Zirconium-Based Metal-Organic Framework for Efficient Photocatalytic Reduction of CO2 to CO: The Influence of Doped Metal Ions.

Recent developments have been highlighted for UiO-type materials, a class of metal-organic frameworks (MOFs) with high stability, as catalysts for photocatalytic CO2 reduction. We design and synthesize two metal ion (Co2+, Re+)-doped UiO-67 as catalysts for the photocatalytic CO2 reduction reaction and demonstrate that Co-UiO-67 exhibits better photocatalytic activity relative to Re-UiO-67. The superior photocatalytic activity of Co-UiO-67 over Re-UiO-67 results from the improved charge transportability and higher CO2 adsorption capacity. Density functional theory (DFT) calculations reveal that the energy barrier of Co-UiO-67 (0.86 eV) for catalytic CO2 reduction to CO is lower than that of Re-UiO-67 (0.92 eV), thus leading to superior photocatalytic performance of Co-UiO-67 than that of Re-UiO-67.

Interactions between soybean ABA receptors and type 2C protein phosphatases.

The plant hormone abscisic acid (ABA) plays important roles in regulating plant growth, development, and responses to environmental stresses. Proteins in the PYR/PYL/RCAR family (hereafter referred to as PYLs) are known as ABA receptors. Since most studies thus far have focused on Arabidopsis PYLs, little is known about PYL homologs in crop plants. We report here the characterization of 21 PYL homologs (GmPYLs) in soybean. Twenty-three putative GmPYLs can be found from soybean genome sequence and categorized into three subgroups. GmPYLs interact with AtABI1 and two GmPP2Cs in diverse manners. A lot of the subgroup I GmPYLs interact with PP2Cs in an ABA-dependent manner, whereas most of the subgroup II and III GmPYLs bind to PP2Cs in an ABA-independent manner. The subgroup III GmPYL23, which cannot interact with any of the tested PP2Cs, differs from other GmPYLs. The CL2/gate domain is crucial for GmPYLs-PP2Cs interaction, and a mutation in the conserved proline (P109S) abolishes the interaction between GmPYL1 and AtABI1. Furthermore, the ABA dependence of GmPYLs-PP2Cs interactions are partially correlated with two amino acid residues preceding the CL2/gate domain of GmPYLs. We also show that GmPYL1 interacts with AtABI1 in an ABA-dependent manner in plant cells. Three GmPYLs differentially inhibit AtABI1 and GmPP2C1 in an ABA-dependent or -enhanced manner in vitro. In addition, ectopically expressing GmPYL1 partially restores ABA sensitivity of the Arabidopsis triple mutant pyr1/pyl1/pyl4. Taken together, our results suggest that soybean GmPYLs are ABA receptors that function by interacting and inhibiting PP2Cs.