scholarly journals LysM receptors in Coffea arabica: identification, characterization, and gene expression in response to Hemileia vastatrix

2021 ◽  
Author(s):  
Mariana Santos ◽  
Mário Lúcio Resende ◽  
Bárbara Santos Ciscon ◽  
Natália Freitas ◽  
Matheus Pereira ◽  
...  

Pathogen‐associated molecular patterns (PAMPs) are recognized by pattern recognition receptors (PRRs) localized on the host plant cell wall.  These receptors activate a broad-spectrum and durable defense, which are desired characteristics for disease resistance in plant breeding programs. In this study, candidate sequences for PRRs with lysin motifs (LysM) were investigated in the Coffea arabica genome. For this, approaches based on the principle of sequence similarity, conservation of motifs and domains, phylogenetic analysis, and modulation of gene expression in response to Hemileia vastatrix were used. The candidate sequences for PRRs in C. arabica ( Ca1-LYP , Ca2-LYP , Ca1-CERK1 , Ca2-CERK1 , Ca-LYK4 , Ca1-LYK5 and Ca2-LYK5 ) showed high similarity with the reference PRRs used: Os-CEBiP , At-CERK1 , At-LYK4 and At-LYK5 . Moreover, the ectodomains of these sequences showed high identity or similarity with the reference sequences, indicating structural and functional conservation. The studied sequences are also phylogenetically related to the reference PRRs described in Arabidopsis, rice, and other plant species. All candidates for receptors had their expression induced after the inoculation with H. vastatrix , since the first time of sampling at 6 hours post‐inoculation (hpi). At 24 hpi, there was a significant increase in expression, for most of the receptors evaluated, and at 48 hpi, a suppression. The results showed that the candidate sequences for PRRs in the C. arabica genome display high homology with fungal PRRs already described in the literature. Besides, they respond to pathogen inoculation and seem to be involved in the perception or signaling of fungal chitin, acting as receptors or coreceptors of this molecule. These findings represent an advance in the understanding of the basal immunity of this species.

2019 ◽  
Author(s):  
Fabián Echeverría-Beirute ◽  
Seth C. Murray ◽  
Benoit Bertrand ◽  
Patricia E. Klein

Background. Coffee leaf rust (CLR) caused by Hemileia vastatrix Berk. & Br, is one of the most threatening diseases for Coffea arabica L. It is hypothesized that host tolerance to CLR relies on non-race-specific resistance genes. Methods. This study evaluated gene expression in leaves of two susceptible coffee cultivars (one inbred and one F1 hybrid) under different stress conditions: rust control (fungicide and untreated) and fruit thinning (thinned and un-thinned) treatments. RNA-seq analysis focused on the association of differentially expressed genes (DEGs) with CLR and associated the effect of the most significant genes into the phenotype, using regression and prediction statistical models. Results. Gene expression and gene ontology (GO) analysis allowed identification of 100 genes associated with quantitative traits. From these, 88 were correlated with rust incidence, rust severity, and rust sporulation. The expression of genes coding for pathogenesis-related proteins increased positively with rust incidence in the inbred, while genes involved in homoeostasis and broader cell wall structuring processes were upregulated in the F1 hybrid. The enriched gene functions and associations revealed that a possible hypersensitive response (HR) in the inbred and a systemic acquired resistance (SAR) in the F1 hybrid were involved in the tolerance mechanisms to CLR stress. This is the first study to demonstrate the specific interactions between CLR and host at a molecular level, useful for identifying control targets for breeding perennial species.


2019 ◽  
Author(s):  
Fabián Echeverría-Beirute ◽  
Seth C. Murray ◽  
Benoit Bertrand ◽  
Patricia E. Klein

Background. Coffee leaf rust (CLR) caused by Hemileia vastatrix Berk. & Br, is one of the most threatening diseases for Coffea arabica L. It is hypothesized that host tolerance to CLR relies on non-race-specific resistance genes. Methods. This study evaluated gene expression in leaves of two susceptible coffee cultivars (one inbred and one F1 hybrid) under different stress conditions: rust control (fungicide and untreated) and fruit thinning (thinned and un-thinned) treatments. RNA-seq analysis focused on the association of differentially expressed genes (DEGs) with CLR and associated the effect of the most significant genes into the phenotype, using regression and prediction statistical models. Results. Gene expression and gene ontology (GO) analysis allowed identification of 100 genes associated with quantitative traits. From these, 88 were correlated with rust incidence, rust severity, and rust sporulation. The expression of genes coding for pathogenesis-related proteins increased positively with rust incidence in the inbred, while genes involved in homoeostasis and broader cell wall structuring processes were upregulated in the F1 hybrid. The enriched gene functions and associations revealed that a possible hypersensitive response (HR) in the inbred and a systemic acquired resistance (SAR) in the F1 hybrid were involved in the tolerance mechanisms to CLR stress. This is the first study to demonstrate the specific interactions between CLR and host at a molecular level, useful for identifying control targets for breeding perennial species.


2019 ◽  
Vol 32 (4) ◽  
pp. 353-370 ◽  
Author(s):  
Mário Costa ◽  
Ana Marta Pereira ◽  
Sara Cristina Pinto ◽  
Jessy Silva ◽  
Luís Gustavo Pereira ◽  
...  

Key message The fasciclin-like arabinogalactan proteins organization into four groups is conserved and may be related to specific roles in developmental processes across angiosperms. Abstract Fasciclin-like arabinogalactan proteins (FLAs) are a subclass of arabinogalactan proteins (AGPs), which contain fasciclin-like domains in addition to typical AGP domains. FLAs are present across all embryophytes, and despite their low overall sequence similarity, conserved regions that define the fasciclin functional domain (FAS) have been identified, suggesting that the cell adhesion property is also conserved. FLAs in Arabidopsis have been organized into four subgroups according to the number and distribution of functional domains. Recent studies associated FLAs with cell wall-related processes where domain organization seemed to be related to functional roles. In Arabidopsis, FLAs containing a single FAS domain were found to be important for the integrity and elasticity of the plant cell wall matrix, and FLAs with two FAS domains and two AGP domains were found to be involved in maintaining proper cell expansion under salt stress conditions. The main purpose of the present work was to elucidate the expression pattern of selected FLA genes during embryo and seed development using RT-qPCR. AtFLA8 and AtFLA10, two Arabidopsis genes that stood out in previous microarray studies of embryo development, were further examined using promoter-driven gene reporter analyses. We also studied the expression of cork oak FLA genes and found that their expression partially parallels the expression patterns of the putative AtFLA orthologs. We propose that the functional organization of FLAs is conserved and may be related to fundamental aspects of embryogenesis and seed development across angiosperms. Phylogenetic studies were performed, and we show that the same basic four-subgroup organization described for Arabidopsis FLA gene classification is valid for most Arabidopsis FLA orthologs of several plant species, namely poplar, corn and cork oak.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 286-286
Author(s):  
Kwangwook Kim ◽  
Sungbong Jang ◽  
Yanhong Liu

Abstract Our previous studies have shown that supplementation of low-dose antibiotic growth promoter (AGP) exacerbated growth performance and systemic inflammation of weaned pigs infected with pathogenic Escherichia coli (E. coli). The objective of this experiment, which is extension of our previous report, was to investigate the effect of low-dose AGP on gene expression in ileal mucosa of weaned pigs experimentally infected with F18 E. coli. Thirty-four pigs (6.88 ± 1.03 kg BW) were individually housed in disease containment rooms and randomly allotted to one of three treatments (9 to 13 pigs/treatment). The three dietary treatments were control diet (control), and 2 additional diets supplemented with 0.5 or 50 mg/kg of AGP (carbadox), respectively. The experiment lasted 18 d [7 d before and 11 d after first inoculation (d 0)]. The F18 E. coli inoculum was orally provided to all pigs with the dose of 1010 cfu/3 mL for 3 consecutive days. Total RNA [4 to 6 pigs/treatment on d 5; 5 to 7 pigs/treatment on 11 post-inoculation (PI)] was extracted from ileal mucosa to analyze gene expression profiles by Batch-Tag-Seq. The modulated differential gene expression were defined by 1.5-fold difference and a cutoff of P < 0.05 using limma-voom package. All processed data were statistically analyzed and evaluated by PANTHER classification system to determine the biological process function of genes in these lists. Compared to control, supplementation of recommended-dose AGP down-regulated genes related to inflammatory responses on d 5 and 11 PI; whereas, feeding low-dose AGP up-regulated genes associated with negative regulation of metabolic process on d 5, but down-regulated the genes related to immune responses on d 11 PI. The present observations support adverse effects of low-dose AGP in our previous study, indicated by exacerbated the detrimental effects of E. coli infection on pigs’ growth rate, diarrhea and systemic inflammation.


Bragantia ◽  
1989 ◽  
Vol 48 (1) ◽  
pp. 73-86 ◽  
Author(s):  
Alcides Carvalho ◽  
Luiz Carlos Fazuoli ◽  
Waldir Marques da Costa

Progênies do café Híbrido de Timor e F02-F4 oriundas de cruzamentos desse café com outros cultivares resistentes ou não a Hemileia vastatrix e cruzamentos entre outras fontes de resistência ao patógeno, foram avaliadas em três experimentos, em Campinas, para observação de sua produtividade, em relação a alguns cultivares de Coffea arabica tomados como testemunhas. As progênies do Híbrido de Timor apresentaram pequena produtividade, indicando baixa adaptação, com exceção daquelas de prefixos C 1737, C 1738 e C 1699. As progênies derivadas de cruzamentos do Híbrido de Timor com cultivares de porte pequeno, como Caturra Vermelho e Vila Sarchi de Coffea arabica, mostraram-se, também, pouco produtivas. Destacou-se apenas a progênie C 1669, rústica. Das combinações do Híbrido de Timor com outros cultivares de C. arabica com resistência a H. vastatrix, apenas a progênie C 1698 se revelou melhor. As progênies F2 derivadas de cruzamentos do cultivar S 795 portador do fator S H3 de resistência com Mundo Novo, deram produções bastante razoáveis. Notou-se, de modo geral, acentuada variabilidade na produção das progênies, o que é indicado pelos elevados valores dos coeficientes de variação obtidos nos três experimentos. Os dados desses experimentos mostraram a dificuldade de aproveitamento das progênies e dos derivados do Híbrido de Timor analisados. Tratando-se, no entanto, de material de elevado grau de resistência às raças de H. vastatrix, novas hibridações deverão ser sintetizadas, com cultivares comerciais, a fim de se conseguirem linhagens resistentes, vigorosas e mais produtivas.


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