1, respectively. This result, together with the finding that the oligomer is absent from NRT2.1 or NAR2.1 mutants, suggests that this complex, rather than monomeric AtNRT2.1, is the form that is active in IHATS

nitrate transport. The molecular mass of the intact oligomer suggests that the functional unit for high-affinity nitrate influx may be a tetramer consisting of two subunits each of AtNRT2.1 and AtNAR2.1.”
“Oxidative stress is commonly induced when plants are grown under high temperature (HT) stress conditions. Selenium often acts as an antioxidant in plants; however, its role under HT-induced oxidative stress is not definite. We hypothesize that selenium application can partly alleviate HT-induced oxidative stress and negative impacts of HT on physiology, growth and yield of grain sorghum [Sorghum bicolor (L.) www.selleckchem.com/products/ldc000067.html Moench]. Objectives of this study

were to investigate the effects of selenium on (a) leaf photosynthesis, membrane stability and antioxidant enzymes activity and (b) grain yield and yield components of grain sorghum plants grown under HT stress in controlled environments. Plants were grown under optimal temperature (OT; 32/22 degrees C daytime maximum/nighttime minimum) from sowing to 63 days after sowing (DAS). All plants were foliar sprayed with sodium selenate (75 mg L(-1)) at 63 DAS, and HT stress (40/30 degrees C) was imposed from 65 DAS through maturity. selleckchem Data on physiological, biochemical and yield traits were measured. High temperature stress decreased chlorophyll content, chlorophyll a fluorescence, photosynthetic rate and antioxidant PS-095760 enzyme activities and increased oxidant production and membrane damage. Decreased antioxidant defense under HT stress resulted in lower grain yield compared with OT. Application of selenium decreased membrane damage by enhancing antioxidant defense resulting in higher grain yield. The increase in antioxidant enzyme activities and decrease in reactive oxygen species (ROS) content

by selenium was greater in HT than in OT. The present study suggests that selenium can play a protective role during HT stress by enhancing the antioxidant defense system. (C) 2010 Elsevier Masson SAS. All rights reserved.”
“Opsins are the universal photoreceptor molecules of all visual systems in the animal kingdom. They can change their conformation from a resting state to a signalling state upon light absorption, which activates the G protein, thereby resulting in a signalling cascade that produces physiological responses. This process of capturing a photon and transforming it into a physiological response is known as phototransduction. Recent cloning techniques have revealed the rich and diverse nature of these molecules, found in organisms ranging from jellyfish to humans, functioning in visual and non-visual phototransduction systems and photoisomerases. Here we describe the diversity of these proteins and their role in phototransduction.