College of Agriculture, Shanxi Agricultural University, Jinzhong 030801, China.
State Key Laboratory of Sustainable Dryland Agriculture (in Preparation), Shanxi Agricultural University, Jinzhong 030801, China.
Int J Mol Sci. 2024 May 27;25(11):5840. doi: 10.3390/ijms25115840.
Amino acid permeases (AAPs) transporters are crucial for the long-distance transport of amino acids in plants, from source to sink. While and rice have been extensively studied, research on foxtail millet is limited. This study identified two transcripts of , both of which were induced by NO and showed similar expression patterns. The overexpression of and in inhibited plant growth and seed size, although SiAAP9 was found to transport more amino acids into seeds. Furthermore, transgenic showed increased tolerance to high concentrations of glutamate (Glu) and histidine (His). The high overexpression level of suggested its protein was not only located on the plasma membrane but potentially on other organelles, as well. Interestingly, sequence deletion reduced SiAAP9's sensitivity to Brefeldin A (BFA), and SiAAP9 had ectopic localization on the endoplasmic reticulum (ER). Protoplast amino acid uptake experiments indicated that SiAAP9 enhanced Glu transport into foxtail millet cells. Overall, the two transcripts of have similar functions, but SiAAP9L shows a higher colocalization with BFA compartments compared to SiAAP9S. Our research identifies a potential candidate gene for enhancing the nutritional quality of foxtail millet through breeding.
氨基酸通透酶（AAPs）转运蛋白对于植物中氨基酸的长距离运输至关重要，从源到汇。尽管 和 已经被广泛研究，但对 的研究有限。本研究鉴定了 的两个转录本，它们都被 NO 诱导，表现出相似的表达模式。在 中过表达 和 抑制了植物生长和种子大小，尽管发现 SiAAP9 将更多的氨基酸运输到种子中。此外， 转基因 对高浓度谷氨酸（Glu）和组氨酸（His）表现出更高的耐受性。 的高过表达水平表明其蛋白不仅位于质膜上，还可能位于其他细胞器上。有趣的是，序列缺失降低了 SiAAP9 对布雷菲德菌素 A（BFA）的敏感性，并且 SiAAP9 在 ER 上发生异位定位。原生质体氨基酸摄取实验表明，SiAAP9 增强了 Glu 向谷子细胞的转运。总的来说， 的两个转录本具有相似的功能，但 SiAAP9L 与 BFA 隔室的共定位比 SiAAP9S 更高。我们的研究确定了一个通过育种提高谷子营养品质的潜在候选基因。
