水稻蛋白酶抑制剂基因OsLTPL164和OsLTPL151的组成型及诱导型表达模式

【目的】蛋白酶抑制剂（protease inhibitor, PI）是一类广泛存在于植物中的蛋白质,具有抵御植食性昆虫取食危害的功能。然而,水稻（Oryza sativa）PI基因在二化螟（Chilo suppressalis）取食过程中的表达模式尚不清楚。本研究旨在分析水稻蛋白酶抑制剂基因OsLTPL164和OsLTPL151在二化螟取食及机械损伤下的表达模式,为明确OsLTPL164和OsLTPL151在水稻防御二化螟中的作用及今后利用这两个基因构建转基因水稻株系打下基础。【方法】以东北地区常规种植的3个水稻品系辽盐2号（1654）、辽星17号（1665）和长白17号（1688）为研究对象,在二化螟危害关键时期（分蘖期）通过机械损伤和接虫处理,在处理后不同时间（0、3、6、12、24、48、72 h）分别对根、茎、叶3个组织进行取样,利用实时荧光定量PCR（RT-qPCR）检测3个水稻品系中OsLTPL164和OsLTPL151的表达模式。【结果】OsLTPL164在3个品系中的组织表达模式一致,在叶片和茎中的表达量均高于根部;OsLTPL151在3个品系中的组织表达模式不一致,在1654品系中茎和叶片中的表达量显著高于根部,但在1688和1665品系中根部的表达量显著高于茎和叶片;此外,这两个基因在3个品系间的相同组织中都有不同的表达模式,OsLTPL164在根、茎、叶中均呈现在1665品系中表达量最高、在1688品系中表达量次之、在1654品系中表达量最低的表达模式,但OsLTPL151在不同组织中的表达模式与OsLTPL164不同：在根中,OsLTPL151在1665品系中的表达量明显高于1688和1654品系;在茎中,OsLTPL151在1654和1665品系中的表达量明显高于1688品系;在叶中,OsLTPL151在1654品系中的表达量明显高于1665和1688品系。二化螟取食诱导OsLTPL164和OsLTPL151在3个品系的叶片中表达上调幅度高于茎和根,且在1665品系中上调的幅度较1688和1654品系中大。在二化螟取食和机械损伤处理不同时间后,两个基因均呈现表达水平先上升后下降再上升的趋势;OsLTPL164和OsLTPL151在机械损伤6 h后才被显著诱导表达,而二化螟取食3 h后便可诱导OsLTPL164和OsLTPL151上调表达。【结论】OsLTPL164和OsLTPL151在3个水稻品系中二化螟取食以及机械损伤均能诱导其表达,推测这两个基因可能与水稻抗二化螟有关,但这两个基因在不同水稻品系中其他具体的功能可能有所不同。     

Molecular characterization of two acetylcholinesterase genes from the brown planthopper, Nilaparvata lugens (Hemiptera: Delphacidae)

Acetylcholinesterase (AChE), which is encoded by the ace gene, catalyzes the hydrolysis of the neurotransmitter acetylcholine to terminate nerve impulses at the postsynaptic membrane. AChE is a primary target of many insecticides including organophosphates (OP) and carbamates (CB). In this study, full-length cDNA sequences of two ace genes (Nlace1 and Nlace2) were sequenced from the brown planthopper (BPH) Nilaparvata lugens, the most destructive insect pest of rice crops. Nlace1 cDNA is 2842 nucleotides long and contains an ORF potentially encoding a 790 amino acid peptide. Nlace2 cDNA is 2852 bp in length and contains an ORF that potentially encodes a 672 amino acid peptide. NlAChE1 has an identity of 40% with NlAChE2 at the amino acid sequence level. Phylogenetic analysis of 59 AChEs from 32 animal species showed that NlAChE1 is most closely related to AChE1s from Blattella germanica and Nephotettix cincticeps, while NlAChE2 is most closely related to AChE2 from N. cincticeps. Quantitative RT-PCR analysis showed that Nlace1 is expressed at a much higher level than Nlace2 in all developmental stages and tissues, demonstrating that NlAChE1 may be the dominant AChE form of the two enzymes. This result will help reveal the resistance mechanism of N. lugens to organophosphorous and carbamate insecticides and promote development of more selective insecticides targeting the main NlAChE1.     

苹果蠹蛾对高效氯氟氰菊酯的抗性现状、机制及治理策略

苹果蠹蛾Cydia pomonella属鳞翅目卷蛾科,是全球仁果类水果种植地区最重要的果树害虫之一,也是我国重大农业入侵物种,对全球水果生产造成严重威胁。当前主要采用高效氯氟氯氰菊酯等杀虫剂对苹果蠹蛾进行防治,杀虫剂的频繁使用导致其对高效氯氟氰菊酯产生了抗性。针对苹果蠹蛾对高效氯氟氰菊酯的抗性问题,该文综述了全球苹果蠹蛾种群对高效氯氟氰菊酯的抗性现状,指出由编码细胞色素P450（cytochrome P450,P450）、羧酸酯酶（carboxylesterase,CarE）和谷胱甘肽S-转移酶（glutathione S-transferase,GST）的解毒酶基因过表达导致代谢能力增强是其最普遍的抗性机制,提出合理的抗性治理策略,并对苹果蠹蛾的绿色防控进行展望。     

Influence of phosphorus and potassium fertilization on damage to alfalfa,Medicago sativa L., by the alfalfa weevil,Hypera postica (Gyllenhall) and potato leafhopper,Empoasca fabae (Harris)

In a field study, the effects of phosphorus and potassium fertilization on damage caused by the potato leafhopper, Empoasca fabae (Harris), and alfalfa weevil, Hypera postica (Gyllenhall), to alfalfa, Medicago sativa L., were studied. Potato leafhopper and alfalfa weevil populations were either controlled with insecticides or allowed to develop as untreated controls. Insect management treatments were applied to alfalfa managed under high and low soil fertility regimes. Alfalfa grown under high soil fertility appeared more favourable for alfalfa weevil populations but was able to tolerate more defoliation. Populations of alfalfa weevil larvae were 34% higher on fertilized stands. On the other hand, potato leafhopper populations were as much as 43% higher on low-fertility stands. Alfalfa weevil damage caused a carry-over effect which reduced both plant height and yield of the second cutting. Fertilization negated this effect on height but not on yield. Stands damaged by potato leafhopper recovered more slowly after harvest, but fertilization reduced this effect. Yields from first-cutting alfalfa (which is not infested by the potato leafhopper) the following year were 10% greater on fertilized stands where leafhopper control had been applied the previous season. Plots infested by potato leafhopper suffered greater yield losses under low-fertility management. Leafhopper control and fertilization, alone and in combination with one another, negated these effects.