https://www.selleckchem.com/products/ABT-888.html Chloroplast function requires the coordinated action of nuclear- and chloroplast-derived proteins, including several hundred nuclear-encoded pentatricopeptide repeat (PPR) proteins that regulate plastid mRNA metabolism. Despite their large number and importance, regulatory mechanisms controlling PPR expression are poorly understood. Here we show that the Arabidopsis NOT4A ubiquitin-ligase positively regulates the expression of PROTON GRADIENT REGULATION 3 (PGR3), a PPR protein required for translating several thylakoid-localised photosynthetic components and ribosome subunits within chloroplasts. Loss of NOT4A function leads to a strong depletion of cytochrome b6f and NAD(P)H dehydrogenase (NDH) complexes, as well as plastid 30 S ribosomes, which reduces mRNA translation and photosynthetic capacity, causing pale-yellow and slow-growth phenotypes. Quantitative transcriptome and proteome analysis of the not4a mutant reveal it lacks PGR3 expression, and that its molecular defects resemble those of a pgr3 mutant. Furthermore, we show that normal plastid function is restored to not4a through transgenic PGR3 expression. Our work identifies NOT4A as crucial for ensuring robust photosynthetic function during development and stress-response, through promoting PGR3 production and chloroplast translation.There is a great need to develop heterostructured nanocrystals which combine two or more different materials into single nanoparticles with combined advantages. Lead halide perovskite quantum dots (QDs) have attracted much attention due to their excellent optical properties but their biological applications have not been much explored due to their poor stability and short penetration depth of the UV excitation light in tissues. Combining perovskite QDs with upconversion nanoparticles (UCNP) to form hybrid nanocrystals that are stable, NIR excitable and emission tunable is important, however, this is challenging because hexagona