scholarly journals Natural Variation at the Pi-ta Rice Blast Resistance Locus

2003 ◽  
Vol 93 (11) ◽  
pp. 1452-1459 ◽  
Author(s):  
Yulin Jia ◽  
Gregory T. Bryan ◽  
Leonard Farrall ◽  
Barbara Valent
Keyword(s):  
Positional Cloning ◽  
Magnaporthe Grisea ◽  
Blast Resistance ◽  
El Paso ◽  
Avirulence Gene ◽  
Resistance Locus ◽  
Japonica Rice ◽  
Breeding Programs ◽  
Rice Blast Resistance ◽  
Intron Region

The resistance gene Pi-ta protects rice crops against the fungal pathogen Magnaporthe grisea expressing the avirulence gene AVR-Pita in a gene-for-gene manner. Pi-ta, originally introgressed into japonica rice from indica origin, was previously isolated by positional cloning. In this study, we report the nucleotide sequence of a 5,113-base pair region containing a japonica susceptibility pi-ta allele, which has overall 99.6% nucleotide identity to the indica Pi-ta allele conferring resistance. The intron region shows the levels of sequence diversity that typically differentiate genes from indica and japonica rices, but the other gene regions show less diversity. Sequences of the Pi-ta allele from resistant cultivars Katy and Drew from the southern United States are identical to the resistance Pi-ta sequence. Sequences from susceptible cultivars El Paso 144 and Cica 9 from Latin America define a third susceptibility haplotype. This brings the total number of Pi-ta haplotypes identified to four, including the resistance allele and three susceptibility alleles. The Pi-ta locus shows low levels of DNA polymorphism compared with other analyzed R genes. Understanding the natural diversity at the Pi-ta locus is important for designing specific markers for incorporation of this R gene into rice-breeding programs.

scholarly journals Identification of a New Locus, Ptr(t), Required for Rice Blast Resistance Gene Pi-ta–Mediated Resistance

2008 ◽  
Vol 21 (4) ◽  
pp. 396-403 ◽  
Author(s):  
Yulin Jia ◽  
Rodger Martin
Keyword(s):  
Resistance Gene ◽  
Blast Resistance ◽  
Nuclear Gene ◽  
Avirulence Gene ◽  
Signal Recognition ◽  
Rice Blast Resistance ◽  
Blast Resistance Gene ◽  
Recognition Specificity ◽  
Origin Identification ◽  
Simple Sequence

Resistance to the blast pathogen Magnaporthe oryzae is proposed to be initiated by physical binding of a putative cytoplasmic receptor encoded by a nucleotide binding site-type resistance gene, Pi-ta, to the processed elicitor encoded by the corresponding avirulence gene AVR-Pita. Here, we report the identification of a new locus, Ptr(t), that is required for Pi-ta–mediated signal recognition. A Pi-ta–expressing susceptible mutant was identified using a genetic screen. Putative mutations at Ptr(t) do not alter recognition specificity to another resistance gene, Pi-ks, in the Pi-ta homozygote, indicating that Ptr(t) is more likely specific to Pi-ta–mediated signal recognition. Genetic crosses of Pi-ta Ptr(t) and Pi-ta ptr(t) homozygotes suggest that Ptr(t) segregates as a single dominant nuclear gene. A ratio of 1:1 (resistant/susceptible) of a population of BC1 of Pi-ta Ptr(t) with pi-ta ptr(t) homozygotes indicates that Pi-ta and Ptr(t) are linked and cosegregate. Genotyping of mutants of pi-ta ptr(t) and Pi-ta Ptr(t) homozygotes using ten simple sequence repeat markers at the Pi-ta region determined that Pi-ta and Ptr(t) are located within a 9-megabase region and are of indica origin. Identification of Ptr(t) is a significant advancement in studying Pi-ta–mediated signal recognition and transduction.

A Telomeric Avirulence Gene Determines Efficacy for the Rice Blast Resistance Gene Pi-ta

2000 ◽  
Vol 12 (11) ◽  
pp. 2019 ◽  
Author(s):  
Marc J. Orbach ◽  
Leonard Farrall ◽  
James A. Sweigard ◽  
Forrest G. Chumley ◽  
Barbara Valent
Keyword(s):  
Resistance Gene ◽  
Rice Blast ◽  
Blast Resistance ◽  
Avirulence Gene ◽  
Rice Blast Resistance ◽  
Blast Resistance Gene

scholarly journals Function and evolution of Magnaporthe oryzae avirulence gene AvrPib responding to the rice blast resistance gene Pib

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Shulin Zhang ◽  
Ling Wang ◽  
Weihuai Wu ◽  
Liyun He ◽  
Xianfeng Yang ◽  
...  
Keyword(s):  
Resistance Gene ◽  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Blast Resistance ◽  
Avirulence Gene ◽  
Rice Blast Resistance ◽  
Blast Resistance Gene

scholarly journals Determination of Host Responses to Magnaporthe grisea on Detached Rice Leaves Using a Spot Inoculation Method

Plant Disease ◽  
2003 ◽  
Vol 87 (2) ◽  
pp. 129-133 ◽  
Author(s):  
Y. Jia ◽  
B. Valent ◽  
F. N. Lee
Keyword(s):  
Rice Blast ◽  
Magnaporthe Grisea ◽  
Blast Resistance ◽  
Host Responses ◽  
Tween 20 ◽  
Rice Blast Resistance ◽  
Exact Number ◽  
Detached Leaves ◽  
Rice Leaves

Through the use of standard assays, where conidia of the pathogen Magnaporthe grisea are sprayed onto rice, it is impossible to determine the exact number of conidia in any given area and to predict the locations of disease lesions in the rice blast system. To develop a localized, quantitative inoculation of M. grisea, a novel spot method was investigated. Serially diluted Tween 20 was added to M. grisea conidial suspensions in 0.25% (wt/vol) gelatin to promote adherence of conidia on detached rice leaves. Standard assays indicated no deleterious effects of Tween 20 to rice blast development and 0.02% (vol/vol) Tween 20 was necessary for promoting adherence of spore suspensions to the detached leaves. The spot method was evaluated using three well-characterized races of M. grisea and confirmed with standard assays. Disease reactions of rice to four predominant races of M. grisea were tested concurrently using the spot method and standard assays. Successful application of this assay will help identify novel sources of rice blast resistance and evaluate virulence of M. grisea to aid in breeding resistance to rice blast.

scholarly journals Cloning and Function Analysis of a Novel Rice Blast Resistance Gene Pi65 in Japonica Rice

2021 ◽  
Author(s):  
Lili Wang ◽  
Zuobin Ma ◽  
Houxiang Kang ◽  
Shuang Gu ◽  
Zhanna Mukhina ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Resistance Gene ◽  
Rice Blast ◽  
Blast Resistance ◽  
Rice Blast Disease ◽  
Blast Disease ◽  
Resistant Variety ◽  
Japonica Rice ◽  
Rice Blast Resistance ◽  
Blast Resistance Gene

Abstract Rice blast seriously threatens rice production worldwide. Utilizing the rice blast resistance gene to breed the rice blast resistant varieties is one of the best ways to control rice blast disease. Using a map-based cloning strategy, here, we cloned a novel rice blast resistance gene, Pi65 from the resistant variety GangYu129 (abbreviated GY129, O. sativa japonica ). Overexpression of Pi65 in the susceptible variety LiaoXing1 (abbreviated LX1, O. sativa japonica ) enhanced rice blast resistance, while knockout of Pi65 in GY129 resulted in susceptible to rice blast disease. Pi65 encodes two transmembrane domains, with 15 LRR domains and one serine/threonine protein kinase catalytic domain, conferring resistance to isolates of M. oryzae collected from northeast China. There are sixteen amino acids differences between the Pi65 resistance and susceptible alleles. Compared with the Pi65 resistant allele, the susceptible allele deleted one LRR domain. Pi65 was constitutively expressed in whole plants, and it could be induce expressed in the early stage of M. oryzae infection . Transcriptome analysis revealed that numerous genes associated with disease resistance were specifically upregulated in GY129 24-hour post inoculation (HPI), on the contrary, the photosynthesis-and carbohydrate metabolism-related genes were particularly downregulated 24 HPI, demonstrating that the disease resistance associated genes has been activated in GY129 (carrying Pi65 ) after rice blast fungal infection, and the cellular basal and energy metabolism was inhibited simultaneously. Our study provides genetic resources for improving rice blast resistance as well as enriches the study of rice blast resistance mechanisms.

Positional cloning of rice blast resistance genes

2008 ◽  
pp. 675-680
Author(s):  
S. Kawasaki ◽  
K. Rybka ◽  
M. Miyamoto ◽  
Y. Tanaka ◽  
M. Kataoka ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Rice Blast ◽  
Positional Cloning ◽  
Blast Resistance ◽  
Rice Blast Resistance ◽  
Blast Resistance Genes

scholarly journals Ultrastructural and Cytochemical Aspects of Silicon-Mediated Rice Blast Resistance

2003 ◽  
Vol 93 (5) ◽  
pp. 535-546 ◽  
Author(s):  
Fabrício Á. Rodrigues ◽  
Nicole Benhamou ◽  
Lawrence E. Datnoff ◽  
Jeffrey B. Jones ◽  
Richard R. Bélanger
Keyword(s):  
Defense Response ◽  
Rice Blast ◽  
Magnaporthe Grisea ◽  
Blast Resistance ◽  
Amorphous Material ◽  
Fungal Colonization ◽  
Primary Role ◽  
Cell Reaction ◽  
Fungal Cell ◽  
Rice Blast Resistance

Although exogenous application of silicon (Si) confers efficient control of rice blast, the probable hypothesis underlying this phenomenon has been confined to that of a mechanical barrier resulting from Si polymerization in planta. However, in this study, we provide the first cytological evidence that Si-mediated resistance to Magnaporthe grisea in rice correlates with specific leaf cell reaction that interfered with the development of the fungus. Accumulation of an amorphous material that stained densely with toluidine blue and reacted positively to osmium tetroxide was a typical feature of cell reaction to infection by M. grisea in samples from Si+ plants. As a result, the extent of fungal colonization was markedly reduced in samples from Si+ plants. In samples from Si- plants, M. grisea grew actively and colonized all leaf tissues. Cytochemi-cal labeling of chitin revealed no difference in the pattern of chitin localization over fungal cell walls of either Si+ or Si- plants at 96 h after inoculation, indicating limited production of chitinases by the rice plant as a mechanism of defense response. On the other hand, the occurrence of empty fungal hyphae, surrounded or trapped in amorphous material, in samples from Si+ plants suggests that phenolic-like compounds or phytoalexins played a primary role in rice defense response against infection by M. grisea. This finding brings new insights into the complex role played by Si in the nature of rice blast resistance.

Sign in / Sign up

Export Citation Format

Share Document