Rice Grassy Stunt Virus Research Articles

Genetic Validation of Advanced Backcross-derived Rice Lines for Nilaparvata lugens (Stal) Resistance via SSR Markers

Nilaparvata lugens (Stål), referred to as the brown planthopper (BPH), is a serious threat to paddy cultivation. It inflicts damage by feeding on rice plants and serves as a vector for the rice ragged stunt virus and the rice grassy stunt virus, both of which contribute to significant yield losses. The research was conducted during kharif-2021 at Regional Agricultural Research Station (RARS), Warangal. SSR markers RM 3766 (for the Bph3 gene) and RM 586 (for the Bph4 gene) were used for molecular confirmation of resistance in BPH. The study revealed the presence of resistance genes in all resistant and moderately resistant lines, except Siddhi-BC2F6 BPH-BL-24, which was heterozygous (partial resistance) for Bph3, and Siddhi-BC2F6 BPH-BL-11 and Siddhi-BC2F6 BPH-BL-52, which were heterozygous (partial resistance) for Bph4. This genetic validation using SSR markers not only confirms the successful introgression of resistance traits but also enhances the efficiency of breeding programs aimed at developing durable BPH-resistant rice cultivars.

A viral protein competitively bound to rice CIPK23 inhibits potassium absorption and facilitates virus systemic infection in rice.

Potassium (K+) plays a crucial role as a macronutrient in the growth and development of plants. Studies have definitely determined the vital roles of K+ in response to pathogen invasion. Our previous investigations revealed that rice plants infected with rice grassy stunt virus (RGSV) displayed a reduction in K+ content, but the mechanism by which RGSV infection subverts K+ uptake remains unknown. In this study, we found that overexpression of RGSV P1, a specific viral protein encoded by viral RNA1, results in enhanced sensitivity to low K+ stress and exhibits a significantly lower rate of K+ influx compared to wild-type rice plants. Further investigation revealed that RGSV P1 interacts with OsCIPK23, an upstream regulator of Shaker K+ channel OsAKT1. Moreover, we found that the P1 protein recruits the OsCIPK23 to the Cajal bodies (CBs). In vivo assays demonstrated that the P1 protein competitively binds to OsCIPK23 with both OsCBL1 and OsAKT1. In the nucleus, the P1 protein enhances the binding of OsCIPK23 to OsCoilin, a homologue of the signature protein of CBs in Arabidopsis, and facilitates their trafficking through these CB structures. Genetic analysis indicates that mutant in oscipk23 suppresses RGSV systemic infection. Conversely, osakt1 mutants exhibited increased sensitivity to RGSV infection. These findings suggest that RGSV P1 hinders the absorption of K+ in rice plants by recruiting the OsCIPK23 to the CB structures. This process potentially promotes virus systemic infection but comes at the expense of inhibiting OsAKT1 activity.

Molecular characterization of Rice ragged stunt virus and Rice grassy stunt virus on Rice in Gianyar, Bali, Indonesia

Rice stunt disease is one of the causes of rice harvest failure. It is caused by the infection of Rice ragged stunt virus (RRSV) and Rice grassy stunt virus (RGSV) infection. Information about disease severity and the molecular characteristics of stunt viruses in Indonesia is still limited. Thus, this research aimed to determine the disease severity and the genetic diversity of rice stunt viruses in Gianyar, Bali. The research method consisted of observation of incidence and disease severity in the field and virus detection by reverse transcription-polymerase chain reaction (RT-PCR) using primers specific for RRSV and RGSV. The observation of the disease incidence and severity were performed in seven districts in Gianyar Regency, Bali, namely Blahbatuh, Gianyar, Payangan, Sukawati, Tampaksiring, Tegallalang, and Ubud. Stunt disease was found in all observation sites. High stunt disease incidence (> 44%) was found in three districts: Ubud, Tampaksiring, and Payangan, while the low disease incidence rate of <10% was found in Blahbatuh and Gianyar Districts. The highest stunt disease severity occurred in Tampaksiring District (60.82%), while the lowest severity occurred in Gianyar District (18.84%). The IR-64 and Ciherang cultivars are vulnerable to rice stunt disease infection. The highest homology of RRSV and RRGV nucleotides was found with Vietnam isolates being >98% and >97%, respectively. The phylogenetic analysis showed that Indonesian isolates of RRSV and RGSV were clustered in the same group as Vietnam isolates.

Performance analysis of various deep learning models for detecting rice diseases

<p>A major portion of the world’s population relies on rice as a staple diet, hence rice is essential to maintaining food security worldwide. Unfortunately, rice crops are susceptible to a number of illnesses that, if detected and treated promptly, can result in significant output losses. Expert visual inspection is a time-consuming and arbitrary part of the conventional procedures for diagnosing diseases in rice. An effective method for automated illness diagnosis in agriculture has evolved in recent years: deep learning, a branch of artificial intelligence. The objective of this research is to compare AlexNet, DCNN, MobileNet, GoogleNet, VGG16, ResNet50 and Xception, these are various deep learning models in order to choose the one that would produce the highest levels of accuracy, precision recall, specificity, and F1-score for detecting rice diseases. In this study we train the model for nine different types of rice diseases named as Rice Blast (Pyricularia oryzae), Rice Sheath Blight (Rhizoctonia Solani), Bacterial Leaf Blight (Xanthomonas oryzae pv. oryzae), Tungro Disease, Rice Grassy Stunt Virus (RGSV), Rice Yellow Mottle Virus (RYMV), Bakanae Disease (Fusarium moniliforme), Brown Spot (Cochliobolus miyabeanus) and Rice Tungro Bacilliform Virus (RTBV) with 30,000 images. For this we used the secondary dataset for analyzing the performance of models. We trained the model for both normalized and non-normalized dataset. After comparing the various models we get the better result from ResNet50 model with accuracy of 97.50%.</p>

RT-RPA-PfAgo System: A Rapid, Sensitive, and Specific Multiplex Detection Method for Rice-Infecting Viruses.

The advancement in CRISPR-Cas biosensors has transmuted the detection of plant viruses owing to their rapid and higher sensitivity. However, false positives and restricted multiplexing capabilities are still the challenges faced by this technology, demanding the exploration of novel methodologies. In this study, a novel detection system was developed by integrating reverse transcriptome (RT) techniques with recombinase polymerase isothermal amplification (RPA) and Pyrococcus furiosus Argonaute (PfAgo). The RT-RPA-PfAgo system enabled the simultaneous detection of rice ragged stunt virus (RRSV), rice grassy stunt virus (RGSV), and rice black streaked dwarf virus (RBSDV). Identifying targets via guide DNA without being hindered by protospacer adjacent motif sequences is the inherent merit of PfAgo, with the additional advantage of it being simple, cost-effective, and exceptionally sensitive, with detection limits between 3.13 and 5.13 copies/µL, in addition to it effectively differentiating between the three distinct viruses. The field evaluations were also in accordance with RT-PCR methods. The RT-RPA-PfAgo system proved to be a robust, versatile, highly specific, and sensitive method with great potential for practicality in future plant virus diagnostics.

Incidence of dwarf disease and yield on Inpari 32 over two sequential seasons in Klaten, Central Java

Rice dwarf disease caused by Rice grassy stunt virus (RGSV) and Rice ragged stunt virus (RRSV) is frequently found in Indonesia. This disease is transmitted by brown planthopper/BPH (Nilaparvata lugens Stål). The infected plants become dwarfs and lead to reduced yields. The purpose of this study is to determine the number of BPH populations due to the occurrences of dwarf disease and yield on Inpari 32 rice over two sequential planting seasons in Klaten, Central Java. The observed parameters were dwarf disease symptoms, incidence and intensity of the disease, BPH population and its natural enemy, the vegetative growth, and yields. The analysis used in this study were descriptive analysis and linear regression. The results showed that, plant growth during the dry season was better than the rainy season based on plant height and tiller number. The average population of BPH in the dry season were 0.2–4 individual/hill which is lower than in the rainy season (0.43–4.4 individual/hill). The incidence and intensity of disease in the dry season were lower than rainy season. The higher incidence and intensity of rice dwarf disease in the rainy season caused a decrease in dry harvest yields and milled dry yields were 10.95% and 10.81%, respectively

Genome-wide analysis of epigenetic and transcriptional changes in the pathogenesis of RGSV in rice.

Rice grassy stunt virus (RGSV), a typical negative single-stranded RNA virus, invades rice and generates several disease signs, including dwarfing, tillering, and sterility. Previous research has revealed that RGSV-encoded proteins can force the host's ubiquitin-proteasome system to utilize them for viral pathogenesis. However, most of the studies were limited to a single omics level and lacked multidimensional data collection and correlation analysis on the mechanisms of RGSV-rice interactions. Here, we performed a comprehensive association analysis of genome-wide methylation sequencing, transcriptome sequencing, and histone H3K9me3 modification in RGSV-infested as well as non-infested rice leaves, and the levels of all three cytosine contexts (CG, CHG and CHH) were found to be slightly lower in RGSV-infected rice leaves than in normal rice. Large proportions of DMRs were distributed in the promoter and intergenic regions, and most DMRs were enriched in the CHH context, where the number of CHH hypo-DMRs was almost twice as high as that of hyper-DMRs. Among the genes with down-regulated expression and hypermethylation, we analyzed and identified 11 transcripts involved in fertility, plant height and tillering, and among the transcribed up-regulated and hypermethylated genes, we excavated 7 transcripts related to fertility, plant height and tillering. By analyzing the changes of histone H3K9me3 modification before and after virus infestation, we found that the distribution of H3K9me3 modification in the whole rice genome was prevalent, mainly concentrated in the gene promoter and gene body regions, which was distinctly different from the characteristics of animals. Combined with transcriptomic data, H3K9me3 mark was found to favor targeting highly expressed genes. After RGSV infection, H3K9me3 modifications in several regions of CTK and BR hormone signaling-related genes were altered, providing important targets for subsequent studies.

Overexpression of OsHAK5 potassium transporter enhances virus resistance in rice (Oryza sativa).

Intracellular potassium (K+) transported by plants under the action of a number of transport proteins is crucial for plant survival under distinct abiotic and biotic stresses. A correlation between K+ status and disease incidence has been found in many studies, but the roles of K+ in regulating disease resistance to viral diseases remain elusive. Here, we report that HIGH‐AFFINITY K+ TRANSPORTER 5 (OsHAK5) regulates the infection of rice grassy stunt virus (RGSV), a negative‐sense single‐stranded bunyavirus, in rice (Oryza sativa). We found the K+ content in rice plants was significantly inhibited on RGSV infection. Meanwhile, a dramatic induction of OsHAK5 transcripts was observed in RGSV‐infected rice plants and in rice plants with K+ deficiency. Genetic analysis indicated that disruption of OsHAK5 facilitated viral pathogenicity. In contrast, overexpression of OsHAK5 enhanced resistance to RGSV infection. Our analysis of reactive oxygen species (ROS) including H2O2 and O2−, by DAB and NBT staining, respectively, indicated that RGSV infection as well as OsHAK5 overexpression increased ROS accumulation in rice leaves. The accumulation of ROS is perhaps involved in the induction of host resistance against RGSV infection in OsHAK5 transgenic overexpression rice plants. Furthermore, RGSV‐encoded P3 induced OsHAK5 promoter activity, suggesting that RGSV P3 is probably an elicitor for the induction of OsHAK5 transcripts during RGSV infection. These findings indicate the crucial role of OsHAK5 in host resistance to virus infection. Our results may be exploited in the future to increase crop yield as well as improve host resistance via genetic manipulations.

Rice grassy stunt virus

Rice grassy stunt virus

Rice grassy stunt virus

This datasheet on Rice grassy stunt virus covers Identity, Overview, Distribution, Dispersal, Hosts/Species Affected, Vectors & Intermediate Hosts, Diagnosis, Biology & Ecology, Impacts, Prevention/Control, Further Information.

Resistance Evaluation of Some Rice Varieties by Feeding Activity of Brown Planthopper Population in Java

Brown Planthopper (BPH), Nilaparvata lugens Stal (Hemiptera: Delpachidae) is the important pest of rice. The infestation of BPH reduced the rice yield on rice producer countries in Asia. In Indonesia, the area of BPH infestation frequently fluctuated over the year. BPH directly caused hopper burn and also vector of rice grassy stunt virus (RGSV) and rice ragged stunt virus (RRSV). This study aimed to evaluate the resistance of some rice varieties to different BPH population in Java. Three BPH populations collected from Karawang (West Java), Pekalongan (Central Java) and Kendal (Central Java) were used in this study. The rice resistance was evaluated by conducting honeydew test. There were eight rice varieties tested i.e Sembada 168, Ciherang, Inpari 32, Inpari 33, IR 64, TN1, Ratu Heenati and PTB 33 with five replications. A number of 200 female adults (five females per plot) were starved for 2 hours before inserting to pot containing one seedling. The BPH adults were allowed to feed 40-day-old plants for 48 hours. The area of honeydew excreted by BPH was measured using software Image J. We used analysis of variance (ANOVA) and cluster analysis with ward method and similarity index of Euclidean distance to analyze the rice resistance to BPH. The study indicated three groups of rice resistance level. The variety of Sembada 168 and TN1 were susceptible to BPH. Variety of Ciherang, Inpari 32, Inpari 33 and IR 64 were moderately resistant to BPH. However, PTB 33 and Ratu Heenati were strongly resistant to BPH population of Java.

Transmission Effectivity of Rice Yellow Stunt Disease by Imidacloprid-Resistant and Susceptible Brown Plant Hopper

The brown plant hopper (BPH) is a major pest of rice and as a vector of Rice ragged stunt virus (RRSV) and Rice grassy stunt virus (RGSV). Curently, numerous rice yellow stunt disease symptoms are found in the field that caused by the single and simultaneous infection of these two viruses. Brown plant hopper population correlate with the incidence and severity of the disease. Misuse of insecticides, would cause of BPH resistances to imidacloprid. This study aimed to investigate the ability of BPH imidacloprid-resistant and susceptible to transmit of rice yellow stunt disease on rice plants. The variables tested were the acquisition period, inoculation period, number of infesting BPH, and lifespans of the viruliferous BPH that used in this research. Experiments were set as separated Completely Randomized Design with 10 replications for each treatment within an experiment. The results showed that both resistant and susceptible BPH to imidacloprid was able to transmit the virus to healthy plants. The acquisition and inoculation period test showed the BPH could transmit the virus with the shortest acquisition time for 30 minutes followed 24 hours of inoculation, as well as the acquisition time of 10 days with the shortest inoculation time for 30 minutes. Based on the incubation time, symptoms variation, and disease severity, susceptible BPH were more effective in transmitting rice yellow stunt disease than imidacloprid-resistant BPH. Single imidacloprid-resistant or susceptible BPH was proven able to transmit rice yellow stunt disease to healthy plants during its lifespan. Lifespans BPH viruliferous of imidacloprid-resistant were shorter than susceptible, which was 16 days for resistant BPH and 21 days for susceptible BPH.

A Bunyavirus-Inducible Ubiquitin Ligase Targets RNA Polymerase IV for Degradation during Viral Pathogenesis in Rice

The ubiquitin-proteasome system (UPS) is an important post-translational regulatory mechanism that controls many cellular functions in eukaryotes. Here, we show that stable expression of P3 protein encoded by Rice grassy stunt virus (RGSV), a negative-strand RNA virus in the Bunyavirales, causes developmental abnormities similar to the disease symptoms caused by RGSV, such as dwarfing and excess tillering, in transgenic rice plants. We found that both transgenic expression of P3 and RGSV infection induce ubiquitination and UPS-dependent degradation of rice NUCLEAR RNA POLYMERASE D1a (OsNRPD1a), one of two orthologs of the largest subunit of plant-specific RNA polymerase IV (Pol IV), which is required for RNA-directed DNA methylation (RdDM). Furthermore, we identified a P3-inducible U-box type E3 ubiquitin ligase, designated as P3-inducible protein 1 (P3IP1), which interacts with OsNRPD1a and mediates its ubiquitination and UPS-dependent degradation in vitro and in vivo. Notably, both knockdown of OsNRPD1 and overexpression of P3IP1 in rice plants induced developmental phenotypes similar to RGSV disease symptomss. Taken together, our findings reveal a novel virulence mechanism whereby plant pathogens target host RNA Pol IV for UPS-dependent degradation to induce disease symptoms. Our study also identified an E3 ubiquitin ligase, which targets the RdDM compotent NRPD1 for UPS-mediated degradation in rice.

Genetic Variability and Heritability of Green Super Rice (GSR) Lines Resistance to Rice Ragged Stunt Virus (RRSV) and Rice Grassy Stunt Virus (RGSV)

<p>Brown plant hopper (BPH) is one of the main pest of rice in Indonesia and it occurred every years with fluctuate acreage. BPH is also vector of Rice Ragged Stunt Virus (RRSV) and Rice Grassy Stunt Virus (RGSV). Green Super Rice (GSR) was designed to have resistance to major pests and diseases so that it need less pesticides and thus save ro environment. GSR was developed in IRRI and China and was tested in Indonesia since 2009 until now (2019). This research was aimed to study the genetic variability and heritability of 26 selected GSR lines to RRSV and RGSV along with four check varieties. The experiment was conducted in ICRR Sukamandi and Pusakanagara Experimental Station. The experiment was arranged following randomized complete block design with three replications. Transplanting was done into 21 days old seedling into 25 cm x 25 cm planting space of 1 m x 1 m plot. BPH and virus investation was occured narturally due to BPH outbreak along the season (DS 2010). Percentage of plant showing RRSV and RGSV symtom was measured as consideration the resistance of plant to the viruses. The results showed that the tested genotypes had high genetic variability and heritability classified as medium in the resistance to RGSV. The genotypes showed low genetic variability and heritability in the resistance to RRSV. It implies that breeder effort is feasible to develop resistant lines to RGSV. HUANGHUAZHAN and HHZ 12-Y4-Y3-Y1 are consistently resistant to RGSV and can be used as donors in further plant breeding activities. The selection of resistant individuals in populations of plant breeding material recommended to be done on earlier generations for RGSV and further generation for RSSV.</p>

DETECTION AND TRANSMISSION OF RICE STUNT VIRUS ON CIHERANG AND SITU BAGENDIT VARIETIES

Detection and Transmission of rice stunt virus on Ciherang and Situ Bagendit Varieties. The explosion of brown planthoppers recently has caused reduction of rice production in Indonesia. Brown planthoppers do not only act as pest, but also transmit Rice grassy stunt virus (RGSV) and Rice ragged stunt virus (RRSV). Detection of the existence of the two viruses in rice plants and vector insects is important to be done to ensure that the virus is infected with the vector. The aim of this research is to detect the existence of virus in varieties of Ciherang and Situ Bagendit as a result of transmission in the laboratory and to find out the ability of brown planthoppers to transmit stunt virus to both of the varieties. This research was compiled using Completely Randomized Design (CRD) with 4 treatments, namely healthy rice plants of Ciherang and Situ Bagendit varieties, Ciherang and Situ Bagendit varieties which were infested by brown planthoppers each with 5 repetitions. The parameters observed were incubation period, symptoms, plant height, number of leaves and incidence of disease. The data on plant height, number of leaves and incidence of disease were analyzed using ANOVA and continued with the Least Significant Difference (LSD) test at the level of 5%. The results showed that Ciherang and Situ Bagendit varieties were only positively infected by Rice ragged stunt virus. The results of the rice transmission showed that Ciherang variety had a faster incubation period of 10 DAI while Situ Bagendit was 14 DAI, but the two varieties showed an inhibition of growth in plant height and number of leaves compared to healthy plants with each incidence of 51.3% and 46.3%.

Detection and Analysis of Protein Profile on Rice Infected by Stunting Virus with Different Severity on Ciherang and Situ Bagendit Varieties

Rice stunt virus is one of the limiting factors in the decline of rice production in Indonesia. The virus consists of rice grassy stunt virus (RGSV) and rice ragged stunt virus (RRSV) that is transmitted by brown planthopper (WBC) in a persistent propagative manner. This study aimed to determine the presence of rice stunt virus in Bantul, Yogyakarta through fast detection using RT-PCR. It also aimed to learn the pattern of total protein profile of healthy and infected rice plants by the virus on different severity level in the field. The results showed that rice varieties of Ciherang and Situ Bagendit in Bantul were infected with RGSV and RRSV. They were classified as mild, moderate, severe, and failure in severity level. Homology analysis using BioEdit showed that the nucleotide sequence of RGSV in Bantul isolate had the highest percentage of nucleic acids similarity with Klaten isolate (98.1%). Meanwhile, RRSV of Bantul isolate had the highest percentage of nucleic acids similarity to Philipines isolate (99.5%). Analysis of protein profiles using SDS-PAGE showed a pattern of protein profiles formed on rice infected with the virus at different severity levels which was not found in healthy rice. These proteins presumably were nonstructural p5 and nucleocapsid protein (NCP) of RGSV with a molecular weight of ~22 and 34-35 kDa; and viral spike protein and protein capsid (S8) of RRSV with MW ~39 and ~43 kDa.

Invasion of midgut epithelial cells by a persistently transmitted virus is mediated by sugar transporter 6 in its insect vector.

Insect transmission is obligatory for persistently transmitted viruses because the vector insect is the only means of virus spread in nature. The insect midgut is the first major barrier limiting virus acquisition, but the mechanisms by which viruses are able to cross the cell membrane and then infect the midgut epithelial cells of the insect have not been elucidated completely. Here, we found that the outer capsid or nucleocapsid protein (NP) of three viruses can interact and colocalize with sugar transporter 6 that is highly expressed in the midgut of Laodelphax striatellus (LsST6). In contrast, LsST6 did not interact with the NP of rice grassy stunt virus, which cannot be transmitted by the same planthopper. LsST6 not only altered the cellular location of viral proteins and then colocalized with them in the cell membrane, but also mediated the entry of rice stripe virus (RSV) particles into Spodoptera frugiperda 9 (Sf9) cells that expressed the heterologous gene LsST6. We further showed that RSV particles initially bound to the cell membrane of midgut epithelial cells where it colocalized with LsST6, and then invaded the cytoplasm. When LsST6 expression was knocked down, viral titre, acquisition percentage and transmission efficiency of the treated insect decreased significantly, but virus replication was not affected. This work thus uncovered a strategy by which LsST6 mediates viral entry into midgut epithelial cells and leads to successful transmission by the insect vector.

Targeting of rice grassy stunt virus pc6 protein to plasmodesmata requires the ER-to-Golgi secretory pathway and an actin-myosin VIII motility system.

The nonstructural protein pc6 encoded by rice grassy stunt virus (RGSV) plays a significant role in viral cell-to-cell movement, presumably by transport through plasmodesmata (PD). We confirmed the association of pc6 with PD, and also elucidated the mechanisms of protein targeting to PD. Several inhibitor treatments showed conclusively that pc6 is targeted to PD via the ER-to-Golgi secretory system and actin filaments. In addition, VIII-1 myosin was also found to be involved in pc6 PD targeting. Deletion mutants demonstrated that C-terminal amino acid residues 209-229 (transmembrane domain 2; TM2) are essential for pc6 to move through PD.

Viral infection induces different detoxification enzyme activities in insecticide-resistant and -susceptible brown planthopper Nilaparvata lugens strains.

This study aimed to describe the relationship between viral infection in Nilaparvata lugens (Stål), the brown planthopper (BPH), and different insecticide susceptibilities. BPH-resistant strains were selected using fenthion (an organophosphate) or etofenprox (a pyrethroid); a susceptible strain was used as the baseline colony before insecticide selection. All strains were infected with rice ragged stunt virus (RRSV) or rice grassy stunt virus (RGSV), after which the activities of three detoxification enzymes, cytochrome-P450-monooxygenase (P450), glutathione S-transferase (GST), and carboxylesterase (CE), were compared. Males of the strains selected for both insecticides showed high P450 and GST-CDNB activities. The activity of all enzymes was higher in males than in females, as a whole. However, males of the susceptible strain infected with RRSV showed decreased CE and GST-CDNB activities. BPH with low susceptibility to etofenprox showed a marked increase in P450 activity after RRSV infection; the GST-CDNB activity of females in the insecticide-resistant strain increased. RGSV infection induced high CE and P450 activities in etofenprox-selected females. The RRSV infection rate, but not the RGSV, decreased in etofenprox-selected strains.

Rice grassy stunt virus p5 interacts with two protein components of the plant-specific CBL-CIPK Ca+2 signaling network of rice.

Rice grassy stunt virus (RGSV) is a tenuivirus posing a threat to rice production in many South, Southeast, and East Asian countries. To date, no host factor interacting with RGSV has been reported. In this study, we screened a rice cDNA library with the GAL4-based yeast two-hybrid system using RGSV p5 as the bait. One of the candidate host factors interacting with RGSV p5 was found to be CBL-interacting protein kinase 25 (OsCIPK25), a member of the plant-specific CBL-CIPK Ca2+ signaling network. The interaction between RGSV p5 and OsCIPK25, as well as OsCIPK5, which is closely related to OsCIPK25, was confirmed by their cellular co-localization and by a bimolecular fluorescence complementation assay in Nicotiana benthamiana cells. Given the importance of CIPKs in the regulation of ion homeostasis and the resemblance of RGSV symptoms to potassium deficiency in rice, we evaluated potassium content of RGSV-infected rice and found it to be much lower than that in the healthy rice.