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Sheath rot and dirty panicle are some of the major diseases of rice in Thailand. The diseases are traditionally considered to be caused by the pathogen Sarocladium oryzae and damage and lower both the quantity and quality of rice grain. In this study, 32 fungal isolates collected from the central and northeastern regions of Thailand were analysed phylogenetically using three molecular markers (ITS, D1/D2 of 28S rDNA and ACT) and physiological races were determined on 10 differential rice cultivars. We found that S. oryzae is not the only causal agent of sheath rot in Thailand, but S. attenuatum was also found. Despite having similar morphological features, the phylogenetic analysis recognised 11 of 32 isolates as S. attenuatum and the remaining isolates as S. oryzae. This is the first report of S. attenuatum causing sheath rot of rice in Thailand in addition to S. oryzae. Evaluation of physiological races revealed high pathogenic diversity of the two species. Thus, 16 and 11 physiological races were recorded from 21 isolates of S. oryzae and 11 isolates of S. attenuatum, respectively. These results indicate that both S. oryzae and S. attenuatum are the causal agents of rice sheath rot and dirty panicle in Thailand and that they are pathologically diverse. [ABSTRACT FROM AUTHOR]

Summary: The clade III subfamily of OsSWEETs includes transmembrane proteins necessary for susceptibility to bacterial blight (BB). These genes are targeted by the specific transcription activator‐like effector (TALE) of Xanthomonas oryzae pv. oryzae and mediate sucrose efflux for bacterial proliferation. However, the mechanism through which OsSWEETs regulate rice immunity has not been fully elucidated. Here, we demonstrated that the cytosolic carboxyl terminus of OsSWEET11a/Xa13 is required for complementing susceptibility to PXO99 in IRBB13 (xa13/xa13). Interestingly, the C‐terminus of ZmXa13, the maize homologue of OsSWEET11a/Xa13, could perfectly substitute for the C‐terminus of OsSWEET11a/Xa13. Furthermore, OsSWEET11a/Xa13 interacted with the high‐mobility group B1 (OsHMGB1) protein and the small heat shock‐like protein OsHsp20L through the same regions in the C‐terminus. Consistent with the physical interactions, knockdown or knockout of either OsHMGB1 or OsHsp20L caused an enhanced PXO99‐resistant phenotype similar to that of OsSWEET11a/OsXa13. Surprisingly, the plants in which OsHMGB1 or OsHsp20L was repressed developed increased resistance to PXO86, PXO61 and YN24, which carry TALEs targeting OsSWEET14/Xa41 or OsSWEET11a/Xa13. Additionally, OsHsp20L can interact with all six members of clade III OsSWEETs, whereas OsHMGB1 can interact with five other members in addition to OsSWEET12. Overall, we revealed that OsHMGB1 and OsHsp20L mediate conserved BB susceptibility by interacting with clade III OsSWEETs, which are candidates for breeding broad‐spectrum disease‐resistant rice. [ABSTRACT FROM AUTHOR]

Simple Summary: We exposed brown planthoppers (BPHs) Nilaparvata lugens to the entomopathogenic fungus Cordyceps javanica PSUC002 and observed morpho-histological changes from 0 to 120 h post-inoculation (pi). At 12 h pi, we observed the first filamentous fungi on the external integument and the first fungal conidia penetrated host planthopper cells at 24 h pi. In contrast, we observed the initial degeneration of BPHs at 6 h pi, especially in the integument and adipose tissue. We also found the degeneration of integument and adipose tissue at 12 h pi, and their completed necrosis became clear at 96 h pi. This study illustrated the process of C. javanica infection in BPHs and demonstrated that fungal agents can be used to control the BPHs in an integrated pest management (IPM) program. The brown planthopper (BPH), Nilaparvata lugens (Stål, 1854), is a pest of rice plants worldwide. Cordyceps javanica is a destructive entomopathogenic fungus known to attack leafhoppers or BPHs specifically. Live adult BPH samples were inoculated with isolated C. javanica PSUC002, and their interaction was morpho-histologically examined from 0 to 120 h post-inoculation (pi). We observed that the mortality of BPH continuously increased until 120 h pi (Day 5). Tissue alterations in the host were examined after infection using morphological and histological methods, including the Grocott Methenamine Silver stain test (GMS). Filamentous fungi were first found on the external integument at 12 h pi, and fungal conidia attached to the integument at 24 h pi. However, the initial degeneration of BPHs was identified by histology at 6 h pi especially in the integument and adipose tissue. We identified the degeneration and loss of integument and adipose tissue of infected BPHs at 12 h pi, and their necrosis was completed at 96 h pi. The enzymatic index of the sampled fungi (chitinase and protease) peaked at 7 days of incubation. This study demonstrated that C. javanica PSUC002 is useful to control the BPHs as an eco-friendly practice and will possibly be applied in agriculture. [ABSTRACT FROM AUTHOR]

Temporal change in vegetation complexity and field management may interactively affect the structure of predator–prey networks in agroecosystems and consequently alter the biocontrol potential of predators. There is a limited number of studies that have addressed these questions for generalist predator–prey networks.We investigated how vegetation complexity during crop development and management type (conventional vs. organic) affect the trophic networks of orb‐weaving spiders and their prey in rainfed lowland rice ecosystems in southern Thailand. Specifically, we investigated orb‐weaving spiders and prey composition, prey selectivity and network structure.Overall, orb‐weaving spiders captured mostly detritus‐associated Diptera, aquatic‐associated Ephemeroptera and Hemiptera pests. The increasing vegetation complexity during rice development significantly restructured the network of orb‐weaving spiders and prey, while field management had only a marginal effect. The increased vegetation complexity during rice development led to an increased number of weak trophic interactions in comparison to few but strong interactions in simple vegetation.Our results indicate that increasing the number of spider species per prey taxon (prey vulnerability) in late rice season may enhance their top‐down control of prey including rice pests. This study also highlights that the network complexity and the stability of rice ecosystems increased during the rice growing season as the vegetation became more complex.Future practices could look for a way to support the densities of detritus and aquatic insects and to artificially increase habitat complexity during the early stage of rice development to improve the biocontrol services provided by the orb‐weaving spiders. [ABSTRACT FROM AUTHOR]

The identification and classification of pests in rice field are the prerequisites of early warning systems for pest dis-asters. Among these pests, the rice planthoppers cause the most serious damage. However, the existing deep learning models for rice planthopper recognition are characterized by large size and numerous parameters, which makes them unsuitable for the deployment on embedded devices with limited computational resources. To address this issue, a lightweight rice planthopper recognition model based on YOLOv5 is proposed in this paper. In the model, a lightweight convolutional network named GhostNet is employed as the backbone to reduce the operational parameters. Additionally, a convolutional attention module (CBAM) is integrated into the backbone network to effectively enhance the transmission of deep information, so as to improve the model's ability of recognizing rice planthopper images. The original CIoU loss function is replaced by the SIoU loss function to expedite model convergence. Experimental results demonstrate that the modified model achieves the mAP@0.5 as 82.8%, with the parameter count of 3.12x106 and the model size of 7.2MB. Compared to the original model, it is a reduction of 46.7% in size and 43.3% in parameters, with a minor accuracy loss of 0.1%. Clearly, the improved model can achieve lightweight characteristics and robust performance, and thus it provides a theoretical and practical foundation for early warning systems against rice planthopper infestations in rice fields. [ABSTRACT FROM AUTHOR]

Small non-coding RNAs (sRNAs) act as post-transcriptional regulators to participate in many cellular processes. Among these, sRNA trans217 has been identified as a key virulent factor associated with pathogenicity in rice, triggering hypersensitive reactions in non-host tobacco and facilitating the secretion of the PthXo1 effector in Xanthomonas oryzae pv. oryzae (Xoo) strain PXO99A. Elucidating potential targets and downstream regulatory genes is crucial for understanding cellular networks governing pathogenicity and plant resistance. To explore the targets regulated by sRNA trans217, transcriptome sequencing was carried out to assess differential expression genes (DEGs) between the wild-type strain PXO99A and a mutant lacking the sRNA fragment under both virulence-inducing or normal growth conditions. DEG analysis revealed that sRNA trans217 was responsible for diverse functions, such as type III secretion system (T3SS), glutamate synthase activity, and oxidative stress response. Three genes were selected for further investigation due to their significant differential expression and biological relevance. Deletion of PXO_RS08490 attenuated the pathogenicity of Xoo in rice and reduced the tolerance level of PXO99A to hydrogen peroxide. These findings suggest a regulatory role of sRNA trans217 in modulating bacterial virulence through multiple gene targets, either directly or indirectly. [ABSTRACT FROM AUTHOR]

BACKGROUND: Bacterial virulence factors are involved in various biological processes and mediate persistent bacterial infections. Focusing on virulence factors of phytopathogenic bacteria is an attractive strategy and crucial direction in pesticide discovery to prevent invasive and persistent bacterial infection. Hence, discovery and development of novel agrochemicals with high activity, low‐risk, and potent anti‐virulence is urgently needed to control plant bacterial diseases. RESULTS: A series of novel β‐hydroxy pyridinium cation decorated pterostilbene derivatives were prepared and their antibacterial activities against Xanthomonas oryzae pv. oryzae (Xoo) were systematacially assessed. Among these pterostilbene derivatives, compound 4S exhibited the best antibacterial activity against Xoo in vitro, with an half maximal effective concentration (EC50) value of 0.28 μg mL−1. A series of biochemical assays including scanning electron microscopy, crystal violet staining, and analysis of biofilm formation, swimming motility, and related virulence factor gene expression levels demonstrated that compound 4S could function as a new anti‐virulence factor inhibitor by interfering with the bacterial infection process. Furthermore, the pot experiments provided convinced evidence that compound 4S had the high control efficacy (curative activity: 71.4%, protective activity: 72.6%), and could be used to effectively manage rice bacterial leaf blight in vivo. CONCLUSION: Compounds 4S is an attractive virulence factor inhibitor with potential for application in treating plant bacterial diseases by suppressing production of several virulence factors. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Xanthomonas oryzae pv. oryzae is a destructive bacterial disease of rice. Due to the development of resistance by the existing bactericides, an alternative eco-friendly management strategy should be identified to contain the disease. The present study focused on the efficacy of salicylic acid (SA) and their metabolically active biomolecules against X. oryzae pv. oryzae during their interaction. The biofilm inhibition clearly expressed the aggregation, separation and presence of dead cells at various concentrations of SA. The highest biofilm production was observed for untreated control with maximum O.D. value. There is a significant difference in their O.D. values on the concentrations of SA. While studying the inhibition percentages, the chloramphenicol @ 0.2% recorded the highest percentage (76.65%) which shows significant results with SA at 250 ppm (75.56) followed by 100 and 50 ppm which exhibited no significant differences in their inhibition percentages (65.78% and 45.74%, respectively). Under CLSM the Xoo cell aggregation and separation has been observed at 50 ppm and 100 ppm and diminished at 250 ppm respectively. Under in silico analysis, the biomolecules from SA, viz., tetradecanoic acid, methyl oleate, and decyl acrylate, were extracted with a higher area percentage against Xoo target proteins with chloramphenicol as a positive control. Tetradecanoic acid has the highest -C DOCKER energy of 39.46 kcal/mol with the effector proteins of Xoo. The docked metabolites, were subjected to in planta assays, among them tetradecanoic acid recorded minimum lesion size of 0.6 cm at 5000 ppm followed by decyl acrylate (1.5 cm).Our results suggest that overexpression of NPR 1, PAL and LOX has been documented at SA at 250 ppm which can be used to improve BLB resistance in rice. The present study concludes that salicylic acid plays a signalling role inhibition of Xoo biofilm, a source of biomolecules, activation of various plant defence responses against Xoo. [ABSTRACT FROM AUTHOR]

This study compares the food-production efficiencies of integrated rice-fish farming and rice monoculture and evaluates how these farming systems contribute to sustainable food production in the Mekong Delta. The study explores how food-production efficiencies are influenced by the systems' ecological connectivity by comparing more integrated systems that apply integrated rice-fish farming and integrated pest management (IPM) with less integrated systems farming only rice. Rice-fish farmers with plenty of fish had significantly higher rice yields than farmers with less or no fish, especially during the second crop when the rice was grown together with the fish. A positive correlation between the fish and rice yields, indicated synergistic effects between the fish and rice, due to strengthened ecological connectivity and trophic interactions within the rice-field ecosystem. Overall, rice-fish farmers had higher rice yields than rice farmers, despite using lower amounts of fertilizers and pesticides. They also had lower rice production costs compared to rice farmers, partly because the fish helped fertilize the rice and control rice pests. They had a significantly higher profit and benefit cost ratio than rice farmers because of lower production costs, and high rice and fish yields. The results indicate that food-production efficiencies in the Mekong Delta can be enhanced through diversification and increased ecological connectivity, leading to a more efficient use of rice field ecosystem services that support a long-term and healthy production of food. [ABSTRACT FROM AUTHOR]

Brown spot (BS) disease causes significant losses to rice productivity. In this study, a roving survey in the Karnataka state of India revealed a wider distribution of BS with a percent disease index range of 20.56–50.74. From the symptomatic geo-distinct samples, pure cultures of 63 isolates were obtained. Based on the conidial morphology, 63 isolates were identified as Bipolaris oryzae (Bo) (n = 40), Curvularia lunata (Cl) (n = 15), and Exserohilum rostratum (Er) (n = 08). The taxonomic identity was further confirmed via ITS-sequencing. A pathogenicity assay on a BS-susceptible rice cultivar GNV-05–01 confirmed the pathogenicity of all three pathogens, which induces typical BS disease on test plants. Further, on PDA media, all isolates of three pathogens showed significant cultural diversity for mycelial color, colony type, and sporulation. We further studied the in-planta distribution of three pathogens on a randomly collected 600 BS spots from 10 different rice fields, which indicated that 77.83%, 17.33%, and 4.83% of the typical BS were produced by Bo, Cl, and Er, respectively. The ITS region was sequenced for selected 9, 7, and 3 isolates of Bo, Cl, and Er, respectively, and analyzed for their nucleotide and haplotype diversity, and phylogenetic relationships. A phylogenetic study identified the unique clustering patterns, and haplotyping indicated 3, 4, and 6 haplotypes. Tajima's D (D) test showed several rare alleles in the ITS regions. This is the first comprehensive study reporting the three fungal pathogens causing BS of rice and it is useful for re-designing the screening protocol for the host plant resistance breeding program. [ABSTRACT FROM AUTHOR]

Objectives: Rice (Oryza sativa) is the most important food for more than two thirds of the world's population. Bangladesh is the third largest producer and consumer of rice globally. Recently, several symptoms of Bacterial Panicle Blight (BPB) in rice, including seedling blight, sheath rot, floret sterility, and spotted grains, have been detected in the country. In addition, the presence of the most prevalent and virulent causative agent of BPB, Burkholderia glumae, has been confirmed in rice displaying symptoms of the disease. BPB could become one of the next emerging diseases of rice in Bangladesh, and a complete genome of a B. glumae strain from the country will help clarify its origin and devise proper management systems to continue sustainable rice production. Data description: We report the first complete genome sequence of a B. glumae strain (BD_21g) isolated from symptomatic rice grains in Bangladesh (Natore District). The genome contains 2 chromosomes (1 and 2, with 3,417,499 and 3,855,283 bp, respectively) and 4 plasmids (1-4, with 123,248, 46,628, 88,744 and 53,064 bp, respectively). [ABSTRACT FROM AUTHOR]

Introduction: Akirin as a highly conserved transcription factor, exerts a profound influence on the growth, development, immune response, and reproductive processes in animals. The brown planthopper (BPH), Nilaparvata lugens, a major pest in rice production in Asia, possesses high reproductive capacity, a critical factor contributing to reduced rice yields. The aims of this study were to demonstrate the regulatory role of Akirin in the reproduction of BPH. Methods: In this study, quantitative PCR (qPCR) was used to detect the mRNA expression of genes. RNA interference (RNAi) was used to downregulate the expression of Akirin gene, and RNA sequencing (RNA-seq) was used to screen for differentially expressed genes caused by Akirin downregulation. Hormone contents were measured with the enzyme linked immunosorbent assay (ELISA), and protein content was evaluated with the bicinchoninic acid (BCA) method. Results: Using BPH genome data, we screened for an Akirin gene (NlAkirin). An analysis of tissue-specific expressions showed that NlAkirin was expressed in all tissues tested in female BPH, but its expression level was highest in the ovary. After inhibiting the mRNA expression of NlAkirin in BPH females, the number of eggs laid, hatching rate, and number of ovarioles decreased. Transcriptome sequencing was performed, following a NlAkirin double-stranded RNA treatment. Compared with the genes of the control, which was injected with GFP double-stranded RNA, there were 438 upregulated genes and 1012 downregulated genes; the expression of vitellogenin (Vg) and vitellogenin receptor (VgR) genes as well as the mRNA expression of genes related to the target of rapamycin (TOR), juvenile hormone (JH), and insulin pathways involved in Vg synthesis was significantly downregulated. As a result of NlAkirin knockdown, the titers of JH III and Ecdysone (Ecd) were downregulated in unmated females but returned to normal levels in mated females. The ovarian protein contents in both unmated and mated females were downregulated. Discussion and conclusion: Our results suggest that NlAkirin affects female BPH reproduction by regulating the mRNA expression of genes related to the Vg, VgR, TOR, JH, and insulin signaling pathways, in addition to the titers of JH III and Ecd. The findings of this research provide novel insights into the regulatory role of Akirin in insect reproductive capacity. [ABSTRACT FROM AUTHOR]

Fusarium fujikuroi, the causal agent of rice bakanae disease (RBD), contains five succinate dehydrogenase (Sdh) subunits: FfSdhA, FfSdhB, FfSdhC1, FfSdhC2, and FfSdhD. However, the role of these subunits in regulating sensitivity to succinate dehydrogenase inhibitors (SDHIs) is largely unknown. Here, we conducted targeted gene disruption and phenotypic assays for all Sdh subunits and found that the deletion mutants of FfSdhA, FfSdhB, and FfSdhD exhibited severe defects in hyphal growth, conidiation, virulence, and sensitivity to CaCl2 and oxidative stresses. To a lesser extent, the mycelial growth rate and conidial production of ΔFfSdhC1 were also decreased as compared to those of the wild-type strain JS16. In addition, fungicide sensitivity assays showed that deletion of FfSdhA, B, C1, or D led to decreased sensitivity to all SDHIs tested. Unexpectedly, we were unable to obtain a FfSdhC1 + C2 double mutant and further found significant up-regulation of FfSdhC2 in ∆FfSdhC1, indicating that FfSdhC1 and -C2 might be essential for fungal growth although the FfSdhC2 deletion mutant was indistinguishable from the wild-type strain. These findings provide useful information for enhancing our understanding of the biological functions of the Sdh subunits in pathogenic fungi. [ABSTRACT FROM AUTHOR]

Rice false smut caused by Ustilaginoidea virens has become one of the most important diseases of rice. Mycoviruses are viruses that can infect fungi with the potential to control fungal diseases. However, little is known about the biocontrol role of hypoviruses in U. virens. In this study, we revealed that the hypovirulence-associated U. virens strain Uv325 was co-infected by four novel mycoviruses from three lineages, designated Ustilaginoidea virens RNA virus 16 (UvRV16), Ustilaginoidea virens botourmiavirus virus 8 (UvBV8), Ustilaginoidea virens botourmiavirus virus 9 (UvBV9), and Ustilaginoidea virens narnavirus virus 13 (UvNV13), respectively. The U. virens strain co-infected by four mycoviruses showed slower growth rates, reduced conidial yield, and attenuated pigmentation. We demonstrated that UvRV16 was not only the major factor responsible for the hypovirulent phenotype in U. vriens, but also able to prevent U. virens to accumulate more mycotoxin, thereby weakening the inhibitory effects on rice seed germination and seedling growth. Additionally, we indicated that UvRV16 can disrupt the antiviral response of U. virens by suppressing the transcriptional expression of multiple genes involved in autophagy and RNA silencing. In conclusion, our study provided new insights into the biological control of rice false smut. [ABSTRACT FROM AUTHOR]

LuxR-type regulators play pivotal roles in regulating numerous bacterial processes, including bacterial motility and virulence, thereby exerting a significant influence on bacterial behavior and pathogenicity. Xanthomonas oryzae pv. oryzicola, a rice pathogen, causes bacterial leaf streak. Our research has identified VmsR, which is a response regulator of the two-component system (TCS) that belongs to the LuxR family. These findings of the experiment reveal that VmsR plays a crucial role in regulating pathogenicity, motility, biofilm formation, and the production of extracellular polysaccharides (EPSs) in Xoc GX01. Notably, our study shows that the vmsR mutant exhibits a reduced swimming motility but an enhanced swarming motility. Furthermore, this mutant displays decreased virulence while significantly increasing EPS production and biofilm formation. We have uncovered that VmsR directly interacts with the promoter regions of fliC and fliS, promoting their expression. In contrast, VmsR specifically binds to the promoter of gumB, resulting in its downregulation. These findings indicate that the knockout of vmsR has profound effects on virulence, motility, biofilm formation, and EPS production in Xoc GX01, providing insights into the intricate regulatory network of Xoc. [ABSTRACT FROM AUTHOR]

Nitrogen (N), as one of the most abundant mineral elements in rice, not only is the primary limiting factor for rice yield, but also impacts plant disease resistance by modulating plant morphology, regulating biochemical characteristics, as well as enhancing metabolic processes. Bacterial blight, a severe bacterial disease caused by Xanthomonas oryzae pv. oryzae (Xoo), significantly impairing rice yield and quality. Previous studies have shown that moderate application of nitrate nitrogen can improve plant disease resistance. However, further exploration is urgently required to investigate the involvement of the nitrate nitrogen signaling pathway in conferring resistance against bacterial leaf blight. In this study, we employed transcriptome sequencing to analyze the differentially expressed genes under various concentrations of nitrate supply duringrice bacterial blight infection. Our research reveals that nitrate nitrogen supply influences rice resistance to bacterial leaf blight. Through transcriptomic profiling of rice leaves inoculated under different nitrate nitrogen concentrations, we identified 4815 differentially expressed genes (DEGs) among four comparison groups, with notable differences in DEG enrichment between low and high nitrate nitrogen conditions, with some members of the NPF family implicated and we preliminarily elucidated the molecular regulatory network in which nitrate nitrogen participates in bacterial leaf blight resistance. Our findings provide a novel insight into a mechanism involving the nitrate nitrogen drive wider defense in rice. [ABSTRACT FROM AUTHOR]

Summary: Plants typically activate distinct defense pathways against various pathogens. Heightened resistance to one pathogen often coincides with increased susceptibility to another pathogen. However, the underlying molecular basis of this antagonistic response remains unclear.Here, we demonstrate that mutants defective in the transcription factor ETHYLENE‐INSENSITIVE 3‐LIKE 2 (OsEIL2) exhibited enhanced resistance to the biotrophic bacterial pathogen Xanthomonas oryzae pv oryzae and to the hemibiotrophic fungal pathogen Magnaporthe oryzae, but enhanced susceptibility to the necrotrophic fungal pathogen Rhizoctonia solani.Furthermore, necrotroph‐induced OsEIL2 binds to the promoter of OsWRKY67 with high affinity, leading to the upregulation of salicylic acid (SA)/jasmonic acid (JA) pathway genes and increased SA/JA levels, ultimately resulting in enhanced resistance.However, biotroph‐ and hemibiotroph‐induced OsEIL2 targets OsERF083, resulting in the inhibition of SA/JA pathway genes and decreased SA/JA levels, ultimately leading to reduced resistance. Our findings unveil a previously uncharacterized defense mechanism wherein two distinct transcriptional regulatory modules differentially mediate immunity against pathogens with different lifestyles through the transcriptional reprogramming of phytohormone pathway genes. [ABSTRACT FROM AUTHOR]

The Rice Sheath Mite, Steneotarsonemus spinki Smiley (Acari: Tarsonemidae) is a pest of Kharif Rice (wet rice) of West Bengal, causing losses every year. It initially infests leaf sheaths, moving later onto the grains. It is not known how the mite survives in the off season, which is important for devising management strategies. The present investigation was conducted to find out the sources of infestation of S. spinki. It was concentrated on four types of substrates: rice associated weeds, soil, rice grains of different ages (before and after harvesting) and rice stubbles. Mites detected in any of those possible sources were slide mounted in modified Berlese medium and examined under phase and differential interference contrast microscope for identification. Tarsonemid mites were found on some grassy weeds, but not Steneotarsonemus spinki Smiley. No tarsonemid mite was found in soil samples from infested fields. Steneotarsonemus spinki was found on rice grains of different ages and in stubbles. Hence, both rice grains and rice stubbles could be important sources of infestation of S. spinki to new plants at each season. [ABSTRACT FROM AUTHOR]

Bakanae disease is mainly caused by Fusarium fujikuroi and is a significant fungal disease with a number of disastrous consequences. It causes great losses in rice production. However, few studies have focused on the details of bakanae disease resistance in rice. Here, we summarize and discuss the progress of bakanae disease resistance in rice. Besides rice germplasm screening and resistance-related gene/quantitative trait locus (QTL) exploration, the route of pathogen invasion in rice plants was determined. We further discussed the regulation of phytohormone-related genes and changes in endogenous phytohormones in rice plants that are induced by the pathogen. To achieve better control of bakanae disease, the use of natural fungicides was assessed in this review. During rice—F. fujikuroi interactions, the infection processes and spatial distribution of F. fujikuroi in infected seedlings and adult plants exhibit different trends. Fungal growth normally occurs both in resistant and susceptible cultivars, with less abundance in the former. Generally, bakanae disease is seed-borne, and seed disinfection using effective fungicides should always be the first and main option to better control the disease. Besides the friendly and effective measure of using natural fungicides, breeding and utilization of resistant rice cultivars is also an effective control method. To some extent, rice cultivars with low grain quality, indica subspecies, and some dwarf or semi-dwarf rice germplasms are more resistant to bakanae disease. Although no highly resistant germplasms were obtained, 37 QTLs were located, with almost half of the QTLs being located on chromosome 1. Using omics methods, WRKYs and MAPKs were usually found to be regulated during rice—F. fujikuroi interactions. The regulation of certain phytohormone-related genes and changes in some endogenous phytohormones induced by the pathogen were clear, i.e., it downregulated gibberellin-related genes and repressed endogenous gibberellins in resistant genotypes, but the opposite results were noted in susceptible rice genotypes. Overall, exploring resistant germplasms or resistance-related genes/QTLs for the breeding of rice with bakanae disease resistance, expanding research on the complex mechanism of rice—F. fujikuroi interactions, and using cost-effective and eco-friendly innovative control methods against the disease are necessary for present and future bakanae disease management. [ABSTRACT FROM AUTHOR]

Enhancing carbohydrate export from source to sink tissues is considered to be a realistic approach for improving photosynthetic efficiency and crop yield. The rice sucrose transporters OsSUT1, OsSWEET11a and OsSWEET14 contribute to sucrose phloem loading and seed filling. Crucially, Xanthomonas oryzae pv. oryzae (Xoo) infection in rice enhances the expression of OsSWEET11a and OsSWEET14 genes, and causes leaf blight. Here we show that co‐overexpression of OsSUT1, OsSWEET11a and OsSWEET14 in rice reduced sucrose synthesis and transport leading to lower growth and yield but reduced susceptibility to Xoo relative to controls. The immunity‐related hypersensitive response (HR) was enhanced in the transformed lines as indicated by the increased expression of defence genes, higher salicylic acid content and presence of HR lesions on the leaves. The results suggest that the increased expression of OsSWEET11a and OsSWEET14 in rice is perceived as a pathogen (Xoo) attack that triggers HR and results in constitutive activation of plant defences that are related to the signalling pathways of pathogen starvation. These findings provide a mechanistic basis for the trade‐off between plant growth and immunity because decreased susceptibility against Xoo compromised plant growth and yield. Summary statement: The study reported in this manuscript concerns the emerging topic of the roles played by SWEET sugar transporters in plant immunity. The data reported in this manuscript show that overexpression of Clade III SWEET sucrose transporters OsSWEET11a and OsSWEET14 that are exploited by bacterial blight pathogen Xanthomonas oryzae pv. oryzae to acquire sugars for its propagation elicits immune responses and activates plant defence responses leading to enhanced resistance against bacterial as well as fungal pathogens. The findings obtained by the overexpression of OsSWEET11a and OsSWEET14 in rice show that sucrose transport occurs via an apoplastic route, and overexpression of these sugar transporters inhibits sucrose synthesis and transport, which explains the inverse relationships between plant growth and yield, and resistance to pathogens. Moreover, our results show that sucrose transport and pathogen responses are coupled processes, and provide evidence for the concept that pathogen‐induced starvation is linked to plant defence. Also, to the best of our knowledge this is the first study where we show that disease susceptibility genes OsSWEET11a and OsSWEET14 can lead to hypersensitive reaction leading to enhanced plant immunity. [ABSTRACT FROM AUTHOR]

Application of radio frequency (RF) treatment has been studied for disinfesting agricultural products, and RF heating non-uniformity has been demonstrated to directly influence pest mortality in treated products. The purpose of this study was to investigate the combined effects of holding time after conveyor movement, layer rearrangement, and sample mixing on the mortality of Rhyzopertha dominica (R. dominica) in milled rice treated with hot air-assisted RF heating. Results showed that hot-air assistance during the process of RF heating can lead to a rapid temperature rise and improve the temperature distribution. RF heating followed by holding samples in hot air for specific time periods effectively improved the heating uniformity of samples and raised the mortality of R. dominica in milled rice. Compared with the stationary conditions, conveyor movement, layer rearrangement, and sample mixing improved the hot air-assisted RF heating uniformity of the sample, raised pest mortality and reduced the thermal holding time after RF treatment required to achieve 100% pest mortality in milled rice. The findings of this study provide a valuable proof of concept for improving RF heating uniformity and optimizing parameters in RF disinfestation protocols for milled rice. [ABSTRACT FROM AUTHOR]

Traditional small‐holder agricultural landscapes in southern China are being consolidated to increase mechanisation levels in agriculture, but it is unclear how this influences rice arthropod communities in these landscapes.Here, based on a six‐year study in 20 rice fields, we evaluated the impact of land consolidation on arthropod communities, crop damage, and rice yield. We also analysed how effects of land consolidation were moderated by the proportion of large semi‐natural habitat patches and insecticide use.We found that, compared to consolidated fields, rice fields in traditional farmlands had a higher abundance and family richness of natural enemies, but a similar abundance of rice pests. Land consolidation did not significantly interact with the proportion of large semi‐natural habitat patches or insecticide application, in terms of affecting arthropods. The proportion of semi‐natural habitat reduced the negative effect of insecticide application on key rice pests, but no equivalent interaction occurred for natural enemies.Synthesis and applications: Land consolidation can have negative impacts on the abundance and richness of natural enemies, but not pests in small‐holder rice systems, and these impacts are independent from insecticide application and proportion of semi‐natural habitat in the landscape. We recommend the implementation of agri‐environmental measures or re‐establishing field margin vegetation during the consolidation process to mitigate these potential negative effects, although trade‐off between enhancing crop yields and preserving rice arthropod biodiversity should be considered. We encourage future research to focus on the detailed assessment of the function of linear habitats for a better understanding of the impact of land consolidation. [ABSTRACT FROM AUTHOR]

[Objectives] Aiming at the lack of disease description in rice diseases and pests image classification technology, a lightweight rice diseases and pests image description model was proposed in this paper to describe rice diseases and pests image more specifically. [Methods] Ten common rice pests and diseases, such as rice bacterial blight, rice bacterial streak disease, rice bakanae disease, rice three chemical borers, rice blast, rice false smut, rice sheath blight, rice planthopper, rice thrip and rice brown spot were studied, and Chinese description data set of rice pests and diseases image was constructed. Firstly, the multimodal pre-training model CLIP was used to generate image vectors, which contained basic image information and rich semantic information. The mapping network was used to map the image vectors into the text space to generate text prompt vectors. Finally, the language model GPT-2 generates image descriptions according to the prompt vectors. [Results] The test results showed that the indexes of the model in this paper were significantly superior to other models in the image description data set of rice pests and diseases. Compared with the traditional CNN_ LSTM model, the indexes of BLEU-1, BLEU-2, BLEU-3, BLEU-4, ROUGE and METEOR improved 0.26, 0.27, 0.24, 0.22, 0.22 and 0.14, respectively. And the generated image description had the advantages of accurate, detailed and rich semantics. The model was tested by using actual rice field pictures. The actual field scenes were more complex and diverse, and the generated image description index only slightly decreased compared with the data set index, which was still higher than other comparison models. The overall recognition accuracy of the model was 97.28%. [Conclusions] The image description method of rice diseases and pests based on multimodal pre-training model can accurately describe the rice diseases and pests, and provide a new idea for the detection of rice diseases and pests. [ABSTRACT FROM AUTHOR]

Sheath blight (ShB) is the most serious disease of rice (Oryza sativa L.), caused by the soil-borne fungus Rhizoctonia solani Kühn (R. solani). It poses a significant threat to global rice productivity, resulting in approximately 50% annual yield loss. Managing ShB is particularly challenging due to the broad host range of the pathogen, its necrotrophic nature, the emergence of new races, and the limited availability of highly resistant germplasm. In this study, we conducted QTL mapping using an F2 population derived from a cross between a partially resistant accession (IRGC81941A) of Oryza nivara and the susceptible rice cultivar Punjab rice 121 (PR121). Our analysis identified 29 QTLs for ShB resistance, collectively explaining a phenotypic variance ranging from 4.70 to 48.05%. Notably, a cluster of four QTLs (qRLH1.1, qRLH1.2, qRLH1.5, and qRLH1.8) on chromosome 1 consistently exhibit a resistant response against R. solani. These QTLs span from 0.096 to 420.1 Kb on the rice reference genome and contain several important genes, including Ser/Thr protein kinase, auxin-responsive protein, protease inhibitor/seed storage/LTP family protein, MLO domain-containing protein, disease-responsive protein, thaumatin-like protein, Avr9/Cf9-eliciting protein, and various transcription factors. Additionally, simple sequence repeats (SSR) markers RM212 and RM246 linked to these QTLs effectively distinguish resistant and susceptible rice cultivars, showing great promise for marker-assisted selection programs. Furthermore, our study identified pre-breeding lines in the advanced backcrossed population that exhibited superior agronomic traits and sheath blight resistance compared to the recurrent parent. These promising lines hold significant potential for enhancing the sheath blight resistance in elite cultivars through targeted improvement efforts. [ABSTRACT FROM AUTHOR]

Half of the world's population depends on rice for their calories. Protecting rice in the growth period from damage caused by phytopathogens is faced with a great challenge under the frequent extreme climate. To find novel fungicides to control rice diseases, 35 novel phenylthiazole‐1,3,4‐oxadiazole‐thioether (sulfone) derivatives were synthesized and evaluated for their efficacy against destructive fungal and bacterial diseases of rice. Bioassay results demonstrated that most of G‐series compounds possessed excellent antifungal and antibacterial activities. In particular, compounds G1 (EC50 = 2.22 μg/mL, R.s) and G7 (EC50 = 2.76 μg/mL, R.s) showed the most promising antifungal activities in vitro and exhibited superior protective and curative activities against rice sheath blight in vivo compared with commercial carbendazim. Surprisingly, compound G2 exhibited the remarkable antibacterial activity against Xanthomonas oryzae pv. oryzae (Xoo) with an EC50 value of 1.98 μg/mL, and demonstrated superior protective activity (88.08%) than thiodiazole copper (79.39%) against rice bacterial leaf blight at 200 μg/mL. The abovementioned results fully manifested that the phenylthiazole‐1,3,4‐oxadiazole‐sulfone structure, especially compounds G1 and G2, had the potential to develop as commercial agents for controlling rice fungal and bacterial diseases. [ABSTRACT FROM AUTHOR]

The article presents a study which evaluated and screened different doses for the management of bacterial blight, false smut and blast diseases of paddy. Topics discussed include assessment of false smut disease on paddy crop, bio-efficacy of cuprous oxide 86.2 percent WG against bacterial blight disease of paddy, and grain yields.

Rice consumption, particularly of highly processed white rice (WR), has been associated with increased risk of insulin resistance (IR). This study aimed to compare the impact of consuming WR versus brown rice (BR) from five common local rice varieties in Nigeria on the development of IR using a Wistar albino rat model. Five local rice cultivars (Jamila, Kwandala, MBC, Yarkatabore, Farar jalof) were collected, with one set kept unpolished (BR) and the other polished (WR). Proximate analysis and quantification of bioactive compounds (total phenols, flavonoids) were performed. Wistar albino rats were fed either a normal diet, high-fat diet, or diets containing 100% BR or WR for 12 weeks. Body weight, fasting blood glucose, glycogen, triglycerides were assessed. BR varieties had higher protein, fiber, and carbohydrate content compared to WR. BR also exhibited significantly greater total phenolic and flavonoid contents. Rats fed BR showed no significant weight gain (p<0.05), while some WR groups gained weight. Fasting blood glucose was elevated in WR groups versus control and BR groups. Blood glycogen was lower, and triglycerides higher, in certain WR groups. Consumption of BR varieties may confer protective effects against IR compared to WR in this rat model. These findings highlight the potential metabolic health benefits of incorporating local BR varieties into the diet to mitigate development of chronic disorders. [ABSTRACT FROM AUTHOR]

Bacterial panicle blight (BPB) is an emerging rice disease in Nigeria, causing up to 75% yield loss and widespread globally. In the 2019 season, rice farmers in Zamfara State's Gusau, Talata Mafara, Maradun, and Bakura communities reported significant yield declines due to an unidentified disease. Infected samples suggested BPB as the cause, yet the pathogen had not been identified in Nigeria. A trial was conducted to identify and characterize BPB pathogens in Zamfara State, aiming to screen rice germplasm and find resistant sources. Infected rice grains from the region were collected and cultured on King's B medium at 37°C for 48 hours in the microbiology lab of Federal University Gusau. The bacteria were purified to single colonies and analyzed morphologically and via polymerase chain reaction (PCR), identifying the strain as Burkholderia glumae. This strain produced toxoflavin, a compound linked to its pathogenicity. PCR amplification of a 1079- bp fragment using gyrB-specific primers confirmed B. glumae as the BPB agent in Nigeria. A pathogenicity test was performed on three commercial rice varieties (Faro 44, FARO 56, and FARO 59) using the syringe inoculation method at the Biological Garden, Department of Biological Sciences, Federal University Gusau. All inoculated rice varieties exhibited typical BPB symptoms within three days, similar to those seen in naturally infected rice panicles. This confirmed B. glumae as the causative pathogen and highlighted the urgent need for resistant rice varieties. [ABSTRACT FROM AUTHOR]

Copyright of Jurnal Fitopatologi Indonesia is the property of IPB University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Jurnal Fitopatologi Indonesia is the property of IPB University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Rice is considered one the most important plants globally because it is a source of food for over half the world’s population. Like other plants, rice is susceptible to diseases that may affect the quantity and quality of produce. Because of this, crops sometimes lose 20% to 40% of their value. A good harvest can depend on early discovery of these diseases, so farmers would need to be able to read and understand images of the diseases. Also, farmers still can't reach their goal of doing daily studies of their huge farmlands. It would be very expensive to do this, so the price of rice for buyers would go up even if it were possible. This paper proposed a pre-trained Deep Convolutional Neural Network (DCNN) method based on optimization for accurately finding and classifying rice leaf disease. It uses both transfer learning and baseline learning. A precise diagnosis method can find and classify eleven different types of rice diseased healthy, leaf blast, brown spot, bacterial blight and bacterial leaf blight, false stump, neck blast, stemborer, tumgro, hispa, and BPH. The most advanced large-scale architecture, such as XceptionNet, ResNet50, DenseNet VGG19, SequeezeNet and CNN used for recognition of the Rice disease, with SGDM, ADAM, RMS propagation optimization methods for predictions for a dataset. The -proposed models were trained and tested using datasets gathered from websites. In the simulation results consistently demonstrate that the XceptionNet model outperforms other architectures in terms of higher accuracy 93.3 %. [ABSTRACT FROM AUTHOR]

BACKGROUND: The Southern rice black‐streaked dwarf virus (SRBSDV) transmitted by Sogatella furcifera constitutes a threat to sustainable rice production. However, most rice varieties are highly vulnerable to SRBSDV, whereas the occurrence of the viral disease varies significantly under field conditions. This study aimed to evaluate the potential of rice varietal resistance to S. furcifera in reducing SRBSDV transmission. RESULTS: Among the five rice varieties, Zhongzheyou8 and Deyou108 exhibited high resistance to S. furcifera, Baixiangnuo33 was susceptible, and TN1 and Diantun502 were highly susceptible. The S. furcifera generally showed non‐preference for and low feeding on the Zhongzheyou8 and Deyou108 plants, which may explain the resistance of these varieties to S. furcifera. Transmission of SRBSDV by S. furcifera was significantly impaired on the resistant varieties, both inoculation and acquisition rates were much lower on Zhongzheyou8 than on TN1. The short durations of S. furcifera salivation and phloem‐related activities and the low S. furcifera feeding amount may explain the reduced SRBSDV inoculation and acquisition rates associated with Zhongzheyou8. Spearman's rank correlation revealed a significant negative correlation between S. furcifera resistance and SRBSDV transmission among the tested varieties. CONCLUSION: The results indicate that rice varietal resistance to the vector S. furcifera hinders SRBSDV transmission, which is largely associated with the host plant selection and feeding behaviors of the vector. The current findings shed light on the management of the SRBSDV viral disease through incorporation of S. furcifera resistant rice varieties in the management protocol. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Rice plants have evolved defense mechanisms against insect attacks, leading to induced defense responses that can influence the composition of arthropod communities in rice fields. Inducing defense responses not only reduces rice pest population densities but also helps minimize the use of insecticides. Both herbivore-induced plant volatiles and elicitors are crucial in controlling insect pests and attracting natural enemies. The volatile profiles of insect-infested and uninfested rice plants were studied under screen house and open field conditions. GC MS/MS analysis of volatile samples of rice plants grown under screen houses and in the field revealed that at different growth stages of the crop (tillering, panicle initiation, and grain maturation), herbivore-infested rice crops contained a higher number of compounds (9 to 34 compounds) when compared to uninfested rice plants. The chemical profiles of infested and uninfested rice plants showed similarity in the presence of Eicosane, which was found in higher quantities in infested rice plants, particularly in the tillering stage. The composition of herbivore-induced plant volatiles varied depending on the growth stage of the rice crop. At the tillering and panicle initiation stages, Eicosane, Tetradecane, and Tridecane dominated the volatile blend in herbivore-infested plants. In contrast, at the grain maturation stage, Tetradecanoic acid and N-Hexadecanoic acid were more prevalent. The number of volatiles released by rice plants also varied across growth stages, with more compounds being released during the tillering stage compared to panicle initiation and grain maturation stages. [ABSTRACT FROM AUTHOR]

Tadpole shrimp (Triops longicaudatus) has become a major pest for California rice farmers. Currently, management relies solely on the insecticide lambda-cyhalothrin. However, resistance to this pyrethroid was confirmed in 2016; thus, identifying an effective and practical biological control method for TPS is a priority. Field trials were conducted from 2017 to 2018 to (1) evaluate the efficacy of the predatory fish Gambusia affinis and the predatory beetles, Laccophilus maculosus (Say) and Tropisternus lateralis (Fabricius), in controlling TPS, (2) test the efficacy of several inoculation rates of Gambusia affinis at controlling TPS and (3) to explore early indicators of TPS activity and damage as monitoring tools. Both Gambusia affinis and the predatory beetle treatments were not significantly different from the commercial standard (lambda-cyhalothrin). Both four and five Gambusia per 1 m2 controlled TPS as well as lambda-cyhalothrin, and we observed that Gambusia affinis was able to reproduce in the field. Water turbidity was significantly correlated with TPS counts (R = 0.85, N = 20, p < 0.0001 (2017); R = 0.58, N = 30, p = 0.0007 (2018)). The number of dislodged seedlings was less reliably correlated with TPS count; in 2017, correlations were significant (R = 0.84, N = 20, p < 0.0001); however, in 2018, correlations were not significant (R = 0.18, N = 30, p = 0.35). With further refinement, water turbidity could play a valuable role in monitoring TPS populations. [ABSTRACT FROM AUTHOR]

Intelligent pest detection algorithms are capable of effectively detecting and recognizing agricultural pests, providing important recommendations for field pest control. However, existing recognition models have shortcomings such as poor accuracy or a large number of parameters. Therefore, this study proposes a lightweight and accurate rice pest detection algorithm based on improved YOLOv8. Firstly, a Multi-branch Convolutional Block Attention Module (M-CBAM) is constructed in the YOLOv8 network to enhance the feature extraction capability for pest targets, yielding better detection results. Secondly, the Minimum Points Distance Intersection over Union (MPDIoU) is introduced as a bounding box loss metric, enabling faster model convergence and improved detection results. Lastly, lightweight Ghost convolutional modules are utilized to significantly reduce model parameters while maintaining optimal detection performance. The experimental results demonstrate that the proposed method outperforms other detection models, with improvements observed in all evaluation metrics compared to the baseline model. On the test set, this method achieves a detection average precision of 95.8% and an F1-score of 94.6%, with a model parameter of 2.15 M, meeting the requirements of both accuracy and lightweightness. The efficacy of this approach is validated by the experimental findings, which provide specific solutions and technical references for intelligent pest detection. [ABSTRACT FROM AUTHOR]

Three rice planthopper species, Nilaparvata lugens, Sogatella furcifera and Laodelphax striatellus, are destructive rice pests that cause serious economic losses in major rice‐producing regions of China. Understanding their dispersal patterns and potential distribution areas is crucial for effective management and control. Based on historical climate data and simulated future climate data combined with species occurrence data, the dispersal patterns of three planthopper species were analysed and their potential distributions were predicted. The results showed that from 1993 to 2022, the suitable areas for the three rice planthoppers gradually expanded. By 2022, the total suitable area for S. furcifera reached 478.35 × 104 km2, followed by 376.02 × 104 km2 for L. striatellus and 264.97 × 104 km2 for N. lugens. The optimum area for S. furcifera exhibited the most significant increase, expanding by 136.07 × 104 km2. The species has extended its range from southern China to the northeastern and northwestern regions within the past three decades. The suitable areas for L. striatellus and N. lugens did not show a significant spread trend. In addition, compared to that in 2022, the total suitable area for the three rice planthopper species increased slightly from 2041 to 2060. The study revealed that the wettest monthly rainfall and the lowest temperature were the most influential factors affecting the distributions of these planthopper species. This study provides valuable insights into the dispersal patterns and potential distribution of rice planthoppers in China and provides a theoretical basis for effective prevention and control strategies for destructive rice pests. [ABSTRACT FROM AUTHOR]

Rice blast, a prevalent and highly destructive rice disease that significantly impacts rice yield, is caused by the rice blast fungus. In the present study, a strain named MTC-8, identified as Bacillus mojavensis, was demonstrated has strong antagonistic activity against the rice blast fungus, Rhizoctonia solani, Ustilaginoidea virens, and Bipolaria maydis. The potential biocontrol agents were identified using ultra-performance liquid chromatography—tandem mass spectrometry (UPLC-MS/MS) analysis and chromatography. Further investigations elucidated the inhibitory mechanism of the isolated compound and demonstrated its ability to suppress spore germination, alter hyphal morphology, disrupt cell membrane integrity, and induce defense-related gene expression in rice. MTC-8 promoted plant growth and may lead to the development of a biocontrol agent that meets agricultural standards. Overall, the Bacillus mojavensis MTC-8 strain exerted beneficial eects on plant growth, immunity and disease resistance against rice blast fungus. In this study, we isolated and purified a bioactive substance from fermentation broth, and the results provide a foundation for the development and application of biopesticides. Elucidation of the inhibitory mechanism against rice blast fungus provides theoretical support for the identification of molecular targets. The successful development of a biocontrol agent lays the groundwork for its practical application in agriculture. [ABSTRACT FROM AUTHOR]

In order to identify the key antioxidant defense systems used to cope with high-temperature stress in rice leaf chloroplasts following biochar supplementation, the present study compared the expression levels of chloroplast proteins related to antioxidant defense in high-temperature stressed rice leaves between without (C0) and with biochar supplementation (C40; 40 g biochar kg–1 soil). A total of sixteen differentially expressed antioxidant chloroplastic proteins were identified. Among them, three antioxidant enzyme proteins and eight thioredoxin proteins were 62–123% and 37–225% higher under the C40 treatment compared to C0, respectively. These results suggest that both antioxidant enzymes and the thioredoxin system are central to the biochar-mediated protection of rice leaves exposed to high-temperature stress. [ABSTRACT FROM AUTHOR]

Our study investigates the genetic mechanisms underlying the spotted leaf phenotype in rice, focusing on the spl43 mutant. This mutant is characterized by persistent reddish-brown leaf spots from the seedling stage to maturity, leading to extensive leaf necrosis. Using map-based cloning, we localized the responsible locus to a 330 Kb region on chromosome 2. We identified LOC_Os02g56000, named OsRPT5A, as the causative gene. A point mutation in OsRPT5A, substituting valine for glutamic acid, was identified as the critical factor for the phenotype. Functional complementation and the generation of CRISPR/Cas9-mediated knockout lines in the IR64 background confirmed the central role of OsRPT5A in controlling this trait. The qPCR results from different parts of the rice plant revealed that OsRPT5A is constitutively expressed across various tissues, with its subcellular localization unaffected by the mutation. Notably, we observed an abnormal accumulation of reactive oxygen species (ROS) in spl43 mutants by examining the physiological indexes of leaves, suggesting a disruption in the ROS system. Complementation studies indicated OsRPT5A's involvement in ROS homeostasis and catalase activity regulation. Moreover, the spl43 mutant exhibited enhanced resistance to Xanthomonas oryzae pv. oryzae (Xoo), highlighting OsRPT5A's role in rice pathogen resistance mechanisms. Overall, our results suggest that OsRPT5A plays a critical role in regulating ROS homeostasis and enhancing pathogen resistance in rice. [ABSTRACT FROM AUTHOR]

BRRI31R is one of the Bangladesh's most promising restorer lines due to its abundant pollen producing capacity, strong restoring ability, good combining ability, high outcrossing rate and genetically diverse from cytoplasmic male sterile (CMS) line. But the drawback of this line is that it is highly susceptible to bacterial blight (BB) disease of rice caused by Xanthomonas oryzae pv. oryzae. The present study highlighted the pyramiding of effective BB resistance genes (xa5, xa13 and Xa21) into the background of BRRI31R, through marker–assisted backcrossing (MABC). Backcross progenies were confirmed and advanced based on the foreground selection of target genes. Pyramided lines were used for pathogenicity test against five Bangladeshi Xanthomonas oryzae (BXo) races (BXo93, BXo220, BXo822, BXo826, BXo887) and confirmed the dominant fertility restore genes, Rf3 and Rf4 and further validated against SNP markers for more confirmation of target resistance genes. All pyramided restorer lines consisted of Xa4 (in built), xa5, xa13, Xa21, and Chalk5 with two fertility restorer genes, Rf3, Rf4. and these restorer lines showed intermediate amylose content (<25%). Restorer lines BRRI31R-MASP3 and BRRI31R-MASP4 showed high levels of resistance against five virulent BXo races and SNP genotyping revealed that these lines also contained a blast resistance gene Pita races. Gene pyramided restorer lines, BRRI31R-MASP3 and BRRI31R-MASP4 can directly be used as a male parent for the development of new BB resistant hybrid rice variety or could be used as a replacement of restorer line of BRRI hybrid dhan5 and 7 to enhance the quality of hybrid seeds as well as rice production in Bangladesh. [ABSTRACT FROM AUTHOR]

Currently, foliar diseases of chili have significantly impacted both yield and quality. Despite effective advancements in deep learning techniques for the classification of chili leaf diseases, most existing classification models still face challenges in terms of accuracy and practical application in disease identification. Therefore, in this study, an optimized and enhanced convolutional neural network model named MCCM (MCSAM-ConvNeXt-MSFFM) is proposed by introducing ConvNeXt. The model incorporates a Multi-Scale Feature Fusion Module (MSFFM) aimed at better capturing disease features of various sizes and positions within the images. Moreover, adjustments are made to the positioning, activation functions, and normalization operations of the MSFFM module to further optimize the overall model. Additionally, a proposed Mixed Channel Spatial Attention Mechanism (MCSAM) strengthens the correlation between non-local channels and spatial features, enhancing the model's extraction of fundamental characteristics of chili leaf diseases. During the training process, pre-trained weights are obtained from the Plant Village dataset using transfer learning to accelerate the model's convergence. Regarding model evaluation, the MCCM model is compared with existing CNN models (Vgg16, ResNet34, GoogLeNet, MobileNetV2, ShuffleNet, EfficientNetV2, ConvNeXt), and Swin-Transformer. The results demonstrate that the MCCM model achieves average improvements of 3.38%, 2.62%, 2.48%, and 2.53% in accuracy, precision, recall, and F1 score, respectively. Particularly noteworthy is that compared to the original ConvNeXt model, the MCCM model exhibits significant enhancements across all performance metrics. Furthermore, classification experiments conducted on rice and maize disease datasets showcase the MCCM model's strong generalization performance. Finally, in terms of application, a chili leaf disease classification website is successfully developed using the Flask framework. This website accurately identifies uploaded chili leaf disease images, demonstrating the practical utility of the model. [ABSTRACT FROM AUTHOR]

Rice blast, caused by the filamentous fungus Magnaporthe oryzae (also known as Pyricularia oryzae), is the most severe disease threatening rice yield. Sakuranetin, an important plant phytoalexin, exhibits inhibitory effects on rice blast fungus growth. However, the underlying molecular mechanism by which sakuranetin enhances plant resistance against pathogens remains unclear. A recent study published in Nature Communications by Jiang et al. (Nat. Commun, 2023, https://doi.org/10.1038/s41467-024-47746-y) elucidated from a cytological perspective how sakuranetin enhances resistance to rice blast disease. The research revealed that elevated accumulation of sakuranetin attenuates the endocytosis of M. oryzae effectors into the cytoplasm of rice host cells. The inhibitory effect of sakuranetin is dosage-dependent and targets clathrin-mediated endocytosis (CME). This study provides novel insights into understanding plant immune mechanisms underlying weakening pathogen virulence weapons. [ABSTRACT FROM AUTHOR]

Conventional breeding approaches often rely on bi-parental crosses, in which analysis occurs only on two alleles, and genetic recombination in such a population is insufficient, limiting genetic diversity. Multi-parent advanced generation inter-cross (MAGIC) populations display large sets of recombinant inbred lines (RILs) that exhibit a genetic mosaic of multiple founder parents. MAGIC populations result in a broader genetic base that has emerged as a powerful tool for genetic analysis and breeding for disease resistance in rice. This study developed the MAGIC population by intermating eight diverse founder parents. Conducting the molecular survey sought to analyze the genes resistant to bacterial blight (BB) and brown planthopper (BPH). The research used primers specific for Xa21, xa13, Xa4, and Bph1 in the polymerase chain reaction (PCR). The survey identified combinations of three genes: (Xa4+xa13+Xa21) in BR52 and (Xa4+xa13+Bph1) in BR43, BR44, BR48, and BR58. Two-gene combination (xa13 and Xa4) materialized in BR53, BR54, BR60, BR73, BR85, and BR86, while identifying a combination of xa13 and Bph1 in BR11, BR41, and BR99. Xa4 was present in 14, xa13 in six, and Bph1 in three lines. Screening the population against Xanthomonas oryzae validated the presence of BB-resistant genes. The consistent finding is that the RILs with a combination of two or more genes express a high level of resistance compared with the RILs with a single gene. The RILs with Xa4 and xa13 expressed more resistance than the lines with xa13 and Bph1. Employing the MAGIC populations approach remains to be effective for gene pyramiding. [ABSTRACT FROM AUTHOR]

A field survey was carried out in the farmer's field located at Chutsolie colony, Chumukedima, Nagaland, from July to November 2022 using light traps to study the incidence of lepidopteran pests occurring in rice, Oryza sativa L. The survey was conducted from the vegetative till harvesting stages of paddy. Fortnightly, observations of the lepidopteran pests were done and correlated with the weather parameters. During the survey, four lepidopteran pests, namely, Cnaphalocrocis medinalis (Guenee), Leucania loreyi (Duponchel), Melanitis leda (Linnaeus), and Scirpophaga incertulas (Walker) were observed. The highest peak population of C. medinalis (Guenee), M. leda (Linnaeus), and S. incertulas (Walker) were observed on the 37th standard mean week (SMW) (i.e., vegetative stage) whereas the highest population of L. loreyi on 41st SMW. (i.e., reproductive stage). The species M. leda constituted the highest population (75) and persisted in the field till the harvest, followed by S. incertulas (51), and C. medinalis (47). The species L. loreyi was the least in numbers (16). Among the species recorded, L. loreyi was the new record from Nagaland. [ABSTRACT FROM AUTHOR]

Manipulative parasitoids manipulate the behaviour of their hosts in such a way as to benefit their own offspring. Paraponyx stagnalis Zeller is a leaf case worm caterpillar pest of rice and pupates in cases made out of cut leaf blades. These shelters are typically open-ended tubular cases. Its solitary primary endoparasitoid – Apanteles sp. – triggers changes in the way it sews the cases. The observed changes in the folded leaf shelter may serve various functions for the developing parasitoid, such as minimising the risk of hyperparasitism and predation, and enhancing structural stability. To obtain evidence to support these hypotheses, we (1) documented the morphotype of the cases/puparia constructed by unparasitised and parasitised P. stagnalis larval instars, (2) studied the overall rate of primary parasitism of P. stagnalis by Apanteles sp. and (3) studied the rate of hyperparasitism of primary parasitoids in 10 rice fields of south India. Unlike the unparasitised third-instar host larvae, the parasitised larvae sealed the open ends of the folded leaf shelter with silken threads, affixed the puparium to rice leaves and made small cases. The overall parasitism rate was about 40%. However, the hyperparasitism was between 0.6 and 1%. Though the primary parasitism by Apanteles sp. is considerably higher in all 10 fields, the meagre incidence of hyperparasitism strengthens our hypothesis that the modified puparium construction might be triggered by the primary parasitoid and beneficial for the offspring of the primary parasitoid. Our field observations suggest that future experimental studies can bring mechanical evidence for host manipulation by Apanteles sp. [ABSTRACT FROM AUTHOR]

Background: Rice is the most important staple food of the world. Rice production is now-a-days reduced due to insect pest attacking to the crop in various growing stages. There are more than 1400 pest species, which are cause great menace to the rice cultivation. Incidences and abundance of pests in rice is growing day by day due to climatic change and excess use of chemical pesticides. In late direct sown paddy is also facing the insect pest problems in different growing stages. The study aimed to layout the different pest's incidence and population dynamics as well, on various stages of direct sown paddy. The knowledge of incidence timing for various pests can be further utilized for the suitable management. Methods: The present study has been conducted during the late Kharif seasons of 2021-22 for 11 most widely grown paddy cultivars of farmers field around the locality of MS Swaminathan School of Agriculture, Centurion University of Technology and Management, Paralakhemundi, Odisha. The surveyed cultivars were Anjali, Arize 8433, BAM-6, Bhuban, Chandra, CR Dhan 100, Varsha Dhan, CR Dhan 306, Sumit, Luna Sankhi and Vandana, respectively. These cultivars were surveyed for the abundance of various associated insect-pests at two different crop growth stages. Result: The results revealed that the incidence of various pests namely Scirpophaga incertulus, Orseolia oryzae, Cnaphalocrocis medinalis, Parapoynx stagnalis, Dicladispa armigera, Leptocorisa acuta, Grasshoppers, Nezara virdula, Nephotettix virescens, Melantis leda and Mythimna separate was found to be significant for both the growth stages. The maximum population on late direct sown rice was found to be of Scirpophaga incertulus (3.67) and Orseolia oryzae (2.67) at the vegetative stage of rice while pests such as Cnaphalocrocis medinalis (6.34), Leptocorisa acuta (7.34) and Mythimna separate (5.67) were recorded maximum during the milking stage of rice. [ABSTRACT FROM AUTHOR]

Pardosa pseudoannulata is key predator in rice ecosystems; it plays a crucial role in rice pest biological control, effectively managing major rice pests such as rice planthopper. At present, there are few related studies on spiders' microRNA (miRNA). Consequently, we initiate a study on miR‐6826‐3p in P. pseudoannulata in response to high temperatures. First, we identified a total of 686 target genes of miR‐6826‐3p, 439 target genes had annotated results in the database, primarily involved in transcription and metabolism functions. Subsequently, quantitative real‐time PCR was employed to assess the relative expression levels of miR‐6826‐3p in P. pseudoannulata under different temperatures (31, 34, 37, 40°C) and various durations (1, 2, 4, 8, 12 h). The results revealed that compared to the control group (25°C), the relative expression level of miR‐6826‐3p in female spiders significantly increased under the same temperature and different duration stresses. The expression level of miR‐6826‐3p in male spiders showed an initial increase followed by a decrease trend, with relatively lower expression levels after 1 and 12 h at the same temperature conditions. Furthermore, under the same duration of stress, compared to the control group (25°C), the relative expression level of miR‐6826‐3p in female spiders significantly increased at different temperatures. These results demonstrate that P. pseudoannulata miR‐6826‐3p plays a significant role in response to high‐temperature stress. The research findings can provide a basis for future in‐depth studies on the miRNA functional of P. pseudoannulata, aiding in the elucidation of the regulatory mechanisms of P. pseudoannulata miRNAs in response to high‐temperature environments. [ABSTRACT FROM AUTHOR]

The rice stem borer (RSB), Chilo suppressalis, a notorious rice pest in China, has evolved a high resistance level to commonly used insecticides. Tetraniliprole, a new anthranilic diamide insecticide, effectively controls multiple pests, including RSB. However, the potential resistance risk of RSB to tetraniliprole is still unknown. In this study, the tetraniliprole‐selection (Tet‐R) strain was obtained through 10 continuous generations of selection with tetraniliprole 30% lethal concentration (LC30). The realized heritability (h2) of the Tet‐R strain was 0.387, indicating that resistance of RSB to tetraniliprole developed rapidly under the continuous selection of tetraniliprole. The Tet‐R strain had a high fitness cost (relative fitness = 0.53). We established the susceptibility baseline of RSB to tetraniliprole (lethal concentration at LC50 = 0.727 mg/L) and investigated the resistance level of 6 field populations to tetraniliprole. All tested strains that had resistance to chlorantraniliprole exhibited moderate‐ to high‐level resistance to tetraniliprole (resistance ratio = 27.7−806.8). Detection of ryanodine receptor (RyR) mutations showed that the Y4667C, Y4667D, I4758M, and Y4891F mutations were present in tested RSB field populations. RyR mutations were responsible for the cross‐resistance between tetraniliprole and chlorantraniliprole. Further, the clustered regularly interspaced palindromic repeats (CRISPR) / CRISPR‐associated protein 9‐mediated genome‐modified flies were used to study the contribution of RyR mutations to tetraniliprole resistance. The order of contribution of a single RyR mutation to tetraniliprole resistance was Y4667D > G4915E > Y4667C ≈ I4758M > Y4891F. In addition, the I4758M and Y4667C double mutations conferred higher tetraniliprole resistance than single Y4667C mutations. These results can guide resistance management practices for diamides in RSB and other arthropods. [ABSTRACT FROM AUTHOR]

In Indonesia, where the agricultural insurance system has been in full operation since 2016, a new damage assessment estimation formula for rice diseases was created through integrating the current damage assessment method and unmanned aerial vehicle (UAV) multispectral remote sensing data to improve the efficiency and precision of damage assessment work performed for the payments of insurance claims. The new method can quickly and efficiently output objective assessment results. In this study, UAV images and bacterial leaf blight (BLB) rice damage assessment data were acquired during the rainy and dry seasons of 2021 and 2022 in West Java, Indonesia, where serious BLB damage occurs every year. The six-level BLB score (0, 1, 3, 5, 7, and 9) and damage intensity calculated from the score were used as the BLB damage assessment data. The relationship between normalized UAV data, normalized difference vegetation index (NDVI), and BLB score showed significant correlations at the 1% level. The analysis of damage intensities and UAV data for paddy plots in all cropping seasons showed high correlation coefficients with the normalized red band, normalized near-infrared band, and NDVI, similar to the results of the BLB score analysis. However, for paddy plots with damage intensities of 70% or higher, the biased numbering of the BLB score data may have affected the evaluation results. Therefore, we conducted an analysis using an average of 1090 survey points for each BLB score and confirmed a strong relationship, with correlation coefficients exceeding 0.9 for the normalized red band, normalized near-infrared band, and NDVI. Through comparing the time required by the current assessment method with that required by the assessment method integrating UAV data, it was demonstrated that the evaluation time was reduced by more than 60% on average. We are able to propose a new assessment method for the Indonesian government to achieve complete objective enumeration. [ABSTRACT FROM AUTHOR]