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Plant disease resistance

About: Plant disease resistance is a research topic. Over the lifetime, 12952 publications have been published within this topic receiving 381820 citations. The topic is also known as: plant innate immunity.


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Journal ArticleDOI
TL;DR: This is the first report documenting the stacking of two major genes (Piz-5 + Xa21) in rice using molecular breeding through MAS and transformation and the endogenous presence of the Xa4 gene, which may show an increased level of resistance to the BB pathogen along with the transformed Xa 21 gene.
Abstract: The objective of this study was to improve IR50, an elite Indica rice line, by molecular breeding approach involving marker-aided selection (MAS) and genetic transformation for resistance against blast (BL) and bacterial blight (BB). On the basis of BL pathogen population dynamics and lineage exclusion assays in southern India, the major BL resistance gene Piz-5 can exclude most Pyricularia grisea Sacc. {= P. oryzae Cavara [teleomorph: Magnaporthe grisea (Hebert) Barr]} lineages. Resistant C039 near-isogenic line (NIL) C101A51 carrying Piz-5 was used as the donor parent and IR50 as the recurrent parent in backcrossing up to four generations. BC4F1 plants were finally selfed to produce BC4F2 seeds. A polymerase chain reaction (PCR)-based sequence-tagged site (STS) marker RG64 was used to identify Piz-5 in the segregating population and the resultant resistant progenies were obtained through phenotypic assays and MAS. To have further resistance to bacterial blight in this cultivar, these blast-resistant isolines were transformed with Xa21, which is known to confer resistance to all races of Xanthomonas oryzae pv. Oryzae [= X. campestris pv. Oryza (Ishiyama 1922) Dye 1978] (Xoo). Stable integration and inheritance of the Xa21 gene were demonstrated by PCR and Southern blot analysis from three independent transformants. Bioassay data showed that transgenic IR50 is resistant to pathogens, M. grisea and Xoo. Apart from that, pedigree analysis and phenotypic studies with IR50 revealed the endogenous presence of the Xa4 gene, which may show an increased level of resistance to the BB pathogen along with the transformed Xa21 gene. This is the first report documenting the stacking of two major genes (Piz-5 + Xa21) in rice using molecular breeding through MAS and transformation.

109 citations

Journal ArticleDOI
TL;DR: The results demonstrate the existence of differing virulences in the pathogen populations from within Africa and between Africa and India, and demonstrate that pathotype-specific resistance is a major mechanism of downy mildew resistance in this cross.
Abstract: Quantitative trait loci (QTLs) for resistance to pathogen populations of Scelerospora graminicola from India, Nigeria, Niger and Senegal were mapped using a resistant x susceptible pearl millet cross. An RFLP map constructed using F2 plants was used to map QTLs for traits scored on F4 families. QTL analysis was carried out using the interval mapping programme Mapmaker/QTL. Independent inheritance of resistance to pathogen populations from India, Senegal, and populations from Niger and Nigeria was shown. These results demonstrate the existence of differing virulences in the pathogen populations from within Africa and between Africa and India. QTLs of large effect, contributing towards a large porportion of the variation in resistance, were consistently detected in repeated screens. QTLs of smaller and more variable effect were also detected. There was no QTLs that were effective against all four pathogen populations, demonstrating that pathotype-specific resistance is a major mechanism of downy mildew resistance in this cross. For all but one of the QTLs, resistance was inherited from the resistant parent and the inheritance of resistance tended to be the result of dominance or over-dominance. The implications of this research for pearl millet breeding are discussed.

109 citations

Journal ArticleDOI
TL;DR: The interaction of T. harzianum and the AMF with the plant produced a characteristic hormonal profile, which differed from that produced by inoculation with each microorganism singly, suggesting an attenuation of the plant response, related to the hormones SA, JA and ethylene.

109 citations

Journal ArticleDOI
TL;DR: It is suggested that C3H12, as a nucleic acid-binding protein, positively and quantitatively regulates rice resistance to Xoo and that its function is likely associated with the JA-dependent pathway.
Abstract: Bacterial blight is a devastating disease of rice (Oryza sativa) caused by Xanthomonas oryzae pv oryzae (Xoo). Zinc finger proteins harboring the motif with three conserved cysteine residues and one histidine residue (CCCH) belong to a large family. Although at least 67 CCCH-type zinc finger protein genes have been identified in the rice genome, their functions are poorly understood. Here, we report that one of the rice CCCH-type zinc finger proteins, C3H12, containing five typical CX8-CX5-CX3-H zinc finger motifs, is involved in the rice-Xoo interaction. Activation of C3H12 partially enhanced resistance to Xoo, accompanied by the accumulation of jasmonic acid (JA) and induced expression of JA signaling genes in rice. In contrast, knockout or suppression of C3H12 resulted in partially increased susceptibility to Xoo, accompanied by decreased levels of JA and expression of JA signaling genes in rice. C3H12 colocalized with a minor disease resistance quantitative trait locus to Xoo, and the enhanced resistance of randomly chosen plants in the quantitative trait locus mapping population correlated with an increased expression level of C3H12. The C3H12 protein localized in the nucleus and possessed nucleic acid-binding activity in vitro. These results suggest that C3H12, as a nucleic acid-binding protein, positively and quantitatively regulates rice resistance to Xoo and that its function is likely associated with the JA-dependent pathway.

109 citations

Journal ArticleDOI
TL;DR: Two pathogenesis-related protein genes consisting of a barley chitinase (chi-2) and a wheat lipid-transfer-protein (ltp) were introduced singly and in combination into carrot plants via Agrobacterium-mediated transformation using the phosphinothricin acetyl transferase (bar) gene as a selectable marker to significantly enhance resistance to necrotrophic fungal pathogens.
Abstract: Two pathogenesis-related (PR) protein genes consisting of a barley chitinase (chi-2) and a wheat lipid-transfer-protein (ltp) were introduced singly and in combination into carrot plants via Agrobacterium-mediated transformation using the phosphinothricin acetyl transferase (bar) gene as a selectable marker. Over 75% of regenerated plants were confirmed to be positive for the transgenes by PCR and RT-PCR and were resistant to the herbicide Liberty (0.2%, v/v). Northern analysis and immunoblotting confirmed the expression of the transgenes in about 70% of the plants, with variable expression levels among individual lines. Southern analysis revealed from one to three copies of each transgene. Transgenic plants were inoculated with two necrotrophic foliar fungal pathogens, Alternaria radicicola and Botrytis cinerea, and showed significantly higher resistance when both PR genes were expressed compared to single-gene transformants. The level of disease reduction in plants expressing both genes was 95% for Botrytis and 90% for Alternaria infection compared to 40–50% for single-gene transformants. The chi2 and ltp genes could be deployed in combination in other crop plants to significantly enhance resistance to necrotrophic fungal pathogens.

109 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023377
2022756
2021410
2020438
2019526
2018640