Rice OsGATA16 is a positive regulator for chlorophyll biosynthesis and
Chloroplasts are essential organelles in plants that contain
chlorophylls and facilitate photosynthesis for growth and development.
As photosynthetic efficiency significantly impacts crop productivity,
understanding the regulatory mechanisms of chloroplast development has
been crucial in increasing grain and biomass production. This study
demonstrates the involvement of OsGATA16, an ortholog of
Arabidopsis GATA, NITRATE INDUCIBLE, CARBON-METABOLISM INVOLVED (
GNC), and GNC-LIKE/CYTOKININ-RESPONSIVE GATA FACTOR 1 (
GNL/CGA1), in chlorophyll biosynthesis and chloroplast
development in rice ( Oryza sativa). The osgata16-1
knockdown mutants produced pale-green leaves, while
OsGATA16-overexpressed plants ( OsGATA16-OE1) generated
dark-green leaves, compared to their parental japonica rice.
Reverse transcription and quantitative PCR analysis revealed
downregulation of genes related to chloroplast division, chlorophyll
biosynthesis, and photosynthesis in the leaves of osgata16-1 and
upregulation in those of OsGATA16-OE1. Additionally, in
vivo binding assays showed that OsGATA16 directly binds to the promoter
regions of OsHEMA, OsCHLH, OsPORA, OsPORB,
and OsFtsZ, and upregulates their expression. These findings
indicate that OsGATA16 serves as a positive regulator controlling
chlorophyll biosynthesis and chloroplast development in rice.