regulates ATP homeostasis in plastid to sustain lipid metabolism and plant growth in .

UNLABELLED

The plastid inner envelope membrane-bond nucleotide triphosphate transporter (NTT) transports cytosolic adenosine triphosphate (ATP) into plastid, which is necessary for the biochemical activities in plastid. We identified a chloroplast-localized BnaC08.NTT2 and obtained the overexpressed lines of and CRISPR/Cas9 edited double mutant lines of and in . Further studies certified that overexpression (OE) of could help transport ATP into chloroplast and exchange adenosine diphosphate (ADP) and this process was inhibited in mutants. Additional results showed that the thylakoid was abnormal in double mutants, which also had lower photosynthetic efficiency, leading to retarded plant growth. The OE plants had higher photosynthetic efficiency and better growth compared to WT. OE of could improve carbon flowing into protein and oil synthesis from glycolysis both in leaves and seeds. Lipid profile analysis showed that the contents of main chloroplast membrane lipids, including monogalactosyldiacylglycerol (MGDG), digalactosyldiacylglycerol (DGDG), and phosphatidylglycerol (PG), were significantly reduced in mutants, while there were no differences in OE lines compared to WT. These results suggest that BnaNTT2 is involved in the regulation of ATP/ADP homeostasis in plastid to impact plant growth and seed oil accumulation in .

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s11032-022-01322-8.