Recent work has suggested that plants differ in their relative reliance on structural avoidance of embolism versus maintenance of the xylem water column through dynamic traits such as capacitance, but we still know little about how and why species differ along this continuum. It is even less clear how or if different parts of a plant vary along this spectrum. Here we examined how traits such as...

Hypericum perforatum L. (St. Johns’ wort) is the most commercially important species of the genus Hypericum and contains a wide range of components including naphthodianthrones, phloroglucinols, tannins, xanthones, phenolic acids and essential oil. In order to establish an efficient protocol for regeneration, the effects of explant type and plant growth regulators on direct and indirect shoot r...

Stem cells in plant shoot and root meristems are maintained throughout the life of the plant and produce somatic daughter cells that make up the body of the plant. Plant stem cells can also be derived from somatic cells in vivo and in vitro. Recent findings are refining our knowledge of signaling pathways that define stem cell fate and specify either shoot or root stem cell function. New eviden...

Plant demographic studies coupled with population modeling are crucial components of invasive plant management because they inform managers when in a plant's life cycle it is most susceptible to control efforts. Providing land managers with appropriate data can be especially challenging when there is limited data on potentially important transitions that occur belowground. For 2 years, we monit...

the water deficiency is one of the serious problems in the arid zones. in order to investigate the effect of cycocel on different growth aspects of two olive cultivars (mary and mission), a greenhouse experiment was conducted using three factors of: cycocel at three levels (0, 500 and 1000 mg l-1), irrigation of three levels (irrigated at 5, 10 and 15 days intervals) and tow olive cultivars (ma...

We have known for many years that the dehydration of plant cells can lead to accumulation of the plant growth regulator ABA. Application of this compound to well-watered plants mimics many of the effects of soil drymg on gene expression, physiology, growth, and development, making this compound a strong candidate for a role in the droughted plant. Dehydration of leaves can result in massive acc...

environmental stresses are one of the most important factors of agricultural products reduction in the world. the influence of different concentrations of nickel nitrate (0, 100, 200 and 500 μm in hoagland’s solution) on dry matter, catalase enzyme, flavonoids, hydrogen peroxide, peroxidase enzyme, mda and accumulation of ni were studied in coriander ( coriandrum sativum ) plants. treatment wit...

Chlorpyrifos is one of the commonly used organophosphorus insecticides that are implicated in serious environmental and human health problems. To evaluate plant potential for uptake of chlorpyrifos, several plant species of poplar (Populus sp.) and willow (Salix sp.) were investigated. Chlorpyrifos was taken up from nutrient solution by all seven plant species. Significant amounts of chlorpyrif...