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The white-backed planthopper (WBPH, Sogatella furcifera) is a notorious pest affecting rice production in many Asian countries. Beauveria bassiana , as the most extensively studied and applied insect pathogenic fungus, is a type of green and safe biological control fungus compared to chemical insecticides, and it does not pose the "3R" problem. In this study, the strain BEdy1, which had better pathogenicity to WBPH, was screened out from eight strains of B. bassiana. The daily growth rate, sporulation, and germination rate of BEdy1 strain were 3.74 mm/d, 1.37 × 108 spores/cm2, and 96.00%, respectively, which were significantly better than those of other strains. At a concentration of 1 × 108 spores/mL, the BEdy1 strain exhibited the smallest LT50 value (5.12 d) against the WBPH, and it caused the highest cumulative mortality and muscardine cadaver rates of the pest, which were 77.67 and 57.78%, respectively. Additionally, BEdy1 exhibited a significant time-dose effect on WBPH. This study further investigated the pathogenic process of BEdy1. The results showed that BEdy1 invaded by penetrating the body wall of the WBPH, with its spores mostly distributed in the insect's abdominal gland pores, compound eyes on the head, and other locations. At 36 h, the germinated hyphae penetrated the insect's body wall and entered the body cavity. At 84 h, the hyphae emerged from the body wall and accumulated in the insect's abdomen, leading to a significant number of insect deaths at this stage. At 120 h, the hyphae entangled the insect's compound eyes and produced new conidia on the insect's body wall, entering a new cycle of infection. These findings indicate that BEdy1 has a strong infection ability against WBPH. In summary, this study provides a new highly pathogenic strain of B. bassiana , BEdy1, for the biological control of WBPH, which is of great significance for the green prevention and control of rice pests. [ABSTRACT FROM AUTHOR]

Although CRISPR/Cas9 has been widely used in insect gene editing, the need for the microinjection of preblastoderm embryos can preclude the technique being used in insect species with eggs that are small, have hard shells, and/or are difficult to collect and maintain outside of their normal environment. Such is the case with Sogatella furcifera, the white‐backed planthopper (WBPH), a significant pest of Oryza sativa (rice) that oviposits inside rice stems. Egg extraction from the stem runs the risk of mechanical damage and hatching is heavily influenced by the micro‐environment of the rice stem. To bypass these issues, we targeted embryos prior to oviposition via direct parental (DIPA)‐CRISPR, in which Cas9 and single‐guide RNAs (sgRNAs) for the WBPH eye pigment gene tryptophan 2,3‐dioxygenase were injected into the hemocoel of adult females. Females at varying numbers of days posteclosion were evaluated to determine at what stage their oocyte might be most capable of taking up the gene‐editing components. An evaluation of the offspring indicated that the highest G0 gene‐edited efficacy (56.7%) occurred in females injected 2 d posteclosion, and that those mutations were heritably transmitted to the G1 generation. This study demonstrates the potential utility of DIPA‐CRISPR for future gene‐editing studies in non‐model insect species and can facilitate the development of novel pest management applications. [ABSTRACT FROM AUTHOR]

The white-backed planthopper (WBPH, Sogatella furcifera) is a notorious pest affecting rice production in many Asian countries. Beauveria bassiana, as the most extensively studied and applied insect pathogenic fungus, is a type of green and safe biological control fungus compared to chemical insecticides, and it does not pose the “3R” problem. In this study, the strain BEdy1, which had better pathogenicity to WBPH, was screened out from eight strains of B. bassiana. The daily growth rate, sporulation, and germination rate of BEdy1 strain were 3.74 mm/d, 1.37 × 108 spores/cm2, and 96.00%, respectively, which were significantly better than those of other strains. At a concentration of 1 × 108 spores/mL, the BEdy1 strain exhibited the smallest LT50 value (5.12 d) against the WBPH, and it caused the highest cumulative mortality and muscardine cadaver rates of the pest, which were 77.67 and 57.78%, respectively. Additionally, BEdy1 exhibited a significant time-dose effect on WBPH. This study further investigated the pathogenic process of BEdy1. The results showed that BEdy1 invaded by penetrating the body wall of the WBPH, with its spores mostly distributed in the insect’s abdominal gland pores, compound eyes on the head, and other locations. At 36 h, the germinated hyphae penetrated the insect’s body wall and entered the body cavity. At 84 h, the hyphae emerged from the body wall and accumulated in the insect’s abdomen, leading to a significant number of insect deaths at this stage. At 120 h, the hyphae entangled the insect’s compound eyes and produced new conidia on the insect’s body wall, entering a new cycle of infection. These findings indicate that BEdy1 has a strong infection ability against WBPH. In summary, this study provides a new highly pathogenic strain of B. bassiana, BEdy1, for the biological control of WBPH, which is of great significance for the green prevention and control of rice pests.

BACKGROUND: The white‐backed planthopper (WBPH, Sogatella furcifera) is a major rice pest that exhibits condition dependent wing dimorphisms – a macropterous (long wing) form and a brachypterous (short wing) form. Although, the gene cascade that regulates wing development and dimorphic differentiation has been largely defined, the utility of these genes as targets for pest control has yet to be fully explored. RESULTS: Five genes typically associated with the developmental signaling network, armadillo (arm), apterous A (apA), scalloped (sd), dachs (d), and yorkie (yki) were identified from the WBPH genome and their roles in wing development assessed following RNA interference (RNAi)‐mediated knockdown. At 5 days‐post injection, transcript levels for all five targets were substantially decreased compared with the dsGFP control group. Among the treatment groups, those injected with dsSfarm had the most pronounced effects on transcript reduction, mortality (95 ± 3%), and incidence (45 ± 3%) of wing deformities, whereas those injected with dsSfyki had the lowest incidence (6.7 ± 4%). To assess the utility of topical RNAi for Sfarm, we used a spray‐based approach that complexed a large‐scale, bacteria‐based double‐stranded RNA (dsRNA) expression pipeline with star polycation (SPc) nanoparticles. Rice seedlings infested with third and fourth instar nymphs were sprayed with SPc–dsRNA formulations and RNAi phenotypic effects were assessed over time. At 2 days post‐spray, Sfarm transcript levels decreased by 86 ± 9.5% compared with dsGFP groups, and the subsequent incidences of mortality and wing defects were elevated in the treatment group. CONCLUSIONS: This study characterized five genes in the WBPH developmental signaling cascade, assessed their impact on survival and wing development via RNAi, and developed a nanoparticle‐dsRNA spray approach for potential field control of WBPH. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Plants are threatened by a wide variety of herbivorous insect assaults, and display a variety of inherent and induced defenses that shield them against herbivore attacks. Looking at the massive damage caused by the white-backed planthopper (WBPH), Sogatella furcifera, we undertook a study to identify and functionally annotate OsWRKY and OsNAC transcription factors (TFs) in rice, especially their involvement in WBPH stress. OsWRKY and OsNAC TFs are involved in various developmental processes and responses to biotic and abiotic stresses. However, no comprehensive reports are available on the specific phycological functions of most of the OsWRKY and OsNAC genes in rice during WBPH infestation. The current study aimed to comprehensively explore the OsWRKY and OsNAC genes by analyzing their phylogenetic relationships, subcellular localizations, exon–intron arrangements, conserved motif identities, chromosomal allocations, interaction networks and differential gene expressions during stress conditions. Comparative phylogenetic trees of 101 OsWRKY with 72 AtWRKY genes, and 121 OsNAC with 110 AtNAC genes were constructed to study relationships among these TFs across species. Phylogenetic relationships classified OsWRKY and OsNAC into eight and nine clades, respectively. Most TFs in the same clade had similar genomic features that represented similar functions, and had a high degree of co-expression. Some OsWRKYs (Os09g0417800 (OsWRKY62), Os11g0117600 (OsWRKY50), Os11g0117400 (OsWRKY104) and OsNACs (Os05g0442700, Os12g0630800, Os01g0862800 and Os12g0156100)) showed significantly higher expressions under WBPH infestation, based on transcriptome datasets. This study provides valuable information and clues about predicting the potential roles of OsWRKYs and OsNACs in rice, by combining their genome-wide characterization, expression profiling, protein–protein interactions and gene expressions under WBPH stress. These findings may require additional investigation to understand their metabolic and expression processes, and to develop rice cultivars that are resistant to WBPH. [ABSTRACT FROM AUTHOR]

The takeout (TO) gene family impacts diverse physiological and behavioral functions in insects, yet specific olfactory-associated roles for the family have yet to be fully elucidated. To provide insights into TO function in rice planthoppers, the genomes of three rice planthoppers (white-backed planthopper, brown planthopper and small brown planthopper) were searched for TO homologs and their degree of conservation assessed via chromosomal localization, exon-intron boundaries, phylogenetic relationships and protein domains/motifs. We performed a tissue-specific expression analysis of the 20 TO genes in the white-backed planthopper (WBPH, Sogatella furcifera) and found that SfTO17 is enriched in adult antennae. RNAi-mediated knockdown of SfTO17 impaired WBPH olfaction and reduced host-seeking responses following exposure to rice plants. The binding profile of β-ionone, hexyl benzoate and benzyl benzoate with recombinant SfTO17 was evaluated via competitive fluorescence binding assays. Conformational prediction of SfTO17 coupled with molecular docking analyses revealed several amino acid residues potentially critical for odorant binding. This study demonstrates the olfactory function of SfTO17 in WBPH and highlights its potential as a target for controlling this rice pest. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

The study on influence of Zn applied in forms of fertilizer formulations was carried out against whitebacked planthopper (WBPH) [Sogatella furcifera (Horvath)] infesting rice under field conditions during kharif 2016, summer 2016-17 and kharif 2017 in the Central Research Farm, College of Agriculture, Odisha University of Agriculture and Technology, Bhubaneswar. It was revealed that application of zinc to rice crop was instrumental in curbing the WBPH population. Basal application of Zn EDTA @ 40 kg/ha along with its foliar spray@ 0.8%, twice at 30 and 45 days after transplanting (DAT) (T6) was the best treatment in reducing the number of WBPH population over seasons as well as in increasing the grain yield. The next better treatment was T7 (ZnSO4 basal @ 25 kg/ha +Zn EDTA foliar spray @ 0.8% twice at 30 and 45 DAT) which also reduced the WBPH population substantially. From the entire study, it was inferred that reduction in WBPH population in various Zn supplementations as compared to control may be attributed to influence of Zn on rice plant physiology. Uptake of zinc definitely altered the nutritional status of rice plant as a result of which the population build up of WBPH on rice was minimized.

RNA interference (RNAi) is a widespread post-transcriptional silencing mechanism that targets homologous mRNA sequences for specific degradation. An RNAi-based pest management strategy is target-specific and considered a sustainable biopesticide. However, the specific genes targeted and the efficiency of the delivery methods can vary widely across species. In this study, a spray-induced and nanocarrier-delivered gene silencing (SI-NDGS) system that incorporated gene-specific dsRNAs targeting conserved genes was used to evaluate phenotypic effects in white-backed planthopper (WBPH). At 2 days postspraying, transcript levels for all target genes were significantly reduced and knockdown of two gene orthologs, hsc70-3 and PP-α, resulted in an elevated mortality (>60%) and impaired ecdysis. These results highlight the utility of the SI-NDGS system for identifying genes involved in WBPH growth and development that could be potentially exploitable as high mortality target genes to develop an alternative method for WBPH control.

Whitebacked Planthopper is a sucking phloem sap insect which can greatly affect quality of the grain and yield losses. Determination of the resistance and susceptibility to WBPH is very important to accurate QTL analysis. The main objective of the study was to examine the level of resistance to determine optimum screening time using 120 doubled haploid lines. CNDH populations were developed from anther culture of F1, which was derived after a crossing WBPH, Sogatella furcifera resistance 'Cheongcheong' and susceptible 'Nagdong' lines. The genetic map with average 9.6 CM between markers was constructed from 120 CNDH populations, which included 217 SSR markers. Four QTLs were detected at different time and points based on the rate of seedling mortality after WBPH infestation. The markers were found to be comprehensive in identification of genotype and phenotype at coincident rate of 95% 14 days after infestation. These markers are efficiently very useful for MAS and develop new varieties in rice breeding program. [ABSTRACT FROM AUTHOR]

During rice cultivation, brown planthopper (BPH, Nilaparvata lugens Stal.) and white-backed planthopper (WBPH, Sogatella furcifera) infestations cause decreased yield and rice quality. In this study, we attempted to develop multi-resistance plants and increase the marker-assisted selection (MAS) efficiency. The frequency of callus induction in 95 F doubled haploid lines (DHLs) derived from JSNDH13 (BPH resistance)/CNDH32 (WBPH resistance) ranged from 3.8 to 15.2 %. The plant regeneration rates varied from 2.9 to 39.3 %. Selected 75 DH plants were used to compare the results of WBPH bioassay and DNA marker reaction. The DHL bioassay showed continuous gene distribution and resistance score ranged from 0.5 to 9.0 (mean, 4.2). The broad-sense heritability for WBPH resistance was 51.7 %. The DHLs from the cross of JSNDH13/CNDH32 were segregated into 39 resistant (R):36 susceptible (S) to WBPH, i.e., 1 RR:SS. For the bioassay and MAS, RM11669 with WBPH resistance was selected. Genetically, the use of resistant cultivars, MAS, and DH breeding has proven to be environment friendly, efficient, and economical. This study confirmed the genetic basis for MAS to improve WBPH resistance in DHLs of WBPH/BPH resistant rice plants. [ABSTRACT FROM AUTHOR]

All ecofriendly alternative to chemical pesticides is biopesticides, which encompasses a broad array of microbial pesticides, biochemicals derived from micro-organisms and other natural sources, and processes involving the genetic incorporation of DNA into agricultural commodities that confer protection against pest damage. The field studies were carried out for effectiveness of insecticides and biopesticides against White backed Plant Hopper on rice in rewa region. Study of insect pest complex was done from 2006-07 to 2007- 08. The observations were made regarding the grain yield monocrotophos was the most efficient insecticide where as among biopescides wanis was the best. [ABSTRACT FROM AUTHOR]

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., (© 2013 Elsevier B.V. All rights reserved.)