Soybean plants and Rhizobium japonicum 122 DES, a hydrogen uptake-positive strain, were cultured in media purified to remove Ni. Supplemental Ni had no significant effect on the dry matter or total N content of plants. However, the addition of Ni to both nitrate-grown and symbiotically grown plants resulted in a 7- to 10-fold increase in urease activity (urea amidohydrolase, EC 3.5.1.5) in leav...

To investigate whether leaves of plane trees (Platanus orientalis) are damaged by traffic pollution, trees from a megacity (Mashhad, Iran) and a rural area were investigated. Soil and air from the urban centre showed enrichment of several toxic elements, but only lead was enriched in leaves. Leaf size and stomata density were lower at the urban site. At the urban site leaf surfaces were heavily...

We describe a weakly mixing 1-dimensional tiling dynamical system in which the tiling space is modeled by a surface M of genus 2. The tiling system satis es an in ation, and the in ation map is modeled by a pseudo-Anosov di eomorphism D on M . The expansion coe cient for D is a non-Pisot number. In particular, the leaves of the expanding foliation for D are tiled by their visits to the elements...

Morpho-anatomical features in leaves, stems and unripe fruits of Solanum pseudocapsicum L., Solanaceae, were investigated by histological methods. Anatomically the plant may be characterised by the presence of uniseriate trichomes, anomocytic stomata, calcium oxalate needles in leaves while presence of oval to circular compound starch grains, angular vessels, vertically upright, uni-biseriate r...

Understanding variation of plant nutrients is largely limited to nitrogen and to a lesser extent phosphorus. Here we analyse patterns of variation in 11 elements (nitrogen/phosphorus/potassium/calcium/magnesium/sulphur/silicon/iron/sodium/manganese/aluminium) in leaves of 1900 plant species across China. The concentrations of these elements show significant latitudinal and longitudinal trends, ...