Lu Ming-Xing, Pan Dan-Dan, Xu Jing, Liu Yang, Wang Gui-Rong, Du Yu-Zhou
College of Horticulture and Plant Protection and Institute of Applied Entomology, Yangzhou University, Yangzhou, China.
Jiangsu Key Laboratory of Crop Genetics and Physiology, Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, China.
Front Physiol. 2018 Feb 5;9:57. doi: 10.3389/fphys.2018.00057. eCollection 2018.
Aquaporins are integral membrane proteins some of which form high capacity water-selective channels, promoting water permeation across cell membranes. In this study, we isolated the aquaporin transcript (Drip1) of , one of the important rice pests. Drip1 included two variants, Drip1_v1 and Drip1_v2. Although Drip1_v2 sequence (>409 bp) was longer than Drip1_v1, they possessed the same open reading frame (ORF). Protein structure and topology of Drip1 was analyzed using a predicted model, and the results demonstrated the conserved properties of insect water-specific aquaporins, including 6 transmembrane domains, 2 NPA motifs, ar/R constriction region (Phe, His, Ser, and Arg) and the C-terminal peptide sequence ending in "SYDF." Our data revealed that the oocytes expressing Drip1 indicated Drip1 could transport water instead of glycerol, trehalose and urea. Further, the transcript of Drip1 expressed ubiquitously but differentially in different tissues or organs and developmental stages of Drip1 mRNA exhibited the highest level of expression within hindgut and the third instar larvae. Regardless of pupae and adults, there were significantly different expression levels of Drip1 gene between male and female. Different from at low temperature, the transcript of Drip1 in larvae exposed to high temperature was increased significantly. Moreover, the mRNA levels of Drip1 in the third instar larvae, the fifth instar larvae, pupae (male and female), and adults (male and female) under different humidities were investigated. However, the mRNA levels of Drip1 of only female and male adults were changed remarkably. In conclusions, Drip1 plays important roles in maintaining water homeostasis in this important rice pest.
水通道蛋白是整合膜蛋白，其中一些形成高容量的水选择性通道，促进水透过细胞膜。在本研究中，我们分离了重要水稻害虫之一的灰飞虱的水通道蛋白转录本（Drip1）。Drip1包括两个变体，Drip1_v1和Drip1_v2。虽然Drip1_v2序列（>409 bp）比Drip1_v1长，但它们具有相同的开放阅读框（ORF）。使用预测模型分析了Drip1的蛋白质结构和拓扑结构，结果表明昆虫水特异性水通道蛋白具有保守特性，包括6个跨膜结构域、2个NPA基序、ar/R收缩区（苯丙氨酸、组氨酸、丝氨酸和精氨酸）以及以“SYDF”结尾的C末端肽序列。我们的数据显示，表达Drip1的卵母细胞表明Drip1可以运输水，而不是甘油、海藻糖和尿素。此外，Drip1的转录本在不同组织或器官以及发育阶段普遍但差异表达，Drip1 mRNA在中肠和三龄幼虫中表达水平最高。无论蛹期和成虫期，Drip1基因在雌雄之间的表达水平都存在显著差异。与低温时不同，暴露于高温下的幼虫中Drip1的转录本显著增加。此外，研究了不同湿度条件下三龄幼虫、五龄幼虫、蛹（雌雄）和成虫（雌雄）中Drip1的mRNA水平。然而，只有雌雄成虫中Drip1的mRNA水平发生了显著变化。总之，Drip1在这种重要水稻害虫维持水平衡中发挥着重要作用。
