A Putative Plasma Membrane Na+/H+ Antiporter GmSOS1 Is Critical for Salt Stress Tolerance in Glycine max.

Soybean (Glycine max) is a staple crop and a major source of vegetable protein and vegetable oil. The growth of soybean is dramatically inhibited by salt stress, especially by the excessive toxic Na+. Salt Overly Sensitive 1 (SOS1) is the only extensively characterized Na+ efflux transporter in multiple plant species so far. However, the role of GmSOS1 in soybean salt stress responses remains unclear. Herein, we created three gmsos1 mutants using the CRISPR-Cas9 system in soybean. We found a significant accumulation of Na+ in the roots of the gmsos1 mutants, resulting in the imbalance of Na+ and K+, which links to impaired Na+ efflux and increased K+ efflux in the roots of the gmsos1 mutants under salt stress. Compared to the wild type, our RNA-seq analysis revealed that the roots of the gmsos1-1 showed preferential up and downregulation of ion transporters under salt stress, supporting impaired stress detection or an inability to develop a comprehensive response to salinity in the gmsos1 mutants. Our findings indicate that the plasma membrane Na+/H+ exchanger GmSOS1 plays a critical role in soybean salt tolerance by maintaining Na+ homeostasis and provides evidence for molecular breeding to improve salt tolerance in soybean and other crops.

Recombinase polymerase amplification integrated with microfluidics for nucleic acid testing at point of care.

Nucleic acid testing (NAT) implemented on a portable, miniaturized, and integrated device with rapid and sensitive results readout is highly demanded for pathogen detection or genetic screening at resource-limited settings, especially after the outbreak of coronavirus disease 2019 (COVID-19). The integration of recombinase polymerase amplification (RPA) with emerging microfluidics, classified by paper-based microfluidics and chip-based microfluidics, shows great potential to perform laboratory independent NAT assays at point of care with minimal labor, time and energy consumption. This review summarizes the state-of-the-art of RPA integrated with paper-based microfluidics and chip-based microfluidics, and discusses their pros and cons. Finally, existing challenges and possible ways for optimization of microfluidics-based RPA are proposed.