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1.
BMC Plant Biol ; 21(1): 412, 2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34496757

RESUMO

BACKGROUND: Fusarium oxysporum f. sp. lycopersici (Fol) is a compendium of pathogenic and non-pathogenic fungal strains. Pathogenic strains may cause vascular wilt disease and produce considerable losses in commercial tomato plots. To gain insight into the molecular mechanisms mediating resistance to Fol in tomato, the aim of our study was to characterize the transcriptional response of three cultivars (CT1, CT2 and IAC391) to a pathogenic (Fol-pt) and a non-pathogenic (Fo-npt) strain of Fo. RESULTS: All cultivars exhibited differentially expressed genes in response to each strain of the fungus at 36 h post-inoculation. For the pathogenic strain, CT1 deployed an apparent active defense response that included upregulation of WRKY transcription factors, an extracellular chitinase, and terpenoid-related genes, among others. In IAC391, differentially expressed genes included upregulated but mostly downregulated genes. Upregulated genes mapped to ethylene regulation, pathogenesis regulation and transcription regulation, while downregulated genes potentially impacted defense responses, lipid transport and metal ion binding. Finally, CT2 exhibited mostly downregulated genes upon Fol-pt infection. This included genes involved in transcription regulation, defense responses, and metal ion binding. CONCLUSIONS: Results suggest that CT1 mounts a defense response against Fol-pt. IAC391 exhibits an intermediate phenotype whereby some defense response genes are activated, and others are suppressed. Finally, the transcriptional profile in the CT2 hints towards lower levels of resistance. Fo-npt also induced transcriptional changes in all cultivars, but to a lesser extent. Results of this study will support genetic breeding programs currently underway in the zone.


Assuntos
Fusarium/patogenicidade , Interações Hospedeiro-Patógeno/genética , Lycopersicon esculentum/genética , Lycopersicon esculentum/microbiologia , Proteínas de Plantas/genética , Cromossomos de Plantas , Colômbia , Resistência à Doença/genética , Etilenos/metabolismo , Regulação da Expressão Gênica de Plantas , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Fatores de Transcrição/genética
2.
J Agric Food Chem ; 69(36): 10678-10687, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34468130

RESUMO

Terpinen-4-ol, the main component of tea tree oil, markedly increases the disease resistance of postharvest strawberry fruit. To understand the mechanism underlying the enhancement of disease resistance, a high-throughput RNA-seq was used to analyze gene transcription in terpinen-4-ol-treated and untreated fruit. The results show that terpinen-4-ol induces the expression of genes in the jasmonic acid (JA) biosynthesis pathway, secondary metabolic pathways such as phenylpropanoid biosynthesis, and pathways involved in plant-pathogen interactions. Terpinen-4-ol treatment reduced disease incidence and lesion diameter in strawberry fruit inoculated with Botrytis cinerea. Terpinen-4-ol treatment enhanced the expression of genes involved in JA synthesis (FaLOX, FaAOC, and FaOPR3) and signaling (FaCOI1), as well as genes related to disease defense (FaPAL, FaCHI, and FaGLU). In contrast, treatment with the JA biosynthesis inhibitor salicylhydroxamic acid (SHAM) accelerated disease development and inhibited the induction of gene expressions by terpinen-4-ol. We conclude that the JA pathway participates in the induction of disease resistance by terpinen-4-ol in strawberry fruit. More generally, the results illuminate the mechanisms by which disease resistance is enhanced by essential oils.


Assuntos
Botrytis , Fragaria , Ciclopentanos , Resistência à Doença/genética , Fragaria/genética , Frutas/genética , Oxilipinas , Doenças das Plantas/genética , Transdução de Sinais , Terpenos
3.
Phytochemistry ; 190: 112884, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34388481

RESUMO

This study analyzed the genetic variability and biochemical characteristics of edible and ornamental accessions of pepper, Capsicum annuum, in response to root and basal rot disease (RCR), caused by Phytophthora capsici, using resistance screening and genetic variability via Inter Simple Sequence Repeat marker (ISSR), bio-mass parameters, and enzymatic activity of Peroxidase or peroxide reductases (POX), Superoxide dismutase (SOD), Polyphenol oxidase (PPOs), Catalase (CAT), Phenylalanine ammonia-lyase (PAL), ß-1,3-glucanase and phenolic content. The resistance in C. annuum '37ChilPPaleo', '19OrnP-PBI' and '23CherryPOrsh' and susceptibility in '2BP-PBI', '24BP-301' and '26BPRStarlet' accessions were confirmed. Nineteen out of 21 ISSR primers generated 185 polymorphic bands with a mean percentage band of 98.5 %, and an average number of bands of 9.9 per primer. Biomass parameters were significantly higher in resistant genotypes than the susceptible ones and non-inoculated controls. All the seven candidate enzymes were highly up-regulated in the resistant C. annuum accessions '19OrnP-PBI', '37ChillP-Paleo' and '23CherryP-Orsh' inoculated with P. capsici The mean level of enzyme activity varied from 1.5 to 5.6-fold higher in the resistant C. annuum, of which SOD was increased by 5.6 fold, followed by PAL 4.40 and PPO 3.75 fold in comparison to susceptible and non-inoculated controls. Overall, there was no significant correlation between resistance and genetic variability, and also between genetic variability and enzyme activity levels. However, there was a highly significant correlation between the resistance, bio-mass parameters and enzyme activity levels.


Assuntos
Capsicum , Phytophthora , Capsicum/genética , Variação Genética , Fenilalanina Amônia-Liase/genética , Doenças das Plantas/genética
4.
Pestic Biochem Physiol ; 178: 104916, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34446192

RESUMO

Soybean root rot occurs globally and seriously affects soybean production. To avoid the many disadvantages of chemical fungicides, the addition of Bacillus is gradually becoming an alternative strategy to tackle soybean root rot. However, the molecular mechanism of phytopathogenic fungi in this process by Bacillus inhibition is rarely reported. In this study, we isolated a strain of B. subtilis HSY21 from soybean rhizosphere soil, which had an inhibition rate of 81.30 ± 0.15% (P < 0.05) against Fusarium oxysporum. The control effects of this strain against soybean root rot under greenhouse and field conditions were 63.83% and 57.07% (P < 0.05), respectively. RNA-seq analysis of F. oxysporum after treatment with strain HSY21 revealed 1445 downregulated genes and 1561 upregulated genes. Among them, genes involved in mycelial growth, metabolism regulation, and disease-related enzymes were mostly downregulated. The activities of cellulase, ß-glucosidase, α-amylase, and pectin-methyl- galacturonase as well as levels of oxalic acid and ergosterol in F. oxysporum were significantly decreased after HSY21 treatment. These results demonstrated that B. subtilis HSY21 could effectively control F. oxysporum by inhibiting its growth and the expression of pathogenic genes, thus indicating that this strain may be an ideal candidate for the prevention and control of soybean root rot.


Assuntos
Fusarium , Bacillus subtilis/genética , Fusarium/genética , Doenças das Plantas/genética , Soja/genética , Virulência
5.
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
6.
Curr Opin Plant Biol ; 62: 102089, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34333377

RESUMO

Plants are resistant to most pathogens because of an immune system that perceives invading microbes and activates defense. A large repertoire of innate immune receptors mediates specific direct or indirect recognition of pathogen-derived molecules. Disease is often a consequence of insufficient immune surveillance, and the transfer of immune receptor genes from resistant plants to susceptible crop varieties is an effective strategy for combating disease outbreaks. We discuss approaches for identifying intracellular and cell surface immune receptors, with particular focus on recently developed and emerging methodologies. We also review considerations for the transfer of immune receptor genes into crop species, including additional host factors that may be required for immune receptor function. Together, these concepts lay out a broadly applicable playbook for developing crop varieties with durable disease resistance.


Assuntos
Doenças das Plantas , Imunidade Vegetal , Produtos Agrícolas/genética , Resistência à Doença/genética , Doenças das Plantas/genética , Imunidade Vegetal/genética
7.
BMC Plant Biol ; 21(1): 397, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34433413

RESUMO

BACKGROUND: Mandarin 'Shatangju' is susceptible to Huanglongbing (HLB) and the HLB-infected fruits are small, off-flavor, and stay-green at the maturity period. To understand the relationship between pericarp color and HLB pathogen and the effect mechanism of HLB on fruit pericarp coloration, quantitative analyses of HLB bacterial pathogens and carotenoids and also the integrative analysis of metabolome and transcriptome profiles were performed in the mandarin 'Shatangju' variety with four different color fruits, whole green fruits (WGF), top-yellow and base-green fruits (TYBGF), whole light-yellow fruits (WLYF), and whole dark-yellow fruits (WDYF) that were infected with HLB. RESULTS: the HLB bacterial population followed the order WGF > TYBGF > WLYF > WDYF. And there were significant differences between each group of samples. Regarding the accumulation of chlorophyll and carotenoid, the chlorophyll-a content in WGF was the highest and in WDYF was the lowest. The content of chlorophyll-b in WGF was significantly higher than that in other three pericarps. There were significant differences in the total content of carotenoid between each group. WGF and TYBGF pericarps were low in phytoene, γ-carotene, ß-cryptoxanthin and apocarotenal, while other kinds of carotenoids were significantly higher than those in WDYF. And WLYF was only short of apocarotenal. We comprehensively compared the transcriptome and metabolite profiles of abnormal (WGF, TYBGF and WLYF) and normal (WDYF, control) pericarps. In total, 2,880, 2,782 and 1,053 differentially expressed genes (DEGs), including 121, 117 and 43 transcription factors were identified in the three comparisons, respectively. The qRT-PCR confirmed the expression levels of genes selected from transcriptome. Additionally, a total of 77 flavonoids and other phenylpropanoid-derived metabolites were identified in the three comparisons. Most (76.65 %) showed markedly lower abundances in the three comparisons. The phenylpropanoid biosynthesis pathway was the major enrichment pathway in the integrative analysis of metabolome and transcriptome profiles. CONCLUSIONS: Synthesizing the above analytical results, this study indicated that different color pericarps were associated with the reduced levels of some carotenoids and phenylpropanoids derivatives products and the down-regulation of proteins in flavonoids, phenylpropanoids derivatives biosynthesis pathway and the photosynthesis-antenna proteins.


Assuntos
Clorofila/análise , Citrus/genética , Citrus/microbiologia , Flavonoides/análise , Frutas/microbiologia , Interações Hospedeiro-Patógeno , Liberibacter/patogenicidade , Pigmentos Biológicos , Produtos Agrícolas/genética , Produtos Agrícolas/microbiologia , Produtos Agrícolas/fisiologia , Frutas/genética , Frutas/fisiologia , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Metaboloma , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Transcriptoma
8.
BMC Genomics ; 22(1): 630, 2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-34461830

RESUMO

BACKGROUND: Fusarium culmorum is an important pathogen causing head blight of cereals in Europe. This disease is of worldwide importance leading to reduced yield, grain quality, and contamination by mycotoxins. These mycotoxins are harmful for livestock and humans; therefore, many countries have strict regulatory limits for raw materials and processed food. Extensive genetic diversity is described among field populations of F. culmorum isolates for aggressiveness and production of the trichothecene mycotoxin deoxynivalenol (DON). However, the causes for this quantitative variation are not clear, yet. We analyzed 92 isolates sampled from different field populations in Germany, Russia, and Syria together with an international collection for aggressiveness and DON production in replicated field experiments at two locations in two years with two hosts, wheat and rye. The 30x coverage whole-genome resequencing of all isolates resulted in the identification of 130,389 high quality single nucleotide polymorphisms (SNPs) that were used for the first genome-wide association study in this phytopathogenic fungus. RESULTS: In wheat, 20 and 27 SNPs were detected for aggressiveness and DON content, respectively, of which 10 overlapped. Additionally, two different SNPs were significantly associated with aggressiveness in rye that were among those SNPs being associated with DON production in wheat. Most of the SNPs explained only a small proportion of genotypic variance (pG), however, four SNPs were associated with major quantitative trait loci (QTLs) with pG ranging from 12 to 48%. The QTL with the highest pG was involved in DON production and associated with a SNP most probably located within the Tri4 gene. CONCLUSIONS: The diversity of 92 isolates of F. culmorum were captured using a heuristic approach. Key phenotypic traits, SNPs, and candidate genes underlying aggressiveness and DON production were identified. Clearly, many QTLs are responsible for aggressiveness and DON content in wheat, both traits following a quantitative inheritance. Several SNPs involved in DON metabolism, among them the Tri4 gene of the trichothecene pathway, were inferred as important source of variation in fungal aggressiveness. Using this information underlying the phenotypic variation will be of paramount importance in evaluating strategies for successful resistance breeding.


Assuntos
Fusarium , Fusarium/genética , Estudo de Associação Genômica Ampla , Humanos , Melhoramento Vegetal , Doenças das Plantas/genética , Secale/genética , Tricotecenos , Triticum/genética
9.
Commun Biol ; 4(1): 947, 2021 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-34373580

RESUMO

Land plant genomes carry tens to hundreds of Resistance (R) genes to combat pathogens. The induction of antiviral R-gene-mediated resistance often results in a hypersensitive response (HR), which is characterized by virus containment in the initially infected tissues and programmed cell death (PCD) of the infected cells. Alternatively, systemic HR (SHR) is sometimes observed in certain R gene-virus combinations, such that the virus systemically infects the plant and PCD induction follows the spread of infection, resulting in systemic plant death. SHR has been suggested to be the result of inefficient resistance induction; however, no quantitative comparison has been performed to support this hypothesis. In this study, we report that the average number of viral genomes that establish cell infection decreased by 28.7% and 12.7% upon HR induction by wild-type cucumber mosaic virus and SHR induction by a single-amino acid variant, respectively. These results suggest that a small decrease in the level of resistance induction can change an HR to an SHR. Although SHR appears to be a failure of resistance at the individual level, our simulations imply that suicidal individual death in SHR may function as an antiviral mechanism at the population level, by protecting neighboring uninfected kin plants.


Assuntos
Cucumovirus/fisiologia , Regulação da Expressão Gênica de Plantas , Genes vpr/fisiologia , Doenças das Plantas/genética , Tabaco/virologia , Cucumovirus/genética , Resistência à Doença/genética , Proteínas de Plantas/genética , Tabaco/genética
10.
Int J Mol Sci ; 22(15)2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34360726

RESUMO

Fungal diseases pose a major threat to ornamental plants, with an increasing percentage of pathogen-driven host losses. In ornamental plants, management of the majority of fungal diseases primarily depends upon chemical control methods that are often non-specific. Host basal resistance, which is deficient in many ornamental plants, plays a key role in combating diseases. Despite their economic importance, conventional and molecular breeding approaches in ornamental plants to facilitate disease resistance are lagging, and this is predominantly due to their complex genomes, limited availability of gene pools, and degree of heterozygosity. Although genetic engineering in ornamental plants offers feasible methods to overcome the intrinsic barriers of classical breeding, achievements have mainly been reported only in regard to the modification of floral attributes in ornamentals. The unavailability of transformation protocols and candidate gene resources for several ornamental crops presents an obstacle for tackling the functional studies on disease resistance. Recently, multiomics technologies, in combination with genome editing tools, have provided shortcuts to examine the molecular and genetic regulatory mechanisms underlying fungal disease resistance, ultimately leading to the subsequent advances in the development of novel cultivars with desired fungal disease-resistant traits, in ornamental crops. Although fungal diseases constitute the majority of ornamental plant diseases, a comprehensive overview of this highly important fungal disease resistance seems to be insufficient in the field of ornamental horticulture. Hence, in this review, we highlight the representative mechanisms of the fungal infection-related resistance to pathogens in plants, with a focus on ornamental crops. Recent progress in molecular breeding, genetic engineering strategies, and RNAi technologies, such as HIGS and SIGS for the enhancement of fungal disease resistance in various important ornamental crops, is also described.


Assuntos
Resistência à Doença/genética , Fungos Mitospóricos/crescimento & desenvolvimento , Melhoramento Vegetal , Doenças das Plantas , Plantas Geneticamente Modificadas , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/microbiologia
11.
Int J Mol Sci ; 22(16)2021 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-34445148

RESUMO

The gram-positive pathogenic bacterium Clavibacter michiganensis subsp. michiganensis (Cmm) causes bacterial canker disease in tomato, affecting crop yield and fruit quality. To understand how tomato plants respond, the dynamic expression profile of host genes was analyzed upon Cmm infection. Symptoms of bacterial canker became evident from the third day. As the disease progressed, the bacterial population increased in planta, reaching the highest level at six days and remained constant till the twelfth day post inoculation. These two time points were selected for transcriptomics. A progressive down-regulation of key genes encoding for components of the photosynthetic apparatus was observed. Two temporally separated defense responses were observed, which were to an extent interdependent. During the primary response, genes of the phenylpropanoid pathway were diverted towards the synthesis of monolignols away from S-lignin. In dicots, lignin polymers mainly consist of G- and S-units, playing an important role in defense. The twist towards G-lignin enrichment is consistent with previous findings, highlighting a response to generate an early protective barrier and to achieve a tight interplay between lignin recomposition and the primary defense response mechanism. Upon progression of Cmm infection, the temporal deactivation of phenylpropanoids coincided with the upregulation of genes that belong in a secondary response mechanism, supporting an elegant reprogramming of the host transcriptome to establish a robust defense apparatus and suppress pathogen invasion. This high-throughput analysis reveals a dynamic reorganization of plant defense mechanisms upon bacterial infection to implement an array of barriers preventing pathogen invasion and spread.


Assuntos
Regulação para Baixo/genética , Lycopersicon esculentum/genética , Lycopersicon esculentum/microbiologia , Fotossíntese/genética , Imunidade Vegetal/genética , Imunidade Vegetal/imunologia , Clavibacter/genética , Infecções por Bactérias Gram-Positivas/genética , Infecções por Bactérias Gram-Positivas/imunologia , Infecções por Bactérias Gram-Positivas/microbiologia , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Fotossíntese/imunologia , Doenças das Plantas/genética , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Transcriptoma/genética , Regulação para Cima/genética
12.
BMC Plant Biol ; 21(1): 358, 2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34348650

RESUMO

BACKGROUND: The South America pinworm, Tuta absoluta, is a destructive pest of tomato that causes important losses worldwide. Breeding of resistant/tolerant tomato cultivars could be an effective strategy for T. absoluta management but, despite the economic importance of tomato, very limited information is available about its response to this treat. To elucidate the defense mechanisms to herbivore feeding a comparative analysis was performed between a tolerant and susceptible cultivated tomato at both morphological and transcriptome level to highlight constitutive leaf barriers, molecular and biochemical mechanisms to counter the effect of T. absoluta attack. RESULTS: The tolerant genotype showed an enhanced constitutive barrier possibly as result of the higher density of trichomes and increased inducible reactions upon mild infestation thanks to the activation/repression of key transcription factors regulating genes involved in cuticle formation and cell wall strength as well as of antinutritive enzymes, and genes involved in the production of chemical toxins and bioactive secondary metabolites. CONCLUSIONS: Overall, our findings suggest that tomato resilience to the South America pinworm is achieved by a combined strategy between constitutive and induced defense system. A well-orchestrated modulation of plant transcription regulation could ensure a trade-off between defense needs and fitness costs. Our finding can be further exploited for developing T. absoluta tolerant cultivars, acting as important component of integrated pest management strategy for more sustainable production.


Assuntos
Regulação da Expressão Gênica de Plantas , Lycopersicon esculentum/genética , Doenças das Plantas/genética , Folhas de Planta/genética , Transcriptoma , Animais , Perfilação da Expressão Gênica/métodos , Ontologia Genética , Interações Hospedeiro-Parasita , Larva/fisiologia , Lycopersicon esculentum/metabolismo , Lycopersicon esculentum/parasitologia , Mariposas/fisiologia , Doenças das Plantas/parasitologia , Folhas de Planta/metabolismo , Folhas de Planta/parasitologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , RNA-Seq/métodos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Tricomas/genética , Tricomas/metabolismo , Tricomas/parasitologia
13.
Plant Physiol Biochem ; 166: 950-957, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34247109

RESUMO

Durable disease resistance genes such as the wheat gene Lr34 are valuable sources of resistance for agricultural breeding programs. Lr34 encodes an ATP-binding cassette transporter protein involved in the transport of the phytohormone abscisic acid. Lr34 from wheat is functionally transferable to barley, maize, rice and sorghum. A pleiotropic effect of Lr34 induces the development of a senescence-like phenotype, referred to as leaf tip necrosis. We used Lr34-expressing wheat and transgenic barley plants to elucidate the role of abscisic acid in the development of leaf tip necrosis. Leaf tips in Lr34-expressing wheat and barley showed an accumulation of abscisic acid. No increase of Lr34 expression was detected in the leaf tip. Instead, the development of ectopic, Lr34-induced leaf tip necrosis after removing the leaf tip suggests an increased flux of abscisic acid towards the tip, where it accumulates and mediates the development of leaf tip necrosis. This redistribution of abscisic acid was also observed in adult transgenic barley plants with a high Lr34 expression level growing in the field and coincided with leaf tip necrosis as well as complete field resistance against Puccinia hordei and Blumeria graminis f. sp. hordei. In a barley transgenic line with a lower Lr34 expression level, a quantitative resistance against Puccinia hordei was still observed, but without a significant redistribution of abscisic acid or apparent leaf tip necrosis. Thus, our results imply that fine-tuning the Lr34 expression level is essential to balance disease resistance versus leaf tip necrosis to deploy transgenic Lr34 in breeding programs.


Assuntos
Basidiomycota , Hordeum , Ácido Abscísico , Ascomicetos , Resistência à Doença/genética , Hordeum/genética , Melhoramento Vegetal , Doenças das Plantas/genética , Folhas de Planta/genética , Triticum/genética
14.
J Genet ; 1002021.
Artigo em Inglês | MEDLINE | ID: mdl-34282731

RESUMO

The gene-for-gene relationship of host-pathogen interaction explained by H. H. Flor in mid of the 20th century set a milestone in understanding the biochemical and genetic basis of plant diseases and several components involved in plant-pathogen interactions. It highlighted the importance of accomplishing differential sets and understanding the pathogen population structure, it further led to the identification and cloning of several resistance (R) genes in plants. These R genes have been deployed and altered for fighting against diseases in a large number of crops using various conventional approaches and biotechnological tools. Identification of R genes and their corresponding Avr genes in many cases played a significant role in understanding of R-Avr gene interactions. Rapid cloning of R genes and editing of susceptible R genes are the other avenues that have broadened the horizon of utilizing R genes in crop improvement programmes. Further, combining R genes with quantitative disease resistance genes has paved the way to develop durable resistance in cultivars. The recent advances in genetics, genomics, bioinformatics and other OMICS tools are now providing greater prospects for deeper understanding of host-pathogen interaction.


Assuntos
Resistência à Doença/genética , Evolução Molecular , Genes vpr/genética , Doenças das Plantas/genética , Produtos Agrícolas/genética , Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/microbiologia , Genômica , Interações Hospedeiro-Patógeno/genética , Doenças das Plantas/microbiologia
15.
Cytogenet Genome Res ; 161(5): 257-271, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34320507

RESUMO

Sweetpotato, Ipomoea batatas (L.) Lam., is an important and widely grown crop, yet its production is affected severely by biotic and abiotic stresses. The nucleotide binding site (NBS)-encoding genes have been shown to improve stress tolerance in several plant species. However, the characterization of NBS-encoding genes in sweetpotato is not well-documented to date. In this study, a comprehensive analysis of NBS-encoding genes has been conducted on this species by using bioinformatics and molecular biology methods. A total of 315 NBS-encoding genes were identified, and 260 of them contained all essential conserved domains while 55 genes were truncated. Based on domain architectures, the 260 NBS-encoding genes were grouped into 6 distinct categories. Phylogenetic analysis grouped these genes into 3 classes: TIR, CC (I), and CC (II). Chromosome location analysis revealed that the distribution of NBS-encoding genes in chromosomes was uneven, with a number ranging from 1 to 34. Multiple stress-related regulatory elements were detected in the promoters, and the NBS-encoding genes' expression profiles under biotic and abiotic stresses were obtained. According to the bioinformatics analysis, 9 genes were selected for RT-qPCR analysis. The results revealed that IbNBS75, IbNBS219, and IbNBS256 respond to stem nematode infection; Ib-NBS240, IbNBS90, and IbNBS80 respond to cold stress, while IbNBS208, IbNBS71, and IbNBS159 respond to 30% PEG treatment. We hope these results will provide new insights into the evolution of NBS-encoding genes in the sweetpotato genome and contribute to the molecular breeding of sweetpotato in the future.


Assuntos
Adaptação Fisiológica/genética , Cromossomos de Plantas , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Ipomoea batatas/genética , Adaptação Fisiológica/imunologia , Animais , Sequência de Bases , Sítios de Ligação , Mapeamento Cromossômico/métodos , Biologia Computacional/métodos , Ipomoea batatas/classificação , Ipomoea batatas/imunologia , Ipomoea batatas/parasitologia , Anotação de Sequência Molecular , Nucleotídeos/genética , Nucleotídeos/metabolismo , Filogenia , Doenças das Plantas/genética , Doenças das Plantas/imunologia , Doenças das Plantas/parasitologia , Imunidade Vegetal/genética , Estresse Fisiológico , Tylenchoidea/crescimento & desenvolvimento , Tylenchoidea/patogenicidade
16.
Methods Mol Biol ; 2288: 49-72, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34270004

RESUMO

Molecular markers are employed for doubled haploid (DH) technology by researchers and applied plant breeders in many crops. In the 1990s, isozymes and RFLPs were commonly used marker technologies to characterize DHs and were later replaced by PCR- based markers (e.g., RAPDs, AFLPs, ISSRs, SSRs) and today by SNPs. Markers are used for multiple purposes in DH production, that is, for the study of genes underlying haploid induction and confirming homozygous plants of gametophytic origin. Furthermore, they are tools for investigating segregation in DH populations and for mapping simple and complex traits using DHs. The deployment of DHs and markers for developing trait-linked markers are demonstrated with examples from rapeseed, wheat, and barley. Marker development for resistance to viruses derived from genetic resources and their use in, for example, pyramiding of resistance genes, are given as an example for the combination of DH-technology and marker development in research. Today, marker systems amenable to automation are frequently used in applied plant breeding. Practical examples are given from Lantmännen (LM) ( https://Lantmannen.com ) using large-scale genotyping for variety development based on SSRs and SNPs.


Assuntos
Produtos Agrícolas/genética , Melhoramento Vegetal/métodos , Brassica napus/genética , Produtos Agrícolas/virologia , DNA de Plantas/genética , Diploide , Resistência à Doença/genética , Genes de Plantas , Marcadores Genéticos , Haploidia , Homozigoto , Hordeum/genética , Isoenzimas/genética , Biologia Molecular/métodos , Doenças das Plantas/genética , Doenças das Plantas/virologia , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Polimorfismo de Nucleotídeo Único , Triticum/genética
17.
Curr Opin Biotechnol ; 70: 196-203, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34198205

RESUMO

Huanglongbing (HLB) disease is threatening the sustainability of citriculture in affected regions because of its rapid spread and the severity of the symptoms it induces. Herein, we summarise the main research findings that can be exploited to develop HLB-resistant cultivars. A major bottleneck has been the lack of a system for the ex vivo cultivation of HLB-associated bacteria (CLs) in true plant hosts, which precludes the evaluation of target genes/metabolites in reliable plant/pathogen/vector environments. With regard to HLB vectors, several biotechnologies which have been proven in laboratory settings to be effective for insect control are presented. Finally, new genotypes that are resistant to CLs or their insect vectors are described, and the most relevant strategies for fighting HLB are highlighted.


Assuntos
Citrus , Hemípteros , Rhizobiaceae , Animais , Citrus/genética , Insetos Vetores , Doenças das Plantas/genética , Rhizobiaceae/genética
18.
Curr Opin Biotechnol ; 70: 226-233, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34217954

RESUMO

Potato production is negatively affected by root-knot nematodes (Meloidogyne spp.). There are no commercially available potato cultivars that are resistant to root-knot nematodes. To reduce the reliance on chemical controls, genetic engineering for nematode resistance in potato shows promise. Genetically modified potatoes that silence a parasitism gene or that express toxic protease inhibitors display reduced nematode infections. Modifying potato immune responses may also offer new opportunities for nematode resistance in potato. Plant defense elicitors, including those secreted by modified bacteria, enhanced resistance against root-knot nematodes in potato. The use of transgenic bacteria as delivery vehicles of defense-related molecules presents several possibilities for sophisticated nematode management and because this does not involve transgenic plants, it may garner greater public acceptance.


Assuntos
Solanum tuberosum , Tylenchoidea , Animais , Doenças das Plantas/genética , Raízes de Plantas/genética , Plantas Geneticamente Modificadas/genética , Solanum tuberosum/genética
19.
Methods Mol Biol ; 2328: 227-252, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34251630

RESUMO

Tracking RNA transcription has been one of the most powerful tools to gain insight into the biological process. While a wide range of molecular methods such as northern blotting, RNA-seq, and quantitative RT-PCR are available, one of the barriers in transcript analysis is an inability to accommodate a sufficient number of samples to achieve high resolution in dynamic transcriptional changes. RASL-seq (RNA-mediated oligonucleotide Annealing, Selection, and Ligation with next-generation sequencing) is a sequencing-based transcription profiling tool that processes hundreds of samples assessing a set of over a hundred genes with a fraction of the cost of a conventional RNA-seq. We described a RASL-seq protocol for assessing 288 genes mostly including defense genes to capture their dynamic nature. We demonstrated that this transcriptional profiling method produced a highly reliable outcome comparable to a conventional RNA-seq and quantitative RT-PCR.


Assuntos
Arabidopsis/metabolismo , Perfilação da Expressão Gênica/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Interações Hospedeiro-Patógeno/genética , Oligonucleotídeos/genética , Doenças das Plantas/genética , Reação em Cadeia da Polimerase em Tempo Real
20.
Nat Commun ; 12(1): 4505, 2021 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-34301941

RESUMO

By structuring farmers' informal networks of seed exchange, kinship systems play a key role in the dynamics of crop genetic diversity in smallholder farming systems. However, because many crop diseases are propagated through infected germplasm, local seed systems can also facilitate the dissemination of seedborne pathogens. Here, we investigate how the interplay of kinship systems and local networks of germplasm exchange influences the metapopulation dynamics of viruses responsible for the cassava mosaic disease (CMD), a major threat to food security in Africa. Combining anthropological, genetic and plant epidemiological data, we analyzed the genetic structure of local populations of the African cassava mosaic virus (ACMV), one of the main causal agents of CMD. Results reveal contrasted patterns of viral diversity in patrilineal and matrilineal communities, consistent with local modes of seed exchange. Our results demonstrate that plant virus ecosystems have also a cultural component and that social factors that shape regional seed exchange networks influence the genetic structure of plant virus populations.


Assuntos
Begomovirus/genética , Variação Genética , Manihot/genética , Doenças das Plantas/genética , Sementes/genética , Agricultura/métodos , Teorema de Bayes , Begomovirus/classificação , Begomovirus/fisiologia , Ecossistema , Família , Fazendeiros , Gabão , Geografia , Interações Hospedeiro-Patógeno/genética , Humanos , Manihot/classificação , Manihot/virologia , Filogenia , Doenças das Plantas/virologia , Sementes/virologia , Especificidade da Espécie
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