Ge Lin-Quan, Jiang Yi-Ping, Xia Ting, Song Qi-Sheng, Stanley David, Kuai Peng, Lu Xiu-Li, Yang Guo-Qing, Wu Jin-Cai
School of Plant Protection Yangzhou University, Yangzhou 225009, P.R. China.
Division of Plant Sciences, University of Missouri, 1-31 Agriculture Building, Columbia, MO 65211, USA.
Sci Rep. 2015 Jul 17;5:12194. doi: 10.1038/srep12194.
The brown planthopper (BPH), Nilaparvata lugens, sugar transporter gene 6 (Nlst6) is a facilitative glucose/fructose transporter (often called a passive carrier) expressed in midgut that mediates sugar transport from the midgut lumen to hemolymph. The influence of down regulating expression of sugar transporter genes on insect growth, development, and fecundity is unknown. Nonetheless, it is reasonable to suspect that transporter-mediated uptake of dietary sugar is essential to the biology of phloem-feeding insects. Based on this reasoning, we posed the hypothesis that silencing, or reducing expression, of a BPH sugar transporter gene would be deleterious to the insects. To test our hypothesis, we examined the effects of Nlst6 knockdown on BPH biology. Reducing expression of Nlst6 led to profound effects on BPHs. It significantly prolonged the pre-oviposition period, shortened the oviposition period, decreased the number of eggs deposited and reduced body weight, compared to controls. Nlst6 knockdown also significantly decreased fat body and ovarian (particularly vitellogenin) protein content as well as vitellogenin gene expression. Experimental BPHs accumulated less fat body glucose compared to controls. We infer that Nlst6 acts in BPH growth and fecundity, and has potential as a novel target gene for control of phloem-feeding pest insects.
褐飞虱（Nilaparvata lugens）的糖转运蛋白基因6（Nlst6）是一种易化型葡萄糖/果糖转运蛋白（通常称为被动载体），在中肠中表达，介导糖分从中肠腔向血淋巴的转运。下调糖转运蛋白基因的表达对昆虫生长、发育和繁殖力的影响尚不清楚。然而，有理由怀疑转运蛋白介导的膳食糖分摄取对吸食韧皮部汁液昆虫的生物学特性至关重要。基于这一推理，我们提出了一个假设，即沉默或降低褐飞虱糖转运蛋白基因的表达会对昆虫有害。为了验证我们的假设，我们研究了敲低Nlst6对褐飞虱生物学特性的影响。与对照组相比，降低Nlst6的表达对褐飞虱产生了深远影响。它显著延长了产卵前期，缩短了产卵期，减少了产卵数量并降低了体重。敲低Nlst6还显著降低了脂肪体和卵巢（特别是卵黄原蛋白）的蛋白质含量以及卵黄原蛋白基因的表达。与对照组相比，实验褐飞虱脂肪体中的葡萄糖积累较少。我们推断Nlst6在褐飞虱的生长和繁殖中起作用，并且有潜力作为控制吸食韧皮部汁液害虫的新型靶标基因。
