Ca2+-permeable mechanosensitive channels MCA1 and MCA2 mediate cold-induced cytosolic Ca2+ increase and cold tolerance in Arabidopsis

Cold shock triggers an immediate rise in the cytosolic free calcium concentration ([Ca2+]cyt) in Arabidopsis thaliana and this cold-induced elevation of [Ca2+]cyt is inhibited by lanthanum or EGTA. It is suggested that intracellular calcium mainly contributes to the cold-induced [Ca2+]cyt response by entering into the cytosol. Two calcium-permeable mechanosensitive channels, MCA1 and MCA2 (mid1-complementing activity), have been identified in Arabidopsis. Here, we demonstrate that MCA1 and MCA2 are involved in a cold-induced increase in [Ca2+]cyt. The cold-induced [Ca2+]cyt increase in mca1 and mca2 mutants was markedly lower than that in wild types. The mca1 mca2 double mutant exhibited chilling and freezing sensitivity, compared to wild-type plants. Expression of At5g61820, At3g51660, and At4g15490, which are not regulated by the CBF/DREB1s transcription factor, was down-regulated in mca1 mca2. These results suggest that MCA1 and MCA2 are involved in the cold-induced elevation of [Ca2+]cyt, cold tolerance, and CBF/DREB1-independent cold signaling

MCA1 and MCA2 That Mediate Ca2+ Uptake Have Distinct and Overlapping Roles in Arabidopsis1[W][OA]

Ca2+ is important for plant growth and development as a nutrient and a second messenger. However, the molecular nature and roles of Ca2+-permeable channels or transporters involved in Ca2+ uptake in roots are largely unknown. We recently identified a candidate for the Ca2+-permeable mechanosensitive channel in Arabidopsis (Arabidopsis thaliana), named MCA1. Here, we investigated the only paralog of MCA1 in Arabidopsis, MCA2. cDNA of MCA2 complemented a Ca2+ uptake deficiency in yeast cells lacking a Ca2+ channel composed of Mid1 and Cch1. Reverse transcription polymerase chain reaction analysis indicated that MCA2 was expressed in leaves, flowers, roots, siliques, and stems, and histochemical observation showed that an MCA2 promoter::GUS fusion reporter gene was universally expressed in 10-d-old seedlings with some exceptions: it was relatively highly expressed in vascular tissues and undetectable in the cap and the elongation zone of the primary root. mca2-null plants were normal in growth and morphology. In addition, the primary root of mca2-null seedlings was able to normally sense the hardness of agar medium, unlike that of mca1-null or mca1-null mca2-null seedlings, as revealed by the two-phase agar method. Ca2+ uptake activity was lower in the roots of mca2-null plants than those of wild-type plants. Finally, growth of mca1-null mca2-null plants was more retarded at a high concentration of Mg2+ added to medium compared with that of mca1-null and mca2-null single mutants and wild-type plants. These results suggest that the MCA2 protein has a distinct role in Ca2+ uptake in roots and an overlapping role with MCA1 in plant growth

Vonoprazan-Based Regimen Is More Useful than PPI-Based One as a First-Line Helicobacter pylori Eradication: A Randomized Controlled Trial

Background. A new agent, potassium-competitive acid blocker vonoprazan (VPZ) has potent acid-inhibitory effects and may offer advantages over conventional H. pylori eradication therapies. We aimed to compare the eradication rate between VPZ-based treatment and PPI-based one. Methods. This randomized controlled trial was designed to assign 141 patients with H. pylori-positive gastritis to VPZ group (VPZ 20 mg, amoxicillin 750 mg, and clarithromycin 200 or 400 mg twice daily for 7 days) or PPI group (rabeprazole 20 mg or lansoprazole 30 mg, amoxicillin 750 mg, and clarithromycin 200 or 400 mg twice daily for 7 days). Primary endpoints were eradication rates and adverse events. Results. Seventy of 72 patients in VPZ group and 63 of 69 patients in PPI group completed the treatment after 7 days. The eradication rate was significantly higher in VPZ group than PPI group by intention-to-treat analysis (95.8% versus 69.6%, P=0.00003, 95% confidence interval [CI] 88.3-99.1% versus 57.3-80.1%) and per-protocol analysis (95.7% versus 71.4%, P=0.0002, 95% CI 88.0-99.1% versus 58.7-82.1%). The incidence of adverse events was not different between the groups (26.3% in VPZ group versus 37.7% in PPI group, P=0.15). Conclusion. VPZ-based regimen is more useful than that PPI-based regimen as a first-line H. pylori eradication therapy

Determinants of the Performance of Microfinance Institutions: A Systematic Review

Microfinance institutions (MFIs) generally aim at improving the access of the poorto financial services while at the same time being financially sustainable. Butwhat do we know about how MFIs reach and combine these two goals? We carryout a systematic review of close to 170 articles discussing the determinants ofthe financial and social performance of MFIs. The review shows that the mostimportant determinants addressed in the literature are MFI characteristics (size,age, type of organization), their funding sources, the quality of organizationalgovernance and the MFIs’ external context such as macroeconomic, institutionaland political conditions. The evidence on these issues is rather mixed. Moreover,the direction of the relationship between these drivers and MFI performancedepends on the context, particularly the country-specific context. Finally, there isa lack of consensus in the literature on the measurement of financial and socialperformance. Due to the complexity of the concept, we argue that socialperformance should only be assessed by using a multidimensional perspective.This can be done either by applying recent and holistic social performancemeasures such as the SPI4, or at least by using a combination of proxies, suchas outreach, gender and rural measures.info:eu-repo/semantics/publishe