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1.
Mol Biol (Mosk) ; 55(1): 96-106, 2021.
Artículo en Ruso | MEDLINE | ID: mdl-33566029

RESUMEN

Cotton leaf curl Multan betasatellite (CLCuMB) is a ubiquitous betasatellite commonly found along with cotton leaf curl disease (CLCuD) associated begomoviruses in the Old World. It has a promiscuous replicative nature and trans-replicated by a diverse range of geminiviruses. CLCuMB encodes a single ORF, ßCl, in the complementary direction and has pathogenicity, symptoms determinant, suppressor of post-transcription and transcription gene silencing functions. After substituting the ßC1 gene with the target gene, it has been used successfully as a gene delivery vector. In the present study, the ßC1 gene of CLCuMB was substituted with the green fluorescent protein (GFP) gene, and the resulting construct utilized as a reporter vector to decipher in planta localization of geminiviruses. The recombinant CLCuMB expressing GFP (CLCuMB-GFP) was co-inoculated to Nicotiana benthamiana plants either with Cotton leaf curl Kokharan virus (CLCuKoV) alone or in a combination with the wild type CLCuMB to investigate the objectives of the study. Results showed that CLCuKoV successfully supported the replication and systemic movement of CLCuMB-GFP either alone or in the presence of wild type CLCuMB. The presence of CLCuMB-GFP was readily detected with PCR and Southern blot hybridization. The modified CLCuMB may serve as a tool useful for in planta localization of geminiviruses.


Asunto(s)
Begomovirus , Geminiviridae , Begomovirus/genética , ADN Satélite/genética , Geminiviridae/genética , Enfermedades de las Plantas/genética , Tabaco/genética , Virulencia
2.
Viruses ; 13(1)2021 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-33478128

RESUMEN

Plant viruses cause devastating diseases in many agriculture systems, being a serious threat for the provision of adequate nourishment to a continuous growing population. At the present, there are no chemical products that directly target the viruses, and their control rely mainly on preventive sanitary measures to reduce viral infections that, although important, have proved to be far from enough. The current most effective and sustainable solution is the use of virus-resistant varieties, but which require too much work and time to obtain. In the recent years, the versatile gene editing technology known as CRISPR/Cas has simplified the engineering of crops and has successfully been used for the development of viral resistant plants. CRISPR stands for 'clustered regularly interspaced short palindromic repeats' and CRISPR-associated (Cas) proteins, and is based on a natural adaptive immune system that most archaeal and some bacterial species present to defend themselves against invading bacteriophages. Plant viral resistance using CRISPR/Cas technology can been achieved either through manipulation of plant genome (plant-mediated resistance), by mutating host factors required for viral infection; or through manipulation of virus genome (virus-mediated resistance), for which CRISPR/Cas systems must specifically target and cleave viral DNA or RNA. Viruses present an efficient machinery and comprehensive genome structure and, in a different, beneficial perspective, they have been used as biotechnological tools in several areas such as medicine, materials industry, and agriculture with several purposes. Due to all this potential, it is not surprising that viruses have also been used as vectors for CRISPR technology; namely, to deliver CRISPR components into plants, a crucial step for the success of CRISPR technology. Here we discuss the basic principles of CRISPR/Cas technology, with a special focus on the advances of CRISPR/Cas to engineer plant resistance against DNA and RNA viruses. We also describe several strategies for the delivery of these systems into plant cells, focusing on the advantages and disadvantages of the use of plant viruses as vectors. We conclude by discussing some of the constrains faced by the application of CRISPR/Cas technology in agriculture and future prospects.


Asunto(s)
Ingeniería Genética , Enfermedades de las Plantas/virología , Virus de Plantas/fisiología , Agricultura/métodos , Sistemas CRISPR-Cas , Productos Agrícolas/virología , Resistencia a la Enfermedad/genética , Edición Génica , Expresión Génica , Técnicas de Transferencia de Gen , Vectores Genéticos/genética , Genoma Viral , Interacciones Huésped-Patógeno/genética , Enfermedades de las Plantas/genética
3.
Food Chem ; 337: 127772, 2021 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-32777571

RESUMEN

Chitosan can function a key role in plant resistant against Botrytis cinerea infection, while its mechanism is unclear in ripened fruits. In this study, we investigated the chitosan effect on two type of ripened fruits including strawberry and grapes (Kyoho and Shine-Muscat) when were infected with B. cinerea. Results showed that chitosan inhibited B. cinerea growth, increased phenolic compounds and cell wall composition, modulated oxidative stress and induced jasmonic acid (JA) production in ripened fruits. Data-independent acquisition (DIA) showed that 224 and 171 proteins were upregulated 1.5-fold by chitosan in Kyoho and Shine-Muscat grape, respectively. Topless-related protein 3 (TPR3) were identified and interacted with histone deacetylase 19 (HDAC19) and negatively regulated by JA and chitosan. Meanwhile, overexpression of VvTPR3 and VvHDAC19 reduced the stability of cell wall against B. cinerea in strawberry. Taken together, chitosan induces defense related genes and protect the fruit quality against Botrytis infection through JA signaling.


Asunto(s)
Botrytis/efectos de los fármacos , Quitosano/farmacología , Ciclopentanos/metabolismo , Fragaria/metabolismo , Oxilipinas/metabolismo , Vitis/metabolismo , Botrytis/fisiología , Pared Celular/metabolismo , Fragaria/microbiología , Frutas/metabolismo , Frutas/microbiología , Histona Desacetilasas/genética , Histona Desacetilasas/metabolismo , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Proteínas de Plantas/antagonistas & inhibidores , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Interferencia de ARN , Esporas Fúngicas/efectos de los fármacos , Regulación hacia Arriba/efectos de los fármacos , Vitis/microbiología
4.
Gene ; 764: 145078, 2021 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-32858175

RESUMEN

In maize, eat rot and stalk rot caused by Fusarium verticillioides and Fusarium graminearum lead to contamination of moldy grains to produce mycotoxins. Identification of resistance genes against these pathogens for maize breeding is an effective way for disease control. Several 2-oxoglutarate-dependent dioxygenase (2OGD) proteins have been found to confer resistance to different pathogens in diverse plant species. However, little is known about the 2OGD superfamily in maize. Here, we identified 103 putative 2OGD genes in maize from a genome-wide analysis, and divided them into three classes - DOXA, DOXB, and DOXC. We further comprehensively investigated their gene structure, chromosome distribution, phylogenetic tree, gene-function enrichment, and expression profiles among different tissues. The genes encoding three 2OGD proteins, ACO, F3H, and NCS involved in ethylene biosynthesis, flavonoids biosynthesis, and alkaloids biosynthesis pathways, respectively, were identified to be induced by F. verticillioides and F. graminearum. The promoters of the three genes contain the binding sites for the transcription factor ZmDOF and ZmHSF, which are also induced by the two pathogens. The results imply that the three 2OGDs and the two transcription factors might be involved in the resistance to the two pathogens. This study provided a comprehensive understanding of the 2OGD superfamily in maize and laid the foundation for the further functional analysis of their roles in maize resistance to eat rot and stalk rot.


Asunto(s)
Dioxigenasas/genética , Fusarium/inmunología , Proteínas de Plantas/genética , Zea mays/fisiología , Secuencia de Bases/genética , Sitios de Unión/genética , Cromosomas de las Plantas/genética , Coenzimas/metabolismo , Secuencia Conservada/genética , Dioxigenasas/inmunología , Dioxigenasas/metabolismo , Resistencia a la Enfermedad/genética , Evolución Molecular , Fusarium/patogenicidad , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas/fisiología , Estudio de Asociación del Genoma Completo , Ácidos Cetoglutáricos/metabolismo , Filogenia , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Proteínas de Plantas/inmunología , Proteínas de Plantas/metabolismo , Tallos de la Planta/enzimología , Tallos de la Planta/crecimiento & desarrollo , Tallos de la Planta/microbiología , Regiones Promotoras Genéticas/genética , RNA-Seq , Factores de Transcripción/metabolismo , Zea mays/microbiología
5.
GM Crops Food ; 12(1): 86-105, 2021 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-33028148

RESUMEN

Potato is the most important non-grain food crop in the world. Viruses, particularly potato virus Y (PVY) and potato virus A (PVA), are among the major agricultural pathogens causing severe reduction in potato yield and quality worldwide. Virus infection induces host factors to interfere with its infection cycle. Evaluation of these factors facilitates the development of intrinsic resistance to plant viruses. In this study, a small G-protein as one of the critical signaling factors was evaluated in plant response to PVY and PVA to enhance resistance. For this purpose, the gene expression dataset of G-proteins in potato plant under five biotic (viruses, bacteria, fungi, nematodes, and insects) and four abiotic (cold, heat, salinity, and drought) stress conditions were collected from gene expression databases. We reduced the number of the selected G-proteins to a single protein, StSAR1A, which is possibly involved in virus inhibition. StSAR1A overexpressed transgenic plants were created via the Agrobacterium-mediated method. Real-time PCR and Enzyme-linked immunosorbent assay tests of transgenic plants mechanically inoculated with PVY and PVA indicated that the overexpression of StSAR1A gene enhanced resistance to both viruses. The virus-infected transgenic plants exhibited a greater stem length, a larger leaf size, a higher fresh/dry weight, and a greater node number than those of the wild-type plants. The maximal photochemical efficiency of photosystem II, stomatal conductivity, and net photosynthetic rate in the virus-infected transgenic plants were also obviously higher than those of the control. The present study may help to understand aspects of resistance against viruses.


Asunto(s)
Potyvirus , Solanum tuberosum , Enfermedades de las Plantas/genética , Plantas Modificadas Genéticamente/virología , Potyvirus/genética , Solanum tuberosum/genética , Solanum tuberosum/virología
6.
GM Crops Food ; 12(1): 125-144, 2021 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-33079628

RESUMEN

Plants are susceptible to phytopathogens, including bacteria, fungi, and viruses, which cause colossal financial shortfalls (pre- and post-harvest) and threaten global food safety. To combat with these phytopathogens, plant possesses two-layer of defense in the form of PAMP-triggered immunity (PTI), or Effectors-triggered immunity (ETI). The understanding of plant-molecular interactions and revolution of high-throughput molecular techniques have opened the door for innovations in developing pathogen-resistant plants. In this context, Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-CRISPR-associated protein 9 (Cas9) has transformed genome editing (GE) technology and being harnessed for altering the traits. Here we have summarized the complexities of plant immune system and the use of CRISPR-Cas9 to edit the various components of plant immune system to acquire long-lasting resistance in plants against phytopathogens. This review also sheds the light on the limitations of CRISPR-Cas9 system, regulation of CRISPR-Cas9 edited crops and future prospective of this technology.


Asunto(s)
Sistemas CRISPR-Cas , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Sistemas CRISPR-Cas/genética , Productos Agrícolas/genética , Edición Génica , Enfermedades de las Plantas/genética
7.
Viruses ; 12(12)2020 12 17.
Artículo en Inglés | MEDLINE | ID: mdl-33348798

RESUMEN

Generation of recombinant negative-stranded RNA viruses (NSVs) from plasmids involves in vivo reconstitution of biologically active nucleocapsids and faces a unique antisense problem where the negative-sense viral genomic RNAs can hybridize to viral messenger RNAs. To overcome this problem, a positive-sense RNA approach has been devised through expression of viral antigenomic (ag)RNA and core proteins for assembly of antigenomic nucleocapsids. Although this detour strategy works for many NSVs, the process is still inefficient. Using Sonchus yellow net rhabdovirus (SYNV) as a model; here, we develop a negative-sense genomic RNA-based approach that increased rescue efficiency by two orders of magnitude compared to the conventional agRNA approach. The system relied on suppression of double-stranded RNA induced antiviral responses by co-expression of plant viruses-encoded RNA silencing suppressors or animal viruses-encoded double-stranded RNA antagonists. With the improved approach, we were able to recover a highly attenuated SYNV mutant with a deletion in the matrix protein gene which otherwise could not be rescued via the agRNA approach. Reverse genetics analyses of the generated mutant virus provided insights into SYNV virion assembly and morphogenesis. This approach may potentially be applicable to other NSVs of plants or animals.


Asunto(s)
Regulación Viral de la Expresión Génica , Ingeniería Genética , Genoma Viral , ARN Viral , Rhabdoviridae/genética , Genes Reporteros , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/virología , Virus de Plantas/genética , Interferencia de ARN , Sonchus/virología , Transcripción Genética
8.
PLoS One ; 15(12): e0243445, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33338052

RESUMEN

Pierce's disease (PD) caused by the bacterium Xylella fastidiosa is a deadly disease of grapevines. This study used 20 SSR markers to genotype 326 accessions of grape species collected from the southeastern and southwestern United States, Mexico and Costa Rica. Two hundred sixty-six of these accessions, and an additional 12 PD resistant hybrid cultivars developed from southeastern US grape species, were evaluated for PD resistance. Disease resistance was evaluated by quantifying the level of bacteria in stems and measuring PD symptoms on the canes and leaves. Both Bayesian clustering and principal coordinate analyses identified two groups with an east-west divide: group 1 consisted of grape species from the southeastern US and Mexico, and group 2 consisted of accessions collected from the southwestern US and Mexico. The Sierra Madre Oriental mountain range appeared to be a phylogeographic barrier. The state of Texas was identified as a potential hybridization zone. The hierarchal STRUCTURE analysis on each group showed clustering of unique grape species. An east-west divide was also observed for PD resistance. With the exception of Vitis candicans and V. cinerea accessions collected from Mexico, all other grape species as well as the resistant southeastern hybrid cultivars were susceptible to the disease. Southwestern US grape accessions from drier desert regions showed stronger resistance to the disease. Strong PD resistance was observed within three distinct genetic clusters of V. arizonica which is adapted to drier environments and hybridizes freely with other species across its wide range.


Asunto(s)
Resistencia a la Enfermedad/genética , Enfermedades de las Plantas/microbiología , Vitis/crecimiento & desarrollo , Xylella/patogenicidad , Costa Rica , Genotipo , Humanos , Hibridación Genética/genética , México , Enfermedades de las Plantas/genética , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/microbiología , Sudoeste de Estados Unidos , Texas , Vitis/genética , Vitis/microbiología
9.
Nat Commun ; 11(1): 5299, 2020 10 20.
Artículo en Inglés | MEDLINE | ID: mdl-33082345

RESUMEN

Parasitic plants of the genus Cuscuta penetrate shoots of host plants with haustoria and build a connection to the host vasculature to exhaust water, solutes and carbohydrates. Such infections usually stay unrecognized by the host and lead to harmful host plant damage. Here, we show a molecular mechanism of how plants can sense parasitic Cuscuta. We isolated an 11 kDa protein of the parasite cell wall and identified it as a glycine-rich protein (GRP). This GRP, as well as its minimal peptide epitope Crip21, serve as a pathogen-associated molecular pattern and specifically bind and activate a membrane-bound immune receptor of tomato, the Cuscuta Receptor 1 (CuRe1), leading to defense responses in resistant hosts. These findings provide the initial steps to understand the resistance mechanisms against parasitic plants and further offer great potential for protecting crops by engineering resistance against parasitic plants.


Asunto(s)
Pared Celular/metabolismo , Cuscuta/metabolismo , Lycopersicon esculentum/metabolismo , Lycopersicon esculentum/parasitología , Enfermedades de las Plantas/parasitología , Proteínas de Plantas/metabolismo , Pared Celular/genética , Cuscuta/genética , Regulación de la Expresión Génica de las Plantas , Interacciones Huésped-Parásitos , Lycopersicon esculentum/genética , Enfermedades de las Plantas/genética , Proteínas de Plantas/genética
10.
PLoS One ; 15(10): e0239763, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33027258

RESUMEN

Anthracnose, caused by the fungal pathogen Colletotrichum lindemuthianum, is one of the world's most destructive diseases of common bean. The use of resistant cultivars is the most cost-effective strategy to manage this disease; however, durable resistance is difficult to achieve due to the vast virulence diversity of the anthracnose pathogen. Finding new genes with broad-spectrum resistance increases the prospect of designing an effective anthracnose-management strategy. Genetic analysis confirmed the presence of a single, dominant anthracnose-resistance locus in AC, which we provisionally named Co-AC. Bulk segregant analysis and genetic mapping of two F2 populations from the crosses AC × PI207262 and AC × G 2333 were used to determine the position of the Co-AC locus in a 631 Kbp genomic region flanked by the SNP markers SS56 and SS92 on the lower arm of chromosome Pv01. By genotyping 77 F3 plants from the AC × PI207262 cross using nine additional markers, we fine-mapped the Co-AC locus to a significantly smaller genomic region (9.4 Kbp) flanked by the SNP markers SS102 and SS165. This 9.4 Kbp region harbors three predicted genes based on the common bean reference genome, notably including the gene model Phvul.001G244300, which encodes Clathrin heavy chain 1, a protein that supports specific stomatal regulation functions and might play a role in plant defense signaling. Because the Co-AC resistance locus is linked in cis, it can be selected with great efficiency using molecular markers. These results will be very useful for breeding programs aimed at developing bean cultivars with anthracnose resistance using marker-assisted selection. This study revealed the broad-spectrum resistance of AC to C. lindemuthianum and the existence of the Co-AC anthracnose-resistance locus. Fine mapping positioned this locus in a small genomic region on the lower end of chromosome Pv01 that contained three candidate genes for the Co-AC locus.


Asunto(s)
Resistencia a la Enfermedad/genética , Phaseolus/genética , Cruzamiento/métodos , Mapeo Cromosómico/métodos , Colletotrichum/patogenicidad , Genes de Plantas/genética , Ligamiento Genético/genética , Marcadores Genéticos/genética , Genotipo , Phaseolus/microbiología , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Polimorfismo de Nucleótido Simple/genética
11.
Plant Genome ; 13(1): e20007, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-33016637

RESUMEN

Crown rust, caused by Puccinia coronata f. sp. avenae Erikss., is the most important disease impacting cultivated oat (Avena sativa L.). Genetic resistance is the most desirable management strategy. The genetic architecture of crown rust resistance is not fully understood, and previous mapping investigations have mostly ignored temporal variation. A collection of elite oat lines sourced from oat breeding programs in the American Upper Midwest and Canada was genotyped using a high-density genotyping-by-sequencing system and evaluated for crown rust disease severity at multiple time points throughout the growing season in three disease nursery environments. Genome-wide association mapping was conducted for disease severity on each observation date of each trial, area under the disease progress curve for each trial, heading date for each trial, and area under the disease progress curve in a multi-environment model. Crown rust resistance quantitative trait loci (QTL) were detected on linkage groups Mrg05, Mrg12, Mrg15, Mrg18, Mrg20, and Mrg33. None of these QTL were coincident with a days-to-heading QTL detected on Mrg02. Only the QTL detected on Mrg15 was detected in multiple mapping models. The QTL on Mrg05, Mrg12, Mrg18, Mrg20, and Mrg33 were detected on only a single observation date and were not detected on observations just days before and after. This result uncovers the importance of temporal variation in mapping experiments which is usually ignored. It is possible that high density temporal data could be used to more precisely characterize the nature of plant resistance in other systems.


Asunto(s)
Avena , Basidiomycota , Avena/genética , Estudio de Asociación del Genoma Completo , Enfermedades de las Plantas/genética , Sitios de Carácter Cuantitativo
12.
PLoS One ; 15(10): e0240029, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33017405

RESUMEN

Lesion mimic (Lm) mutants display hypersensitive responses (HR) without any pathogen attack; their symptoms are similar to those produced by a pathogen and result in cell death. In wheat, such mutants have been reported to be resistant against leaf rust due to their biotrophic nature. However, Lm mutants tend to encourage spot blotch (SB) disease caused by Bipolarissorokiniana since dead cells facilitate pathogen multiplication. In this study, 289 diverse wheat germplasm lines were phenotyped in three consecutive growing seasons (2012-2015). Genotype data was generated using the Illumina iSelect beadchip assay platform for wheat germplasm lines. A total of 13,589 single-nucleotide polymorphisms (SNPs) were selected andused for further association mapping. Lm was positively associated with Area Under Disease Progress Curve (AUDPC) for SB but negatively with glaucous index (GI), leaf tip necrosis (Ltn) and latent period (LP). Ltn had a negative association with AUDPC and Lm but a positive one with LP. In a genome-wide association study (GWAS), 29 markers were significantly associated with these traits and 27 were an notated. Seven SNP markers associated with Lm were on chromosome 6A; another on 1B was found to be linked with Ltn. Like wise, seven SNP markers were associated with GI; one on chromosome 6A with the others on 6B. Five SNP markers on chromosomes 3B and 3Dwere significantly correlated with LP, while nine SNP markers on chromosomes 5A and 5B were significantly associated with AUDPC for SB. This study is the first to explore the interaction in wheat between Lm mutants and the hemibiotrophic SB pathogen B.sorokiniana.


Asunto(s)
Resistencia a la Enfermedad/genética , Enfermedades de las Plantas/genética , Triticum/genética , Área Bajo la Curva , Basidiomycota/patogenicidad , Mapeo Cromosómico , Estudio de Asociación del Genoma Completo , Genotipo , Desequilibrio de Ligamiento , Fenotipo , Enfermedades de las Plantas/microbiología , Polimorfismo de Nucleótido Simple , Sitios de Carácter Cuantitativo , Curva ROC , Estaciones del Año
13.
Plant Dis ; 104(11): 2940-2948, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32897842

RESUMEN

Wheat-rye T1RS·1BL translocations have been widely used worldwide in wheat production for multiple disease resistance and superior yield traits. However, many T1RS·1BL translocations have successively lost their resistance to pathogens due to the coevolution of pathogen virulence with host resistance. Because of the extensive variation in rye (Secale cereale L.) as a naturally cross-pollinating relative of wheat, it still has promise to widen the variation of 1RS and to fully realize its application value in wheat improvement. In the present study, the wheat-rye breeding line R2207 was characterized by comprehensive analyses using genomic in situ hybridization (GISH), multicolor fluorescence in situ hybridization with multiple probes, multicolor GISH, and molecular marker analysis, and then was proven to be a cytogenetically stable wheat-rye T1RS·1BL translocation line. Based on the disease responses to different isolates of powdery mildew and genetic analysis, R2207 appears to possess a novel variation for resistance, which was confirmed to be located on the rye chromosome arm 1RS. Line R2207 also exhibited high levels of resistance to stripe rust at both seedling and adult stages, as well as enhanced agronomic performance, so it has been transferred into a large number of commercial cultivars using an efficient 1RS-specific kompetitive allele specific PCR marker for marker-assisted selection.


Asunto(s)
Secale , Triticum , Cromosomas de las Plantas/genética , Hibridación Fluorescente in Situ , Enfermedades de las Plantas/genética , Secale/genética , Triticum/genética
14.
PLoS One ; 15(9): e0239085, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32960916

RESUMEN

Rice root-knot nematode (RRKN), Meloidogyne graminicola is one of the major biotic constraints in rice-growing countries of Southeast Asia. Host plant resistance is an environmentally-friendly and cost-effective mean to mitigate RRKN damage to rice. Considering the limited availability of genetic resources in the Asian rice (Oryza sativa) cultivars, exploration of novel sources and genetic basis of RRKN resistance is necessary. We screened 272 diverse wild rice accessions (O. nivara, O. rufipogon, O. sativa f. spontanea) to identify genotypes resistant to RRKN. We dissected the genetic basis of RRKN resistance using a genome-wide association study with SNPs (single nucleotide polymorphism) genotyped by 50K "OsSNPnks" genic Affymetrix chip. Population structure analysis revealed that these accessions were stratified into three major sub-populations. Overall, 40 resistant accessions (nematode gall number and multiplication factor/MF < 2) were identified, with 17 novel SNPs being significantly associated with phenotypic traits such as number of galls, egg masses, eggs/egg mass and MF per plant. SNPs were localized to the quantitative trait loci (QTL) on chromosome 1, 2, 3, 4, 6, 10 and 11 harboring the candidate genes including NBS-LRR, Cf2/Cf5 resistance protein, MYB, bZIP, ARF, SCARECROW and WRKY transcription factors. Expression of these identified genes was significantly (P < 0.01) upregulated in RRKN-infected plants compared to mock-inoculated plants at 7 days after inoculation. The identified SNPs enrich the repository of candidate genes for future marker-assisted breeding program to alleviate the damage of RRKN in rice.


Asunto(s)
Oryza/genética , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/parasitología , Tylenchoidea/fisiología , Animales , Resistencia a la Enfermedad , Estudio de Asociación del Genoma Completo , Interacciones Huésped-Parásitos , Oryza/fisiología , Polimorfismo de Nucleótido Simple , Sitios de Carácter Cuantitativo
15.
PLoS One ; 15(9): e0238876, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32970702

RESUMEN

Apple replant disease (ARD) is a serious threat to producers of apple trees and fruits worldwide. The ARD etiology is not unraveled and managing options are either economically not applicable or environmentally harmful. Thus, interest is given in biomarkers that allow to indicate ARD situations at early time points in order to classify soils according to ARD severity but also to analyze the effectiveness to potential countermeasures. This study aimed at (i) identifying ARD biomarkers on the transcriptional level in root tissue by analyzing the expression of previously identified candidate genes in ARD soils of different origin and texture and (ii) testing the specificity of these marker genes to ARD. In vitro propagated M26 plantlets were submitted to a bio-test with three ARD soils, either untreated or disinfected by γ-irradiation. Expression of seven candidate genes identified in a previous transcriptomic study was investigated by RT-qPCR in a time course experiment. Already three days after planting, a prominent upregulation of the phytoalexin biosynthesis genes biphenyl synthase 3 (BIS3) and biphenyl 4-hydroxylase (B4Hb) was observed in the untreated ARD variants of all three soils. The phytoalexin composition in roots was comparable for all three soils and the total phytoalexin content correlated with the expression of BIS3 and B4Hb. The third promising candidate gene that was upregulated under ARD conditions was the ethylene-responsive transcription factor 1B-like (ERF1B). In a second experiment M26 plantlets were exposed to different abiotic stressors, namely heat, salt and nutrient starvation, and candidate gene expression was determined in the roots. The expression levels of BIS3 and B4Hb were highly and specifically upregulated in ARD soil, but not upon the abiotic stress conditions, whereas ERF1B also showed higher expression under heat stress. In conclusion, BIS3 and B4Hb are recommended as early ARD biomarkers due to their high expression levels and their high specificity.


Asunto(s)
Marcadores Genéticos , Malus/crecimiento & desarrollo , Enfermedades de las Plantas/genética , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Malus/genética , Malus/metabolismo , Proteínas de Plantas/genética , Raíces de Plantas/química , Reacción en Cadena en Tiempo Real de la Polimerasa , Sesquiterpenos/análisis , Microbiología del Suelo , Factores de Transcripción/genética
16.
Nat Genet ; 52(10): 1111-1121, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32989321

RESUMEN

Wild tomato species represent a rich gene pool for numerous desirable traits lost during domestication. Here, we exploited an introgression population representing wild desert-adapted species and a domesticated cultivar to establish the genetic basis of gene expression and chemical variation accompanying the transfer of wild-species-associated fruit traits. Transcriptome and metabolome analysis of 580 lines coupled to pathogen sensitivity assays resulted in the identification of genomic loci associated with levels of hundreds of transcripts and metabolites. These associations occurred in hotspots representing coordinated perturbation of metabolic pathways and ripening-related processes. Here, we identify components of the Solanum alkaloid pathway, as well as genes and metabolites involved in pathogen defense and linking fungal resistance with changes in the fruit ripening regulatory network. Our results outline a framework for understanding metabolism and pathogen resistance during tomato fruit ripening and provide insights into key fruit quality traits.


Asunto(s)
Resistencia a la Enfermedad/genética , Lycopersicon esculentum/genética , Metaboloma/genética , Transcriptoma/genética , Alcaloides/genética , Domesticación , Frutas/genética , Frutas/crecimiento & desarrollo , Frutas/parasitología , Hongos/genética , Hongos/patogenicidad , Regulación de la Expresión Génica de las Plantas/genética , Lycopersicon esculentum/crecimiento & desarrollo , Lycopersicon esculentum/microbiología , Redes y Vías Metabólicas/genética , Fenotipo , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Solanum/genética , Solanum/microbiología
17.
PLoS Biol ; 18(9): e3000783, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32925907

RESUMEN

Plant nucleotide-binding (NB) leucine-rich repeat (LRR) receptor (NLR) proteins function as intracellular immune receptors that perceive the presence of pathogen-derived virulence proteins (effectors) to induce immune responses. The 2 major types of plant NLRs that "sense" pathogen effectors differ in their N-terminal domains: these are Toll/interleukin-1 receptor resistance (TIR) domain-containing NLRs (TNLs) and coiled-coil (CC) domain-containing NLRs (CNLs). In many angiosperms, the RESISTANCE TO POWDERY MILDEW 8 (RPW8)-CC domain containing NLR (RNL) subclass of CNLs is encoded by 2 gene families, ACTIVATED DISEASE RESISTANCE 1 (ADR1) and N REQUIREMENT GENE 1 (NRG1), that act as "helper" NLRs during multiple sensor NLR-mediated immune responses. Despite their important role in sensor NLR-mediated immunity, knowledge of the specific, redundant, and synergistic functions of helper RNLs is limited. We demonstrate that the ADR1 and NRG1 families act in an unequally redundant manner in basal resistance, effector-triggered immunity (ETI) and regulation of defense gene expression. We define RNL redundancy in ETI conferred by some TNLs and in basal resistance against virulent pathogens. We demonstrate that, in Arabidopsis thaliana, the 2 RNL families contribute specific functions in ETI initiated by specific CNLs and TNLs. Time-resolved whole genome expression profiling revealed that RNLs and "classical" CNLs trigger similar transcriptome changes, suggesting that RNLs act like other CNLs to mediate ETI downstream of sensor NLR activation. Together, our genetic data confirm that RNLs contribute to basal resistance, are fully required for TNL signaling, and can also support defense activation during CNL-mediated ETI.


Asunto(s)
Arabidopsis/inmunología , Proteínas NLR/fisiología , Inmunidad de la Planta/genética , Receptores Inmunológicos/fisiología , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/fisiología , Resistencia a la Enfermedad/genética , Resistencia a la Enfermedad/inmunología , Regulación de la Expresión Génica de las Plantas , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/fisiología , Familia de Multigenes/genética , Familia de Multigenes/fisiología , Proteínas NLR/genética , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/inmunología , Plantas Modificadas Genéticamente , Receptores Inmunológicos/genética , Transducción de Señal/genética , Transducción de Señal/inmunología , Transcriptoma
18.
PLoS One ; 15(9): e0239205, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32925954

RESUMEN

Striga is an important biotic factor limiting maize production in sub-Saharan Africa and can cause yield losses as high as 100%. Marker-assisted selection (MAS) approaches hold a great potential for improving Striga resistance but requires identification and use of markers associated with Striga resistance for adequate genetic gains from selection. However, there is no report on the discovery of quantitative trait loci (QTL) for resistance to Striga in maize under artificial field infestation. In the present study, 198 BC1S1 families obtained from a cross involving TZEEI 29 (Striga resistant inbred line) and TZEEI 23 (Striga susceptible inbred line) plus the two parental lines were screened under artificial Striga-infested conditions at two Striga-endemic locations in Nigeria in 2018, to identify QTL associated with Striga resistance indicator traits, including grain yield, ears per plant, Striga damage and number of emerged Striga plants. Genetic map was constructed using 1,386 DArTseq markers distributed across the 10 maize chromosomes, covering 2076 cM of the total genome with a mean spacing of 0.11 cM between the markers. Using composite interval mapping (CIM), fourteen QTL were identified for key Striga resistance/tolerance indicator traits: 3 QTL for grain yield, 4 for ears per plant and 7 for Striga damage at 10 weeks after planting (WAP), across environments. Putative candidate genes which encode major transcription factor families WRKY, bHLH, AP2-EREBPs, MYB, and bZIP involved in plant defense signaling were detected for Striga resistance/tolerance indicator traits. The QTL detected in the present study would be useful for rapid transfer of Striga resistance/tolerance genes into Striga susceptible but high yielding maize genotypes using MAS approaches after validation. Further studies on validation of the QTL in different genetic backgrounds and in different environments would help verify their reproducibility and effective use in breeding for Striga resistance/tolerance.


Asunto(s)
Resistencia a la Enfermedad/genética , Enfermedades de las Plantas/genética , Sitios de Carácter Cuantitativo , Zea mays/genética , Nigeria , Striga
19.
Plant Dis ; 104(11): 2875-2884, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32954987

RESUMEN

Powdery mildew infections are among the most severe foliar biotrophic fungal diseases in grain legumes. Several accessions of Lathyrus cicera (chickling pea) show levels of partial resistance to Erysiphe pisi, the causal agent of pea powdery mildew, and to E. trifolii, a powdery mildew pathogen recently confirmed to infect pea and Lathyrus spp. Nevertheless, the underlying L. cicera resistance mechanisms against powdery mildews are poorly understood. To unveil the genetic control of resistance against powdery mildews in L. cicera, a recombinant inbred line population segregating for response to both species was used in resistance linkage analysis. An improved L. cicera genetic linkage map was used in this analysis. The new higher-density linkage map contains 1,468 polymorphic loci mapped on seven major and two minor linkage groups, covering a total of 712.4 cM. The percentage of the leaf area affected by either E. pisi or E. trifolii was recorded in independent screenings of the recombinant inbred line population, identifying a continuous range of resistance-susceptibility responses. Distinct quantitative trait loci (QTLs) for partial resistance against each pathogen were identified, suggesting different genetic bases are involved in the response to E. pisi and E. trifolii in L. cicera. Moreover, through comparative mapping of L. cicera QTL regions with the pea reference genome, candidate genes and pathways involved in resistance against powdery mildews were identified. This study extended the previously available genetic and genomic tools in Lathyrus species, providing clues about diverse powdery mildew resistance mechanisms useful for future resistance breeding of L. cicera and related species.


Asunto(s)
Ascomicetos , Lathyrus , Mapeo Cromosómico , Lathyrus/genética , Enfermedades de las Plantas/genética , Sitios de Carácter Cuantitativo/genética
20.
PLoS One ; 15(9): e0238523, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32911522

RESUMEN

Brazil and South Africa, countries with economies in transition, are characterized by a dual agrarian structure co-occurring, sometimes, alongside in the same region. Large-scale commercial farming produces crops for export to global markets on the one hand, and small-scale farming, on the other hand, provides for subsistence and local markets. In both systems, maize (Zea mays) is a key crop for these two countries. For the commercial system, maize is a commodity crop while for the small-scale system it is the prime staple crop. In commercial systems, farmers predominantly grow genetically modified (GM) hybrid maize. In small-scale systems, farmers rely on open pollinated varieties (OPVs) and/or landraces and are largely dependent on seed saving systems. The aim of this study was to understand the relationship between transgene expression rates, the resulting concentrations of the transgene product (Bt protein) and its bioactivity in insect pests following transgene flow from GM hybrid maize into non-genetically modified, non-GM near-isogenic maize hybrid (ISO) and OPVs. We modeled segregation patterns and measured cry1Ab transgene expression (mRNA quantification), Cry1Ab protein concentration and pest survival. Two groups of F1, F2 crosses and backcrosses with GM, ISO and OPV maize varieties from Brazil and South Africa were used. Bioassays with the larvae of two lepidopteran maize pest species, Helicoverpa armigera and Spodoptera littoralis, were carried out. Overall, the cry1Ab transgene outcrossed effectively into the genetic backgrounds tested. The cry1Ab transgene was stably expressed in both ISO and OPV genetic backgrounds. Transgene introgression led to consistent, though highly variable, concentrations of Cry1Ab toxins that were similar to those observed in GM parental maize. Most crosses, but not all, suggested the expected Mendelian segregation pattern. Transgene expression rates were significantly higher than expected from purely Mendelian segregation in the South African crosses. In South African materials, ISO and OPV crosses produced significantly lower Cry1Ab concentrations compared to the GM parental maize. The Cry1Ab toxins from crosses were bioactive and induced mortality rates of ≥92.19% in H. armigera and ≥40.63% in S. littoralis after a period of only 4 days. However, no correlations were observed between the quantitation of mRNA for cry1Ab and the corresponding Cry1Ab protein concentrations, nor between the Cry1Ab concentrations and insect mortality rates across different genetic backgrounds. We therefore suggest that while transcription of the cry1Ab transgene reliably determines the presence of Cry1Ab protein, mRNA levels do not reflect, by themselves, the end Cry1Ab protein concentrations found in the plant. Because predictably high Cry1Ab concentrations are a key prerequisite for effective insect resistance management (IRM) programs, this observation raises questions about the effectiveness of such programs in scenarios with complex crop genetic backgrounds. On the other hand, confirmed bioactivity in all crosses should be expected to impact small farmer's selection behavior, unknowingly favoring the insecticidal trait. This may lead to a fixation of the trait in the wider population, and may influence the genetic diversity of varieties maintained by small-scale farmers.


Asunto(s)
Proteínas Bacterianas/genética , Endotoxinas/genética , Proteínas Hemolisinas/genética , Control Biológico de Vectores , Plantas Modificadas Genéticamente/genética , Zea mays/genética , Animales , Productos Agrícolas/genética , Cruzamientos Genéticos , Resistencia a la Enfermedad , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/parasitología , Plantas Modificadas Genéticamente/parasitología , Spodoptera/fisiología , Transgenes , Zea mays/parasitología
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