The small brown planthopper (SBPH), Laodelphax striatellus, is a major insect pest for the rice plants. SBPH is also a known vector of rice stripe virus (RSV), which causes severe yield losses in rice crops throughout the East Asia. RSV is persistently transmitted by SBPH and can also be transmitted to offspring through transovarial transmission. SBPH is known to migrate from China to the west coast of the Republic of Korea (ROK). The study investigated the impact of temperature on the acquisition and transmission of RSV by SBPH in ROK, which is expected to experience increased migration and emergence of SBPH due to climate change. The results revealed that the acquisition and transmission rates of RSV were higher at 27°C compared to 24°C, with rates of 100% and 78.3%, respectively. However, at 30°C, the acquisition and transmission rates of RSV was decreased. The results suggests that temperature can impact the transmission of RSV by SBPH. To investigate this further, SBPH adults were fed on RSV-infected plants and infection rates were compared across various tissues, including the head, salivary glands, midgut, Malpighian tubules, ovary, and hindgut. Results showed that at 36 hours post-infection, RSV was highly detected in the Malpighian tubules, ovary, and hindgut. At 48 hours post-infection, RSV was also detected in the thorax. These results suggest that the transmission rates of RSV in SBPH increase with temperature between 24-27°C, but decrease at 30°C, indicating that the vectorial capacity of SBPH for RSV decreases above a certain threshold.

The small brown planthopper (SBPH), Laodelphax striatellus, which transmits rice stripe virus (RSV) is one of thenotorious pests of rice plants. To investigate the factors of vector insect responding to virus introduction, the total RNAof RSV-viruliferous SBPHs was subjected to RNA-Seq to analyze the SBPH-RSV interactome. Based on the transcriptomicchanges of RSV carrying SBPHs, eight cDNA sequences possibly related to RSV replication in SBPH were selected,and dsRNAs targeting those sequences were synthesized and applied to SBPH. Three of those dsRNAs showed over 90%of substantial RSV suppression efficiency in SBPH, that demonstrated a potential of RNAi-based virus-vector managementprogram.

애멸구(Laodelphax striatellus)는 rice stripe virus (RSV)의 매개충으로 벼에 큰 피해를 주는 해충이다. 본 연구에서는 애멸구의 장·단시형, 암·수, 약·성충에 대한 RSV 보독률과 이병률을 비교하였다. 애멸구의 장·단시형의 RSV 보독률은 각각 60.7%, 63.1%로 크게 차이는 없었다. 암·수에 대한 RSV 보독률은 각각 61.9%, 52.2%로 암컷의 보독률이 더 높았으나 유의성은 없었다. 약·성충의 보독률을 비교한 결과 각각 51.2%, 58.7%로 역시 크게 차이가 나지는 않았다. RSV에 감염된 애멸구에 노출된 건전한 벼의 이병률은 장시형은 53.3%, 단시형은 48.2%를 보였으며, 약·성충의 이병률은 각각 38.2%, 42.6%를 보여 유의성은 없었다. 반면 암컷은 50.5%의 이병률을 보이고 수컷은 22.3%의 이병률을 보여 암컷이 수컷에 비해 22.3% 이병률이 높아 유의성이 있었다. 또한 벼와 애멸구의 RSV 감염여부에 의한 애멸구의 발육기간은 건전한 벼에 RSV 감염 애멸구를 접종 했을 때 가장 긴 것으로 나타났으며, 건전한 벼에 건전한 애멸구를 접종 했을 때 발육기간이 가장 짧은 것으로 나타났다.

Rice stripe virus (RSV) is one of the serious plant pathogenic viruses for rice transmitted by small brown planthopper, SBPH, Laodalphax striatellus. RNA interference (RNAi) is an universal gene-knockdown mechanism in eukaryotic organisms which includes insects，and has been considered as an alternative strategy to control insect pests. Hence, we applied this technique to interfere the translation of target RNA genes to knockdown the virus gene on RSV-viruliferous L. striatellus. Three out of seven RSV genes, RdRp, NS3, and NCP were used as target genes and each dsRNA targeting the viral genes were delivered to the insects indirectly through the rice leaves by irrigation. As a result, not only the relative expression level of target genes decreased but also those of non-target genes and the replication of RSV genome as well. In summary, leaf-mediated dsRNA feeding methods would be useful in the knockdown of target genes on piercing-sucking insects. The genes used in this experiment can be utilized for the development of pest-resistant transgenic plants based on RNAi.

애멸구(Laodelphax striatellus)의 내생미생물인 Wolbachia에 의해 발현되는 GroEL이 벼줄무늬잎마름병바이러스(Rice stripe virus, RSV)와 결합 반응함에 따라 GroEL 재조합단백질을 이용한 Immunocapture (IC) RT-PCR 검정법에 의해 RSV 이병벼 및 보독충을 진단하는 i-RSVTM Kit를 개발하였다. i-RSVTM Kit는, 반응 용기 표면에 코팅되어있는 GroEL이 시료 마쇄액에서 RSV를 선택적으로 결합하여 분리하는 isolation kit와 분리된 RSV를 95℃에서 10분간 처리하여 RSV의 유전자를 분리시키고 one step RT-PCR을 수행하는 detection kit로 구성되어있다. i-RSVTM Kit를 활용한 애멸구 RSV 보독충 발생예찰 기술을 확립하고자 기존의 ELISA 검정법과 상관 관계를 조사하였다. ELISA 검정법은 벼에서 3.1 ㎍ml-1, 애멸구 1마리ml-1이상의 검출 한계를 보였으나 i-RSVTM Kit를 이용한 IC-RT-PCR 검정법은 벼에서 0.2㎍ml-1, 애멸구 0.2마리ml-1의 검출 한계를 나타냈다. 각 지역에서 채집된 애멸구 월동충 7 개체군의 보독충률을 i-RSVTM Kit를 이용한 분자 검정과 ELISA 검정을 동시에 수행한 결과 i-RSVTM Kit 검정법이 ELISA에 비해 충태와 무관하게 높은 민감도를 나타내었으며 두 검정법간에 r2=0.89의 3차원 상관관계식이 도출되었다. 즉 i-RSVTM Kit 검정법으로 검정시 보독충률 10～70%일 때 ELISA는 9～30%로 보독충률 검정의 정확도에 있어서 i-RSVTM Kit 검정법이 우수한 결과를 나타냈다. 본 검정법을 이용하여 2007년 12월～2008년 3월에 전국 20 여 개 시군에서 채집된 애멸구 월동충의 보독충률을 검정한 결과 충남 서천, 태안, 충북 진천, 전북 부안, 익산에서 20% 이상의 높은 보독충률을 나타내었으며 이 중 서천, 태안, 부안 등은 충의 밀도가 10마리ml-1 이상 상대적으로 높아 RSV 대발생 위험이 높을 것으로 우려된다.

Effector-triggered immunity (ETI) is an active immune response triggered by interactions between host resistance proteins and their cognate effectors. Although ETI is often associated with the hypersensitive response (HR), various R genes mediate an HR-independent process known as extreme resistance (ER). In the soybean-Soybean mosaic virus (SMV) pathosystem, the strain-specific CI protein of SMV functions as an effector of Rsv3-mediated ER. In this study, we used the soybean (Rsv3)-SMV (CI) pathosystem to gain insight into the molecular signaling pathway involved in ER. We used genome-wide transcriptome analysis to identify a subset of the type 2C protein phophatase (PP2C) genes that are specifically up-regulated in Rsv3-mediated ER. Gain-of-function analysis of the most significantly expressed soybean PP2C gene, GmPP2C3a, showed that ABA-induced GmPP2C3a functions as a key regulator of Rsv3-mediated ER. Our results further suggest that the primary mechanism of ER against viruses is the inhibition of viral cell-to-cell movement by callose deposition in an ABA signaling-dependent manner.

Rice stripe disease, caused by rice stripe virus (RSV), is one of the major virus diseases in east Asia. The objective of this study was conducted to identify new resistance genetic source to rice stripe virus (RSV) disease. Genetic diversity of 155 rice cultivars was evaluated using 9 co-dominant InDel markers and STS marker ST10. These cultivars were classified into two groups by cluster analysis based on Nei`s genetic distances. The marker showed different band pattern among RSV resistance or susceptible cultivar. In comparison with bioassay for RSV resistance and genotyping using SSR markers showed that Stv-bi and InDel 7 marker observed recombination value within 3.8% and RSV resistance gene was closely related to InDel 7. Also InDel 7 divided as resistance type alleles and susceptible type alleles except for some varieties. Interestingly, 02428, Daw dam, Erguailai, Padi Adongdumarat, PERVOMAJSZKIJ, and Tung Ting Wan Hien 1 showed Japonica type in InDel 7 marker. However, these cultivars revealed resistant to RSV bioassay. These results indicate that those cultivar can be able to get the different gene resistance with Stv-bi gene. Newly identified resistance gene is considered useful for improving RSV resistance in japonica rice. Therefore, we will progress the allelism test and genetic analysis for identification of new gene source.

We previously reported that reverse transcription-polymerase chain reaction/restriction fragment length polymorphism (RT- PCR/RFLP) was an effective method to identify SMV strains. Using this method a new SMV strain G6H was successfully identified. To introduce resistance locus Rsv4 of V94-5152, we made crosses between two parents, Hwanggumkong and V94-5152, and obtained 6 BC3 F3 progeny lines, which have different size of DNA fragment of Rsv4 locus region. To confirm the virus resistance of progeny lines, artificial inoculation were conducted with 10 SMV strains, G1-G7, G7A, G6H, and G7H. Genomic DNA of tested lines was extracted and used marker genotyping using 9 SSR marker, which covered about 20 cM genetic distance including Rsv4 locus. In the virulence test, only two progeny lines showed resistance to all the SMV strains like a V94-5152. However, the other lines showed necrotic symptoms to G6H strain. It is considered that a minor gene is located near the Rsv4 locus between Satt157 and Sat_254 marker which interacts with G6H. A new strain can be a clue to find a minor gene in the SMV resistance soybean breeding.

"조광" 은 밀양187호와 YR21113-B-B(삼백벼/그루벼)를 교배하여 육성된 소득작물 전 후작에 적응하는 조생종 신품종으로 주요특성을 요약하면 다음과 같다. 1. 조광은 영남지역 만기재배에서 평균 출수기가 8월 29일로 표준품종인 금오벼 보다 2일정도 빠른 조생종 품종이다. 간장은 63 cm로 금오벼보다 3 cm 짧으며, 수장, 주당수수 및 수당립수는 금오벼와 비슷하며, 등숙비율은 87.6%로 금오벼보다 높고, 현미 천립중은 금오벼보다 약간 무거운