Glutamine synthetase and asparagine synthetase are two master enzymes involved in ammonium assimilation in plants. Their roles in nitrogen remobilization and nitrogen use efficiency have been proposed. In this report, the genes coding for the cytosolic glutamine synthetases (HvGS1) and asparagine synthetases (HvASN) in barley were identified. In addition to the three HvGS1 and two HvASN sequenc...

The inhibition of photosynthesis at low leaf water potentials was studied in soil-grown sunflower to determine the degree to which photosynthesis under high light was affected by stomatal and nonstomatal factors. Below leaf water potentials of -11 to -12 bars, rates of photosynthesis at high light intensities were insensitive to external concentrations of CO(2) between 200 and 400 microliters p...

Sulfate translocation in soybean (Glycine max L. Merr) was investigated. More than 90% of the sulfate entering the shoot system was recoverable in one or two developing trifoliate leaves. In young plants, the first trifoliate leaf contained between 10 to 20 times as much sulfate as the primary leaves, even though both types of leaf had similar rates of transpiration and photosynthesis. We concl...

1. We evaluated the potential for three species of deciduous-forest herbs to exploit seasonal periods of direct irradiance. In particular, we investigated the importance of photosynthetic acclimation as a mechanism for shade-tolerant herbs to utilize direct light reaching the forest floor before canopy expansion in the spring and after canopy leaf drop in the autumn. 2. We measured the photosyn...

BACKGROUND The efficacy of systemic applications of imidacloprid for the management of avocado thrips and avocado lace bug was determined in field trials. Following insecticide treatment by chemigation, leaves of appropriate age for each insect were sampled over a 6 month period and used for bioassays. Imidacloprid residues were measured by ELISA in leaves used for bioassays to determine concen...

wheat crop, considering its high planting area and consumption at national scale, demand a regular yield increase. humic acid, as an organic acid obtained from humus and organic sources without any environmental destructive effects, improves wheat yield particularly in variable environment conditions. in order to evaluate the effects of different levels of humic acid on shoot and wheat yield, a...

hybrid rice varieties are potentially higher yielding than the best inbred varieties and perform better under adverse conditions of drought and salinity. one of the major impediments for seed production of hybrid rice is incomplete panicle exsertion in the cytoplasmic male sterile lines. the unexserted spikelets which are left inside the flag leaf sheath remain unfertile. this research was focu...

Polarimetric Xand C-band measurements by the University of Sheffield ground-based synthetic aperture radar (GB-SAR) indoor system provide three-dimensional images of the scattering processes in wheat canopies, at resolutions of around a wavelength (3–6 cm). The scattering shows a pronounced layered structure, with strong returns from the soil and the flag leaves, and in some cases a second leaf...

Barley (Hordeum vulgare L.) is among the most stress-tolerant crops; however, not much is known about the genetic and environmental control of metabolic adaptation of barley to abiotic stresses. We have subjected a genetically diverse set of 81 barley accessions, consisting of Mediterranean landrace genotypes and German elite breeding lines, to drought and combined heat and drought stress at an...