Leaf hydraulic conductance (K(leaf)) is a major determinant of photosynthetic rate in well-watered and drought-stressed plants. Previous work assessed the decline of K(leaf) with decreasing leaf water potential (Ψ(leaf)), most typically using rehydration kinetics methods, and found that species varied in the shape of their vulnerability curve, and that hydraulic vulnerability correlated with ot...

Escape from the renal actions of vasopressin is said to occur in rats with chronic hyponatremia. Our objective was to provide specific evidence to test this hypothesis. Hence the osmolality in the excised renal papilla and in simultaneously voided urine (U(Osm)) was measured in rats with and without hyponatremia. To induce hyponatremia, rats were fed low-electrolyte chow for 6 days. In the firs...

The Mexican rice borer, Eoreuma loftini (Dyar) (Lepidoptera: Crambidae), a key pest of sugarcane (Saccharum spp.) and rice, Oryza sativa L., in Texas, has not been controlled with chemical insecticides or biological agents, but some sugarcane varieties have shown degrees of resistance. Assessment of selected sugarcane leaf characteristics indicate that preference for oviposition sites is mostly...

The potential antisenescence effect of eight synthetic urea compounds was investigated in excised barley (Hordeum vulgare L.) leaves which were induced to senesce by incubation in complete darkness. The compounds having uncyclic ureido group showed higher chlorophyll retention activity than those with cyclic ureido group. Compounds 1, 6 and 4PU had long-term protecting effects on chlorophyll de...

ABSTRACT Septoria musiva causes leaf spot and canker diseases of trees in the genus Populus, and is one of the most damaging fungal pathogens of hybrid poplar in eastern North America. The effect of host water stress on Septoria canker development was studied in two separate greenhouse experiments. Hybrid poplar clones NM6, NC11396, and NE308 were stressed by withholding water until predawn wat...

drought, ultraviolet radiation and atmospheric co2 are some three environmental factors that seriously affect future food security. the objective followed in the present research was to study the effect of two levels of carbon dioxide (400 and 900 ppm), ultraviolet radiation (uv a, b and c with intensities of 18, 25 and 40 microw.cm-2 respectively) and water deficit (%100 and %60 of field capac...

in this regard, the morphophysiologic and anatomic characteristics of six olive cultivars (nabali, feshomi, arbequin, zard, gordal and roghani) were investigated under drought. experiments were designed based on factorial and complete block random plot with two control treatments, -1.5 mpa stress and three replicates. the investigated factors were as follows: leaf area, specific leaf area, leaf...

Arbuscular mycorrhizal fungi (AMF) proliferate in soil pores, on the surface of soil particles and affect soil structure. Although modifications in substrate moisture retention depend on structure and could influence plant water extraction, mycorrhizal impacts on water retention and hydraulic conductivity were rarely quantified. Hence, we asked whether inoculation with AMF affects substrate wat...

Among the numerous molecular and physiological modifications induced by water deficit, one of the earliest events observed in maize mature leaves subjected to water deprivation was a strong enhancement of acid vacuolar invertase activity, which occurred before the classical reduction in gas exchange due to stomatal closure. The increase in invertase activity coincided with the rapid accumulatio...