Interactions between plants and microorganisms in the rhizosphere (rhizobacteria) can clearly affect crop yields. Rhizobacteria that benefit plant growth and development are called PGPR. the most studied PGPR belong to gramnegative genera, and the greatest number of strains are members of the fluorescent pseudomonads in our present investigation was to study the plant growth promoting (PGP) act...

The state of knowledge of grass carp ( Ctenopharyngodon idella Val.) effects on water bodies are summarized based on a review of selected literature and my own experience from South Bohemian ponds. The subjects considered include aquatic plant control using grass carp, fish age and stocking densities, and direct and indirect consequences of its introduction to water bodies including impacts on ...

Beetles in the genus Tetraopes share a long evolutionary history with milkweeds (Asclepias spp.), feeding on roots as larvae and leaves as adults. Despite their extreme specialization on milkweed, Tetraopes require drying grass stems as oviposition sites, even though they do not consume grass. The natural history of the interaction suggests that herbivory may be likely only when milkweeds are i...

The gibberellin content of pea seeds developing in excised pea pods cultured on a medium containing the plant growth retardant AMO-1618 was reduced in comparison with pea seeds cultured on retardant-free medium. The reduction increased with increasing concentrations of AMO-1618. However, at the lowest concentration tested (5 milligrams per liter) the growth of the seeds was not affected whereas...

The effects of exogenously applied silicon (Si) on plant growth and the isoform patterns of NAD-dependent malate dehydrogenase (NAD-MDH, EC 1.1.1.37) and NADPdependent malic enzyme (NADP-ME, EC 1.1.1.40) were studied in two pea genotypes (cultivar Auralia and mutant line 1/220) subjected to differential Mn treatments (50, 200 and 500 μM Mn) under control conditions. The excess Mn inhibited plan...

Biotin synthase, encoded by the bio2 gene in Arabidopsis, catalyzes the final step in the biotin biosynthetic pathway. The development of radiochemical and biological detection methods allowed the first detection and accurate quantification of a plant biotin synthase activity, using protein extracts from bacteria overexpressing the Arabidopsis Bio2 protein. Under optimized conditions, the turno...

The ability of green pea (Pisum sativum var. Alaska) stem sections to elongate in response to H(+) has been reinvestigated. Contrary to the conclusions of Barkley and Leopold, (Plant Physiol. 1973. 52: 76-78) these sections elongate in response to H(+) whenever H(+) entry through the cuticle is facilitated by slits, holes, or removal. Both live and frozen-thawed sections can undergo acid-induce...

The evolution of herbivore-host plant specialization requires low levels of gene flow between populations on alternate plant species. Accordingly, selection for host plant specialization is most effective when genotypes have minimal exposure to, and few mating opportunities with individuals from, alternate habitats. Maternally transmitted bacterial symbionts are common in insect herbivores and ...

Within the Oltenia surface mining region of Romania, 14,890 ha have been disturbed and only 1,002 ha have been reclaimed. The majority of this disturbance has involved agricultural land (12,208 ha), of which only a small amount has been reclaimed (552 ha). Forest land disturbed by surface mining in this region amounted to 2,682 ha, of which only 450 ha have been reclaimed. Therefore, huge land ...