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1.
Nat Commun ; 12(1): 5462, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34526503

RESUMO

Salicylic acid is a phenolic phytohormone which controls plant growth and development. A methyl ester (MSA) derivative thereof is volatile and involved in plant-insect or plant-plant communication. Here we show that the nematode-trapping fungus Duddingtonia flagrans uses a methyl-salicylic acid isomer, 6-MSA as morphogen for spatiotemporal control of trap formation and as chemoattractant to lure Caenorhabditis elegans into fungal colonies. 6-MSA is the product of a polyketide synthase and an intermediate in the biosynthesis of arthrosporols. The polyketide synthase (ArtA), produces 6-MSA in hyphal tips, and is uncoupled from other enzymes required for the conversion of 6-MSA to arthrosporols, which are produced in older hyphae. 6-MSA and arthrosporols both block trap formation. The presence of nematodes inhibits 6-MSA and arthrosporol biosyntheses and thereby enables trap formation. 6-MSA and arthrosporols are thus morphogens with some functions similar to quorum-sensing molecules. We show that 6-MSA is important in interkingdom communication between fungi and nematodes.


Assuntos
Ascomicetos/fisiologia , Caenorhabditis elegans/fisiologia , Hifas/fisiologia , Comportamento Predatório/fisiologia , Ácido Salicílico/metabolismo , Animais , Ascomicetos/genética , Ascomicetos/metabolismo , Quimiotaxia/fisiologia , Proteínas Fúngicas/metabolismo , Hifas/genética , Hifas/metabolismo , Policetídeo Sintases/metabolismo , Ácido Salicílico/química , Esporos Fúngicos/genética , Esporos Fúngicos/metabolismo
2.
Molecules ; 26(15)2021 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-34361827

RESUMO

Grammicin, a polyketide metabolite produced by the endolichenic fungus Xylaria grammica KCTC 13121BP, shows strong nematicidal activity against Meloidogyne incognita. This study was performed to elucidate the grammicin biosynthesis pathway of X. grammica KCTC 13121BP and to examine the nematicidal activity of the biosynthesis intermediates and derivatives against M. incognita. Two grammicin biosynthesis intermediates were isolated from a T-DNA insertion transformant (strain TR-74) of X. grammica KCTC 13121BP and identified as 2-(hydroxymethyl)cyclohexa-2,5-diene-1,4-dione (compound 1) and 2,5-dihydroxybenzaldehyde (compound 2), which were also reported to be intermediates in the biosynthesis pathway of patulin, an isomer of grammicin. This indicates that the grammicin biosynthesis pathway overlaps almost with that of patulin, except for the last few steps. Among 13 grammicin biosynthesis intermediates and their derivatives (except grammicin), toluquinol caused the highest M. incognita J2 mortality, with an LC50/72 h value of 11.13 µg/mL, which is similar to grammicin with an LC50/72 h value of 15.95 µg/mL. In tomato pot experiments, the wettable powder type formulations (WP) of toluquinol (17.78 µg/mL) and grammicin (17.78 µg/mL) also effectively reduced gall formation on the roots of tomato plants with control values of 72.22% and 77.76%, respectively, which are much higher than abamectin (16.67%), but lower than fosthiazate (100%). The results suggest that toluquinol can be used directly as a biochemical nematicide or as a lead molecule for the development of new synthetic nematicides for the control of root-knot nematode diseases.


Assuntos
Antinematódeos/farmacologia , Ascomicetos/fisiologia , Lycopersicon esculentum/efeitos dos fármacos , Doenças das Plantas/prevenção & controle , Policetídeos/farmacologia , Tylenchoidea/efeitos dos fármacos , Animais , Lycopersicon esculentum/microbiologia , Doenças das Plantas/parasitologia
3.
Int J Mol Sci ; 22(16)2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34445571

RESUMO

Photosynthesis is a universal process for plant survival, and immune defense is also a key process in adapting to the growth environment. Various studies have indicated that these two processes are interconnected in a complex network. Photosynthesis can influence signaling pathways and provide both materials and energy for immune defense, while the immune defense process can also have feedback effects on photosynthesis. Pathogen infection inevitably leads to changes in photosynthesis parameters, including Pn, Gs, and Ci; biochemical materials such as SOD and CAT; signaling molecules such as H2O2 and hormones; and the expression of genes involved in photosynthesis. Some researchers have found that changes in photosynthesis activity are related to the resistance level of the host, the duration after infection, and the infection position (photosynthetic source or sink). Interactions between wheat and the main fungal pathogens, such as Puccinia striiformis, Blumeria graminis, and Fusarium graminearum, constitute an ideal study system to elucidate the relationship between changes in host photosynthesis and resistance levels, based on the accessibility of methods for artificially controlling infection and detecting changes in photosynthesis, the presence of multiple pathogens infecting different positions, and the abundance of host materials with various resistance levels. This review is written only from the perspective of plant pathologists, and after providing an overview of the available data, we generally found that changes in photosynthesis in the early stage of pathogen infection could be a causal factor influencing acquired resistance, while those in the late stage could be the result of resistance formation.


Assuntos
Ascomicetos/fisiologia , Interações Hospedeiro-Patógeno , Fotossíntese , Doenças das Plantas/imunologia , Triticum/imunologia , Doenças das Plantas/microbiologia , Triticum/metabolismo , Triticum/microbiologia
4.
BMC Plant Biol ; 21(1): 366, 2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34380425

RESUMO

BACKGROUND: Small RNAs are short non-coding RNAs that are key gene regulators controlling various biological processes in eukaryotes. Plants may regulate discrete sets of sRNAs in response to pathogen attack. Sclerotinia sclerotiorum is an economically important pathogen affecting hundreds of plant species, including the economically important oilseed B. napus. However, there are limited studies on how regulation of sRNAs occurs in the S. sclerotiorum and B. napus pathosystem. RESULTS: We identified different classes of sRNAs from B. napus using high throughput sequencing of replicated mock and infected samples at 24 h post-inoculation (HPI). Overall, 3999 sRNA loci were highly expressed, of which 730 were significantly upregulated during infection. These 730 up-regulated sRNAs targeted 64 genes, including disease resistance proteins and transcriptional regulators. A total of 73 conserved miRNA families were identified in our dataset. Degradome sequencing identified 2124 cleaved mRNA products from these miRNAs from combined mock and infected samples. Among these, 50 genes were specific to infection. Altogether, 20 conserved miRNAs were differentially expressed and 8 transcripts were cleaved by the differentially expressed miRNAs miR159, miR5139, and miR390, suggesting they may have a role in the S. sclerotiorum response. A miR1885-triggered disease resistance gene-derived secondary sRNA locus was also identified and verified with degradome sequencing. We also found further evidence for silencing of a plant immunity related ethylene response factor gene by a novel sRNA using 5'-RACE and RT-qPCR. CONCLUSIONS: The findings in this study expand the framework for understanding the molecular mechanisms of the S. sclerotiorum and B. napus pathosystem at the sRNA level.


Assuntos
Ascomicetos/fisiologia , Brassica napus/genética , Brassica napus/microbiologia , Doenças das Plantas/microbiologia , RNA de Plantas , Pequeno RNA não Traduzido , Sequência Conservada , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas , Doenças das Plantas/genética , Análise de Sequência de RNA , Regulação para Cima
5.
Microbiol Mol Biol Rev ; 85(3): e0022020, 2021 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-34319143

RESUMO

True morels (Morchella spp., Morchellaceae, Ascomycota) are widely regarded as a highly prized delicacy and are of great economic and scientific value. Recently, the rapid development of cultivation technology and expansion of areas for artificial morel cultivation have propelled morel research into a hot topic. Many studies have been conducted in various aspects of morel biology, but despite this, cultivation sites still frequently report failure to fruit or only low production of fruiting bodies. Key problems include the gap between cultivation practices and basic knowledge of morel biology. In this review, in an effort to highlight the mating systems, evolution, and life cycle of morels, we summarize the current state of knowledge of morel sexual reproduction, the structure and evolution of mating-type genes, the sexual process itself, and the influence of mating-type genes on the asexual stages and conidium production. Understanding of these processes is critical for improving technology for the cultivation of morels and for scaling up their commercial production. Morel species may well be good candidates as model species for improving sexual development research in ascomycetes in the future.


Assuntos
Ascomicetos/genética , Ascomicetos/fisiologia , Animais , DNA Fúngico/genética , Evolução Molecular , Estágios do Ciclo de Vida/genética , Estágios do Ciclo de Vida/fisiologia
6.
Fungal Biol ; 125(8): 585-595, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34281652

RESUMO

The introduction, spread, and impact of fungal plant pathogens is a critical concern in ecological systems. In this study, we were motivated by the rather sudden appearance of Acermacrophyllum heavily infected with powdery mildew. We used morphological and genetic analyses to confirm the pathogen causing the epidemic was Sawadaea bicornis. In subsequent field studies, this pathogen was found in several locations in western North America, and in greenhouse studies, A. macrophyllum was found to be significantly more susceptible to S. bicornis than nine other Acer species tested. A genetic analysis of 178 specimens of powdery mildew from freshly collected and old herbarium specimens from 15 countries revealed seven different haplotypes. The high diversity of haplotypes found in Europe coupled with sequence results from a specimen from 1864 provides evidence that S. bicornis has a European origin. Furthermore, sequence data from a specimen from 1938 in Canada show that the pathogen has been present in North America for at least 82 years revealing a considerable lag time between the introduction and current epidemic. This study used old herbarium specimens to genetically hypothesize the origin, the native host, and the invasion time of a detrimental fungal plant pathogen.


Assuntos
Acer , Ascomicetos , Espécies Introduzidas , Doenças das Plantas , Acer/microbiologia , Ascomicetos/fisiologia , Ecossistema , Doenças das Plantas/microbiologia
7.
Fungal Biol ; 125(8): 609-620, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34281654

RESUMO

Subterranean Cultural Heritage sites are frequently subject to biological colonization due to the high levels of humidity, even in conditions of low irradiance and oligotrophy. Here microorganisms form complex communities that may be dangerous through mineral precipitation, through the softening of materials or causing frequent surface discolorations. A reduction of contamination's sources along with the control of microclimatic conditions and biocide treatments (overall performed with benzalkonium chloride) are necessary to reduce microbial growths. Dark discolorations have been recorded in the painted Etruscan tombs of Tarquinia, two of which have been analyzed to collect taxonomical, physiological, and ecological information. Eighteen dark-pigmented fungi were isolated among a wider culturable fraction: nine from blackening areas and nine from door sealings, a possible route of contamination. Isolates belonged to three major groups: Chaetothyriales, Capnodiales (Family Cladosporiaceae), and Acremonium-like fungi. Exophiala angulospora and Cyphellophora olivacea, a novelty for hypogea, were identified, while others need further investigations as possible new taxa. The metabolic skills of the detected species showed their potential dangerousness for the materials. Their tolerance to benzalkonium chloride-based products suggested a certain favouring effect through the decreasing competitiveness of less resistant species. The type of covering of the dromos may influence the risk of outer contamination. Fungal occurrence can be favoured by root penetration.


Assuntos
Biodiversidade , Farmacorresistência Fúngica , Microbiologia Ambiental , Fungos , Ascomicetos/efeitos dos fármacos , Ascomicetos/fisiologia , Compostos de Benzalcônio/farmacologia , Exophiala/efeitos dos fármacos , Exophiala/fisiologia , Fungos/efeitos dos fármacos , Fungos/isolamento & purificação , Itália
8.
BMC Plant Biol ; 21(1): 304, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34193039

RESUMO

BACKGROUND: The production of cereal crops is frequently affected by diseases caused by Fusarium graminearum and Magnaporthe oryzae, two devastating fungal pathogens. To improve crop resistance, many studies have focused on understanding the mechanisms of host defense against these two fungi individually. However, our knowledge of the common and different host defenses against these pathogens is very limited. RESULTS: In this study, we employed Brachypodium distachyon as a model for cereal crops and performed comparative transcriptomics to study the dynamics of host gene expression at different infection stages. We found that infection with either F. graminearum or M. oryzae triggered massive transcriptomic reprogramming in the diseased tissues. Numerous defense-related genes were induced with dynamic changes during the time course of infection, including genes that function in pattern detection, MAPK cascade, phytohormone signaling, transcription, protein degradation, and secondary metabolism. In particular, the expression of jasmonic acid signaling genes and proteasome component genes were likely specifically inhibited or manipulated upon infection by F. graminearum. CONCLUSIONS: Our analysis showed that, although the affected host pathways are similar, their expression programs and regulations are distinct during infection by F. graminearum and M. oryzae. The results provide valuable insight into the interactions between B. distachyon and two important cereal pathogens.


Assuntos
Ascomicetos/fisiologia , Brachypodium/genética , Brachypodium/microbiologia , Fusarium/fisiologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Ontologia Genética , Redes Reguladoras de Genes , Interações Hospedeiro-Patógeno/genética , Doenças das Plantas/microbiologia , Mapas de Interação de Proteínas/genética
9.
Int J Mol Sci ; 22(13)2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34281204

RESUMO

Verticillium dahliae is a soil-borne plant pathogenic fungus that causes Verticillium wilt on hundreds of dicotyledonous plant species. V. dahliae is considered an asexually (clonal) reproducing fungus, although both mating type idiomorphs (MAT1-1 and MAT1-2) are present, and is heterothallic. Most of the available information on V. dahliae strains, including their biology, pathology, and genomics comes from studies on isolates with the MAT1-2 idiomorph, and thus little information is available on the MAT1-1 V. dahliae strains in the literature. We therefore evaluated the growth responses of MAT1-1 and MAT1-2 V. dahliae strains to various stimuli. Growth rates and melanin production in response to increased temperature, alkaline pH, light, and H2O2 stress were higher in the MAT1-2 strains than in the MAT1-1 strains. In addition, the MAT1-2 strains showed an enhanced ability to degrade complex polysaccharides, especially starch, pectin, and cellulose. Furthermore, several MAT1-2 strains from both potato and sunflower showed increased virulence on their original hosts, relative to their MAT1-1 counterparts. Thus, compared to MAT1-1 strains, MAT1-2 strains derive their potentially greater fitness from an increased capacity to adapt to their environment and exhibit higher virulence. These competitive advantages might explain the current abundance of MAT1-2 strains relative to MAT1-1 strains in the agricultural and sylvicultural ecosystems, and this study provides the baseline information on the two mating idiomorphs to study sexual reproduction in V. dahliae under natural and laboratory conditions.


Assuntos
Ascomicetos/fisiologia , Ascomicetos/genética , Ascomicetos/crescimento & desenvolvimento , Ascomicetos/metabolismo , Proteínas Fúngicas/metabolismo , Genes Fúngicos Tipo Acasalamento , Genômica , Doenças das Plantas/microbiologia , Reprodução Assexuada , Virulência
10.
Theor Appl Genet ; 134(9): 2823-2839, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34061222

RESUMO

KEY MESSAGE: QTL mapping identified key genomic regions associated with adult-plant resistance to tan spot, which are effective even in the presence of the sensitivity gene Tsn1, thus serving as a new genetic solution to develop disease-resistant wheat cultivars. Improving resistance to tan spot (Pyrenophora tritici-repentis; Ptr) in wheat by eliminating race-specific susceptibility genes is a common breeding approach worldwide. The potential to exploit variation in quantitative forms of resistance, such as adult-plant resistance (APR), offers an alternative approach that could lead to broad-spectrum protection. We previously identified wheat landraces in the Vavilov diversity panel that exhibited high levels of APR despite carrying the sensitivity gene Tsn1. In this study, we characterised the genetic control of APR by developing a recombinant inbred line population fixed for Tsn1, but segregating for the APR trait. Linkage mapping using DArTseq markers and disease response phenotypes identified a QTL associated with APR to Ptr race 1 (producing Ptr ToxA- and Ptr ToxC) on chromosome 2B (Qts.313-2B), which was consistently detected in multiple adult-plant experiments. Additional loci were also detected on chromosomes 2A, 3D, 5A, 5D, 6A, 6B and 7A at the seedling stage, and on chromosomes 1A and 5B at the adult stage. We demonstrate that Qts.313-2B can be combined with other adult-plant QTL (i.e. Qts.313-1A and Qts.313-5B) to strengthen resistance levels. The APR QTL reported in this study provide a new genetic solution to tan spot in Australia and could be deployed in wheat cultivars, even in the presence of Tsn1, to decrease production losses and reduce the application of fungicides.


Assuntos
Ascomicetos/fisiologia , Cromossomos de Plantas/genética , Resistência à Doença/imunologia , Doenças das Plantas/imunologia , Proteínas de Plantas/metabolismo , Locos de Características Quantitativas , Triticum/genética , Mapeamento Cromossômico/métodos , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas , Interações Hospedeiro-Patógeno , Fenótipo , Melhoramento Vegetal , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Triticum/crescimento & desenvolvimento , Triticum/microbiologia
11.
Theor Appl Genet ; 134(9): 2777-2793, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34104998

RESUMO

KEY MESSAGE: We identified TdPm60 alleles from wild emmer wheat (WEW), an ortholog of Pm60 from T. urartu, which constitutes a strong candidate for PmG16 mildew resistance. Deployment of PmG16 in Israeli modern bread wheat cultivar Ruta improved the resistance to several local Bgt isolates. Wild emmer wheat (WEW), the tetraploid progenitor of durum and bread wheat, is a valuable genetic resource for resistance to powdery mildew fungal disease caused by Blumeria graminis f. sp. tritici (Bgt). PmG16 gene, derived from WEW, confers high resistance to most tested Bgt isolates. We mapped PmG16 to a 1.4-cM interval between the flanking markers uhw386 and uhw390 on Chromosome 7AL. Based on gene annotation of WEW reference genome Zavitan_V1, 34 predicted genes were identified within the ~ 3.48-Mb target region. Six genes were annotated as associated with disease resistance, of which TRIDC7AG077150.1 was found to be highly similar to Pm60, previously cloned from Triticum urartu, and resides in the same syntenic region. The functional molecular marker (FMM) for Pm60 (M-Pm60-S1) co-segregated with PmG16, suggesting the Pm60 ortholog from WEW (designated here as TdPm60) as a strong candidate for PmG16. Sequence alignment identified only eight SNPs that differentiate between TdPm60 and TuPm60. Furthermore, TdPm60 was found to be present also in the WEW donor lines of the powdery mildew resistance genes MlIW172 and MlIW72, mapped to the same region of Chromosome 7AL as PmG16, suggesting that TdPm60 constitutes a candidate also for these genes. Furthermore, screening of additional 230 WEW accessions with Pm60 specific markers revealed 58 resistant accessions from the Southern Levant that harbored TdPm60, while none of the susceptible accessions showed the presence of this gene. Deployment of PmG16 in Israeli modern bread wheat cultivar Ruta conferred resistance against several local Bgt isolates.


Assuntos
Ascomicetos/fisiologia , Mapeamento Cromossômico/métodos , Cromossomos de Plantas/genética , Resistência à Doença/imunologia , Doenças das Plantas/imunologia , Proteínas de Plantas/metabolismo , Triticum/genética , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Triticum/crescimento & desenvolvimento , Triticum/microbiologia
12.
Theor Appl Genet ; 134(9): 3051-3067, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34120211

RESUMO

KEY MESSAGE: The mutations BnA1.CER4 and BnC1.CER4 produce disordered wax crystals types and alter the composition of epidermal wax, causing increased cuticular permeability and sclerotium resistance. The aerial surfaces of land plants are coated with a cuticle, comprised of cutin and wax, which is a hydrophobic barrier for preventing uncontrolled water loss and environmental damage. However, the mechanisms by which cuticle components are formed are still unknown in Brassica napus L. and were therefore assessed here. BnA1.CER4 and BnC1.CER4, encoding fatty acyl-coenzyme A reductases localizing to the endoplasmic reticulum and highly expressed in leaves, were identified and functionally characterized. Expression of BnA1.CER4 and BnC1.CER4 cDNA in yeast (Saccharomyces cerevisiae) induced the accumulation of primary alcohols with chain lengths of 26 carbons. The mutant line Nilla glossy2 exhibited reduced wax crystal types, and wax composition analysis showed that the levels of branched primary alcohols were decreased, whereas those of the other branched components were increased. Further analysis showed that the mutant had reduced water retention but enhanced resistance to Sclerotinia sclerotiorum. Collectively, our study reports that BnA1.CER4 and BnC1.CER4 are fatty acyl-coenzyme A reductase genes in B. napus with a preference for branched substrates that participate in the biosynthesis of anteiso-primary alcohols.


Assuntos
Álcoois/metabolismo , Ascomicetos/fisiologia , Brassica napus/genética , Cromossomos de Plantas/genética , Resistência à Doença/imunologia , Doenças das Plantas/imunologia , Proteínas de Plantas/metabolismo , Álcoois/química , Brassica napus/crescimento & desenvolvimento , Brassica napus/microbiologia , Mapeamento Cromossômico/métodos , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas , Mutação , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Ceras/química , Ceras/metabolismo
13.
Theor Appl Genet ; 134(9): 2931-2945, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34128088

RESUMO

KEY MESSAGE: Blossom-End Rot is Quantitatively Inherited and Maps to Four Loci in Tomato. Blossom-end rot (BER) is a devastating physiological disorder that affects tomato and other vegetables, resulting in significant crop losses. To date, most studies on BER have focused on the environmental factors that affect calcium translocation to the fruit; however, the genetic basis of this disorder remains unknown. To investigate the genetic basis of BER, two F2 and F3:4 populations along with a BC1 population that segregated for BER occurrence were evaluated in the greenhouse. Using the QTL-seq approach, quantitative trait loci (QTL) associated with BER Incidence were identified at the bottom of chromosome (ch) 3 and ch11. Additionally, linkage-based QTL mapping detected another QTL, BER3.1, on ch3 and BER4.1 on ch4. To fine map the QTLs identified by QTL-seq, recombinant screening was performed. BER3.2, the major BER QTL on ch3, was narrowed down from 5.68 to 1.58 Mbp with a 1.5-LOD support interval (SI) corresponding to 209 candidate genes. BER3.2 colocalizes with the fruit weight gene FW3.2/SlKLUH, an ortholog of cytochrome P450 KLUH in Arabidopsis. Further, BER11.1, the major BER QTL on ch11, was narrowed down from 3.99 to 1.13 Mbp with a 1.5-LOD SI interval comprising of 141 candidate genes. Taken together, our results identified and fine mapped the first loci for BER resistance in tomato that will facilitate marker-assistant breeding not only in tomato but also in many other vegetables suffering for BER.


Assuntos
Ascomicetos/fisiologia , Cromossomos de Plantas/genética , Resistência à Doença/imunologia , Lycopersicon esculentum/genética , Doenças das Plantas/imunologia , Proteínas de Plantas/metabolismo , Locos de Características Quantitativas , Mapeamento Cromossômico/métodos , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas , Ligação Genética , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/microbiologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética
14.
Theor Appl Genet ; 134(10): 3279-3286, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34164708

RESUMO

KEY MESSAGE: We fine-mapped QBp.caas-3BL for black point resistance in an interval of 1.7 Mb containing five high-confidence annotated genes and developed a KASP marker suitable for selection of QBp.caas-3BL. Wheat black point, which occurs in most wheat-growing regions of the world, is detrimental to grain appearance, processing and nutrient quality. Mining and characterization of genetic loci for black point resistance are helpful for breeding resistant wheat cultivars. We previously identified a major QTL QBp.caas-3BL in a recombinant inbred line (RIL) population of Linmai 2/Zhong 892 across five environments. Here we confirmed the QTL in two additional environments. The genetic region of QBp.caas-3BL was enriched with newly developed markers. Using four sets of near isogenic lines, QBp.caas-3BL was narrowed down to a physical interval of approximately 1.7 Mb, including five annotated genes according to IWGSC reference genome. TraesCS3B02G404300, TraesCS3B02G404600 and TraesCS3B02G404700 were predicted as candidate genes based on the analyses of sequence polymorphisms and differential expression. We also converted a SNP of TraesCS3B02G404700 into a breeding-applicable KASP marker and verified its efficacy for marker-assisted breeding in a panel of germplasm. The findings not only lay a foundation for map-based cloning of QBp.caas-3BL but also provide a useful marker for selection of resistant cultivars genotypes in wheat breeding.


Assuntos
Ascomicetos/fisiologia , Mapeamento Cromossômico/métodos , Cromossomos de Plantas/genética , Resistência à Doença/imunologia , Doenças das Plantas/imunologia , Proteínas de Plantas/metabolismo , Triticum/genética , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas , Loci Gênicos , Fenótipo , Melhoramento Vegetal , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Polimorfismo de Nucleotídeo Único , Triticum/crescimento & desenvolvimento , Triticum/microbiologia
15.
Int J Mol Sci ; 22(9)2021 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-34066846

RESUMO

In plant-pathogen interactions, a proper light environment affects the establishment of defense responses in plants. In our previous experiments, we found that nonhost resistance (NHR) to Pyricularia oryzae Cav. in Arabidopsis thaliana (L.) Heynh. (Arabidopsis), in diurnal conditions, varies with the inoculation time. Moreover, we indicated that the circadian clock plays an important role in regulating time-of-day differences in NHR to P. oryzae in Arabidopsis. However, the involvement of photoperiod in regulating NHR was still not understood. To determine the photoperiod role, we performed the experiments in continuous light and darkness during the early Arabidopsis-P. oryzae interaction. We found that the light period after the inoculation in the evening enhanced the resistance to penetration. However, the dark period after the inoculation in the morning suppressed the penetration resistance. Furthermore, the genetic analysis indicated that jasmonic acid, reactive oxygen species, and tryptophan-derived metabolite(s) contribute to the photoperiod regulation of NHR in Arabidopsis. The present results denote that photoperiod plays an important role in regulating time-of-day differences in NHR to P. oryzae in Arabidopsis.


Assuntos
Arabidopsis/microbiologia , Arabidopsis/fisiologia , Ascomicetos/fisiologia , Interações Hospedeiro-Patógeno , Fotoperíodo , Arabidopsis/genética , Escuridão , Resistência à Doença/imunologia , Genes de Plantas , Mutação/genética , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia
16.
Plant Mol Biol ; 106(6): 505-520, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34176052

RESUMO

KEY MESSAGE: Gene expression analysis coupled with in-planta studies showed that specific Gßγ combination regulates plant growth and defence traits in the allotetraploid Brassica juncea. Plant heterotrimeric G-proteins regulate a wide range of responses despite their limited repertoire of core components. The roles and functional interactions between different G-protein subunits are quite perplexing, which get further complicated with polyploidy. Here, we show that the allotetraploid Brassica juncea comprises multiple homologs of G-protein genes, encoding six BjuGß and ten highly divergent BjuGγ subunit proteins, later being classified into type-A1, type-A2 and type-C Gγ proteins. The encoded BjuGß and BjuGγ proteins shared close evolutionary relationship and have retained distinct spatio-temporal expression patterns during plant developmental stages and in response to the necrotrophic pathogen, Sclerotinia sclerotiorum. RNAi based suppression of BjuGß and BjuGγ genes suggested functional overlap and selectivity of BjuGßs with three distinct BjuGγ type subunits, to regulate plant height (BjuGßγA2 and BjuGßγC), seed weight (BjuGßGγA1 and BjuGßGγC), silique size (BjuGßGγC) and pathogen response (BjuGßGγA1 and BjuGßGγC). Further, the triplicated BjuGß genes, formed due to Brassica specific whole-genome-triplication event, showed differential involvement during pathogen response, wherein overexpression of BjuGß2 displayed higher resistance to Sclerotinia infection. Taken together, our study demonstrates that multiple BjuGß and BjuGγ proteins have retained distinct spatio-temporal expression and functional selectivity to regulate specific plant growth and defence traits in the oilseed B. juncea.


Assuntos
Subunidades beta da Proteína de Ligação ao GTP/genética , Subunidades gama da Proteína de Ligação ao GTP/genética , Mostardeira/genética , Doenças das Plantas/genética , Proteínas de Plantas/genética , Poliploidia , Ascomicetos/fisiologia , Resistência à Doença/genética , Subunidades beta da Proteína de Ligação ao GTP/classificação , Subunidades beta da Proteína de Ligação ao GTP/metabolismo , Subunidades gama da Proteína de Ligação ao GTP/classificação , Subunidades gama da Proteína de Ligação ao GTP/metabolismo , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas , Interações Hospedeiro-Patógeno , Modelos Genéticos , Mostardeira/crescimento & desenvolvimento , Mostardeira/microbiologia , Filogenia , Doenças das Plantas/microbiologia , Proteínas de Plantas/classificação , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Ligação Proteica , Interferência de RNA
17.
Plant Sci ; 309: 110954, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34134849

RESUMO

Powdery mildew caused by Podosphaera xanthii (P. xanthii) severely endangers melon (Cucumis melo L.) production, while the mechanistic understanding about its resistance to powdery mildew remains largely limited. In this study, we integrated transcriptomic and methylomic analyses to explore whether DNA methylation was involved in modulating transcriptional acclimation of melon to P. xanthii infection. Net photosynthetic rate (Pn), stomatal conductance (Gs), actual photochemical efficiency (ФPSII) and maximum PSII quantum yield (Fv/Fm) were significantly decreased in P. xanthii-infected plants relative to uninfected ones (Control), revealing apparent physiological disorders. Totally 4808 differentially expressed genes (DEGs) were identified by global analysis of gene expression in Control and P. xanthii-infected plants. Comparative methylome uncovered that 932 DEGs were associated with hypermethylation, while 603 DEGs were associated with hypomethylation in melon upon P. xanthii infection. Among these differential methylation-involved DEGs, a set of resistance-related genes including R genes and candidate genes in metabolic and defense pathways were further identified, demonstrating that DNA methylation might function as a new regulatory layer for melon resistance to P. xanthii infection. Altogether our study sheds new insights into the molecular mechanisms of melon against powdery mildew and provides some potential targets for improving melon disease resistance in future.


Assuntos
Ascomicetos/fisiologia , Cucurbitaceae/genética , Epigenoma , Doenças das Plantas/imunologia , Cucurbitaceae/imunologia , Cucurbitaceae/microbiologia , Metilação de DNA , Doenças das Plantas/microbiologia
18.
Theor Appl Genet ; 134(8): 2495-2515, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33934211

RESUMO

KEY MESSAGE: Rose has 19 MLO genes. Of these, RhMLO1 and RhMLO2 were shown to be required for powdery mildew infection, which suggests their potential as susceptibility targets towards disease resistance. Powdery mildew, caused by Podosphaera pannosa, is one of the most serious and widespread fungal diseases for roses, especially in greenhouse-grown cut roses. It has been shown that certain MLO genes are involved in powdery mildew susceptibility and that loss of function in these genes in various crops leads to broad-spectrum, long-lasting resistance against this fungal disease. For this reason, these MLO genes are called susceptibility genes. We carried out a genome-wide identification of the MLO gene family in the Rosa chinensis genome, and screened for allelic variants among 22 accessions from seven different Rosa species using re-sequencing and transcriptome data. We identified 19 MLO genes in rose, of which four are candidate genes for functional homologs in clade V, which is the clade containing all dicot MLO susceptibility genes. We detected a total of 198 different allelic variants in the set of Rosa species and accessions, corresponding to 5-15 different alleles for each of the genes. Some diploid Rosa species shared alleles with tetraploid rose cultivars, consistent with the notion that diploid species have contributed to the formation of tetraploid roses. Among the four RhMLO genes in clade V, we demonstrated using expression study, virus-induced gene silencing as well as transient RNAi silencing that two of them, RhMLO1 and RhMLO2, are required for infection by P. pannosa and suggest their potential as susceptibility targets for powdery mildew resistance breeding in rose.


Assuntos
Ascomicetos/fisiologia , Mapeamento Cromossômico/métodos , Cromossomos de Plantas/genética , Resistência à Doença/imunologia , Doenças das Plantas/imunologia , Proteínas de Plantas/metabolismo , Rosa/genética , Alelos , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas , Filogenia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Rosa/crescimento & desenvolvimento , Rosa/microbiologia
19.
Theor Appl Genet ; 134(8): 2577-2586, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33950283

RESUMO

KEY MESSAGE: This is the first identification of QTLs underlying resistance to Pseudoperonospora cubensis in Cucumis melo using a genetically characterized isolate. Pseudoperonospora cubensis, causal organism of cucurbit downy mildew (CDM), is one of the largest threats to cucurbit production in the eastern USA. Currently, no Cucumis melo (melon) cultivars have significant levels of resistance. Additionally, little is understood about the genetic basis of resistance in C. melo. Recombinant inbred lines (RILs; N = 169) generated from a cross between the resistant melon breeding line MR-1 and susceptible cultivar Ananas Yok'neam were phenotyped for CDM resistance in both greenhouse and growth chamber studies. A high-density genetic linkage map with 5,663 binned SNPs created from the RIL population was utilized for QTL mapping. Nine QTLs, including two major QTLs, were associated with CDM resistance. Of the major QTLs, qPcub-10.1 was stable across growth chamber and greenhouse tests, whereas qPcub-8.2 was detected only in growth chamber tests. qPcub-10.1 co-located with an MLO-like protein coding gene, which has been shown to confer resistance to powdery mildew and Phytophthora in other plants. This is the first screening of C. melo germplasm with a genetically characterized P. cubensis isolate.


Assuntos
Ascomicetos/fisiologia , Mapeamento Cromossômico/métodos , Cromossomos de Plantas/genética , Cucumis melo/genética , Resistência à Doença/imunologia , Doenças das Plantas/imunologia , Locos de Características Quantitativas , Cucumis melo/crescimento & desenvolvimento , Cucumis melo/microbiologia , Resistência à Doença/genética , Ligação Genética , Melhoramento Vegetal , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Polimorfismo de Nucleotídeo Único , Reprodução
20.
Theor Appl Genet ; 134(8): 2561-2575, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33983452

RESUMO

KEY MESSAGE: We identified cryptic early blight resistance introgressions in tomato breeding lines and demonstrated efficient genotypic selection for resistance in the context of a tomato breeding program. Early blight is a widespread and problematic disease affecting tomatoes (Solanum lycopersicum). Caused by the fungal pathogen Alternaria linariae (syn. A. tomatophila), symptoms include lesions on tomato stems, fruit, and foliage, often resulting in yield losses. Breeding tomatoes with genetic resistance would enhance production sustainability. Using cross-market breeding populations, we identified several quantitative trait loci (QTL) associated with early blight resistance. Early blight resistance putatively derived from 'Campbell 1943' was confirmed in modern fresh market tomato breeding lines. This resistance offered substantial protection against early blight stem lesions (collar rot) and moderate protection from defoliation. A distinctive and potentially novel form of early blight foliar resistance was discovered in a processing tomato breeding line and is probably derived from S. pimpinellifolium via 'Hawaii 7998'. Additional field trials validated the three most promising large-effect QTL, EB-1.2, EB-5, and EB-9. Resistance effects for EB-5 and EB-9 were consistent across breeding populations and environments, while EB-1.2's effect was population specific. Using genome-wide marker-assisted backcrossing, we developed fresh market tomato lines that were near-isogenic for early blight QTL. Resistance in these lines was largely mediated by just two QTL, EB-5 and EB-9, that together captured 49.0 and 68.7% of the defoliation and stem lesion variance, respectively. Our work showcases the value of mining cryptic introgressions in tomato lines, and across market classes, for use as additional sources of disease resistance.


Assuntos
Ascomicetos/fisiologia , Mapeamento Cromossômico/métodos , Segregação de Cromossomos , Cromossomos de Plantas/genética , Resistência à Doença/imunologia , Lycopersicon esculentum/genética , Doenças das Plantas/imunologia , Resistência à Doença/genética , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/microbiologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Locos de Características Quantitativas
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