Abstract：
Amino acids are necessary nutrients for the growth of Oryza sativa (rice), which can be mediated by amino acid transporter; however, our understanding of these transporters is still limited. This study found that the expression levels of amino acid permease gene OsAAP12 differed between indica and japonica rice. Altered expression of OsAAP12 negatively regulated tillering and yield in transgenic rice lines. Subcellular localization revealed that OsAAP12 was primarily localized to the plasma membrane. Moreover, it was indicated that OsAAP12 transported polar neutral amino acids asparagine (Asn), threonine (Thr), and serine (Ser) through experiments involving yeast heterologous complementation, fluorescence amino acid uptake, and amino acid content determination. Additionally, exogenous application of amino acids Asn, Thr, and Ser suppressed axillary buds outgrowth in OsAAP12 overexpression lines compared with wild-type ZH11. Conversely, the opposite trend was observed in CRISPR mutant lines. RNA-seq analysis showed that the expression patterns of genes involved in the nitrogen and cytokinin pathways were generally altered in OsAAP12 modified lines. Hormone assays indicated that OsAAP12 mutant lines accumulated cytokinins in the basal part of rice, whereas overexpression lines had the opposite effect. In summary, CRISPR mutant of OsAAP12 boosted rice tillering and grain yield by coordinating the content of amino acids and cytokinins, which has potential application value in high-yield rice breeding.
摘要：
氨基酸是水稻生长所必需的营养物质,它可以由氨基酸转运蛋白介导；然而，我们对这些运输机的了解仍然有限。本研究发现氨基酸通透酶基因OsAAP12的表达水平在in稻和粳稻之间存在差异。OsAAP12的表达改变对转基因水稻的分till和产量产生负调控作用。亚细胞定位显示OsAAP12主要定位于质膜。此外，表明OsAAP12转运极性中性氨基酸天冬酰胺（Asn），苏氨酸(Thr),和丝氨酸（Ser）通过涉及酵母异源互补的实验，荧光氨基酸吸收，和氨基酸含量测定。此外,外源施用氨基酸Asn,Thr,与野生型ZH11相比，Ser抑制了OsAAP12过表达系的腋芽生长。相反，在CRISPR突变系中观察到相反的趋势。RNA-seq分析表明，在OsAAP12修饰品系中，参与氮和细胞分裂素途径的基因的表达模式通常会发生变化。激素分析表明，OsAAP12突变品系在水稻的基部积累了细胞分裂素，而过表达系具有相反的作用。总之,通过协调氨基酸和细胞分裂素的含量，OsAAP12的CRISPR突变体提高了水稻分ill和籽粒产量。在水稻高产育种中具有潜在的应用价值。
