Biological Control Activities of Plant Growth Promoting Rhizobacteria from Organic and Nonorganic Rice Fields against Rice Sheath Blight Pathogen (Rhizoctonia solani Kühn)

( Yuniar Harvianti ),( Rina Sri Kasiamdari ) 한국미생물 · 생명공학회 2021 한국미생물·생명공학회지 Vol.49 No.3

Rhizoctonia solani is one of the major pathogens that cause sheath blight disease in rice. Sheath blight is one of the most difficult diseases to control. Biological control (with the use of rhizobacteria) is one of the ways to control this disease. Plant Growth Promoting Rhizobacteria (PGPR) is a rhizosphere bacterium that can be used to enhance plant growth. The composition of the rhizobacteria in organic and nonorganic soil is affected by the chemical characteristics of the soil - which influences plant physiology and root exudation patterns. This study aimed to obtain a species of rhizobacteria which shows PGPR activity, from organic and nonorganic rice fields and test their capability to suppress R. solani growth. Out of 23 isolates screened for PGPR activity, the following isolates showed high PGPR activity and were selected for in vitro antagonistic activity testing against R. solani: ISO6, ISO11, ISO15, ISN2, ISN3, and ISN7, The six isolates produced 43,42-75,23 ppm of IAA, possessed phosphorus solubilization capability, and chitinase-producing activity. ISO6 (54.88%) and ISN7 (83.33%) displayed high inhibition capacities against R. solani, in vitro. ISO6 and ISN7 inhibited the growth of R. solani lesions on rice leaves by 89% and 100% (without lesion), respectively, after 7 days of incubation. Analysis of their 16S rRNA sequences revealed that the ISO6 isolate was Citrobacter freundii and ISN7 isolate was Pseudomonas aeruginosa.

Quantification of Rice Sheath Blight Progression Caused by Rhizoctonia solani

Mukhamad Su’udi,박종미,강우리,황덕주,김순옥,안일평 한국미생물학회 2013 The journal of microbiology Vol.51 No.3

Rhizoctonia solani has a wide host range, including almost all cultivated crops and its subgroup anastomosis group (AG)-1 IA causes sheath blight in rice. An accurate measurement of pathogen’s biomass is a convincing tool for enumeration of this disease. Mycological characteristics and molecular diagnosis simultaneously supported that all six strains in this study were R. solani AG-1 IA. Heterokaryons between strains Rs40104, Rs40105, and Rs45811 were stable and viable, whereas Rs40103 and Rs40106 did not form viable fused cells, except for the combination of Rs40106 and Rs40104. A primer pair was highly specific to RsAROM gene of R. solani strains and the amplified fragment exists as double copies within fungal genome. The relationship between crossing point (CP) values and the amount of fungal DNA was reliable (R2>0.99). Based on these results, we determined R. solani’s proliferation within infected stems through real time PCR using a primer pair and a Taqman probe specific to the RsAROM gene. The amount of fungal DNA within the 250 ng of tissue DNA from rice cv. Dongjin infected with Rs40104, Rs40105, and Rs45811 were 7.436, 5.830, and 5.085 ng, respectively. In contrast, the fungal DNAs within the stems inoculated with Rs40103 and Rs40106 were 0.091 and 0.842 ng. The sheath blight symptom progression approximately coincided with the amount of fungal DNA within the symptoms. In summary, our quantitative evaluation method provided reliable and objective results reflecting the amount of fungal biomass within the infected tissues and would be useful for evaluation of resistance germplasm or fungicides and estimation of inoculum potential.

무인 항공기 이용 벼 병해충 방제기술 연구

박광호,김장규,Park, K.H.,Kim, J.K. 국립한국농수산대학교 교육개발센터 2008 현장농업연구지 = Journal of practical agricultural resear Vol.10 No.1

This research was conducted to determine the alternative tool of chemical spray for rice cultivation using the unmanned helicopter(Yamaha, R-Max Type 2G-remote controlled system) at farmer's field in Korea. The unmanned helicopter tested was introduced form Japan. In Korea the application of chemicals by machine sprayer for pest management in rice cultivation has been ordinarily used at the farmer's level. However, it involved a relatively high cost and laborious for the small scale of cultivation per farm household. Farm population has been highly decreased to 7.5% in 2002 and the population is expected to rapidly reduce by 3.5% in 2012. In Japan, pest control depending on unmanned helicopter has been increased by leaps and bounds. This was due in part to the materialization of the low-cost production technology under agricultural policy and demand environmentally friendly farm products. The practicability of the unmanned helicopter in terms of super efficiency and effectiveness has been proven, and the farmers have understood that the unmanned helicopter is indispensable in the future farming system that they visualized. Also, the unmanned helicopter has been applied to rice, wheat, soybean, vegetables, fruit trees, pine trees for spraying chemicals and/or fertilizers in Japan Effect of disease control by unmanned helicopter was partially approved against rice blast and sheath blight. However, the result was not satisfactory due to the weather conditions and cultural practices. The spray density was also determined in this experiment at 0, 15, 30, and 60cm height from the paddy soil surface and there was 968 spots at 0cm, 1,560 spots at 15cm, 1,923 spots at 30cm, and 2,999 spots at 60cm height. However, no significant difference was found among the treatments. At the same time, there was no phytotoxicity observed under the chemical stray using this unmanned helicopter, nor the rice plant itself was damaged by the wind during the operation.

Expression of antimicrobial peptide snakin‑1 confers efective protection in rice against sheath blight pathogen, Rhizoctonia solani

Kaushik Das,Karabi Datta,Sailendra Nath Sarkar,Swapan Kumar Datta 한국식물생명공학회 2021 Plant biotechnology reports Vol.15 No.1

Rice sheath blight disease caused by the necrotrophic fungus Rhizoctonia solani, is an economically detrimental fungal disease which signifcantly afects rice productivity worldwide. Potato snakin-1, a cysteine-rich basic antimicrobial peptide (AMP), is a member of the novel Snakin AMP family. In order to assess the ability of the snakin-1 peptide in protecting rice against the sheath blight disease, we have developed transgenic rice constitutively expressing the snakin-1 peptide. The antimicrobial activity of snakin-1 was evaluated against the sheath blight pathogen Rhizoctonia solani both in vitro and in planta. Crude protein from transgenic rice leaves showed in vitro antifungal activity against Rhizoctonia solani. Moreover, in planta bioassay results also confrmed the same, wherein snakin-1 expressing rice plants showed signifcantly enhanced protection against the sheath blight disease. This report demonstrates how a member of the Snakin family of antimicrobial peptides has been successfully used to generate sheath blight resistance in rice, without compromising on its agronomic characteristics and at no phenotypic cost.

Field Sanitation and Foliar Application of Streptomyces padanus PMS-702 for the Control of Rice Sheath Blight

Chia-Jung Yang,Tzu-Pi Huang,Jenn-Wen Huang 한국식물병리학회 2021 Plant Pathology Journal Vol.37 No.1

Rice sheath blight (ShB), caused by Rhizoctonia solani Kühn AG1-IA, is one of the destructive rice diseases worldwide. The aims of this study were to develop bio- control strategies focusing on field sanitation and foliar application with a biocontrol agent for ShB manage- ment. Streptomyces padanus PMS-702 showed a great antagonistic activity against R. solani. Fungichromin produced by S. padanus PMS-702, at 3.07 mg/l inhib- ited 50% mycelial growth, caused leakage of cytoplasm, and inhibited the formation of infection structures of R. solani. Fungichromin could reach to 802 mg/l when S. padanus PMS-702 was cultured in MACC broth for 6 days. Addition of 0.5% S. padanus PMS-702 broth into soil decreased the survival rate of the pathogen compared to the control. Soil amended with 0.5% S. padanus broth and 0.5% tea seed pomace resulted in the death of R. solani mycelia in the infested rice straws, and the germination of sclerotia was inhibited 21 days after treatment. Greenhouse trials revealed that S. padanus cultured in soybean meal–glucose (SMGC-2) medium after mixing with different surfactants could enhance its efficacy for inhibiting the pathogen. Of six surfactants tested, the addition of 2% tea saponin was the most effective in suppressing the pathogen. S. pada- nus broth after being fermented in SMGC-2, mixed with 2% tea saponin, diluted 100 fold, and sprayed onto rice plants significantly reduced ShB disease severity. Thus, S. padanus PMS-702 is an effective biocontrol agent. The efficacy of S. padanus PMS-702 for disease control could be improved through formulation.

New Sources of Resistance and Identification of DNA Marker Loci for Sheath Blight Disease Caused by Rhizoctonia solani Kuhn, in Rice

Pachai Poonguzhali(Pachai Poonguzhali ),Ashish Chauhan(Ashish Chauhan ),Abinash Kar(Abinash Kar ),Shivaji Lavale(Shivaji Lavale ),Spurthi N. Nayak(Spurthi N. Nayak ),S. K. Prashanthi(S. K. Prashanthi 한국식물병리학회 2022 Plant Pathology Journal Vol.38 No.6

Sheath blight disease caused by the necrotrophic, soilborne pathogen Rhizoctonia solani Kuhn, is the global threat to rice production. Lack of reliable stable resistance sources in rice germplasm pool for sheath blight has made resistance breeding a very difficult task. In the current study, 101 rice landraces were screened against R. solani under artificial epiphytotics and identified six moderately resistant landraces, Jigguvaratiga, Honasu, Jeer Sali, Jeeraga-2, BiliKagga, and Medini Sannabatta with relative lesion height (RLH) range of 21-30%. Landrace Jigguvaratiga with consistent and better level of resistance (21% RLH) than resistant check Tetep (RLH 28%) was used to develop mapping population. DNA markers associated with ShB resistance were identified in F2 mapping population developed from Jigguvaratiga × BPT5204 (susceptible variety) using bulk segregant analysis. Among 56 parental polymorphic markers, RM5556, RM6208, and RM7 were polymorphic between the bulks. Single marker analysis indicated the significant association of ShB with RM5556 and RM6208 with phenotypic variance (R2) of 28.29 and 20.06%, respectively. Co-segregation analysis confirmed the strong association of RM5556 and RM6208 located on chromosome 8 for ShB trait. This is the first report on association of RM6208 marker for ShB resistance. In silico analysis revealed that RM6208 loci resides the stearoyl ACP desaturases protein, which is involved in defense mechanism against plant pathogens. RM5556 loci resides a protein, with unknown function. The putative candidate genes or quantitative trait locus harbouring at the marker interval of RM5556 and RM6208 can be further used to develop ShB resistant varieties using molecular breeding approaches.

유묘접종에 의한 벼 유전자원의 벼잎집무늬마름병 저항성 평가

김정주,백만기,원용재,조영찬,김보경 韓國作物學會 2013 한국작물학회지 Vol.58 No.4

벼 벼잎집무늬마름병에 대한 저항성 품종 육성에 이용할 유전자원을 탐색하기 위하여 주요 농업적 특성 및 벼잎집무 늬마름병 저항성 검정 결과를 요약하면 다음과 같다. 1. 40개 벼 유전자원의 주요 농업적 특성은 파종 후 출수 까지 일수는 62일에서 112일까지 분포하였고 간장은 최소 59 cm에서 129 cm 범위에 분포하였으며, 이삭길 이는 가장 짧은 품종은 PL3212가 17 cm, 가장 긴 품 종은 Moroberekan가 29 cm이었다. 수량 구성요소 중 수수는 최소 5개에서 최대 15개 범위에 분포하였고, 수당립수는 최저 77개에서 최고 240개 범위에 분포하 였다. 현미천립중은 평균 22.1 g으로 최저 13.6 g인 소 립종에서 최고 29.3 g의 대립종까지 분포하였다. 2. 인디카형 조생종 1품종, 중생종 8품종, 중만생종 10품 종 및 만생종 2품종에 대해 벼잎집무늬마름병에 의한 평균 병반형성비율은 각각 27.2, 45.3, 58.1 및 36.0% 이었다. 자포니카형 조생종 5품종, 중생종 1품종, 중만 생종 1품종 및 만생종 1품종의 벼잎집무늬마름병에 의한 평균병반형성비율은 각각 48.8, 34.2, 56.9 및 69.0% 이었고, 통일형 품종은 중생종과 중만생종 각각 2품종의 평균 병반형성비율이 32.0 및 28.9% 이었다. 3. 인디카형 중만생 품종 IR579-Es44와 IR64, 통일형 중 생종 가야벼와 중만생종 아름벼 등 4품종은 벼잎집무 늬마름병균 KACC No. 40101에 의한 병반형성비율이 22.9~27.2%로 중도저항성 반응을 보였다. 4. 벼잎집무늬마름병에 대해 중도 저항성을 나타낸 IR579- Es44, IR64, 가야벼 및 아름벼는 흰잎마름병에 대해 저항성이고 아름벼를 제외한 나머지 품종은 도열병에 도 저항성을 보였으며 특히 간장이 작아 도복의 위험 이 적고 기타 농업적 특성이 우수한 IR579-Es44, 가야 벼, IR64는 각각 조생종, 중생종, 중만생 등 숙기별로 벼잎집무늬마름병 저항성 품종을 육성하는데 활용할 가치가 높을 것으로 생각된다. Rice sheath blight (ShB), caused by Rhizoctonia solani Kühn, is one of the serious fungal disease resulting in severe yield loss in rice field worldwide. There are limited sources of genetic resistance and no commercial cultivar with high level of ShB resistance is currently available in Korea. In order to seek available resources with high level of resistance to ShB, 40 rice germplasms were used to evaluate disease reactions including ShB, leaf blast and bacterial leaf blight and these germplasms also examined agronomic traits such as days to heading, culm length, panicle length, No. of panicles, No. of spikelets per panicle and so on. There is wide variation in agronomic characters and disease reactions. Rice germplasms also showed considerably different ShB reaction caused by inoculation at seedling stage. Areumbyeo, Gayabyeo, IR579-Es44 and IR64 showed more strong reaction to ShB than the others. Especially, Gayabyeo is considerably available to develop a new variety with resistance to ShB in Korea.

Transcriptome analysis of rice leaves in response to Rhizoctonia solani infection and reveals a novel regulatory mechanism

De Peng Yuan,Xiao Feng Xu,Hong Woo-Jong,Si Ting Wang,Xin Tong Jia,Yang Liu,Shuang Li,Zhi Min Li,Qian Sun,Qiong Mei,Shuai Li,정기홍,Song Hong Wei,Yuan Hu Xuan 한국식물생명공학회 2020 Plant biotechnology reports Vol.14 No.5

Sheath blight disease (ShB) severely afects rice production; however, the details of defense against ShB remain unclear. To understand the rice defense mechanism against ShB, an RNA sequencing analysis was performed using Rhizoctonia solani inoculated rice leaves after 48 h of inoculation. Among them, 3417 genes were upregulated and 2532 were downregulated when compared with the control group (>twofold or<1/2). In addition, the diferentially expressed genes were classifed via Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and MapMan analyses. Fifty-nine GO terms and seven KEGG pathways were signifcantly enriched. A MapMan analysis demonstrated that the phytohormone and metabolic pathways were signifcantly altered. Interestingly, the expression levels of 359 transcription factors, including WRKY, MYB, and NAC family members, as well as 239 transporter genes, including ABC, MFS, and SWEET, were signifcantly changed in response to R. solani AG1-IA inoculation. Additionally, OsWRKY53 and OsAKT1 negatively regulate the defense response in rice against R. solani via gain of function study for OsWRKY53 and loss of function study for OsAKT1, respectively. Furthermore, several diferentially expressed genes contain R. solani-responsive cis acting regulatory elements in their promoter regions. Taken together, our analyses provide valuable information for the additional study of the defense mechanisms against ShB, and the candidate genes identifed in this study will be useful resource for future breeding to enhance resistance against ShB.

Comparative Transcriptome Analysis of Rhizoctonia solani-resistant and -Susceptible Rice Cultivars Reveals the Importance of Pathogen Recognition and Active Immune Responses in Host Resistance

Guo-Liang Wang,Shaohong Qu,Zhengjie Yuan,Yu Zhang,Guojuan Xu,Dongling Bi,Haiyan Qu,Xiaowei Zou,Xiaoqing Gao,Haihe Yang,Haiyan He,Xuli Wang,Jiandong Bao,Shimin Zuo,Xuebiao Pan,Bo Zhou 한국식물학회 2018 Journal of Plant Biology Vol.61 No.3

Rice sheath blight (SB), caused by Rhizoctoniasolani (R. solani), is a major threat to rice productionworldwide. The molecular mechanisms of the SB resistancein rice are poorly understood. The transcriptomes of the SBresistantrice cultivar YSBR1 and the susceptible cultivarLemont were analyzed after R. solani infection. A total of7624 differentially expressed genes (DEGs) were identifiedat one or more timepoints in a cultivar. 5526 and 5618 DEGswere differentially expressed in Lemont and YSBR1,respectively. YSBR1 exhibited stronger and earlier transcriptionalresponse to R. solani than Lemont. Gene ontology enrichmentanalysis revealed that genes that encode cell wall-modifyingand glycosyl-degrading enzymes or anti-microbial proteinswere specifically induced in YSBR1 at 6 hpi. MapMananalysis revealed that more DEGs related with cell wall, β-glucanses, respiratory burst, phenylpropanoids and ligninwere highly induced by R. solani in YSBR1 than in Lemont. The results also showed that receptor-like kinases and jasmonicacid signaling may play important roles in host resistance toR. solani. This study highlights potential candidate genes andsignaling pathways involved in rice sheath resistance and canhelp to further clarify the mechanistic events underlyingresistance and susceptibility to R. solani.

Biological Control Activity of Two Isolates of Pseudomonas fluorescens against Rice Sheath Blight

Choi Gyung-Ja,Kim Jin-Cheol,Park Eun-Jin,Choi Yong-Ho,Jang Kyoung-Soo,Lim He-Kyoung,Cho Kwang-Yun,Lee Seon-Woo The Korean Society of Plant Pathology 2006 Plant Pathology Journal Vol.22 No.3

Two isolates of mucous bacteria, mc75 and pc78, were isolated from fungal culture plate as culture contaminants with an interesting swarming motility. Both isolates were identified as Pseudomonas fluorescens based on microscopy, biochemical analysis, Biolog test and DNA sequence analysis of the 16S rRNA gene. Both strains have the exactly the same 16S rRNA gene sequences, and yet their biological control activity were not identical each other. In vitro analysis of antagonistic activity of two isolates against several plant pathogenic fungi indicated that both produced diffusible and volatile antifungal compounds of unknown identities. Treatment of the bacterial culture of P. fluorescens pc78 and its culture filtrate exhibited a strong biological control activity against rice sheath blight in vivo among six plant diseases tested. More effective disease control activity was obtained from treatment of bacterial culture than that of culture filtrate. Therefore, in addition to antifungal compound and siderophore production, other traits such as biofilm formation and swarming motility on plant surface may contribute to the biological control activity of P.fluorescens pc78 and mc75.