Open stomata 1 (OST1) kinase controls R–type anion channel QUAC1 in Arabidopsis guard cells

Under drought stress, the stress hormone ABA addresses the SnR kinase OST1 via its cytosolic receptor and the protein phosphatase ABI1. Upon activation, OST1 phosphorylates the guard cell S–type anion channel SLAC1. Arabidopsis ABI1 and OST1 loss-of-function mutants are characterized by an extreme wilting 'open stomata′ phenotype. Given the fact that guard cells express both SLAC- and R–/QUAC-type anion channels, we questioned whether OST1, besides SLAC1, also controls the QUAC1 channel. In other words, are ABI1/OST1 defects preventing both of the guard cell anion channel types from operating properly in terms of stomatal closure? The activation of the R–/QUAC-type anion channel by ABA signaling kinase OST1 and phosphatase ABI1 was analyzed in two experimental systems: Arabidopsis guard cells and the plant cell-free background of Xenopus oocytes. Patch-clamp studies on guard cells show that ABA activates R–/QUAC-type currents of wild-type plants, but to a much lesser extent in those of abi1–1 and ost1–2 mutants. In the oocyte system the co-expression of QUAC1 and OST1 resulted in a pronounced activation of the R–type anion channel. These studies indicate that OST1 is addressing both S–/SLAC- and R–/QUAC-type guard cell anion channels, and explain why the ost1–2 mutant is much more sensitive to drought than single slac1 or quac1 mutants

Media reports about 'The Venus flytrap Dionaea muscipula counts prey-induced action potentials to induce sodium uptake'

Media stories about the paper "The Venus flytrap Dionaea muscipula counts prey-induced action potentials to induce sodium uptake": BBC News - Venus flytrap 'counts' to control digestion The Denver Post - You can count on Venus flytraps knowing when to chomp Mid Day Daily - Venus flytraps use math in order to catch prey Nature - Plants count to five Washington Post - The venus flytrap has a really creepy trick for catching its prey/ ScienceDaily - Hunting secrets of the Venus flytrap (hint: They can count) Telegraph UK - Venus flytraps use maths to trap and eat their prey ABC News Australia - Venus flytrap plants can count to five SciNews - Biologists: carnivorous Venus flytraps can count Fox News - Deadly math: Venus flytraps calculate when killing prey The Venus flytrap Dionaea muscipula counts prey-induced action potentials to induce sodium uptake</p

Understanding the molecular basis of salt sequestration in epidermal bladder cells of Chenopodium quinoa

Soil salinity is destroying arable land and is considered to be one of the major threats to global food security in the 21st century. Therefore, the ability of naturally salt-tolerant halophyte plants to sequester large quantities of salt in external structures, such as epidermal bladder cells (EBCs), is of great interest. Using Chenopodium quinoa, a pseudo-cereal halophyte of great economic potential, we have shown previously that, upon removal of salt bladders, quinoa becomes salt sensitive. In this work, we analyzed the molecular mechanism underlying the unique salt dumping capabilities of bladder cells in quinoa. The transporters differentially expressed in the EBC transcriptome and functional electrophysiological testing of key EBC transporters in Xenopus oocytes revealed that loading of Na+ and Cl− into EBCs is mediated by a set of tailored plasma and vacuole membrane-based sodium-selective channel and chloride-permeable transporter

Kenya: Joy As Firebrand Academician Is Back After Twelve Years Of Political Asylum

An article, by Dr Joseph Adero Ngala, an Associate Professor of International Relations at the United States International University – Africa