No abstract

Some industrial barren areas are extreme habitats created by the deposition of airborne pollutants from non-ferrous smelters. One of such barrens exists in the vicinities of the Cu/Ni smelter, located at the Kola Peninsula, Murmansk region, Russia. This study aimed at evaluating in laboratory conditions the efficiency of various vermiculite-lizardite wastes (industrial wastes of local origin) as soil amendments for plant growth promotion. Peat topsoil (0-20 cm) was collected in the vicinity of the Cu/Ni smelter. Total soil concentrations were 1612, 1481, and 63 mg kg −1 for Ni, Cu, and Co, respectively, and soil pH was 4.3. Soils were amended with lime waste and different types of vermiculite-lizardite wastes (coarse, fine, and thermo-activated at 700°C), leaving one soil untreated. Weekly wetting-drying cycles, performed during 1 month, allowed amendments to react in the soil. All soils were cultivated with Lolium perenne L. for 21 days under controlled conditions. The plant growth was not influenced by high soil Cu concentration, while Ni and Co caused phytotoxicity. A mix of 10% (w/w) of different vermiculite-lizardite wastes with 10% (w/w) of lime improved the plant growth. Thermo-activated waste showed the best results for promoting plant growth and reducing foliar Ni concentrations from 1022 to 88-117 mg kg −1. However, the plants presented Ni phytotoxicity even in the amended soils and this requires further studies to find a way to reduce it.

No abstract

No abstract

Effects of clinorotation on the mitochondrial ultrastructure in cells of meristem, distal and central elongation zones of 3-and 5-day-old etiolated roots of pea seedling roots were studied. It was shown that mitochondria in cells of examined root growth zones revealed a different sensitivity to clinorotation. The ultrastructure of mitochondria in the meristem and central elongation zone cells did not substantially change in comparison with stationary control. At the same time, changes in the mitochondrial ultrastructure in cells of the distal elongation zone under clinorotation were observed, namely: decrease in the size of mitochondria, as well as increase in both matrix electron density and crista volume. Such changes in the mitochondrial ultrastructure under clinorotation are supposed to display the rearrangements of energy metabolism in cells of the distal elongation zone in these conditions.

Aerenchyma is a plant tissue characterized by prominent intercellular spaces facilitating gas diffusion between roots and the aerial environment. The classical formation of intercellular spaces is thought to be the result of schizogeny and lysogeny during development of wetland species and in some dry-land species in response to different abiotic stress, including drought, high temperature, and nutrient deficiency. The plant cytoskeleton is known to play a major role in cellular organization and signaling pathways. It is emphasized a lot of ambiguity as to the cytoskeleton function in the constitutive and induced aerenchyma development, especially at the earliest stages of this process. In the present review, we focus on some aspects of the cytoskeleton behavior during the formation of schizogenous and lysigenous aerenchyma in wetland and terrestrial plants growing both in the nature and experimental conditions.

No abstract

No abstract