细胞黏附蛋白NlPER1影响褐飞虱的存活与繁殖

The peroxinectin NlPER1 influences the survival and fecundity of the rice brown planthopper Nilaparvata lugens(St?l)

为明确褐飞虱Nilaparvata lugens(St?l)细胞黏附蛋白(peroxinectin 1,NlPER1)在调控褐飞虱生长、发育及繁殖中的作用及其机理,通过克隆NlPER1基因的cDNA全长,分析NlPER1在褐飞虱不同组织和龄期中的表达谱,同时利用RNA干扰技术探究其生物学功能。结果显示,NlPER1包含1个1 560 bp的开放阅读框(open reading frame,ORF),编码519个氨基酸;预测该基因编码的蛋白分子量为58.9 kD,等电点为5.61,无分泌信号肽和跨膜区,具有亚铁血红素结合位点和Ca^(2+)结合位点。该基因在褐飞虱头部组织中的相对表达量最高,并显著高于其它组织;在5龄若虫和初羽化成虫中的相对表达量显著高于其它龄期;其转录水平不受球孢白僵菌Beauveria bassiana侵染的影响。沉默NlPER1不影响褐飞虱若虫体内的H_2O_2含量,但会导致褐飞虱若虫存活率、雌成虫蜜露分泌量及产卵量显著下降,分别只有dsGFP对照组的52.94%、69.86%和69.00%。表明NlPER1在褐飞虱生长发育、存活与繁殖中发挥着重要作用,但这些作用与清除褐飞虱体内的H_2O_2无关。

To understand the role of NlPER1, a peroxinectin gene in the brown planthopper（BPH）Nilaparvata lugens, in regulating the growth, development and reproduction of BPH and its underlying mechanisms, the full length cDNA sequence of NlPER1 was cloned, and its expression patterns in different developmental stages and tissues of BPH were analyzed. Moreover, by using RNA interference technique, the biological function of NlPER1 was explored. The results showed that NlPER1 contained a1 560 bp opening reading frame（ORF） which encodes a protein with 519 amino acids and with a predicted molecular weight of 58.9 kD and a theoretical pI of 5.61. Sequence analysis indicated that this protein had several heme binding sites and Ca^（2＋）binding sites, but had no signal peptide and transmembrance domain. Transcriptional analysis revealed that the mRNA level of NlPER1 was significantly higher in the head of BPH and newly emerged adults than those of other tissues and developmental ages. Infection by Beauveria bassiana couldn＇t induce the expression of NlPER1. Silencing of NlPER1 couldn＇t affect the level of H_2O_2 in BPH nymphs, but did significantly decrease the survival rate of BPH nymphs, the amount of honeydew excreted by BPH female adult and the number of eggs laid by BPH female adults： they were only 52.94%, 69.86% and 69.00% of those from control BPH（injected with dsGFP）, respectively. The results indicated that NlPER1 played an important role in the growth,development and reproduction of BPH, but this role was not related to the removal of H_2O_2 from BPH.