scholarly journals Osa-miR162a balances rice yield and resistance to Magnaporthe oryzae

2020 ◽  
Author(s):  
Xu-Pu Li ◽  
Xiao-Chun Ma ◽  
He Wang ◽  
Yong Zhu ◽  
Xin-Xian Liu ◽  
...  
Keyword(s):  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Rice Yield ◽  
Blast Resistance ◽  
Blast Disease ◽  
Mirna Biogenesis ◽  
Trade Off ◽  
Rice Blast Resistance ◽  
Defense Related Gene ◽  
Transgenic Lines

Abstract MicroRNAs (miRNAs) play essential roles in rice immunity against Magnaporthe oryzae, the causative agent of rice blast disease. Osa-miR162a targets Dicer-like 1 (DCL1) genes, which play vital roles in miRNA biogenesis and act as negative regulators in rice immunity. Here we demonstrate that Osa-miR162a improves rice immunity against M. oryzae and balances the trade-off between rice yield and resistance. Overexpression of Osa-miR162a compromises rice susceptibility to M. oryzae accompanying enhanced induction of defense-related genes and accumulation of hydrogen peroxide (H2O2). In contrast, blocking miR162 by overexpressing a target mimic of miR162 enhances susceptibility to blast fungus associating with compromised induction of defense-related gene expression and H2O2 accumulation. Moreover, the transgenic lines overexpressing Osa-miR162a display decreased seed setting rate resulting in reduced yield per plant, whereas blocking miR162 leads to an increased number of grains per panicle, resulting in increased yield per plant. Altered accumulation of miR162 had limited impact on the expression of OsDCL1. Together, our results indicate that Osa-miR162a improves rice blast resistance and plays a role in the balance of trade-off between resistance and yield.

scholarly journals Overexpression of Magnaporthe Oryzae Systemic Defense Trigger 1 (MoSDT1) Confers Improved Rice Blast Resistance in Rice

2019 ◽  
Vol 20 (19) ◽  
pp. 4762 ◽  
Author(s):  
Wang ◽  
Li ◽  
Duan ◽  
Wang ◽  
Zhang ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Blast Resistance ◽  
Plant Defense Response ◽  
Callose Deposition ◽  
Primary Metabolites ◽  
Rice Blast Resistance ◽  
Ros Accumulation ◽  
Transgenic Lines

The effector proteins secreted by a pathogen not only promote virulence and infection of the pathogen, but also trigger plant defense response. Therefore, these proteins could be used as important genetic resources for transgenic improvement of plant disease resistance. Magnaporthe oryzae systemic defense trigger 1 (MoSDT1) is an effector protein. In this study, we compared the agronomic traits and blast disease resistance between wild type (WT) and MoSDT1 overexpressing lines in rice. Under control conditions, MoSDT1 transgenic lines increased the number of tillers without affecting kernel morphology. In addition, MoSDT1 transgenic lines conferred improved blast resistance, with significant effects on the activation of callose deposition, reactive oxygen species (ROS) accumulation and cell death. On the one hand, overexpression of MoSDT1 could delay biotrophy–necrotrophy switch through regulating the expression of biotrophy-associated secreted protein 4 (BAS4) and Magnaporthe oryzaecell death inducing protein 1 (MoCDIP1), and activate plant defense response by regulating the expression of Bsr-d1, MYBS1, WRKY45, peroxidase (POD), heat shock protein 90 (HSP90), allenoxide synthase 2 (AOS2), phenylalanine ammonia lyase (PAL), pathogenesis-related protein 1a (PR1a) in rice. On the other hand, overexpression of MoSDT1 could increase the accumulation of some defense-related primary metabolites such as two aromatic amino acids (L-tyrosine and L-tryptohan), 1-aminocyclopropane carboxylic acid, which could be converted to ethylene, vanillic acid and L-saccharopine. Taken together, overexpression of MoSDT1 confers improved rice blast resistance in rice, through modulation of callose deposition, ROS accumulation, the expression of defense-related genes, and the accumulation of some primary metabolites.

scholarly journals Study of pathogenicity and genetic diversity of Magnaporthe oryzae isolated from rice hybrid Wuyou 308 and detection of resistance genes

2020 ◽  
Vol 56 (No. 3) ◽  
pp. 93-101
Author(s):  
Bo Lan ◽  
Ying-Qing Yang ◽  
Qiang Sun ◽  
Hong-Fan Chen ◽  
Jian Chen ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Blast Resistance ◽  
Rice Variety ◽  
Climatic Conditions ◽  
Blast Disease ◽  
Rice Varieties ◽  
Rice Blast Resistance ◽  
Rice Hybrid

To understand the cause of loss of rice blast resistance, we studied the pathogenicity of Magnaporthe oryzae strains isolated from rice hybrid Wuyou 308 and evaluated its resistance genes. A total of 62 M. oryzae strains were isolated and tested in 7 Chinese rice varieties with varying degrees of resistance to rice blast and 30 blast-resistant monogenic lines. Fourteen physiological races of M. oryzae were identified: 8.55% belonging to the ZA group, 86.67% to the ZB group, and 5.00% to the ZC group. ZB15 was the most abundant race (45.00%). Five resistance genes, Pi-3(1), Pi-z5, Pi-k, Pi-kp(C), and Pi-k(C), conferred good resistance to the 62 strains, with resistance frequencies of 95.56, 91.11, 88.89, 82.22, and 82.22%, respectively. In contrast, Pi-a(2) had a resistance frequency of 0%. The hybrid combination Wuyou 308 was found to carry Pi-ta and Pi-b genes. Because Pi-ta and Pi-b both showed low resistance frequencies to M. oryzae isolated from Jiangxi, the hybrid rice variety Wuyou 308 could be infected by most of the 62 M. oryzae strains. The emergence and spread of rice blast disease in Wuyou 308 may thus be difficult to avoid when climatic conditions are favourable.

Effector genes in Magnaporthe oryzae Triticum as Potential Targets for Incorporating Blast Resistance in Wheat

Plant Disease ◽  
2021 ◽  
Author(s):  
Monica Navia-Urrutia ◽  
Gloria Mosquera ◽  
Rebekah Ellsworth ◽  
Mark Farman ◽  
Harold N. Trick ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Blast Resistance ◽  
Genetic Resistance ◽  
Avirulence Gene ◽  
Avirulence Genes ◽  
Rice Blast Resistance ◽  
Effector Genes ◽  
Transgenic Lines

Wheat blast (WB), caused by Magnaporthe oryzae Triticum pathotype, recently emerged as a destructive disease that threatens global wheat production. Since few sources of genetic resistance have been identified in wheat, genetic transformation of wheat with rice blast resistance genes could expand resistance to WB. We evaluated the presence/absence of homologs of rice blast effector genes in Triticum isolates with the aim of identifying avirulence genes in field populations whose cognate rice resistance genes could potentially confer resistance to WB. We also assessed presence of the wheat pathogen AVR-Rmg8 gene, and identified new alleles. A total of 102 isolates collected in Brazil, Bolivia and Paraguay from 1986 to 2018 were evaluated by PCR using 21 pairs of gene-specific primers. Effector gene composition was highly variable, with homologs to AvrPiz-t, AVR-Pi9, AVR-Pi54 and ACE1 showing the highest amplification frequencies (>94%). We identified Triticum isolates with a functional AvrPiz-t homolog that triggers Piz-t-mediated resistance in the rice pathosystem, and produced transgenic wheat plants expressing the rice Piz-t gene. Seedlings and heads of the transgenic lines were challenged with isolate T25 carrying functional AvrPiz-t. Although slight decreases in the percentage of diseased spikelets and leaf area infected were observed in two transgenic lines, our results indicated that Piz-t did not confer useful WB resistance. Monitoring of avirulence genes in populations is fundamental to identifying effective resistance genes for incorporation into wheat by conventional breeding or transgenesis. Based on avirulence gene distributions, rice resistance genes Pi9 and Pi54 might be candidates for future studies.

scholarly journals Fine-Tuning Roles of Osa-miR159a in Rice Immunity Against Magnaporthe oryzae and Development

Rice ◽  
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Jin-Feng Chen ◽  
Zhi-Xue Zhao ◽  
Yan Li ◽  
Ting-Ting Li ◽  
Yong Zhu ◽  
...  
Keyword(s):  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Target Genes ◽  
Blast Resistance ◽  
Fine Tuning ◽  
Post Inoculation ◽  
Grain Development ◽  
Positive Role ◽  
Rice Blast Resistance ◽  
Transgenic Lines

Abstract Background Rice blast caused by Magnaporthe oryzae is one of the most destructive diseases of rice. An increasing number of microRNAs (miRNAs) have been reported to fine-tune rice immunity against M. oryzae and coordinate with growth and development. Results Here, we showed that rice microRNA159a (Osa-miR159a) played a positive role in rice resistance to M. oryzae. The expression of Osa-miR159a was suppressed in a susceptible accession at 12, 24, and 48 h post-inoculation (hpi); it was upregulated in a resistant accession of M. oryzae at 24 hpi. The transgenic rice lines overexpressing Osa-miR159a were highly resistant to M. oryzae. In contrast, the transgenic lines expressing a short tandem target mimic (STTM) to block Osa-miR159a showed enhanced susceptibility. Knockout mutations of the target genes of Osa-miR159a, including OsGAMYB, OsGAMYBL, and OsZF, led to resistance to M. oryzae. Alteration of the expression of Osa-miR159a impacted yield traits including pollen and grain development. Conclusions Our results indicated that Osa-miR159a positively regulated rice immunity against M. oryzae by downregulating its target genes. Proper expression of Osa-miR159a was critical for coordinating rice blast resistance with grain development.

scholarly journals Fine-tuning roles of Osa-miR159a in rice immunity against Magnaporthe oryzae and development

2020 ◽  
Author(s):  
Jin-Feng Chen ◽  
Zhi-Xue Zhao ◽  
Yan Li ◽  
Ting-Ting Li ◽  
Yong Zhu ◽  
...  
Keyword(s):  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Target Genes ◽  
Blast Resistance ◽  
Fine Tuning ◽  
Post Inoculation ◽  
Grain Development ◽  
Positive Role ◽  
Rice Blast Resistance ◽  
Transgenic Lines

Abstract Background Rice blast caused by Magnaporthe oryzae is one of the most destructive diseases of rice. An increasing number of microRNAs (miRNAs) have been reported to fine-tune rice immunity against M. oryzae and coordinate with growth and development. Results Here, we showed that rice microRNA159a (Osa-miR159a) played a positive role in rice resistance to M. oryzae. The expression of Osa-miR159a was suppressed in a susceptible accession at 12, 24, and 48 hours post-inoculation (hpi); it was upregulated in a resistant accession of M. oryzae at 24 hpi. The transgenic rice lines overexpressing Osa-miR159a were highly resistant to M. oryzae. In contrast, the transgenic lines expressing a short tandem target mimic (STTM) to block Osa-miR159 showed enhanced susceptibility. Knockout mutations of the target genes of Osa-miR159, including OsGAMYB, OsGAMYBL, and OsZF, led to resistance to M. oryzae. Alteration of the expression of Osa-miR159a impacted yield traits including pollen and grain development. Conclusions Our results indicated that Osa-miR159a positively regulated rice immunity against M. oryzae by downregulating its target genes. Proper expression of Osa-miR159a was critical for coordinating rice blast resistance with grain development.

scholarly journals Fine-tuning roles of Osa-miR159a in rice immunity against Magnaporthe oryzae and development

2020 ◽  
Author(s):  
Jin-Feng Chen ◽  
Zhi-Xue Zhao ◽  
Yan Li ◽  
Ting-Ting Li ◽  
Yong Zhu ◽  
...  
Keyword(s):  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Target Genes ◽  
Blast Resistance ◽  
Fine Tuning ◽  
Post Inoculation ◽  
Grain Development ◽  
Positive Role ◽  
Rice Blast Resistance ◽  
Transgenic Lines

Abstract Background: Rice blast caused by Magnaporthe oryzae is one of the most destructive diseases of rice. An increasing number of microRNAs (miRNAs) have been reported to fine-tune rice immunity against M. oryzae and coordinate with growth and development.Results: Here, we showed that rice microRNA159a (Osa-miR159a) played a positive role in rice resistance to M. oryzae. The expression of Osa-miR159a was suppressed in a susceptible accession at 12, 24, and 48 hours post-inoculation (hpi); it was upregulated in a resistant accession of M. oryzae at 24 hpi. The transgenic rice lines overexpressing Osa-miR159a were highly resistant to M. oryzae. In contrast, the transgenic lines expressing a short tandem target mimic (STTM) to block Osa-miR159a showed enhanced susceptibility. Knockout mutations of the target genes of Osa-miR159a, including OsGAMYB, OsGAMYBL, and OsZF, led to resistance to M. oryzae. Alteration of the expression of Osa-miR159a impacted yield traits including pollen and grain development.Conclusions: Our results indicated that Osa-miR159a positively regulated rice immunity against M. oryzae by downregulating its target genes. Proper expression of Osa-miR159a was critical for coordinating rice blast resistance with grain development.

scholarly journals Characterization of Molecular Identity and Pathogenicity of Rice Blast Fungus in Hunan Province of China

Plant Disease ◽  
2017 ◽  
Vol 101 (4) ◽  
pp. 557-561 ◽  
Author(s):  
Junjie Xing ◽  
Yulin Jia ◽  
Zhirong Peng ◽  
Yinfeng Shi ◽  
Qiang He ◽  
...  
Keyword(s):  
Rice Blast ◽  
Blast Resistance ◽  
Pcr Amplification ◽  
Blast Disease ◽  
Hunan Province ◽  
R Genes ◽  
Rice Blast Resistance ◽  
Molecular Identity ◽  
Polymerase Chain

The blast (Magnaporthe oryzae) resistance (R) gene is the most economical and environmental method to control rice blast disease. Characterization of molecular identity and pathogenicity of M. oryzae benefits the deployment of effective blast R genes. In order to identify blast R genes that would be effective in Hunan Province,182 M. oryzae strains were analyzed with a Chinese differential system (CDS), repetitive element-based polymerase chain reaction (rep-PCR), and the presence and absence of avirulence (AVR) genes by PCR amplification with gene-specific primers. Identified blast R genes were validated with 24 monogenic lines (ML) carrying 24 major R genes. In total, 28 races (isolates) of M. oryzae was identified with CDS, and classified into 20 distinct groups with rep-PCR. Interestingly, AVR-Pia, AVR-Pik, AVR-Pizt, AVR-Pib, and AVR-Pi9 were detected in more than 86.8% of the isolates; AVR-Pita1 was in 51.3% and AVR-Pii was in only 2.5%. In contrast, pathogenicity assays on 24 ML demonstrated that Pi9, Piz5, Pikh, and Pikm were more effective, with resistant frequencies of 91.6, 91, 87.9, and 87.3%, respectively; Pia, Piks, Pit, Pi12, and Pib were less than 15%. These findings revealed the complexity of a genetic basis of rice blast resistance, and shed light on useful blast R genes in Hunan Province.

Sign in / Sign up

Export Citation Format

Share Document