scholarly journals Studies on the Behavior of the Rice Blast Fungus Spore and the Application for Forecasting Method of the Rice Blast Disease

1974 ◽  
Vol 40 (3) ◽  
pp. 165-167
Author(s):  
Hozumi SUZUKI
Author(s):  
Sergio M. Latorre ◽  
C. Sarai Reyes-Avila ◽  
Angus Malmgren ◽  
Joe Win ◽  
Sophien Kamoun ◽  
...  

AbstractBackgroundUnderstanding the mechanisms and timescales of plant pathogen outbreaks requires a detailed genome-scale analysis of their population history. The fungus Magnaporthe (Syn. Pyricularia) oryzae —the causal agent of blast disease of cereals— is among the most destructive plant pathogens to world agriculture and a major threat to the production of rice, wheat and other cereals. Although M. oryzae is a multihost pathogen that infects more than 50 species of cereals and grasses, all rice-infecting isolates belong to a single genetically defined lineage. Here, we combined multiple genomics datasets to reconstruct the genetic history of the rice-infecting lineage of M. oryzae based on 131 isolates from 21 countries.ResultsThe global population of the rice blast fungus consists of a diverse set of individuals and three well-defined genetic groups. Multiple population genetic tests revealed that the rice-infecting lineage of the blast fungus probably originated from a recombining diverse group in South East Asia followed by three independent clonal expansions that took place over the last ∼200 years. Patterns of allele sharing identified a subpopulation from the recombining diverse group that introgressed with one of the clonal lineages before its global expansion. Remarkably, the four genetic lineages of the rice blast fungus vary in the number and patterns of presence/absence of candidate effector genes. In particular, clonal lineages carry a reduced repertoire of effector genes compared with the diverse group, and specific combinations of effector presence/absence define each of the pandemic clonal lineages.ConclusionsOur analyses reconstruct the genetic history of the rice-infecting lineage of M. oryzae revealing three clonal lineages associated with rice blast pandemics. Each of these lineages displays a specific pattern of presence/absence of effector genes that may have shaped their adaptation to the rice host and their evolutionary history.


2020 ◽  
Vol 6 (1) ◽  
pp. 38 ◽  
Author(s):  
Apinya Longya ◽  
Sucheela Talumphai ◽  
Chatchawan Jantasuriyarat

Rice blast disease is caused by the ascomycete fungus Pyricularia oryzae and is one of the most destructive rice diseases in the world. The objectives of this study were investigating various fungal morphological characteristics and performing a phylogenetic analysis. Inter-simple sequence repeat (ISSR) and sequence-related amplified polymorphism (SRAP) markers were used to examine the genetic variation of 59 rice blast fungus strains, including 57 strains collected from different fields in Thailand and two reference strains, 70-15 and Guy11. All isolates used in this study were determined to be P. oryzae by internal transcribed spacer (ITS) sequence confirmation. A total of 14 ISSR primers and 17 pairs of SRAP primers, which produced clear and polymorphic bands, were selected for assessing genetic diversity. A total of 123 polymorphic bands were generated. The similarity index value for the strains ranged from 0.25 to 0.95. The results showed that the blast fungus population in Thailand has both morphological and genetic variations. A high level of genetic variation, or genome adaptation, is one of the fungal mechanisms that could overcome host resistance to avoid host recognition. Results from this research study could bring substantial benefits and ultimately help to understand the blast fungal pathogen genome and the population structure in Thai blast fungus.


2017 ◽  
Vol 61 ◽  
pp. 1-7
Author(s):  
Nguyen Phu Toan ◽  
Pham Thi Thu Ha ◽  
Tran Dang Xuan

Rice blast fungus (Pyricularia grisea) is one of the most problematic pathogen to significantly reduce rice production worldwide. In this study, after being inoculated withP. grisea, changes in phenolic components and antioxidant capacity and correlation with the resistant level against rice blast fungus were investigated. Among screened rice cultivars, AV-3 was the strongest resistant, whereas BII-3 was the most susceptible. It was found that although total contents of phenolics and flavonoids, and antioxidant capacities varied among studied varieties, no significant coefficient with the resistance againstP. griseawas observed. After rice was affected by rice blast fungus, total phenolics and flavonoids were markedly reduced, but in contrast, the DPPH scavenging activities of only the susceptible rice cultivars was reduced. Among the 11 phenolic acids detected, catechol was found only in the tolerant cultivar AV-3, whereas the amount of cinnamic acid was increased after infection. Quantity of vanillin was also promoted, except in the susceptible cultivar BII-3 that was significantly reduced. Findings of this study showed that the resistant level againstP. griseawas proportionally correlated to the antioxidant capacity. Catechol, cinnamic acid, and vanillin may play a role but it needs further elaboration. Observations of this study suggested that the infection of blast disease by reducing amount of phenolics and flavonoids that may weaken the resistance of rice against this detrimental fungus.


2014 ◽  
Vol 27 (10) ◽  
pp. 1027-1034 ◽  
Author(s):  
Naoki Yokotani ◽  
Tomoko Tsuchida-Mayama ◽  
Hiroaki Ichikawa ◽  
Nobutaka Mitsuda ◽  
Masaru Ohme-Takagi ◽  
...  

Plants respond to pathogen attack by transcriptionally regulating defense-related genes via various types of transcription factors. We identified a transcription factor in rice, OsNAC111, belonging to the TERN subgroup of the NAC family that was transcriptionally upregulated after rice blast fungus (Magnaporthe oryzae) inoculation. OsNAC111 was localized in the nucleus of rice cells and had transcriptional activation activity in yeast and rice cells. Transgenic rice plants overexpressing OsNAC111 showed increased resistance to the rice blast fungus. In OsNAC111-overexpressing plants, the expression of several defense-related genes, including pathogenesis-related (PR) genes, was constitutively high compared with the control. These genes all showed blast disease-responsive expression in leaves. Among them, two chitinase genes and one β-1,3-glucanase gene showed reduced expression in transgenic rice plants in which OsNAC111 function was suppressed by a chimeric repressor (OsNAC111-SRDX). OsNAC111 activated transcription from the promoters of the chitinase and β-1,3-glucanase genes in rice cells. In addition, brown pigmentation at the infection sites, a defense response of rice cells to the blast fungus, was lowered in OsNAC111-SRDX plants at the early infection stage. These results indicate that OsNAC111 positively regulates the expression of a specific set of PR genes in the disease response and contributes to disease resistance.


2020 ◽  
Vol 31 (21) ◽  
pp. 2298-2305
Author(s):  
Audra Mae Rogers ◽  
Martin John Egan

The fungus Magnaporthe oryzae causes rice blast disease, which destroys enough rice annually to feed 60 million people. M. oryzae forms a specialized infection cell, which it uses to break into host tissue. Here we investigate how M. oryzae spatially and temporally manages stress-induced protein damage during infection-related development.


2021 ◽  
pp. 103562
Author(s):  
Alice Bisola Eseola ◽  
Lauren S. Ryder ◽  
Míriam Osés-Ruiz ◽  
Kim Findlay ◽  
Xia Yan ◽  
...  

1994 ◽  
Vol 269 (5) ◽  
pp. 3755-3761 ◽  
Author(s):  
Y.L. Peng ◽  
Y. Shirano ◽  
H. Ohta ◽  
T. Hibino ◽  
K. Tanaka ◽  
...  

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