ABSTRACT
Hydrogen (H2), a regenerable and promising energy carrier, acts as an essential role in the construction of a sustainable energy system. Formic acid (HCOOH, FA), a natural biological metabolic products and also accessible through carbon dioxide (CO2) reduction, has a great potential to serve as a prospective H2 supplier for the fuel cell. Herein, ultrafine and electron-rich IrPdAu alloy nanoparticles with a size of 1.4 nm are highly dispersed on amine-modified mesoporous SiO2 (NH2-SBA-15) and used as a highly active and selective catalyst for fast H2 production from FA. The as-synthesized IrPdAu/NH2-SBA-15 possesses superior catalytic activity and 100% H2 selectivity with initial turnover frequency values of 6316 h-1 with the additive of sodium formate (SF) and 4737 h-1 even without SF at 298 K, comparable to the most effective heterogeneous catalysts ever published. The excellent performance of IrPdAu/NH2-SBA-15 was not only ascribed to the combination of the electronic synergistic effect of trimetallic alloys and the strong metal-support interaction effect but also attributed to the amine (-NH2) alkaline groups grafted on SBA-15, which is beneficial to boost the split of the O-H bond of FA.
ABSTRACT
Chloroplast genes are transcribed by the plastid-encoded RNA polymerase (PEP) or nucleus-encoded RNA polymerase. FRUCTOKINASE-LIKE PROTEINS (FLNs) are phosphofructokinase-B (PfkB)-type carbohydrate kinases that act as part of the PEP complex; however, the molecular mechanisms underlying FLN activity in rice remain elusive. Previously, we identified and characterized a heat-stress sensitive albino (hsa1) mutant in rice. Map-based cloning revealed that HSA1 encodes a putative OsFLN2. Here, we further demonstrated that knockdown or knockout of the OsFLN1, a close homolog of HSA1/OsFLN2, considerably inhibits chloroplast biogenesis and the fln1 knockout mutants, created by clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associate protein 9, exhibit severe albino phenotype and seedling lethality. Moreover, OsFLN1 localizes to the chloroplast. Yeast two-hybrid, pull-down and bimolecular fluorescence complementation experiments revealed that OsFLN1 and HSA1/OsFLN2 interact with THIOREDOXINZ (OsTRXz) to regulate chloroplast development. In agreement with this, knockout of OsTRXz resulted in a similar albino and seedling lethality phenotype to that of the fln1 mutants. Quantitative reverse transcription polymerase chain reaction and immunoblot analysis revealed that the transcription and translation of PEP-dependent genes were strongly inhibited in fln1 and trxz mutants, indicating that loss of OsFLN1, HSA1/OsFLN2, or OsTRXz function perturbs the stability of the transcriptionally active chromosome complex and PEP activity. These results show that OsFLN1 and HSA1/OsFLN2 contribute to chloroplast biogenesis and plant growth.
