• Molecules and Cells
• /
• 제20권3호
• /
• pp.385-391
• /
• 2005

As a first step towards identifying genes involving in the signal transduction pathways mediating rice blast resistance, we isolated 3 mutants lines that showed enhanced susceptibility to rice blast KJ105 (91-033) from a T-DNA insertion library of the japonica rice cultivar, Hwayeong. Since none of the susceptible phenotypes co-segregated with the T-DNA insertion we adapted a map-based cloning strategy to isolate the gene(s) responsible for the enhanced susceptibility of the Hwayeong mutants. A genetic mapping population was produced by crossing the resistant wild type Hwayeong with the susceptible cultivar, Nagdong. Chi-square analysis of the $F_2$ segregating population indicated that resistance in Hwayeong was controlled by a single major gene that we tentatively named Pi-hy. Randomly selected susceptible plants in the $F_2$ population were used to build an initial map of Pi-hy. The SSLP marker RM2265 on chromosome 2 was closely linked to resistance. High resolution mapping using 105 $F_2$ plants revealed that the resistance gene was tightly linked, or identical, to Pib, a resistance gene with a nucleotide binding sequence and leucine-rich repeats (NB-LRR) previously isolated. Sequence analysis of the Pib locus amplified from three susceptible mutants revealed lesions within this gene, demonstrating that the Pi-hy gene is Pib. The Pib mutations in 1D-22-10-13, 1D-54-16-8, and 1C-143-16-1 were, respectively, a missense mutation in the conserved NB domain 3, a nonsense mutation in the 5th LRR, and a nonsense mutation in the C terminus following the LRRs that causes a small deletion of the C terminus. These findings provide evidence that NB domain 3 and the C terminus are required for full activity of the plant R gene. They also suggest that alterations of the resistance gene can cause major differences in pathogen specificity by affecting interactions with an avirulence factor.

• 한국작물학회지
• /
• 제15권
• /
• pp.141-143
• /
• 1974

본답에서 재배되고 있는 방사선돌연변이계통들의 도열병 저항성 검정을 위하여 절리엽편접종법이 시도되었다. 즉 포장에서 절취한 잎을 항온항습실내에서 punch압상을 만들고 그 위에 도열병균의 포자현탁액을 접종한 후 형성된 병반의 크기를 측정하여 계통간의 저항성정도를 비교한 결과 방사선조사된 풍광으로부터 Upland short row method에 의하여 선발된 저항성계통들은 모품종 풍광에 비하여 저항성으로 나타났다. 따라서 이 방법은 포장에서 재배되는 성숙식물체의 도열병저항성 검정을 위한 하나의 선발방법으로서 효과적이라 생각되었다.

• Molecules and Cells
• /
• 제42권9호
• /
• pp.637-645
• /
• 2019

Effector-triggered immunity (ETI) is an effective layer of plant defense initiated upon recognition of avirulence (Avr) effectors from pathogens by cognate plant disease resistance (R) proteins. In rice, a large number of R genes have been characterized from various cultivars and have greatly contributed to breeding programs to improve resistance against the rice blast pathogen Magnaporthe oryzae. The extreme diversity of R gene repertoires is thought to be a result of co-evolutionary history between rice and its pathogens including M. oryzae. Here we show that Pii is an allele of Pi5 by DNA sequence characterization and complementation analysis. Pii-1 and Pii-2 cDNAs were cloned by reverse transcription polymerase chain reaction from the Pii-carrying cultivar Fujisaka5. The complementation test in susceptible rice cultivar Dongjin demonstrated that the rice blast resistance mediated by Pii, similar to Pi5, requires the presence of two nucleotide-binding leucine-rich repeat genes, Pii-1 and Pii-2. Consistent with our hypothesis that Pi5 and Pii are functionally indistinguishable, the replacement of Pii-1 by Pi5-1 and Pii-2 by Pi5-2, respectively, does not change the level of disease resistance to M. oryzae carrying AVR-Pii. Surprisingly, Exo70F3, required for Pii-mediated resistance, is dispensable for Pi5-mediated resistance. Based on our results, despite similarities observed between Pi5 and Pii, we hypothesize that Pi5 and Pii pairs require partially distinct mechanisms to function.

• 한국농림기상학회지
• /
• 제25권4호
• /
• pp.245-257
• /
• 2023

우리나라 대표적인 식량 작물인 벼는 넓은 면적에서 장기간 재배되어 병해충에 대한 저항성이 낮아지고 있다. 대표적인 벼 질병 중 하나인 도열병이 대규모로 발생하면 수확량이 감소하여 조기에 병을 발견하고 방제를 하여야 한다. 하지만 농지 중심에서 도열병이 발생 하면 육안으로 병을 발견하기 어렵다. 드론을 이용한 작물 모니터링 기법은 생육 이상을 탐지하는데 유용하나 언제 발생할지 모르는 도열병 발생을 위해 빈번하게 촬영을 하는 것은 많은 인력과 비용이 소모된다. 본 연구의 목적은 드론, 위성과 같은 원격탐사 자료와 기상자료를 공동 활용하여 벼 도열병을 조기에 탐지하는 것이다. 위성영상은 벼 재배 필지를 추출하는데 유용하였다. 식생지수와 수분지수의 특성을 이용하여 관개가 된 논을 효과적으로 탐지하였다. 이후 기온, 상대습도, 강우일수 자료를 활용하여 벼 도열병 발생위험도를 계산하였다. 도열병 발생위험도가 증가하면 병이 발생할 가능성이 높아진다는 것을 의미하며, 해당 시점에 드론 관측을 수행하였다. 병이 발생한 지점, 병이 발생한 지점과 일반 벼가 혼재되어 있는 지점, 일반 벼 지점에서 분광반사도의 변화를 살펴보았으며, 갈색 병반을 가지는 도열병 특성상 적색과 근적외선 파장대에서 분광반사도의 변화가 급격한 것을 확인하였다. 도열병이 발생한 지점에서는 주변 지점에 비해 식생지수 값이 낮은 군집이 나타났으며, 시계열 드론 영상을 통해 해당 지점으로부터 벼 도열병 확산을 추적하였다. 최종적으로 수확 전 드론 영상을 활용하여 필지별 도열병 발생률에 대한 공간정보를 생산하였다.

• 한국식물병리학회:학술대회논문집
• /
• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
• /
• pp.105.3-106
• /
• 2003

Bacillus subtilis strain BAC02-4 was tested for its ability induced systemic resistance(ISR) in rice against Magnaporthe grisea We extend these studies to investigate the biological induction of systemic resistance in rice following treatment with the inducer isolate BAC02-4 and naturally infested with Pyricularia oryzae. We also determine levels of ISR activity during the period between disease development and the onset of systemic resistance. Comparition of lesion number according to applied concentration of BAC02-4 to 'Nagdongbyeo' when naturally infested with the conidia of P. grisea. Results from the blast nusery trial using the 'Nagdongbyeo' showed very low rice blast severity with the inducer concentration of 10$\^$8/ cfu level. Considering the low level of treatment and untreated control were observed to have developed typical susceptible lesion type. Highest protection against the rice blast pathogen when applied three times with 5 days interval as root drench at 5 to 6 leaf stage before pathogen challenge. But higher dose of bacterial inducer produced a little stunted plants with less number lesions and delayed disease development. Diseased leaf area of treated with suspension of the isolate which gave about 80％ of control efficacy at 20 days later comparable to that in noninfested, inducer-free soil.

• 한국식물병리학회:학술대회논문집
• /
• 한국식물병리학회 2002년도 총회 및 추계학술발표회
• /
• pp.77-77
• /
• 2002

• 한국작물학회지
• /
• 제65권3호
• /
• pp.172-181
• /
• 2020

고시히카리는 도열병과 쓰러짐에 약하지만 밥맛 좋은 쌀로 유명하고, 육성된 지 60년이 넘은 지금까지도 일본에서 가장 많이 재배되는 품종이다. 고시히카리에 도열병에 강하면서 생육이 빠른 백일미를 교배한 RIL집단(KBRIL)에서 도열병 저항성에 대한 유전분석을 수행하여 저항성 유전자의 염색체 상 위치를 규명하고, 고시히카리의 우수한 미질을 보유하면서 도열병에도 강한 계통을 선발하기 위해 본 연구를 수행하였다. 주요 결과는 다음과 같다. 1. 고시히카리×백일미 RIL 394계통과 모·부본의 도열병 저항성(전주, 남원) 및 주요 농업형질을 조사하고, 유전 분석을 위해 사용된 142계통으로 총 130개 SNP 마커, 1,272.7cM의 유전자지도를 작성하였다. 도열병 저항성 QTL 분석 결과 전주에서는 1번 염색체의 qBL1.1이, 남원에서는 전주와 동일한 qBL1.1과 추가로 2번 염색체의 qBL2.1이 탐지되었다. 2. RIL 394계통의 qBL1.1과 qBL2.1 유전자형을 도출하고 각 QTL의 백일미 대립인자 집적에 의한 도열병 저항성 강화 효과를 관찰하였다. 전주에서는 qBL1.1의 경우에만 백일미 대립인자 집적에 의하여 도열병 저항성이 강화되었다. 반면 남원에서는 qBL1.1, qBL2.1 모두 백일미 대립인자가 집적될 때 도열병 저항성이 강화되었다. qBL1.1, qBL2.1은 출수기, 간장, 수장, 수수를 포함한 주요 농업형질에는 영향을 미치지 않았다. 3. 고시히카리×백일미 RIL 394계통 중에서 출수기와 간장을 기준으로 고시히카리와 유사하면서 도열병에 약/강한(KS/KR) 계통과 백일미와 유사하면서 도열병에 강한(BR) 계통을 각 15계통씩 선발하였다. KR 그룹은 완전 미율이 가장 우수하여 밥맛 검정, 수량성 등 추가조사를 통해 고시히카리의 우수한 밥맛을 지니면서 도열병 저항성을 보유한 고품질 밥쌀용 품종개발에 활용할 계획이다. 또한 BR그룹은 미질이 우수하면서 출수가 빠른 고품질 품종 개발에 유용할 것으로 기대된다.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2017년도 9th Asian Crop Science Association conference
• /
• pp.134-134
• /
• 2017

Recently, host-induced gene silencing (HIGS) system has been successfully applied into development of resistant crops against insects, fungal and viral pathogens. To test HIGS-mediated resistance in rice against rice blast fungus, Magnaporthe oryzae, we first tested possibility of movement of small non-coding RNA from rice cells to rice blast fungus. The rice blast fungus expressing GFP transgene were inoculated to transgenic rice plants ectopically expressing dsRNAi construct targeting fungal GFP gene. Expression of dsRNAi construct for GFP gene in transgenic plants significantly suppressed GFP expression in infected fungal cells indicating that small RNAs generated in plant cells can move into infected fungal cells and efficiently suppress the expression of fungal GFP gene. Consistent with these results, expression of dsRNAi constructs against 3 fungal pathogenic genes of M. oryzae in transgenic rice specifically and efficiently suppressed not only the expression of fungal pathogenic genes, but also fungal infection. The conidia of M. oryzae applied on leaf sheath of transgenic rice expressing dsRNAs against 3 fungal pathogenic genes showed abnormal development of primary hyphae and malfunction of appressorium, which is consistent with the phenotypes of corresponding fungal knock-out mutants. Taken these results together, here, we suggest a novel strategy for development of antifungal crops by means of HIGS system.

• The Plant Pathology Journal
• /
• 제32권4호
• /
• pp.357-362
• /
• 2016

ALD1 (ABERRANT GROWTH AND DEATH2 [AGD2]-LIKE DEFENSE1) is one of the key defense regulators in Arabidopsis thaliana and Nicotiana benthamiana. In these model plants, ALD1 is responsible for triggering basal defense response and systemic resistance against bacterial infection. As well ALD1 is involved in the production of pipecolic acid and an unidentified compound(s) for systemic resistance and priming syndrome, respectively. These previous studies proposed that ALD1 is a potential candidate for developing genetically modified (GM) plants that may be resistant to pathogen infection. Here we introduce a role of ALD1-LIKE gene of Oryza sativa, named as OsALD1, during plant immunity. OsALD1 mRNA was strongly transcribed in the infected leaves of rice plants by Magnaporthe oryzae, the rice blast fungus. OsALD1 proteins predominantly localized at the chloroplast in the plant cells. GM rice plants over-expressing OsALD1 were resistant to the fungal infection. The stable expression of OsALD1 also triggered strong mRNA expression of PATHOGENESIS-RELATED PROTEIN1 genes in the leaves of rice plants during infection. Taken together, we conclude that OsALD1 plays a role in disease resistance response of rice against the infection with rice blast fungus.

• 한국응용곤충학회지
• /
• 제22권2호
• /
• pp.74-83
• /
• 1983

Yield losses due to diseases and insect pests were mentioned and emphasized the efficiency of resistant cultivars in curving the yield losses and increasing chemical efficiency. Present status of resistance breeding for blast, bacterial leaf blight viruses, brown planthopper and white backed planthopper were introduced and the resistance sources for those are discussed. Breeding strategies for above items were presented. Specially for the blast resistance, discussions were made in some detail. With brief future prospects of resistance breeding in Korea, a suggestion was made for pathologists to make clear about whether the blast spores will be brought from mainland China as we see with Bph and Wbph or not.