Small brown planthopper resistance loci in wild rice (Oryza officinalis)

Host-plant resistance is the most practical and economical approach to control the rice planthoppers. However, up to date, few rice germplasm accessions that are resistant to the all three kinds of planthoppers (1) brown planthopper (BPH; Nilaparvata lugens Stål), (2) the small brown planthopper (SBPH; Laodelphax striatellus Fallen), and (3) the whitebacked planthopper (WBPH, Sogatella furcifera Horvath) have been identified; consequently, the genetic basis for host-plant broad spectrum resistance to rice planthoppers in a single variety has been seldom studied. Here, one wild species, Oryza officinalis (Acc. HY018, 2n = 24, CC), was detected showing resistance to the all three kinds of planthoppers. Because resistance to WBPH and BPH in O. officinalis has previously been reported, the study mainly focused on its SBPH resistance. The SBPH resistance gene(s) was (were) introduced into cultivated rice via asymmetric somatic hybridization. Three QTLs for SBPH resistance detected by the SSST method were mapped and confirmed on chromosomes 3, 7, and 12, respectively. The allelic/non-allelic relationship and relative map positions of the three kinds of planthopper resistance genes in O. officinalis show that the SBPH, WBPH, and BPH resistance genes in O. officinalis were governed by multiple genes, but not by any major gene. The data on the genetics of host-plant broad spectrum resistance to planthoppers in a single accession suggested that the most ideally practical and economical approach for rice breeders is to screen the sources of broad spectrum resistance to planthoppers, but not to employ broad spectrum resistance gene for the management of planthoppers. Pyramiding these genes in a variety can be an effective way for the management of planthoppers.     

Genetic and biochemical mechanisms of rice resistance to planthopper

Key message

This article presents a comprehensive review on the genetic and biochemicalmechanisms governing rice-planthopper interactions, aiming to contribute substantialplanthopper control and facilitate breeding for resistance to planthoppers in rice.

Abstract

The rice planthopper is the most destructive pest of rice and a substantial threat to rice production. The brown planthopper (BPH), white-backed planthopper (WBPH) and small brown planthopper (SBPH) are three species of delphacid planthoppers and important piercing-sucking pests of rice. Host-plant resistance has been recognized as the most practical, economical and environmentally friendly strategy to control planthoppers. Until now, at least 30, 14 and 34 major genes/quantitative trait loci for resistance to BPH, WBPH and SBPH have been identified, respectively. Recent inheritance and molecular mapping of gene analysis showed that some planthopper-resistance genes in rice derived from different donors aggregate in clusters, while resistance to these three species of planthoppers in a single donor is governed not by any one dominant gene but by multiple genes. Notably, Bph14, Bph26, Bph3 and Bph29 were successfully identified as BPH-resistance genes in rice. Biological and chemical studies on the feeding of planthoppers indicate that rice plants have acquired various forms of defence against planthoppers. Between the rice-planthopper interactions, rice plants defend against planthoppers through activation the salicylic acid-dependent systemic acquired resistance but not jasmonate-dependent hormone response pathways. Transgenic rice for the planthopper-resistance mechanism shows that jasmonate and its metabolites function diversely in rice’s resistance to planthopper. Understanding the genetic and biochemical mechanisms underlying resistance in rice will contribute to the substantial control of such pests and facilitate breeding for rice’s resistance to planthopper more efficiently.

     

The complete mitochondrial genome sequence of Sogatella furcifera (Horváth) and a comparative mitogenomic analysis of three predominant rice planthoppers

The white-backed planthopper (WBPH), Sogatella furcifera (Horváth), is one of the most destructive pests of rice crops in many Asian countries. Using long-PCR and shotgun library methods, we sequenced the entire mitochondrial genomes (mt-genomes) of two WBPH individuals. Total lengths of the mt-genome of the two WBPH individuals were 16,612 bp and 16,654 bp with an identical AT content of 76.19%. Among the 13 protein coding genes (PCGs), only nad5 used an atypical initiation codon GTG. Most of the tRNA genes had the typical cloverleaf secondary structure except that the dihydrouridine (DHU) arms in two trnS genes and the TΨC arm of trnG gene did not form a stable stem-loop structure. Similar to the brown planthopper (BPH), Nilaparvata lugens (Stål), and the small brown planthopper (SBPH), Laodelphax striatellus (Fallén), some extraordinary features were observed in the WBPH mt-genome. These include similar gene rearrangement pattern, unusually short length of the atp8 gene and variable numbers of tandem repeat (VNTR) structure in control region. Interestingly, the same tandem repeat unit with stable secondary structure appeared in two different planthoppers, WBPH and SBPH, which belong to two different genera of the Delphacidae. This peculiar feature provides a direct evidence for the close relationship between the two planthoppers and updates our understanding of the evolutionary characteristics of mitochondrial control region. Comparison with two other predominant rice planthoppers (BPH and SBPH) revealed that different PCGs of mitochondria exhibit different evolutionary patterns.     

稻飞虱迁飞种群的上灯行为节律研究

【目的】明确稻飞虱迁飞种群的上灯行为节律,以指导其大田迁入种群和迁出种群的发生预测与灾变预警。【方法】本研究运用逐时自动灯诱装置对2010和2011连续两年稻飞虱迁飞种群的上灯行为节律进行了系统研究。【结果】灰飞虱Laodelphax striatellus迁飞种群上灯始见期和灯诱虫量年际间差异不明显,白背飞虱Sogatella furcifera和褐飞虱Nilaparvata lugens迁飞过境种群上灯始见期和灯诱虫量年际间差异较大。此外,灰飞虱迁飞种群的特大高峰期和高峰期逐时灯诱虫量百分比与一般上灯期和零星上灯期相比突出了晨暮双峰型中的暮峰型上灯行为特点;白背飞虱迁飞种群特大高峰期逐时灯诱虫量百分比与高峰期和一般期相比突出了晨暮双峰型中的晨峰型生物学特性。【结论】稻飞虱迁飞种群的上灯行为节律存在种的特异性,这一行为节律除了受环境因素的影响外主要与其生物学特性有关。     

稻飞虱翅型纯系后代个体的翅型分化对光周期变化不敏感

【目的】为了明确光周期和遗传因子在稻飞虱翅型分化中的作用, 研究了3种稻飞虱（褐飞虱Nilaparvata lugens、白背飞虱Sogatella furcifera和灰飞虱Laodelphax striatellus）翅型纯系或近纯系在不同光照时数下的翅型分化比率。【方法】以经过5~45代连续翅型筛选后的褐飞虱、白背飞虱和灰飞虱的长翅型和短翅型纯系或近纯系为材料, 在室内分别测定了其在长光照（16和20 h）、短光照(4~12 h)和正常光照(14 h) 3类光周期条件下饲养后, 雌、雄成虫中长翅和短翅个体出现的比率及存活率。【结果】白背飞虱和灰飞虱的长翅型纯系M♂×M♀或短翅型纯系B♂×B♀在不同光周期下的翅型比率均无显著差异（P>0.05）。褐飞虱短翅型近纯系B♂×B♀的雌虫短翅率和成虫总短翅率在不同光周期下也无显著差异（P>0.05）, 但雄虫短翅率在正常光照14 h和短光照4 h下显著高于长光照20 h下的（P<0.05）。当褐飞虱短翅型达到纯系后, 其后代翅型在6~16 h光照条件下无显著差异。褐飞虱长翅型近纯系M♂×M♀的后代虽有短翅个体出现, 但是雌虫和雄虫的各自短翅率在不同光周期下无显著差异（P>0.05), 仅总体短翅率在12 h光照条件下的显著高于16 h下的（P<0.05）。褐飞虱长、短翅型杂交筛选品系M♂×B♀的雌虫短翅率随光照时数的延长而升高; 灰飞虱杂交筛选品系M♂×B♀的短翅雄虫随光照时数的缩短而增多（P<0.05）, 但当筛选代次达到45代时, 这种趋势不再显著。3种稻飞虱长翅型和短翅型纯系或近纯系若虫的存活率会稍低于长、短翅型杂交后代的存活率, 但长、短翅型品系的存活率在6~16 h光照条件下差异不显著(P>0.05)。【结论】稻飞虱翅型分化对光周期的反应受飞虱本身遗传背景的影响, 翅型纯系后代个体的翅型分化对光周期变化不敏感。     

稻飞虱种群发生的调查与取样技术

稻飞虱是中国和许多国家水稻生产上的主要害虫,属r对策暴发危害类型。其中,褐飞虱和白背飞虱是典型的远距离迁飞性害虫,具有大区域同期"突增"和"突减"的灾变特性;灰飞虱则主要以本地越冬为主,远距离迁飞对种群结构的影响较小,但其传播的病毒病对水稻生产的影响更甚。针对3种稻飞虱的生物学特性,本文发展了稻飞虱田间种群发生与危害等的调查与取样技术,为其种群发生及其监测预警提供技术支撑。     

QUANTIFYING PREDATION BY UMMELIATA INSEC-TICEPS BOES. ET STR. (ARANEAE: LINYPHIIDAE) ON RICE PLANTHOPPERS USING ELISA*

Abstract An enzyme-linked immunosorbent assay (ELISA) has been developed to quantify predation by Ummeliata insecticeps Boes. et Str. on rice planthoppers in paddy fields in Dasha Township, Guangdong Province. The assay was completely specific for rice planthopper materials. The detection periods for antigens after an adult of U. insecticeps had fed on three 3–5th instar nymphs of white-back planthopper (WBPH), Sogatella furcifera (Horvath), and brown planthopper (BPH), Nilaparvata lugens (Stal), at room temperature were 96 h and 120 h, respectively. The proportion of individual species of predators scoring positive ranged from 19. 05% to 47. 34% for WBPH, and from 9. 25% to 66. 67% for BPH in the early rice season. Although the numbers of the rice planthoppers consumed by U. insecticeps increased with increasing prey densities, the predation rates declined. When rice planthopper densities were low, the predation rates were relatively high. This kind of predation can explain why the rice planthoppers have never reached outbreak levels in rice fields in Dasha Township since 1973.     

用ELISA方法定量评价食虫沟瘤蛛对稻飞虱的捕食作用(英文)

对捕食性节肢动物的捕食作用进行评价是害虫生物防治研究的一个重要内容。本文利用酶联免疫吸附试验（ＥＬＩＳＡ）定量评价了食虫沟瘤蛛对稻飞虱的捕食作用。结果表明,方法特异性完全符合试验要求;食虫沟瘤蛛在捕食３头３－５龄白背飞虱或褐飞虱若虫后的检出期分别为９６小时和１２０小时;在早稻田中,捕食性天敌对白背飞虱和褐飞虱的阳性反应率分别为１９．０５％－４７．３４％和１９．０５％－６６．６７％,在飞虱密度较低时,捕食性天敌仍表现出较高的阳性率;捕食量随飞虱密度的增加而增加,但捕食率下降。捕食性节肢动物是调节褐飞虱种群动态的重要因子之一。     

Identification of egg parasitoids of rice leafhoppers and planthoppers (Hemiptera: Cicadellidae and Delphacidae) of economic importance in Taiwan,part 1: Mymaridae (Hymenoptera)

Fairyfly egg parasitoids (Hymenoptera: Mymaridae) of rice leafhoppers and planthoppers (Hemiptera: Cicadellidae and Delphacidae) known from Taiwan are identified taxonomically, keyed, and illustrated. Their host associations are determined by rearings using sentinel eggs of mainly four key pest species. The previously published records of such egg parasitoids in Taiwan are critically analyzed in the unfortunate absence of almost any voucher specimens. Three species of Mymaridae are shown to be the predominant egg parasitoids of one leafhopper and three planthopper major pests of rice in Taiwan: Anagrus (Anagrus) incarnatus Haliday of the green rice leafhopper Nephotettix cincticeps (Uhler) and the delphacids Laodelphax striatella (Fallén) (small brown planthopper), Nilaparvata lugens (Stål) (brown planthopper), and Sogatella furcifera (Horváth) (whitebacked planthopper), as well as Gonatocerus aegyptiacus Soyka and Mymar taprobanicum Ward of N. cincticeps. The zig-zag leafhopper Maiestas dorsalis (Motschulsky), which is also common in paddy fields, is newly recorded as a host for A. incarnatus, G. aegyptiacus, Lymaenon litoralis (Haliday), and M. taprobanicum. Additional new records of some other Mymaridae in Taiwan, mostly from the rice field agroecosystems, are indicated. Litus assamensis Rehmat and Anis, syn. nov. from India, is synonymized with L. sutil Triapitsyn and Berezovskiy from Thailand, which is also newly recorded from Taiwan.     

稻虱缨小蜂对褐飞虱和白背飞虱卵的识别机制

研究了室内条件下信息化合物及稻飞虱卵的形态特征在稻虱缨小蜂识别2种卵寄主褐飞虱和白背飞虱中的作用。结果表明,褐飞虱和白背飞虱雌成虫诱导的水稻挥发物对稻虱缨小蜂的引诱作用无显著差异,各自的引诱比例(头数)分别为57.50%(23头)和42.50%(17头)。稻虱缨小蜂对2种飞虱4组材料,完整卵、磨碎卵、带卵叶鞘和若虫为害叶鞘的行为反应,除了在褐飞虱完整卵上的搜索时间极显著地长于在白背飞虱完整卵上的以外,其余的均不存在差异。挥发物捕集结果表明,褐飞虱和白背飞虱雌成虫诱导的水稻挥发物组成相非常一致。上述结果表明水稻挥发物、稻飞虱利它素及飞虱卵的形态特征在稻虱缨小蜂识别褐飞虱和白背飞虱卵中的作用不明显。文中就稻虱缨小蜂识别2种寄主的机制进行了讨论。     

Identification of egg parasitoids of rice leafhoppers and planthoppers (Hemiptera: Cicadellidae and Delphacidae) of economic importance in Taiwan,part 2: Trichogrammatidae (Hymenoptera)

Trichogrammatid egg parasitoids (Hymenoptera: Trichogrammatidae) of rice leafhoppers and planthoppers (Hemiptera: Cicadellidae and Delphacidae) known from Taiwan are identified taxonomically and illustrated, and their host associations are determined by rearings using sentinel eggs of the key pest species. The previously published records of such egg parasitoids in Taiwan are critically analyzed in the unfortunate absence of almost any voucher specimens. Pseudoligosita nephotetticum (Mani) is shown to be the most common egg parasitoid of the two leafhopper and three planthopper pests of rice in Taiwan: the zig-zag leafhopper Maiestas dorsalis (Motschulsky) (a new host record), the green rice leafhopper Nephotettix cincticeps (Uhler), and the delphacids Laodelphax striatella (Fallén) (small brown planthopper), Nilaparvata lugens (Stål) (brown planthopper), and Sogatella furcifera (Horváth) (whitebacked planthopper). Paracentrobia (Brachistella) andoi (Ishii) syn. nov., originally described from Japan as Japania andoi Ishii, and Paracentrobia (Brachistella) garuda Subba Rao syn. nov. from Thailand are synonymized under Paracentrobia (Brachistella) bicolor (Girault) from northern Queensland, Australia; Pseudoligosita tachikawai (Yashiro) syn. nov., originally described as Oligosita tachikawai Yashiro from Japan, is synonymized under Pseudoligosita nephotetticum. Lectotypes are designated for Japania andoi and Oligosita shibuyae Ishii.     

Pyramided rice lines harbouring Allium sativum (asal) and Galanthus nivalis (gna) lectin genes impart enhanced resistance against major sap-sucking pests

We have developed transgene pyramided rice lines, endowed with enhanced resistance to major sap-sucking insects, through sexual crosses made between two stable transgenic rice lines containing Allium sativum (asal) and Galanthus nivalis (gna) lectin genes. Presence and expression of asal and gna genes in pyramided lines were confirmed by PCR and western blot analyses. Segregation analysis of F₂ progenies disclosed digenic (9:3:3:1) inheritance of the transgenes. Homozygous F₃ plants carrying asal and gna genes were identified employing genetic and molecular methods besides insect bioassays. Pyramided lines, infested with brown planthopper (BPH), green leafhopper (GLH) and whitebacked planthopper (WBPH), proved more effective in reducing insect survival, fecundity, feeding ability besides delayed development of insects as compared to the parental transgenics. Under infested conditions, pyramided lines were found superior to the parental transgenics in their seed yield potential. This study represents first report on pyramiding of two lectin genes into rice exhibiting enhanced resistance against major sucking pests. The pyramided lines appear promising and might serve as a novel genetic resource in rice breeding aimed at durable and broad based resistance against hoppers.     

Development and preliminary application of a triplex real‐time polymerase chain reaction assay for evaluating predation on three planthoppers in a rice ecosystem

A multiplex real‐time quantitative polymerase chain reaction (PCR) assay was developed to simultaneously detect the DNA of three rice planthoppers, that is, Sogatella furcifera (Horváth) (white‐backed planthopper), Nilaparvata lugens (Stål) (brown planthopper) and Laodelphax striatellus (Fallén) (small brown planthopper), in the gut of their predators. The sets of primers and ALLGlo probes were targeted to the regions of internal transcribed spacer 2 (ITS2) genes in nuclear ribosomal DNA (rDNA). The sensitivity, specificity and interference test for the multiplex real‐time quantitative PCR assay were analysed. The assay's detection limits were 100, 1000 and 100 copies for the white‐backed planthopper, the brown planthopper and the small brown planthopper, respectively. The specificity tests showed no cross‐reactivity with genomic DNA from 30 other dominant herbivores, saprophagous insects and predators from rice ecosystem for each planthopper species. The assay was used in a preliminary study of predation events on the three planthoppers by three major spiders viz., Pardosa pseudoannulata (Bösenberg et Strand), Ummeliata insecticeps (Bösenberg et Strand) and Tetragnatha maxillosa Thorell which each differ in their preferred microhabitat as well as their predatory habits in rice field, and the results showed their predation on each planthopper species could be well evaluated using this method. Therefore, the multiplex real‐time quantitative PCR assay provides a new tool to study the mechanisms of prey shifting and natural regulation of the three rice planthoppers by generalist predators in rice ecosystem.     

褐飞虱和白背飞虱的取食为害对水稻营养生长的影响

对塑料钵栽培的水稻进行罩宠试验,研究了褐飞虱和白背飞虱在不同若虫密度下取食为害对水稻营养生长的影响．结果表明,两种飞虱的成虫干重、水稻叶面积和其地上部干重因若虫密度的增加而下降．叶片干重占地上部干重的比例和稻株分配给叶片干物质量随为害程度的加重而增大;褐飞虱和白背飞虱总干重（X）与稻株地上部损失量（Y）之间存在着极显著的线性关系．两种飞虱干重每增加1mg,水稻地上部干重则分别损失26.01mg和21．90mg．讨论了稻飞虱取食为害对水稻致害的可能机制．     

Two whitebacked planthopper resistance genes in rice share the same loci with those for brown planthopper resistance

The whitebacked planthopper (WBPH), Sogatella furcifera, and brown planthopper (BPH) Nilaparvata lugens St?l are important sucking insects of rice (Oryza sativa L.) crops throughout the world. Rice 'B5', which has derived its resistance genes from the wild rice O. officinalis Wall ex Watt, is a line that is highly resistant to both WBPH and BPH. Previously, two resistance genes against BPH, Qbp1, and Qbp2 in 'B5' had been mapped onto chromosome 3 and chromosome 4, respectively. In this study, we employed a mapping population composed of 187 recombinant inbred lines (RILs), produced from a cross between 'B5' and susceptible variety 'Minghui63', to locate the WBPH and BPH resistance genes. A RFLP survey of the bulked extremes from the RIL population identified two genomic regions, one on chromosome 3 and the other on chromosome 4, likely containing the resistance genes to planthoppers. QTL analysis of the RILs further confirmed that two WBPH resistance genes were mapped on the same loci as Qbp1 and Qbp2, using a linkage map with 242 molecular markers distributed on 12 rice chromosomes. Of the two WBPH resistance genes, one designated Wbph7(t) was located within a 1.1-cM region between R1925 and G1318 on chromosome 3, the other designated Wbph8(t) was within a 0.3-cM region flanked by R288 and S11182 on chromosome 4. A two-way analysis of variance showed that two loci acted independently with each other in determining WBPH resistance. The results have significant implications in studying the interactions between sucking insects and plants and in breeding programs of resistance to rice planthoppers.     

Influence of pymetrozine on feeding behaviors of three rice planthoppers and a rice leafhopper using electrical penetration graphs

Pymetrozine reportedly inhibits feeding of plant sap-sucking insects, such as aphids and brown planthopper (Nilaparvata lugens (St?l)). By using electrical penetration graph (EPG), this study was conducted to investigate any differential effect of pymetrozine on the feeding behaviors of four major rice sap-sucking insect species, 1) N. lugens, 2) white-backed planthopper (Sogatella furcifera (Horváth)), 3) small brown planthopper (Laodelphax striatellus (Fallen)), and 4) green rice leafhopper (Nephotettix cincticeps Uhler). On pymetrozine-free TN1 rice plants, white-backed planthopper and small brown planthopper showed a significantly less activity in the phloem phases than brown planthopper or green rice leafhopper while green rice leafhopper engaged in relatively more xylem ingestion than brown planthopper, white-backed planthopper, and small brown planthopper. On the plants treated with 100 mg liter(-1) of pymetrozine, all four insect species showed significant increases, in total duration of nonprobing and significant decreases in the activities in phloem tissue, while all species showed similar feeding behavior during the pathway and xylem phases. This study revealed that, regardless of whether the insects on untreated plants spent more time feeding on phloem than xylem (brown planthopper) or more time on xylem than phloem (green rice leafhopper) or similar times on phloem and xylem (white-backed planthopper and small brown planthopper), their feeding behavior was disturbed by pymetrozine and exhibited similar patterns of sharp decline in activity in the phloem tissue and a significant increase the nonprobing.     

2020年江苏省稻飞虱虫源地及暴发成因分析

为了明确江苏省稻飞虱（白背飞虱Sogatella furcifera Horváth和褐飞虱Nilaparvata lugens Stal）在沉寂近10年后再次暴发的成因,通过分析江苏2020年白背飞虱和褐飞虱的田间调查及灯诱数据,并结合气象条件,研究了江苏省稻飞虱暴发的主要影响因素。结果表明：（1）2020年,江苏省白背飞虱虫源主要来自于江西中、北部,湖南东部以及湖北东部;褐飞虱虫源主要来自于安徽南部、浙江北部、本省南部以及江西省中北部。（2）江淮地区自6月中旬至7月下旬的超长降雨期有利于江苏省早期迁入虫源大量降落。（3）9月初,田间已存在大量褐飞虱短翅型成虫,适宜的秋季温度促使田间短翅型褐飞虱大量繁殖,导致后期田间褐飞虱大暴发。总而言之,超长降雨期有利于早期稻飞虱的迁入降落,而秋季的适宜温度引发短翅型成虫大量繁殖,是导致江苏省稻飞虱在沉寂近10年后再次暴发的主要因素。这些结果为稻飞虱暴发规律的阐明及可持续治理提供了理论依据和参考价值。     

The strepsipteran parasite <Emphasis Type="Italic">Elenchus japonicus</Emphasis> (Strepsiptera,Elenchidae) of planthoppers consists of three genotypes

The twisted-wing parasite Elenchus japonicus is a major parasitoid of rice planthoppers (Hemiptera: Delphacidae), including the brown planthopper Nilaparvata lugens, the white-backed planthopper Sogatella furcifera, and the small brown planthopper Laodelphax striatellus. Another Elenchus species, E. yasumatsui, which is considered to be synonymous with E. japonicus, has also been described in southern Asia. However, limited biological and molecular data on this important parasitoid of rice planthoppers are available. In this study, E. japonicas-stylopized planthoppers were obtained from various regions in Asia and Japan. Sequences of the nuclear 18S ribosomal RNA gene and the mitochondrial cytochrome oxidase I gene of the strepsipterans were analyzed from 40 samples of E. japonicus: 14 from N. lugens, 6 from S. furcifera and 20 from L. striatellus. Sequence analysis of these samples revealed three genotypes of E. japonicus. Of the three types of E. japonicus, one was isolated only from L. striatellus from northern Japan. The other two types were found in all three rice planthopper species collected from a wide area in Asia. These results suggest that the three different genotypes of Elenchus can be associated with a particular geographical region and/or planthopper species. The relationship between two previously described Elenchus species and the present three genotypes needs to be elucidated.     

Transgenic rice plants expressing the snowdrop lectin gene (<Emphasis Type="Italic">gna</Emphasis>) exhibit high-level resistance to the whitebacked planthopper (<Emphasis Type="Italic">Sogatella furcifera</Emphasis>)

Transgenic rice plants, expressing snowdrop lectin [Galanthus nivalis agglutinin (GNA)], obtained by Agrobacterium-mediated genetic transformation, were evaluated for resistance against the insect, the whitebacked planthopper (WBPH). The transgene gna was driven by the phloem-specific, rice-sucrose synthase promoter RSs1, and the bar was driven by the CaMV 35S promoter. In our previous study, the transgenic status of these lines was confirmed by Southern, Northern and Western blot analyses. Both the transgenes, gna and bar, were stably inherited and co-segregated into progenies in T₁ to T₅ generations. Insect bioassays on transgenic plants revealed the potent entomotoxic effects of GNA on the WBPH. Also, significant decreases were observed in the survival, development and fecundity of the insects fed on transgenic plants. Furthermore, intact GNA was detected in the total proteins of WBPHs fed on these plants. Western blot analysis revealed stable and consistent expression of GNA throughout the growth and development of transgenic plants. Transgenic lines expressing GNA exhibited high-level resistance against the WBPH. As reported earlier, these transgenics also showed substantial resistance against the brown planthopper and green leafhopper .