.

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.

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.