Xiao Yongxin, Hu Ciyin, Hsiang Tom, Li Junkai
Hubei Key Laboratory of Waterlogging Disaster and Agricultural Use of Wetland, College of Agriculture, Yangtze University, Jingzhou, China.
School of Environmental Sciences, University of Guelph, Guelph, ON, Canada.
Front Plant Sci. 2023 Jun 2;14:1191250. doi: 10.3389/fpls.2023.1191250. eCollection 2023.
Amino acid conjugates of pesticides can promote the phloem translocation of parent ingredients, allowing for the reduction of usage, and decreased environmental pollution. Plant transporters play important roles in the uptake and phloem translocation of such amino acid-pesticide conjugates such as L-Val-PCA (L-valine-phenazine-1-carboxylic acid conjugate). However, the effects of an amino acid permease, RcAAP1, on the uptake and phloem mobility of L-Val-PCA are still unclear. Here, the relative expression levels of were found to be up-regulated 2.7-fold and 2.2-fold by the qRT-PCR after L-Val-PCA treatments of cotyledons for 1 h and 3 h, respectively. Subsequently, expression of in yeast cells increased the L-Val-PCA uptake (0.36 μmol/10 cells), which was 2.1-fold higher than the control (0.17 μmol/10 cells). Pfam analysis suggested RcAAP1 with its 11 transmembrane domains belongs to the amino acid transporter family. Phylogenetic analysis found RcAAP1 to be strongly similar to AAP3 in nine other species. Subcellular localization showed that fusion RcAAP1-eGFP proteins were observed in the plasma membrane of mesophyll cells and phloem cells. Furthermore, overexpression of for 72 h significantly increased the phloem mobility of L-Val-PCA in seedlings, and phloem sap concentration of the conjugate was 1.8-fold higher than the control. Our study suggested that RcAAP1 as carrier was involved in the uptake and phloem translocation of L-Val-PCA, which could lay foundation for the utilization of amino acids and further development of vectorized agrochemicals.
农药的氨基酸共轭物可促进母体成分在韧皮部的转运，从而减少用量并降低环境污染。植物转运蛋白在这类氨基酸 - 农药共轭物（如L - 缬氨酸 - 吩嗪 - 1 - 羧酸共轭物）的吸收和韧皮部转运中发挥着重要作用。然而，氨基酸通透酶RcAAP1对L - 缬氨酸 - 吩嗪 - 1 - 羧酸共轭物吸收和韧皮部移动性的影响仍不清楚。在此，经qRT - PCR检测发现，用L - 缬氨酸 - 吩嗪 - 1 - 羧酸共轭物处理子叶1小时和3小时后，[具体基因名称]的相对表达水平分别上调了2.7倍和2.2倍。随后，[具体基因名称]在酵母细胞中的表达增加了L - 缬氨酸 - 吩嗪 - 1 - 羧酸共轭物的吸收（0.36 μmol/10个细胞），比对照（0.17 μmol/10个细胞）高2.1倍。Pfam分析表明，具有11个跨膜结构域的RcAAP1属于氨基酸转运蛋白家族。系统发育分析发现，RcAAP1与其他九个物种中的AAP3高度相似。亚细胞定位显示，融合的RcAAP1 - eGFP蛋白在叶肉细胞和韧皮部细胞的质膜中被观察到。此外，[具体基因名称]过表达72小时显著增加了L - 缬氨酸 - 吩嗪 - 1 - 羧酸共轭物在[具体植物名称]幼苗中的韧皮部移动性，共轭物的韧皮部汁液浓度比对照高1.8倍。我们的研究表明，RcAAP1作为载体参与了L - 缬氨酸 - 吩嗪 - 1 - 羧酸共轭物的吸收和韧皮部转运，这可为氨基酸的利用和载体化农用化学品的进一步开发奠定基础。
