Summary Grapevine (Vitis vinifera), the genome sequence of which has recently been reported, is considered as a model species to study fleshy fruit development and acid fruit physiology. Grape berry acidity is quantitatively and qualitatively affected upon increased K+ accumulation, resulting in deleterious effects on fruit (and wine) quality. Aiming at identifying molecular determinants of K+ transport in grapevine, we have identified a K+ channel, named VvK1.1, from the Shaker family. In silico analyses indicated that VvK1.1 is the grapevine counterpart of the Arabidopsis AKT1 channel, known to dominate the plasma membrane inward conductance to K+ in root periphery cells, and to play a major role in K+ uptake from the soil solution. VvK1.1 shares common functional properties with AKT1, such as inward rectification (resulting from voltage sensitivity) or regulation by calcineurin B‐like (CBL)‐interacting protein kinase (CIPK) and Ca2+‐sensing CBL partners (shown upon heterologous expression in Xenopus oocytes). It also displays distinctive features such as activation at much more negative membrane voltages or expression strongly sensitive to drought stress and ABA (upregulation in aerial parts, downregulation in roots). In roots, VvK1.1 is mainly expressed in cortical cells, like AKT1. In aerial parts, VvK1.1 transcripts were detected in most organs, with expression levels being the highest in the berries. VvK1.1 expression in the berry is localized in the phloem vasculature and pip teguments, and displays strong upregulation upon drought stress, by about 10‐fold.VvK1.1 could thus play a major role in K+ loading into berry tissues, especially upon drought stress.

R-GemOx shows promising activity with acceptable toxicity in patients with relapsed/refractory B-cell lymphoma who are not eligible for HDT.

Olfaction is an ancient sensory system allowing an organism to detect chemicals in its environment. The first step in odor transduction is mediated by binding odorants to olfactory receptors (ORs) which belong to the heptahelical G-protein-coupled receptor (GPCR) superfamily. Mammalian ORs are disposed in clusters on virtually all chromosomes. They are encoded by the largest multigene family (approximately 1000 members) in the genome of mammals and Caenorhabditis elegans, whereas Drosophila contains only 60 genes. Each OR specifically recognizes a set of odorous molecules that share common molecular features. In mammals, signal transduces through the G-protein-dependent signal pathway in the olfactory sensory neurons that synapse ultimately in the glomeruli of the olfactory bulb, and is finally processed in higher brain structures. The expression of a given OR conditions neuron and glomerulus choices. To date, the processes which monitor OR expression and axon wiring have emerged but are not completely elucidated.

A B S T R A C T PurposeTo assess the efficacy of gonadotropin-releasing hormone agonist (GnRHa) in preventing chemotherapy-induced ovarian failure in patients treated for Hodgkin or non-Hodgkin lymphoma within the setting of a multicenter, randomized, prospective trial. Patients and MethodsPatients age 18 to 45 years were randomly assigned to receive either the GnRHa triptorelin plus norethisterone (GnRHa group) or norethisterone alone (control group) concomitantly with alkylating agents containing chemotherapy. The primary end point was the premature ovarian failure (POF) rate (follicle-stimulating hormone [FSH] Ն 40 IU/L) after 1 year of follow-up. ResultsEighty-four of 129 randomly assigned patients completed the 1-year follow-up. The mean FSH values were higher in the control group than in the GnRHa group during chemotherapy; however, this difference was no longer observed after 6 months of follow-up. After 1 year, 20% and 19% of patients in the GnRHa and control groups, respectively, exhibited POF (P ϭ 1.00). More than half of patients in each group completely restored their ovarian function (FSH Ͻ 10 IU/L), but the anti-Mü llerian hormone values were higher in the GnRHa group than in the control group (1.4 Ϯ 0.35 v 0.5 Ϯ 0.15 ng/mL, respectively; P ϭ .040). The occurrence of adverse events was similar in both groups with the exception of metrorrhagia, which was more frequently observed in the control group than the GnRHa group (38.4% v 15.6%, respectively; P ϭ .024). ConclusionApproximately 20% of patients in both groups exhibited POF after 1 year of follow-up. Triptorelin was not associated with a significant decreased risk of POF in young patients treated for lymphoma but may provide protection of the ovarian reserve.J Clin Oncol 30.

In most plants, NO(3)(-) constitutes the major source of nitrogen, and its assimilation into amino acids is mainly achieved in shoots. Furthermore, recent reports have revealed that reduction of NO(3)(-) translocation from roots to shoots is involved in plant acclimation to abiotic stress. NPF2.3, a member of the NAXT (nitrate excretion transporter) sub-group of the NRT1/PTR family (NPF) from Arabidopsis, is expressed in root pericycle cells, where it is targeted to the plasma membrane. Transport assays using NPF2.3-enriched Lactococcus lactis membranes showed that this protein is endowed with NO(3)(-) transport activity, displaying a strong selectivity for NO(3)(-) against Cl(-). In response to salt stress, NO(3)(-) translocation to shoots is reduced, at least partly because expression of the root stele NO(3)(-) transporter gene NPF7.3 is decreased. In contrast, NPF2.3 expression was maintained under these conditions. A loss-of-function mutation in NPF2.3 resulted in decreased root-to-shoot NO(3)(-) translocation and reduced shoot NO(3)(-) content in plants grown under salt stress. Also, the mutant displayed impaired shoot biomass production when plants were grown under mild salt stress. These mutant phenotypes were dependent on the presence of Na(+) in the external medium. Our data indicate that NPF2.3 is a constitutively expressed transporter whose contribution to NO(3)(-) translocation to the shoots is quantitatively and physiologically significant under salinity.

SUMMARYA functional Shaker potassium channel requires assembly of four a-subunits encoded by a single gene or various genes from the Shaker family. In Arabidopsis thaliana, AtKC1, a Shaker a-subunit that is silent when expressed alone, has been shown to regulate the activity of AKT1 by forming heteromeric AtKC1-AKT1 channels. Here, we investigated whether AtKC1 is a general regulator of channel activity. Co-expression in Xenopus oocytes of a dominant negative (pore-mutated) AtKC1 subunit with the inward Shaker channel subunits KAT1, KAT2 or AKT2, or the outward subunits SKOR or GORK, revealed that the three inward subunits functionally interact with AtKC1 while the outward ones cannot. Localization experiments in plant protoplasts showed that KAT2 was able to re-locate AtKC1 fused to GFP from endomembranes to the plasma membrane, indicating that heteromeric AtKC1-KAT2 channels are efficiently targeted to the plasma membrane. Functional properties of heteromeric channels involving AtKC1 and KAT1, KAT2 or AKT2 were analysed by voltage clamp after co-expression of the respective subunits in Xenopus oocytes. AtKC1 behaved as a regulatory subunit within the heterotetrameric channel, reducing the macroscopic conductance and negatively shifting the channel activation potential. Expression studies showed that AtKC1 and its identified Shaker partners have overlapping expression patterns, supporting the hypothesis of a general regulation of inward channel activity by AtKC1 in planta. Lastly, AtKC1 disruption appeared to reduce plant biomass production, showing that AtKC1-mediated channel activity regulation is required for normal plant growth.

Building a proton gradient across a biological membrane and between different tissues is a matter of great importance for plant development and nutrition. To gain a better understanding of proton distribution in the plant root apoplast as well as across the plasma membrane, we generated plants expressing stable membrane-anchored ratiometric fluorescent sensors based on pHluorin. These sensors enabled noninvasive pH-specific measurements in mature root cells from the medium-epidermis interface up to the inner cell layers that lie beyond the Casparian strip. The membrane-associated apoplastic pH was much more alkaline than the overall apoplastic space pH. Proton concentration associated with the plasma membrane was very stable, even when the growth medium pH was altered. This is in apparent contradiction with the direct connection between root intercellular space and the external medium. The plasma membrane-associated pH in the stele was the most preserved and displayed the lowest apoplastic pH (6.0 to 6.1) and the highest transmembrane delta pH (1.5 to 2.2). Both pH values also correlated well with optimal activities of channels and transporters involved in ion uptake and redistribution from the root to the aerial part. In growth medium where ionic content is minimized, the root plasma membrane-associated pH was more affected by environmental proton changes, especially for the most external cell layers. Calcium concentration appears to play a major role in apoplastic pH under these restrictive conditions, supporting a role for the cell wall in pH homeostasis of the unstirredsurface layer of plasma membrane in mature roots.

SUMMARYThe grape berry provides a model for investigating the physiology of non-climacteric fruits. Increased K + accumulation in the berry has a strong negative impact on fruit acidity (and quality). In maturing berries, we identified a K + channel from the Shaker family, VvK1.2, and two CBL-interacting protein kinase (CIPK)/calcineurin B-like calcium sensor (CBL) pairs, VvCIPK04-VvCBL01 and VvCIPK03-VvCBL02, that may control the activity of this channel. VvCBL01 and VvCIPK04 are homologues of Arabidopsis AtCBL1 and AtCIPK23, respectively, which form a complex that controls the activity of the Shaker K + channel AKT1 in Arabidopsis roots. VvK1.2 remained electrically silent when expressed alone in Xenopus oocytes, but gave rise to K + currents when co-expressed with the pairs VvCIPK03-VvCBL02 or VvCIPK04-VvCBL01, the second pair inducing much larger currents than the first one. Other tested CIPK-CBL pairs expressed in maturing berries were found to be unable to activate VvK1.2. When activated by its CIPK-CBL partners, VvK1.2 acts as a voltagegated inwardly rectifying K + channel that is activated at voltages more negative than -100 mV and is stimulated upon external acidification. This channel is specifically expressed in the berry, where it displays a very strong induction at veraison (the inception of ripening) in flesh cells, phloem tissues and perivascular cells surrounding vascular bundles. Its expression in these tissues is further greatly increased upon mild drought stress. VvK1.2 is thus likely to mediate rapid K + transport in the berry and to contribute to the extensive reorganization of the translocation pathways and transport mechanisms that occurs at veraison.