Whitebacked Planthopper Resistance Research Articles

Gamma-aminobutyric acid treatment promotes resistance against Sogatella furcifera in rice.

The Sogatella furcifera (Horváth) (Homoptera: Delphacidae) is a white-backed planthopper (WBPH) that causes "hopper burn" in rice, resulting in severe yield loss. Gamma-aminobutyric acid (GABA) is a well-known neurotransmitter that inhibits neurotransmission in insects by binding to specific receptors. In this study, we investigated the potential role of GABA in modulating rice resistance to WBPH and evaluated possible defense mechanisms. The experiment was conducted in green house in pots consist of four groups: control, GABA-treated, WBPH-infested, and WBPH-infested treated with GABA. Among the various tested concentration of GABA, 15 mM GABA was applied as a single treatment in water. The treatment was administered one week before WBPH infestation. The results revealed that 15 mM GABA treatment strongly increased WBPH resistance. A plate-based assay indicated that direct application of 15 mM GABA increased the mortality rate of WBPH and increased the damage recovery rate in rice plants. We found that GABA treatment increased the activation of antioxidant enzymes and reduced the reactive oxygen species content and malondialdehyde contents, and reduced the damage rate caused by WBPH. Interestingly, GABA-supplemented plants infested with WBPH exhibited increased phenylalanine ammonia-lyase and pathogenesis-related (PR) genes expression levels. GABA induced the accumulation of abscisic acid (ABA) and salicylic acid (SA) and enhanced the stomata closure and reduced leaf vessels to reduce water conductance during WBPH stress. Furthermore, we found that GABA application to the plant induced the expression of Jasmonic acid (JA) biosynthesis genes (LOX, AOS, AOC, and OPR) and melatonin biosynthesis-related genes (TDC, T5H, ASMT, and SNAT). Our study suggested that GABA increases resistance against WBPH infestation by regulating antioxidant defense system, TCA cycle regulation, phytohormonal signaling, and PR gene regulation.

The Quantitative Trait Loci Mapping of Rice Plant and the Components of Its Extract Confirmed the Anti-Inflammatory and Platelet Aggregation Effects In Vitro and In Vivo.

Unpredictable climate change might cause serious lack of food in the world. Therefore, in the present world, it is urgent to prepare countermeasures to solve problems in terms of human survival. In this research, quantitative trait loci (QTLs) were analyzed when rice attacked by white backed planthopper (WBPH) were analyzed using 120 Cheongcheong/Nagdong double haploid lines. Moreover, from the detected QTLs, WBPH resistance-related genes were screened in large candidate genes. Among them, OsCM, a major gene in the synthesis of Cochlioquinone-9 (cq-9), was screened. OsCM has high homology with the sequence of chorismate mutase, and exists in various functional and structural forms in plants that produce aromatic amino acids. It also induces resistance to biotic stress through the synthesis of secondary metabolites in plants. The WBPH resistance was improved in rice overexpressed through map-based cloning of the WBPH resistance-related gene OsCM, which was finally detected by QTL mapping. In addition, cq-9 increased the survival rate of caecal ligation puncture (CLP)-surgery mice by 60%. Moreover, the aorta of rat treated with cq-9 was effective in vasodilation response and significantly reduced the aggregation of rat platelets induced by collagen treatment. A cq-9, which is strongly associated with resistance to WBPH in rice, is also associated with positive effect of CLP surgery mice survival rate, vasodilation, and significantly reduced rat platelet aggregation induced by collagen treatment. Therefore, cq-9 presents research possibilities as a substance in a new paradigm that can act on both Plant-Insect in response to the present unpredictable future.

Identification of F3H, Major Secondary Metabolite-Related Gene That Confers Resistance against Whitebacked Planthopper through QTL Mapping in Rice.

Whitebacked planthopper (WBPH) is a pest that causes serious damage to rice in Asian countries with a mild climate. WBPH causes severely rice yield losses and grain poor quality each year so needs biological control. Plants resist biotic and abiotic stress using expressing variety genes, such as kinase, phytohormones, transcription factors, and especially secondary metabolites. In this research, quantitative trait locus (QTL) mapping was performed by assigning the WBPH resistance score in the Cheongcheong/Nagdong doubled haploid (CNDH) line in 2018 and 2019. The RM280-RM6909 on chromosome 4 was detected as a duplicate in 2018, 2019, and derived from Cheongcheong. This region includes cell function, kinase, signaling, transcription factors, and secondary metabolites that protect plants from the stress of WBPH. The RM280-RM6909 on chromosome 4 contains candidate genes that are similar to the flavanone 3-hydroxylase (F3H) of rice. The F3H are homologous genes, which play an important role in biosynthesis defending against biotic stress in plants. After WBPH inoculation, the relative expression level of F3H was higher in resistant line than in a susceptible line. The newly identified WBPH resistance gene F3H by QTL mapping can be used for the breeding of rice cultivars that are resistant against WBPH.

Defence response of local rice variety Acuce in Hani terraced fields in Yunnan against the feeding of Sogatella furcifera

[Objective] To study the main defensive response of Acuce, a local rice variety in the Hani terraced fields in Yuanyang, Yunnan under the feeding stress of white-backed planthopper (WBPH), and to clarify its WBPH resistance mechanism. To provide a basis for rice insect-resistant breeding and utilization of insect-resistant germplasm resources. [Method] The contents of nutrient soluble sugar, secondary products malondialdehyde (MDA) and hydrogen peroxide (H 2O 2) in rice plants were determined by colorimetric method at 0, 3, 6, 12, 24, 48, 72 and 96 h after WBPH feeding on Acuce, insect susceptible variety Taichung Native 1 (TN1) and insect resistant variety Rathu Heenati (RHT) in the meantime, the main defense reaction of main protective enzyme activity including peroxidase (POD), phenylalanine ammonia-lyase (PAL) and catalase (CAT) were measured and analyzed. [Result] After WBPH feeding stress 3-96 h, the soluble sugar content of the Acuce increased by 93.19%. The increase rate was significantly lower than TN1(176.23%) ( P<0.05, the same as below), there was no significant difference with RHT(89.16%) ( P>0.05, the same as below). The increase rate of H 2O 2 content was 44.13%, significantly higher than TN1(13.18%) and significantly lower than RHT(83.01%). The content of MDA in the rice plant of Acuce increased, and the mean increase rate was 145.38%, significantly higher than that of TNI(36.84%) and RHT(57.06%). The activities of POD, CAT and PAL were increased after feeding stress. The mean increase rate of POD activity (52.78%) was not significantly different with TN1(52.30%), but was significantly lower than that of RHT(154.53%). The mean increase rate of CAT activity (26.24%) was significantly higher than that of RHT(-9.32%) and TN1(-14.18%). The mean increase rate of PAL activity (3.80%) was significantly higher than that of RHT(-32.01%) and significantly lower than that of TN1(74.03%). [Conclusion] After WBPH feeding, the local rice variety Acuce is more sensitive in nutrients, secondary substances, and major protective enzymes than the insect susceptible variety TN1 and resistant variety RHT, showing a strong defense response. Acuce can be used as the WBPH resistance varieties in the field. 摘要: 【目的】 研究云南元阳哈尼梯山水稻地方品种月亮谷对白背飞虱取食胁迫的主要防御反应,明确月亮谷抗 白背飞虱机制,为水稻抗虫育种及抗虫种质资源利用提供科学依据。 【方法】 以元阳地方水稻品种月亮谷、感虫水稻品 种Taichung Native 1 (TN1) 和抗虫品种Rathu Heenati(RHT)为材料, 采用比色法测定3个水稻品种在白背飞虱取食胁 迫0、3、6、12、24、48、72和96 h后稻株内营养物质可溶性糖、次生产物丙二醛(MDA)和过氧化氢(H 2O)含量及保护酶 过氧化物酶(POD)、苯内'氨酸解氨酶(PAL)和过氧化氢酶(CAT)活性。 【结果】 白背飞虱取食胁迫3~96 h后, 月亮谷稻 株内可溶性糖平均含量增加率为93.19%, 显著小于TN1(176.23%) ( P<0.05,下同), 而与RHT(89.16%)无显著差异( P>0.05,下同)；H 2O 2平均含量增加率为44.13%, 显著高于TN1(13.18%), 而显著低于RHT(83.01%);MDA平均含量增加 率为145.38%, 显著高于TN1 (36.84%)和RHT(57.06%); POD、CAT和PAL活性均增加, 其中POD活性平均增加率 (52.78%)与TN1 (52.30%)无显著差异而显著低于RHT (154.53%), CAT活性平均增加率(26.24%)均显著高于RHT (-9.32%)和TN1(-14.18%), PAL活性平均增加率(3.80%)显著高于RHT(-32.01%)而显著低于TN1(74.03%)。 【结论】 月亮谷受白背飞虱取食胁迫后, 其营养物质、次生产物及主要保护酶活性均较感虫品种TN1和抗虫品种RHT反应敏 感, 表现出强烈的防御反应, 月亮谷可作为抗白背飞虱品种在山间应用。

Identification of a novel planthopper resistance gene from wild rice (Oryza rufipogon Griff.)

Rice planthoppers, including brown planthopper (BPH) and white-backed planthopper (WBPH), are the most destructive pests in Asian rice cultivation regions. Planthopper resistance genes that have been mapped and characterized advance our understanding of underlying resistance mechanisms and facilitate the breeding of resistant varieties, thereby contributing to an efficient pest management strategy. In this study, a novel resistance gene Bph38 derived from the wild rice species Oryza rufipogon Griff. was found to confer high resistance to BPH and WBPH. Conventional mapping was performed to identify regions associated with BPH and WBPH resistance, and two mapping efforts led to the same region on chromosome 4 flanked by markers RM16563 and RM16763. Bulked-segregant analysis and next-generation sequencing were performed using the same population to detect the resistance gene. Conventional mapping narrowed the region to a 12.3-Mb segment, and fine mapping using BC1F2 recombinants identified a 79-kb segment flanked by markers YM112 and YM190. Near-isogenic lines (NILs) carrying Bph38 in the 9311 (indica) and BR54 (japonica) genetic backgrounds were developed by crossing and backcrossing with marker-assisted selection. The agronomic traits and BPH and WBPH resistance of the NILs were similar to those of the recurrent parents. Mandatory feeding and host-choice tests revealed that Bph38 showed both antibiotic and antixenotic effects in both insects, with stronger effects in indica-background lines. Further fine mapping and characterization of the major gene may result in map-based cloning of the gene and allow its application in breeding insect-resistant rice varieties.

Identification of QTLs for Blast, Bacterial Blight, and Planthopper Resistance Using SNP-Based Linkage Maps from Two Recombinant Inbred Rice Lines

Rice is the most significant global food security. Several biotic factors limit rice production, breeding biotic-resistant rice has, therefore, become an increasingly important goal. Two elite rice lines, IR71033-121-15 (IR71033) and IR57514-PMI-5-B-1-2 (IR57514), provide potential genes for biotic stress resistance traits. In this study, genotyping by sequencing (GBS) for single nucleotide polymorphism (SNP)-based linkage map construction was used to detect quantitative trait loci (QTLs) for blast (BL), bacterial blight (BB), whitebacked planthopper (WBPH), and brown planthopper (BPH) resistance. IR71033 was derived from Oryza minuta and carried BL, BB, WBPH, and BPH resistance QTLs. IR57514 is a well-adapted rainfed lowland line that carries BL and BB resistance QTLs. Two sets of recombinant inbred line (RIL) populations derived from crosses of KDML105 × IR71033 and KDML105 × IR57514 were used to dissect the genetic basis of disease and insect pest resistance. The RIL populations were evaluated for BL, BB, WBPH, and BPH resistance from 2016 to 2018 at four rice research centers in Thailand. From these, we identified a large number of SNPs through GBS and constructed high-resolution linkage maps. By combining phenotypic evaluation with the GBS data, a total of 24 QTLs on four chromosomes were detected that confered pest resistance and explained 7.3% - 61.4% of the phenotypic variance. These findings should facilitate identifying novel resistance genes and applying marker-assisted selection for resistance to the four major rice pests investigated here. These strategies will improve the resilience and reliability of rice varieties adapted to the low-yielding environment of rainfed lowland areas worldwide.

Identification and fine mapping of qWBPH11 conferring resistance to whitebacked planthopper (Sogatella furcifera Horvath) in rice (Oryza sativa L.)

The whitebacked planthopper (WBPH), Sogatella furcifera Horvath, is one of the most destructive pests in rice (Oryza sativa L.) production. Host-plant resistance has been considered as an efficient and eco-friendly strategy to reduce yield losses caused by WBPH. In this study, we found that an indica rice cultivar IR54751-2-44-15-24-2 (IR54751) displayed high resistance to WBPH at both seedling and tillering stages. The resistance of IR54751 was mainly contributed by antixenosis and tolerance rather than antibiosis. An F2 population derived from a cross between IR54751 and a susceptible japonica cultivar 02428 was constructed to detect the quantitative trait loci (QTLs) conferring the resistance to WBPH. In total, four QTLs including qWBPH3.1, qWBPH3.2, qWBPH11, and qWBPH12 were identified and distributed on three different chromosomes. The four QTLs had LOD scores of 3.8, 8.2, 5.8, and 3.9, accounting for 8.2, 21.5, 13.9, and 10.4% of the phenotypic variation, respectively. Except for qWBPH3.1, the resistance alleles of the other three QTLs were all from IR54751. Further, a secondary population harboring only single qWBPH11 locus was developed from the F2 population by marker-assisted selection. Finally, qWBPH11 was delimited in a 450-kb region between markers DJ53973 and SNP56. The identification of WBPH resistance QTLs and the fine mapping of qWBPH11 will be helpful for cloning resistance genes and breeding resistant rice cultivars.

Whitebacked planthopper Sogatella furcifera (Horváth) (Homoptera: Delphacidae) resistance in rice variety Sinna Sivappu

Whitebacked planthopper (WBPH) along with brown planthopper (BPH) has emerged as a major pest of rice in several Asian countries. Development and cultivation of varieties resistant to both planthoppers is an ecologically acceptable strategy to manage these pests. Sinna Sivappu, a Sri Lankan landrace, was reported to be resistant to both planthoppers. While inheritance of BPH resistance has been reported, the genetics of WBPH resistance in this variety is not known. Using a mapping population of 255 F2:3 families from Taichung Native (TN)1/Sinna Sivappu cross and 128 polymorphic simple sequence repeat (SSR) markers, genes or quantitative trait loci (QTLs) for WBPH resistance quantified in ten phenotypic tests were identified, adopting classical Mendelian segregation, correlation and QTL analyses. The inheritance pattern suggested that a single recessive gene controlled regulation of seedling damage score. Antixenosis or nymphal preference was influenced by two complementary recessive genes, whereas tolerance in terms of days to wilt was under the influence of a single dominant gene. Several of these phenotypic tests recorded high degree of positive or negative correlation between them, suggesting dependence or redundancy of the tests. QTL analysis revealed 13 loci associated with nine traits. Five major-effect QTLs were detected for damage score (chromosome 6), nymphal survival (chromosome 12), and days to wilt (three QTLs on chromosome 4). We suggest involvement of four WBPH resistance genes in Sinna Sivappu, designated as wbph9(t), wbph10(t), wbph11(t), and Wbph12(t). One of the recessive genes could be allelic to any of the recessive genes reported in cluster C on chromosome 6 which might confer resistance to both BPH and WBPH.

Evaluation of rice germplasm for resistance to a leaffolder, stemborer and planthopper under field and glasshouse conditions in India

Rice germplasm comprising 66 lines/varieties was evaluated under field conditions for two wet seasons against a yellow stemborer, leaffolder and whitebacked planthopper (WBPH) at the vegetative and panicle initiation crop stages. Glasshouse screening of germplasm for WBPH resistance was done at the seedling stage. At the vegetative stage, over the 2 years, 18 lines/varieties showed leaffolder damage from 6.21 ± 0.33 to 9.99 ± 4.07%, while at the panicle initiation stage, six lines/varieties showed damage from 8.77 ± 1.25 to 12.25 ± 4.67%. A highly significant correlation between flag leaf width and per cent infested leaves at the vegetative (r = 0.88) and panicle initiation (r = 0.79) stages was recorded. No significant correlation was observed between plant height and leaffolder infestation at the vegetative stage; however, it was significant at the panicle initiation stage (r = 0.37). The dead heart (DH) damage at the vegetative stage over the years was less than 1% in six lines/varieties, while at the panicle initiation stage, seven lines/varieties showed whitehead (WH) damage ranging from 1.29 to 1.92%. A highly significant correlation was observed between plant height and per cent DH and WH at the vegetative (r = 0.73) and panicle initiation stages (r = 0.81). Such a relationship was not observed between leaf width and stemborer infestation at both stages. Two lines, viz. IR 59 547-235-3-3 and SPR 85 163-5-1-2-4, were resistant to the WBPH under glasshouse screening, whereas 20 lines were moderately resistant and the remaining lines were susceptible.

Effective Procedure for Development of EST-SSR Markers Using cDNA Library

The present study was conducted to develop EST-SSR markers using the cDNA library from rice plant. Total RNA extracted from the leaves of brown plant hopper resistance gene originated from a rice cultivar “Cheongcheong” and sensitive rice cultivar “Nakdong” were used to synthesize a cDNA library. As a result of analyzing the cDNA library, the 17 EST-SSR primer sets were developed. This study enables to provide effective marker assisted selection (MAS) methods on the selection of white-backed planthopper resistance gene originated from a rice plant more simply, quickly and precisely. Furthermore, using this marker’s advantage of deriving from cDNA, it is possible to identify the white-backed planthopper resistance gene. In addition, this study introduces a technique for construction of a cDNA library safely without using radioactivity.

English

The experimental material consisted of two parents Gurjari (white backed plant hopper resistant) and Jaya (white backed plant hopper susceptible) and their F2 progeny.&nbsp;The purpose of the study was the identification of RAPD (Random Amplified Polymorphic DNA) marker for white backed plant hopper (WBPH) resistant gene. The RAPD analysis was done group wise as well as combined for the bulk segregant analysis (BSA). For the BSA, of the total 50 random primers surveyed, a single linked primer, OPA 08, was identified. This primer generated 8-bands, one of which, OPA08-7, was putatively linked to resistant gene as was evident by its presence in almost all the resistant bulks and vice-versa. This band had molecular weight equal to 1219.38 bp and was found in resistant parent, Gurjari, and in almost all the resistant bulks (the four susceptible bulks revealed absence of the same band) indicating the band OPA08-7 as a marker for WBPH resistance among the screened rice genotypes. &nbsp; Key words:&nbsp;Rice, random amplified polymorphic DNA, white backed plant hopper, resistant, susceptible, gene.

Identification of quantitative trait loci for resistance to whitebacked planthopper, Sogatella furcifera, from an interspecific cross Oryza sativa * O. rufipogon

Quantitative trait loci (QTLs) for resistance to whitebacked planthopper (WBPH), Sogatella furcifera, were determined using 202 backcrossed inbred lines derived from a cross between the recurrent parent Xieqingzao B and an accession of Oryza rufipogon, and then tested using chromosome segment substitution lines (CSSLs) selected from BC3F3 populations of the same cross. Seedling mortality with WBPH infestation was measured to evaluate the resistance. Three QTLs were detected and the wild alleles always had the effect for decreasing seedling mortality. There were qWph2 located in the interval RM1285-RM555 on the short arm of chromosome 2, qWph5 in RM3870-RZ70 on the long arm of chromosomes 5, and qWph9 in RG451-RM245 on the long arm of chromosomes 9, among which qWph9 had the most stable effect. Duplicate lines of seven CSSLs carrying homozygous alleles of O. rufipogon at qWph9 were tested with WBPH infestation. Significant effects at P = 0.01 were observed for all the 14 lines. On the average, the seedling mortality was decreased by 55.2%. Validation of the major effect of qWph9 on enhancing WBPH resistance not only provides a useful QTL but also a series of breeding materials for rice improvement.

Detection of quantitative trait loci (QTL) associated with resistance to whitebacked planthopper (Sogatella furcifera) in rice (Oryza sativa)

Whitebacked planthopper (WBPH) is an important insect pest of rice. In this study, we report quantitative trait loci (QTL) associated with resistance to WBPH using a doubled-haploid (DH) mapping population derived from the cross IR64/Azucena. We evaluated a set of 91 DH lines using various screening tests which measure seedling resistance, antibiosis and tolerance to WBPH. QTL analysis involving a RFLP map of 175 markers detected a significant QTL on chromosome 7 (RG511-RG477) associated with seedling resistance to WBPH. In addition, QTL analysis involving available defence related candidate genes as markers on a sub set of 60 DH lines showed significant association of genomic regions on chromosome 1 (W1-pMRF1), 2 (XLRfrI7-RG157) and 7 (RG711-CD0418) with resistance to WBPH. Several suggestive QTL were detected on chromosomes 2, 3, 6, 7, 8 and 11 showing the possibility of their association with resistance to WBPH. The phenotypic contribution of the QTL ranged from 8.4% to 32.1%. Some of the WBPH resistance QTL detected in this study showed similar map positions with the QTL reported for resistance to brown planthopper (BPH) in the same mapping population. These results would be useful for attempts to trace the genes associated with resistance to planthoppers in rice.

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 Stål 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.

中国稲「春江０６」のセジロウンカ抵抗性の遺伝様式と中国ジャポニカ稲における同抵抗性形質の分布

春江06のセジロウンカ抵抗性形質の遺伝様式を,春江06とTN1の正逆交雑によって得られたF2イネを用いて調べた。交雑F2イネにおける抵抗性形質の分離比は,2個の優性吸汁抑制遺伝子と,1個の劣性殺卵遺伝子を仮定した場合の期待値に適合した。中国産ジャポニカ水稲35品種中,4品種に吸汁抑制型,11品種に殺卵型セジロウンカ抵抗性が認められた。しかし,両抵抗性形質を兼備した品種は,春江06の他に検出できなかった。