Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan; National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8634, Japan.
Insect Biochem Mol Biol. 2010 Nov;40(11):805-13. doi: 10.1016/j.ibmb.2010.07.008. Epub 2010 Aug 10.
The brown planthopper (BPH), Nilaparvata lugens, attacks rice plants and feeds on their phloem sap, which contains large amounts of sugars. The main sugar component of phloem sap is sucrose, a disaccharide composed of glucose and fructose. Sugars appear to be incorporated into the planthopper body by sugar transporters in the midgut. A total of 93 expressed sequence tags (ESTs) for putative sugar transporters were obtained from a BPH EST database, and 18 putative sugar transporter genes (Nlst1-18) were identified. The most abundantly expressed of these genes was Nlst1. This gene has previously been identified in the BPH as the glucose transporter gene NlHT1, which belongs to the major facilitator superfamily. Nlst1, 4, 6, 9, 12, 16, and 18 were highly expressed in the midgut, and Nlst2, 7, 8, 10, 15, 17, and 18 were highly expressed during the embryonic stages. Functional analyses were performed using Xenopus oocytes expressing NlST1 or 6. This showed that NlST6 is a facilitative glucose/fructose transporter that mediates sugar uptake from rice phloem sap in the BPH midgut in a manner similar to NlST1.
褐飞虱（BPH），Nilaparvata lugens，攻击水稻植株并以其韧皮部汁液为食，其中含有大量糖分。韧皮部汁液的主要糖分成分是蔗糖，一种由葡萄糖和果糖组成的二糖。糖分似乎通过中肠中的糖转运蛋白被转运到飞虱体内。从 BPH EST 数据库中获得了 93 个推定的糖转运蛋白的表达序列标签（EST），并鉴定了 18 个推定的糖转运蛋白基因（Nlst1-18）。这些基因中表达最丰富的是 Nlst1。该基因先前已在 BPH 中被鉴定为葡萄糖转运蛋白基因 NlHT1，属于主要易化因子超家族。Nlst1、4、6、9、12、16 和 18 在中肠中高度表达，而 Nlst2、7、8、10、15、17 和 18 在胚胎阶段高度表达。使用表达 NlST1 或 6 的非洲爪蟾卵母细胞进行功能分析。结果表明，NlST6 是一种促进型葡萄糖/果糖转运蛋白，可通过类似于 NlST1 的方式介导 BPH 中肠从水稻韧皮部汁液中摄取糖分。
