The Amino Acid Transporter OsAAP4 Contributes to Rice Tillering and Grain Yield by Regulating Neutral Amino Acid Allocation through Two Splicing Variants

Abstract Background Amino acids, which are transported by amino acid transporters, the major forms of organic nitrogen utilized higher plants. Among 19 Acid Permease transporters (AAPs) in rice, only a small number these genes have been reported to influence rice growth and development. However, whether other OsAAPs responsible for development is unclear. Results In this study, we demonstrate that OsAAP4 promoter sequences divergent between Indica Japonica , with expression former, produces more tillers grain yield than does . Overexpression two different splicing variants ZH11 significantly increased tillering as result enhancing neutral concentrations Val, Pro, Thr Leu. RNA interference (RNAi) mutant lines displayed opposite trends compared overexpresing (OE) lines. addition, exogenous Val or Pro at 0.5 mM promoted bud outgrowth overexpressing an OsAAP4a variant ZH11, 2.0 enhanced OsAAP4b ZH11. Of note, results protoplast acid-uptake assay showed was specifically accumulated Transcriptome analysis further demonstrated may affect transport metabolism, auxin, cytokinin signaling regulating tillering. Conclusion Our suggested contributes tiller allocation through might potential applications breeding.