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Projeto de investigação
Exploring new sources of coffee resistance to leaf rust (Hemileia vastatrix)
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Publicações
Identification of HIR, EDS1 and PAD4 genes reveals differences between Coffea species that may impact disease resistance
Publication . Tavares, Sílvia; Azinheira, Helena; Valverde, Javier; Muñoz-Pajares, A. Jesus; Talhinhas, Pedro; Silva, Maria do Céu
Coffee, a widely consumed important agricultural product, is mainly produced from
two species, Coffea arabica (Arabica coffee) and C. canephora (Robusta coffee). Timor Hybrid (HDT)
is a population resulting from a natural cross between C. arabica and C. canephora. HDT derivatives
have a high spectrum of resistance to different races of Hemileia vastatrix (Hv), the causal agent of
coffee leaf rust. A RNAseq database, obtained from HDT832/2 leaves inoculated with Hv (Host
Resistance) and Uromyces vignae (Uv, Nonhost Resistance), showed the presence of genes implicated
in the hypersensitive response and salicylic acid pathway. Hypersensitive Induced Reaction (HIR)
gene family, Enhanced Disease Susceptibility1 gene (EDS1), and Phytoalexin Deficient 4 (PAD4) gene
are involved in host and nonhost resistance. Relative expression calculated by RT-qPCR was used
to confirm and expand the transcriptome analysis. HDTHIR4, HDTEDS1, and HDTPAD4 showed
the highest upregulation in response to Hv and Uv inoculation, confirming a similar trend in host
and nonhost resistance in HDT. HIR and EDS1/PAD4 gene families were characterized for the first
time in the three available Coffea genomes. HIR genes were quite conserved between Coffea species.
Surprisingly, EDS1 and PAD4 genes revealed major differences in gene structure. The PAD4 predicted
protein from C. arabica does not include both conserved domains of the EDS1/PAD4 family, and
the EDS1 putative protein from C. canephora includes a formin domain unusual in the same protein
family. The variability shown by EDS1/PAD4 gene family may impact the disease resistance
response of Coffea species, which can be surveyed for the gene sequences that will produce a more
resistant phenotype.
An Overview of the Mechanisms Involved in Coffee-Hemileia vastatrix Interactions: Plant and Pathogen Perspectives
Publication . Silva, M.C.; Guerra-Guimarães, Leonor; Diniz, I.; Loureiro, A.; Azinheira, H.; Pereira, A.P.; Tavares, S.; Batista, D.; Várzea, V.
Coffee is one of the most consumed beverages in the world. It is also one of the most
globally traded commodities. Coffee leaf rust (CLR), caused by the biotrophic fungus Hemileia vastatrix,
is the most important disease affecting Arabica coffee growing worldwide, leading to significant
yield losses if no control measures are applied. A deep understanding of the complex mechanisms
involved in coffee-H. vastatrix interactions, such as the pathogen variability and the mechanisms
governing plant resistance and susceptibility, is required to breed efficiently for durable resistance
and design new approaches for crop protection. Here we summarize our current understanding
across multiple areas related to pathogen infection, variability and candidate effectors,
breeding for disease resistance, and the various components of the coffee immune system, by reviewing
a comprehensive body of research on CLR and the advances recently made. We also update
information about the defense responses activated by the application of plant resistance inducers, a
promising alternative to fungicides in the control of CLR. Moreover, we identify and discuss future
directions for further research
Identification of NLR proteins in the coffee genotype HDT 8232/2 challenged with Hemileia vastatrix (host resistance) and Uromyces vignae (nonhost resistance)
Publication . Tavares, S.; Azinheira, H.; Santos, D.; Batista, D.; Várzea, V.; Talhinhas, P.; Silva, M.C.
Metabolicoffee - How primary metabolism modulates coffea spp. - Hemileia Vastatrix interactions?
Publication . Guerra-Guimarães, Leonor; Pinheiro, Carla; Martins, Maria de Fátima; Diniz, Inês; Loureiro, Andreia; Silva, Maria do Céu; D'Auria, John
Coffee leaf rust (Hemileia vastatrix) is the most important disease of Coffea arabica. This
project aims to identify coffee’s primary metabolic components essential for growth and
development that are simultaneously involved in plant defense responses. We studied the
interaction of two contrasting coffee genotypes [C. arabica S4 Agaro and Kawisari hybrid
(C. arabica × C. liberica)] inoculated with different H. vastatrix races to establish compatible
(susceptible - S) and incompatible (resistant - R) interactions. Mock-inoculated leaves were
used as control (C). Leaves were collected during the infection process, and the fungal
colonization was cytologically evaluated. Inoculated and mock-inoculated coffee leaves were
prepared and, metabolites, proteins, and starch were extracted from a single sample using a
fractionated extraction method. At IPK, metabolite analysis by GC-TOF was undertaken while
using the Golm Metabolome Database (GMD). The microscopic evaluation of H. vastatrix pre-penetration stages revealed a high rate of urediniospore germination and appressoria
differentiation over the stomata which ensured the success of the infection. For both
genotypes, starch content increased along the infection process. A preliminary Principal
Component Analysis (PCA) was performed on GC-TOF data showing a clear separation of the
two coffee genotypes. In the Kawisari genotype, the PCA analysis of sugar-related features
revealed an evident split between samples C, R and S, at each time point. The role of these
metabolic features in the coffee defense responses will be discussed.
Coffee Leaf Rust Resistance: An Overview
Publication . Guerra-Guimarães, Leonor; Diniz, Inês; Azinheira, Helena Gil; Loureiro, Andreia; Pereira, Ana Paula; Tavares, Sílvia; Batista, Dora; Varzea, Vitor; Silva, Maria do Céu Lavado da
Coffee is one of the most important cash crops and beverages. Several diseases caused by fungi, bacteria, and viruses can affect coffee plantations and compromise production. Coffee leaf rust (CLR), caused by the biotrophic fungus Hemileia vastatrix is the top fungal disease, representing a permanent threat to sustainable Arabica coffee production for more than a century. This review provides a comprehensive survey of the most common coffee diseases, their importance, and geographic distribution, with an emphasis on coffee leaf rust. Summing up the progress obtained so far from different research fields on the coffee–H. vastatrix interaction, we revisited the pathogen genetic diversity and population dynamics, and the complex mechanisms underlying plant resistance/immunity. We also highlight how new advanced technologies can provide avenues for a deeper understanding of this pathosystem, which is crucial for devising more reliable and long-term strategies for disease control.
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Entidade financiadora
Fundação para a Ciência e a Tecnologia
Programa de financiamento
9471 - RIDTI
Número da atribuição
PTDC/ASP-PLA/29779/2017