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Sustainable soil management to optimize water use and enhance nutrient uptake is a promising approach for decreasing the incidence of coffee leaf rust. This work analysed soil coverings, fertilizers and soil conditioners to optimize water usage and nutrients in coffee rust management. The experiment was set up in the field in January 2016, with seedlings of Coffea arabica ‘Mundo Novo IAC – 379‐19’, susceptible to rust. The experimental design was in randomized blocks with three replications and arranged in a 3 × 2 × 5 factorial scheme. We assessed the combination of three soil coverings (plastic film, Urochloa decumbens and bare soil), two fertilizer types (conventional and controlled release) and five soil conditioners (organic compound, coffee husk, agricultural gypsum, water‐retaining polymer and control without soil conditioner). The rust incidence and foliage progress curve were integrated into the area under the rust incidence or foliage progress curve. Additionally, we assessed the leaf area index and coffee yield. The association of U. decumbens with controlled‐release fertilizers and organic compound or coffee husk increased coffee foliage and yield despite higher disease incidence. [ABSTRACT FROM AUTHOR]

Coffee leaf rust (CLR), caused by Hemileia vastatrix, poses a significant threat to global coffee production, resulting in substantial economic losses. This study explores the effectiveness of triazole derivatives synthesized from glycerol in controlling CLR in conilon coffee (Coffea canephora). In vitro assays evaluated the inhibitory effect of triazole derivatives (4a–4q) at concentrations of 10, 25, 50, 75 and 100 ppm on H. vastatrix urediniospore germination, followed by greenhouse experiments to assess their preventive and curative potential. Preventive and curative sprayings of the four most efficient triazoles were conducted on seedlings inoculated with H. vastatrix at concentrations ranging from 0 to 400 ppm, evaluating severity, sporulation, incubation and latent periods. Triazole derivatives 4b, 4d, 4f and 4o effectively suppressed H. vastatrix urediniospore germination, achieving reductions between 9.9% and 78.8%. In greenhouse trials, these compounds demonstrated preventive efficacy by prolonging incubation and latent periods, reducing sporulation and mitigating rust severity, with triazole 4f exhibiting the highest efficiency. Furthermore, the derivatives showed effectiveness in curative treatments, particularly triazole 4f. Physiological analyses indicated no significant alterations in coffee plant metabolism, suggesting the safety of these compounds for agricultural use. Molecular docking studies elucidated their mechanism of action, suggesting their potential as antifungal agents by interacting with the HvCYP51 enzyme involved in ergosterol biosynthesis. Overall, the study underscores the promising efficacy of glycerol‐derived triazole derivatives in managing CLR, providing sustainable solutions for disease control in agriculture. [ABSTRACT FROM AUTHOR]

During surveys in the centres of origin of the coffee leaf rust (CLR), Hemileia vastatrix in Africa, as well as in its exotic range in Brazil, 23 isolates of the genus Cladosporium were obtained from uredinial pustules. Using a phylogenetic analysis of all isolates involving a combination of partial sequences of the internal transcribed spacer region of rDNA (ITS) and two gene regions: actin (act) and translation elongation factor-1a (tef1), 12 species were delimited; including four new species - Cladosporium chlamydosporiformans, C. hemileiicola, C. mucilaginosum and C. setoides. GCPSR criteria were employed for species recognition, supported by morphological and cultural characters. The potential of these purported mycoparasites is discussed in the context of biological control of CLR in Latin America. [ABSTRACT FROM AUTHOR]

IPR Pérola is a Coffea arabica cultivar developed from a cross between IAPAR 59 and Mundo Novo IAC 376-4. It features a dwarf-medium size, high yield, excellent cup quality, a medium-early ripening cycle, and large beans. Additionally, it boasts high resistance to coffee leaf rust. [ABSTRACT FROM AUTHOR]

Coffee leaf rust, caused by Hemileia vastatrix, is the most important disease affecting Coffea arabica. The use of molecular markers through marker-assisted selection (MAS) is an effective approach to develop cultivars with multiple and durable resistance, which is economically and environmentally beneficial for this disease control. In this work, a new molecular marker based on allele-specific polymerase chain reaction (AS-PCR) associated with the quantitative trait locus (QTL) of the linkage group 5 (LG5), which confers resistance to races I, II and pathotype 001 of H. vastatrix, was developed. The CaRHv10-AS marker was validated in a segregating genetic mapping population of 247 F2 genotypes and demonstrated selection efficiency greater than 97% for genotypes with resistance to three races. Thus, this work provides a fast, robust, and affordable molecular marker for use in MAS, facilitating the development of coffee plants with multiple resistance and ensuring sustainable coffee production. [ABSTRACT FROM AUTHOR]

Coffee leaf rust (CLR) is caused by the biotrophic pathogenic fungus Hemileia vastatrix. Despite being the most researched coffee disease, mysteries still exist relating to its epidemiology and biology. The objective of this work is to highlight past and present events concerning this prominent coffee disease. We start with an historical overview of the homeland of Coffea arabica, the Afromontane forest of south‐west Ethiopia, and then follow its journey across the globe linked to colonial trade and power struggles. We report the relevance of CLR to coffee production today, with a focus on the Americas and summarize unproven hypotheses in relation to the cause of recent epidemics. We present an original hypothesis concerning the first major outbreak occurring in 1869 in Ceylon (Sri Lanka), based on geopolitical connections to global trade. We review old and new options for management of the disease. The likelihood of a yet undetected alternate host of H. vastatrix is also considered as an additional piece of the epidemiological puzzle. Finally, we reflect on the interactions between H. vastatrix and a changing climate. By better understanding past events, linked to CLR, we may be better prepared for future outbreaks. [ABSTRACT FROM AUTHOR]

(1) The fungal genus Simplicillium (Cordycipitaceae: Hypocreales) has an extensive distribution and a broad spectrum of hosts and substrates. The species Simplicillium lanosoniveum is a mycoparasite with potential for biological control of coffee leaf rust, Hemileia vastatrix. Morphologically, Simplicillium closely resembles mycoparasitic and entomopathogenic Lecanicillium fungi, often resulting in misidentification. A fungal isolate was obtained from leaf-rust-infested coffee plants from Cienfuegos Province, Cuba. (2) Combined analyses of morphology and molecular markers (ITS, LSU, EF-1alpha) were used for fungal identification. (3) In the NJ, ML, and BI phylogenies which were reconstructed, the isolate LBSim-01 was located in the Simplicillium lanosoniveum clade. This species-level identification was supported by morphological features. (4) The isolate LBSim-01 was assigned to the species Simplicillium lanosoniveum. This is the first description of a Simplicillium fungus associated with coffee leaf rust in Cuba. The presented results hold implications for the biological control of this economically relevant plant disease. [ABSTRACT FROM AUTHOR]

Natural enemies of plant pathogens might play an important role in controlling plant disease levels in natural and agricultural systems. Yet, plant pathogen–natural enemy interactions might be sensitive to climatic changes. Understanding the relationship between climate, plant pathogens and their natural enemies is thus important for developing climate‐resilient, sustainable agriculture.To this aim, we recorded shade cover, daily minimum and maximum temperature, relative humidity, coffee leaf rust and its hyperparasite at 58 sites in southwestern Ethiopia during the dry and wet season for 2 years.Coffee leaf rust severity was positively related to the maximum temperature. Hyperparasite severity was higher when the minimum temperature was low (i.e. in places with cold night temperatures). While canopy cover did not have a direct effect on rust severity, it reduced rust severity indirectly by lowering the maximum temperature. Canopy cover had a direct positive effect on the hyperparasite severity during one surveying period.Synthesis and applications. Our findings highlight that coffee leaf rust and its hyperparasite are both affected by shade cover and temperature, but in different ways. On the one hand, these niche differences lead to the worrying prediction that levels of coffee leaf rust will increase, and its hyperparasite will decrease, with climate change. On the other hand, these niche differences between coffee leaf rust and its hyperparasite provide opportunities to develop strategies to manage the environment (such as shade cover and microclimate) in such a way that the rust is disfavoured and the hyperparasite is favoured. [ABSTRACT FROM AUTHOR]

Tryptophan synthase (TRPS) is a complex enzyme responsible for tryptophan biosynthesis. It occurs in bacteria, plants, and fungi as an αββα heterotetramer. Although encoded by independent genes in bacteria and plants, in fungi, TRPS is generated by a single gene that concurrently expresses the α and β entities, which are linked by an elongated peculiar segment. We conducted 1 µs all-atom molecular dynamics simulations on Hemileia vastatrix TRPS to address two questions: (i) the role of the linker segment and (ii) the comparative mode of action. Since there is not an experimental structure, we started our simulations with homology modeling. Based on the results, it seems that TRPS makes use of an already-existing tunnel that can spontaneously move the indole moiety from the α catalytic pocket to the β one. Such behavior was completely disrupted in the simulation without the linker. In light of these results and the αβ dimer's low stability, the full-working TRPS single genes might be the result of a particular evolution. Considering the significant losses that Hemileia vastatrix causes to coffee plantations, our next course of action will be to use the TRPS to look for substances that can block tryptophan production and therefore control the disease. [ABSTRACT FROM AUTHOR]

The coffee industry faces coffee leaf rust caused by Hemileia vastratix, which is considered the most devastating disease of the crop, as it reduces the photosynthetic rate and limits productivity. The use of plant resistance inducers, such as chitosan, is an alternative for the control of the disease by inducing the synthesis of phytoalexins, as well as the activation of resistance genes. Previously, the effect of chitosan from different sources and physicochemical properties was studied; however, its mechanisms of action have not been fully elucidated. In this work, the ability of food-grade high-density chitosan (0.01% and 0.05%) to control the infection caused by the pathogen was evaluated. Subsequently, the effect of high-density chitosan (0.05%) on the induction of pathogenesis-related gene expression (GLUC, POX, PAL, NPR1, and CAT), the enzymatic activity of pathogenesis-related proteins (GLUC, POX, SOD, PPO, and APX), and phytoalexin production were evaluated. The results showed that 0.05% chitosan increased the activity and gene expression of ß-1,3 glucanases and induced a differentiated response in enzymes related to the antioxidant system of plants. In addition, a correlation was observed between the activities of polyphenol oxidase and the production of phytoalexin, which allowed an effective defense response in coffee plants. [ABSTRACT FROM AUTHOR]

The aim of this work was to validate markers linked to the SH3 gene of coffee leaf rust (CLR) resistance and use them in assisted selection. Initially, we validated the markers in genotypes already known to carry SH3. Next, we performed phenotype and genotype evaluation for resistance to CLR in coffee plants growing under field conditions. We used Arabica coffee progenies derived from BA-10, which carries the SH3 gene due to introgression of C. liberica. Three SCAR markers (SP-M16-SH3, BA-48-21O-f, and BA-124-12K-f) and one SSR marker (Sat244) linked to SH3 gene were used to amplify the coffee plants' DNA. Our assessments of markers validation in resistant genotypes, SP-M16-SH3 and BA-124-12K-f, were efficient to identify the SH3 gene. These two markers were used to evaluate the progenies derived from BA-10 and were significantly linked to the phenotype evaluations. The SP-M16-SH3 marker was more efficient, with the advantage of being codominant. [ABSTRACT FROM AUTHOR]

Background: Coffee is an important plantation crop in Indonesia. The coffee cultivation process was disrupted due to the fungus Hemileia vastatrix which causes rust disease. Biological control has the potential to suppress disease development. The diversity of antagonistic fungi such as Trichoderma in nature is very abundant, so it is necessary to explore and find Trichoderma which has the potential as a biological agent in controlling coffee leaf rust. The research aimed to obtain antagonist fungi that have the potential as biological agents in controlling coffee leaf rust naturally in the coffee plant ecosystem. Result: Morphology of a local antagonist fungus isolate, coded TBK1, was identified as Trichoderma atroviride which had the potential to naturally control coffee leaf rust by H. vastatrix through a mycoparasitic mechanism. Conclusion: In the Dieng Plateau, Banjarnegara Indonesia, an antagonistic fungus as a biological agent, T. atroviride, was found to control H. vastatrix coffee leaf rust. [ABSTRACT FROM AUTHOR]

Coffee (Coffea spp.) is the second most significant commodity worldwide, with C. arabica being its most representative species. The coffee crop is affected by different fungal diseases that reduce the photosynthetically active area of its leaves and the production of grains. In order of agronomic importance, the rust caused by the biotrophic pathogen Hemileia vastatrix is a disease difficult to manage due to its type of reproduction. Another no less important, Thread Blight, caused by the basidiomycetes Ceratobasidium noxium (Syn. Corticium koleroga) and C. chavesanum, affects all aerial tissues of plants. The third disease, Cercospora leaf spot caused by Cercospora coffeicola, infects both leaves and grains, making it difficult to manage. Although there is enough scientific information on Rust, very little is known about the etiology, symptomatology, life cycle, and management of Thread Blight and Cercospora leaf spot. High-resolution photographs and micrographs were used and related with available scientific information. In addition, current scientific information on each disease was compiled, and with that, the life cycles were developed. Likewise, this manuscript describes the management of the three diseases based mainly on the use of genetic, cultural, physical, biological, and chemical measures and their integration as a sustainable alternative in the coffee agroecosystem. Current and future challenges in coffee include the evaluation of cultivars, genetic diversity of Ceratobasidium spp. and C. coffeicola, plant-pathogen interactions, and agroecological management practices. [ABSTRACT FROM AUTHOR]

Coffee production is negatively affected by coffee leaf rust, a disease caused by the fungus Hemileia vastatrix. As a natural product-based alternative to chemically control the disease, this study evaluated the effect of two chitosan-coated nanoemulsions prepared from Cymbopogon citratus essential oil (EO) and the thymol: pyruvic acid (1:1) natural deep eutectic solvent (NADES) on the in vitro germination of H. vastatrix urediospores and on the in vivo control of the disease in Coffea arabica plants under greenhouse conditions. Both nanoformulations inhibited urediospores in vitro germination but only that prepared with EO did it significantly more than its free form active ingredient (the observed reduction was around 60 %). On the other hand, the in vivo experiment showed that the EO and NADES chitosan-coated nanoemulsions offered similar and significant protection for Coffea arabica plants against leaf rust; the disease severity level was found to be less than 2.6 % after 81 days from the application of the treatments to the plants (comparable to the cooper oxychloride, which is one of the commercial fungicides traditionally used), while the free components did not (9.0–13.3 % of severity level by day 81, such as the control). This is the first report demonstrating that chitosan-coated nanoemulsions, containing NADES or EO, protect coffee plants against H. vastatrix infection and can be two alternatives for sustainable pest management. Furthermore, this study contributes to broadening the prospects for using hydrophobic NADES in the design of biopesticides. [Display omitted] • Natural deep eutectic solvents inhibit the germination of urediospores. • Lemongrass oil and a eutectic solvent were nanoemulsified and chitosan-coated. • Chitosan-coated nanoemulsions showed a slow release of monoterpene over 36 days. • Nanostructured systems protect coffee plants from rust under greenhouse conditions. [ABSTRACT FROM AUTHOR]

Endophyte microorganisms live in symbiosis inside of plant healthy tissues. These fungi help their hosts to tolerate pathogen affectation, pest damage, and to adapt to extreme conditions of salinity and temperatures. The coffee leaf rust, Hemileia vastatrix Berkeley & Broome, affects coffee crop, and its management is based on chemical fungicide application. In view of the world agriculture challenges, it is necessary to develop sustainable strategies. The endophytic fungi represent a potential for biological control of plant diseases. [ABSTRACT FROM AUTHOR]

Global climate change is increasing pest and pathogen pressures on plant communities, deteriorating optimal plant functioning. In plant communities, root functional trait expression and microbial communities are important indicators of plant functioning belowground, and, when confronted with pathogens aboveground, can simultaneously reflect plant defence strategies. Yet, while research is continuing to emerge on the response of root functional traits and microbial processes to pathogens aboveground, little work has investigated these interactions in tree‐crops, or the role organic amendments play in moderating these relationships. The main objective of this study is to disentangle the dynamic effects of pathogens and amendments on root functional traits (i.e. specific root length and area, root diameter, root length density, root nitrogen and root carbon to nitrogen ratio) and root endophytic fungal communities. As a model, we use Coffea arabica (coffee) variety Caturra along a gradient of coffee leaf rust – a foliar disease prominent in coffee systems – under contrasting but widespread amendment regimes in biodiverse agroforestry systems. We found that root trait expression varies along established conservation and collaboration gradients, where fungal endophyte community composition varies significantly as a function of root traits. Belowground resource acquisition strategies do not change with foliar disease incidence, suggesting they may be decoupled. Rather, amendment regimes differentially shape root trait expression and microbial communities, where coffee plants under organic amendments, regardless of foliar disease incidence, expressed greater acquisitive traits and enhanced collaboration with symbiotic fungi. This is an important first step in disentangling the dynamic inter‐relationships between plant traits, endophytes and pathogens, generating new questions on the role of amendments in sustainable pathogen management in biodiverse agroecosystems. [ABSTRACT FROM AUTHOR]

The development of disease resistant coffee cultivars is of paramount importance to increase grain yield and decrease production costs. The lack of information on how the new cultivars resist the attack of diseases and pests is a limiting factor in the selection of the best cultivars. Thus, the objective of the present work was to select superior genotypes of the Big Coffee VL group for resistance to Hemileia vastatrix and Cercospora coffeicola. The experiment consisted of 18 progenies pre-selected from a group of 100 genetic materials, for the trait of productivity. The experiment was carried out in a randomized block design, with six blocks and one plant per experimental plot, totaling 108 individuals. The selected coffee plants were evaluated for 10 months for injuries caused by coffee leaf rust and brown eye spot using commonly used diagrammatic scales. During the evaluated months, the genotypes G10, P32 and M22 were more tolerant to rust and brown eye spot. Thus, they are good candidates for genetic improvement programs with the objective of producing larger grains and adding resistance to the main diseases of arabica coffee. [ABSTRACT FROM AUTHOR]

The advancement of digital technology has made it possible to conceive automated Epidemiological Surveillance Systems (ESS) with a holistic-systemic approach allowing effective operation, management, and processing of phytosanitary data for fast decisionmaking applied to regional prevention and pest management. This surveillance type focuses on plant health, overcoming the reductionist pest vision of the conventional normative surveillance. An ESS implies the precise definition of the regional framework, objectives, pest(s) in widesense, human/financial resources, regulatory context, support research planning, operational structure, and innovation models. These elements determine the precision, frequency, and type of sampling and monitoring and the selection of variables related to a novel epidemiological system. In contrast to the normative surveillance, a systemic ESS has descriptive and risk forecasting capabilities, including early warnings, based on spatial and temporal analyses. A web-based ESS assures a flexible-dynamic generation of reports and automated analysis. An ESS operated on web platforms, emphasizing open source software and tools, can be hosted on generic or dedicated servers for metadata storage configured with Linux / Apache technologies with 24/7 (h day-1) functional capabilities. Open source tools include MySQL / MariaDB and other systems as database managers; PHP / Node.js, and JavaScript, Ajax, HTML5 and CSS as web design base 'back-end' and 'front-end' programs, respectively. This review focuses on principles, conceptual attributes, general methodological approaches, and objectives of web-based ESS. An overview is presented with an ESS developed in Mexico for coffee plantations (Coffea spp.), which allowed the surveillance of 19 pests, nine under quarantine status, through the generation, management, and analysis of 87.4 million climatic data and 15.7 million epidemiological records over 2013-2019. [ABSTRACT FROM AUTHOR]

In this perspective, we draw on recent scientific research on the coffee leaf rust (CLR) epidemic that severely impacted several countries across Latin America and the Caribbean over the last decade, to explore how the socioeconomic impacts from COVID-19 could lead to the reemergence of another rust epidemic. We describe how past CLR outbreaks have been linked to reduced crop care and investment in coffee farms, as evidenced in the years following the 2008 global financial crisis. We discuss relationships between CLR incidence, farmer-scale agricultural practices, and economic signals transferred through global and local effects. We contextualize how current COVID-19 impacts on labor, unemployment, stay-at-home orders, and international border policies could affect farmer investments in coffee plants and in turn create conditions favorable for future shocks. We conclude by arguing that COVID-19's socioeconomic disruptions are likely to drive the coffee industry into another severe production crisis. While this argument illustrates the vulnerabilities that come from a globalized coffee system, it also highlights the necessity of ensuring the well-being of all. By increasing investments in coffee institutions and paying smallholders more, we can create a fairer and healthier system that is more resilient to future socialecological shocks. [ABSTRACT FROM AUTHOR]

The degree of technification and the conditions for the production of coffee (Coffea arabica) in producing countries differ from one to another, although they share low prices for the grain in the market as a particular problem. The decrease in production aggravates losses, since coffee rust is the disease with the greatest economic importance. The aim of this study was to examine the traditional management of the coffee crop regarding the control of rust in small production units in the region of Tierradentro, department of Cauca, Colombia, as well as to identify the main problems in the design of lines of action to solve them. The methodology consisted in selecting production units, using an intentional or convenience collection of samples, with the application of semi-structured interviews, and the information was analyzed using descriptive statistics. The results obtained indicated that farmers continue using the traditional farming system and incorporate agronomic practices to increase yields and improve grain quality. Such practices include renovation of the coffee plantation with rust-resistant varieties, the use of fertilizers, soil analysis, planting under shade and cleaning the plantation. The main problem identified was the high cost of inputs and the low prices of coffee in the market. We therefore conclude that the traditional coffee plantation methods, along with the adoption of others agricultural practices, helped to modify the hierarchy of the problems by facing the importance of rust, since it allowed to control the incidence of the disease in the coffee plantations. [ABSTRACT FROM AUTHOR]

We report Hemileia strophanthi and H. wrightiae for the first time from Thailand. Both species produce spores acropetally on columnar sori, that develop from a few emergent hyphae passing through narrow host stoma. Hemileia strophanthi occurs on an unidentified apocynaceous tree in Khlong Lan National Park, Kamphaeng Phet Prov. Hemileia wrightiae occurs on Wrightia arborea（ Apocynaceae） in Phuket, Phuket Prov. Hemileia strophanthi has been recorded on two Strophanthus species in Indonesia in Asia and two other Strophanthus species in western and southeastern Africa. Hemileia wrightiae has been recorded on several Wrightia species in tropical and subtropical regions in Asia. [ABSTRACT FROM AUTHOR]

Coffee leaf rust is the main disease that causes significant losses in Coffea arabica. In Peru, this disease caused epidemics between 2008 and 2013 with production losses of 35 %. The objective was to identify H. vastatrix using a morphological and molecular approach based on a phylogenetic species concept. Coffee leaf samples with symptoms of chlorotic lesions with the presence of yellow uredospores at different severity stages of different cultivars were collected from 11 locations in the departments of Pasco and Junin during 2017-2018. DNA was purified as proposed by Cristancho and coworkers. The major subunit of ribosomal DNA was amplified with universal primers LR0R and LR5, and sequenced by Macrogen and deposited in GenBank. Sequences from the genera Achrotelium, Blastospora, Cystopsora, Hemileia, and Mikronegeria were included for phylogenetic analysis. The results showed that the rust was distributed in coffee growing regions of Pasco: Villa Rica (Catimor, Caturra, and Gran Colombia); Oxapampa (Yellow Caturra), and Junín: San Luis de Shuaro (Catimor), Chanchamayo (Catimor), San Ramón (Catimor), Vitoc (Caturra), Pichanaki (Caturra), Río Negro (Caturra), Pangoa (Yellow Caturra, Gran Colombia, Limani). It was also grouped into a single clade with isolated H. vastatrix from Mexico and Australia, suggesting that they come from a common ancestor. This is the first confirmed report using molecular barcoding of H. vastatrix in the central jungle of Peru. [ABSTRACT FROM AUTHOR]

Coffee is an important agricultural commodity in the world. However, it is susceptible to Hemileia vastatrix (Hv), an obligatory biotrophic fungus that causes coffee leaf rust (CLR). Natural resistance to rust has been identified in the wild species Coffea canephora and Coffea liberica. These species have been used in breeding programs where interspecific resistant hybrids have been generated. The SH3 gene, derived from C. liberica, has been shown to confer extreme and long-lasting resistance to Hv. A total of 167 accessions of the INIA’s Coffee Germplasm Collection of Peru (INIA-CGC) were screened with 4 markers linked to the SH3 gene. As positive controls, EA67 (C. liberica) and the hybrid S.288 (C. arabica x C. liberica) were used. Separation of PCR products was done by capillary electrophoresis, which allow to discriminate the alleles of each marker. For three markers, specific alleles for either C. arabica or C. liberica species were found. In all cases, S.288 exhibited specific alleles for both species; whereas the INIA-CGC accessions had exclusively C. arabica alleles and EA67 had C. liberica alleles. The BA-48-21O-f marker did not produce PCR fragments for any of the positive controls, suggesting that this marker is not as predictive as the other three to determine the presence of SH3. This work reports the existence of multiple alleles for the Sat244 marker; however, the collection does not have the SH3 mediated-resistance gene. Finally, the utility of capillary electrophoresis as a tool to identify alleles linked to SH3 was demonstrated. [ABSTRACT FROM AUTHOR]

During the Cold War, coffee became a strategically important crop in the global contest between the United States and the Soviet Union. The economies of many US allies in Latin America depended upon coffee. In the Cold War context, then, the coffee leaf rust (Hemileia vastatrix) became a geopolitical problem. Coffee experts in Latin America, which produced most of the world's coffee, began to prepare for an outbreak. In the 1950s, they built a global network of coffee experts. This network was sustained by US-led Cold War programs that promoted technical collaboration across the Global South, such as Harry Truman's Point Four programs. We explore the network's growth and evolution through one of its central figures, the American plant pathologist Frederick L. Wellman. This network has survived the end of the Cold War and evolved to reflect the new geopolitical context. [ABSTRACT FROM AUTHOR]

Crop health management systems can be designed according to practices that help to reduce crop losses by restricting pathogen development and promoting host plant growth. A good understanding of pathogen and host dynamics, which are interdependent, is therefore needed. In this article, we used a holistic approach to explain the behavior of coffee leaf rust (CLR), a major coffee disease. We monitored coffee plant and CLR dynamics simultaneously in plots under different disease management and agroforestry systems. Diseased leaves were also collected to characterize inoculum stock and rust life stages (latent rust area, area with uredospores, necrosis due to rust) through picture analysis. We used structural equation modeling to obtain an overview of CLR pathosystem functioning on a plant scale. This overview integrates processes such as disease dilution by host leaf renewal, direct and indirect effects of fruit load on CLR development, antagonistic effects of shading depending on rust life stages, the tonic effect of copper-based fungicides on leaf retention, and effects on rust life stages depending on fungicide types. From our results, we also deduced that the inoculum stock could be calculated in unsprayed plots from the rust area with uredospores, with uredospores at 58 × 10³ cm-2, on average. [ABSTRACT FROM AUTHOR]

Shade effects on coffee diseases are ambiguous because they vary depending on the season and environment. Using Coffee Leaf Rust (CLR) as an example, we demonstrate relationships between the environment and shading systems and their effects on disease intensity. We characterized seasonal variations in microclimate and CLR incidence across different altitudes and shading systems, and integrated effects between the environment, shading systems, microclimate and CLR into a piecewise structural equation model. The diurnal temperature range was higher in unshaded systems, but differences decreased with altitude. Humidity related indicators in shaded systems decreased with altitude. At mid and high altitudes, high CLR incidence occurred in the shading system showing a low diurnal temperature range and a high dew point temperature. Our study demonstrates how microclimatic indicators vary as a function of the season, altitude and the coffee shading system, and how this in turn is related to CLR. [ABSTRACT FROM AUTHOR]

Coffee leaf rust (CLR), caused by the fungal pathogen Hemileia vastatrix, has plagued coffee production worldwide for over 150 years. Hemileia vastatrix produces urediniospores, teliospores, and the sexual basidiospores. Infection of coffee by basidiospores of H. vastatrix has never been reported and thus far, no alternate host, capable of supporting an aecial stage in the disease cycle, has been found. Due to this, some argue that an alternate host of H. vastatrix does not exist. Yet, to date, the plant pathology community has been puzzled by the ability of H. vastatrix to overcome resistance in coffee cultivars despite the apparent lack of sexual reproduction and an aecidial stage. The purpose of this study was to introduce a new method to search for the alternate host(s) of H. vastatrix. To do this, we present the novel hypothetical alternate host ranking (HAHR) method and an automated text mining (ATM) procedure, utilizing comprehensive biogeographical botanical data from the designated sites of interests (Ethiopia, Kenya and Sri Lanka) and plant pathology insights. With the HAHR/ATM methods, we produced prioritized lists of potential alternate hosts plant of coffee leaf rust. This is a first attempt to seek out an alternate plant host of a pathogenic fungus in this manner. The HAHR method showed the highest‐ranking probable alternate host as Psychotria mahonii, Rubus apetalus, and Rhamnus prinoides. The cross‐referenced results by the two methods suggest that plant genera of interest are Croton, Euphorbia, and Rubus. The HAHR and ATM methods may also be applied to other plant–rust interactions that include an unknown alternate host or any other biological system, which rely on data mining of published data. [ABSTRACT FROM AUTHOR]

The use of resistance inducers is a promising development in the management of plant diseases, owing to their ability to control a broad spectrum of pathogens and improve the efficacy of fungicides. This study evaluates different sources of phosphonates (potassium, manganese, copper), a formulation prepared from the by‐products of the coffee industry (Greenforce CuCa), as well as the effects of their application, alone or in association with fungicide, in the management of two important coffee fungal diseases in Brazil: leaf rust and brown eye spot, caused by Hemileia vastatrix and Cercospora coffeicola, respectively. The effect of these products on defoliation, productivity and chemical composition of coffee beans (content of trigonelline, chlorogenic acid, caffeine and total soluble solids) was evaluated. Among all the alternative products tested individually, potassium phosphonate (P2O5—33.6% + K2O—29%) stood out, particularly for rust control, which was similar to the results of fungicide treatments. Treatments with fungicide, Greenforce CuCa and cuprous oxide, individually, caused less plant defoliation. Regarding the chemical composition of the coffee beans, the manganese phosphonate treatment showed the highest values for trigonelline, chlorogenic acid, caffeine and total soluble solid content. The results of this study show that resistance inducers can be useful in disease management, may come to eventually replace traditional fungicides and can also contribute to the beverage quality. [ABSTRACT FROM AUTHOR]

The coffee rust is a devastating disease that causes large economic losses across the world. The severity of this disease changes over time so the farmers are not fully aware of the economic importance of the rust disease in the coffee crops. From a computational science perspective, several investigations have been proposed to decrease the effects caused by the coffee rust appearance from Expert systems based on machine learning techniques. However, because samples about coffee rust incidence are few, the rules created from machine learning techniques do not contain enough information to consider the diversity of scenarios for detecting coffee rust. This paper proposes an expert system based on rules, where the rules are created considering the expert knowledge of specialists and technical reports about the behavior of the disease during a crop year. As far as we know, this is the first expert system proposed using not only expert knowledge but also technical reports in the coffee rust problem. The Buchanan methodology is used to design the proposed system. Experiment results present an average accuracy of 66,67% to detect a correct warning of coffee rust levels. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • New nickel(II) complexes with N -R-sulfonyldithiocarbimate and phosphines are described. • Their structures were investigated by X-ray diffraction, IR, NMR and UV–Vis spectroscopies. • The complexes with PPh 3 present intramolecular anagostic interactions of the type Ni H C. • The complexes inhibit the germination of Hemileia vastatrix and Phakopsora pachyrhizi at low doses. • The best results were achieved when the phosphine is PPh 3 and with R = butyl and 4-isopropylphenyl. Abstract Nickel(II) complexes of general formula [Ni(RSO 2 N = CS 2)(PPh 3) 2 ] (2a – h) or [Ni(RSO 2 N = CS 2)dppe] (3a – h), where R = methyl (a), ethyl (b), butyl (c), octyl (d), phenyl (e), 4-isopropylphenyl (f) , 4- tert -butylphenyl (g) , 2-naphthyl (h), PPh 3 = triphenylphosphine and dppe = 1,2-bis(diphenylphosphine)ethane were prepared, from which six are new substances (2f – h and 3f – h). The new compounds were characterized by elemental analysis of C, H, N and Ni, and by IR, UV–Vis and 1H, 13C and 31P NMR spectroscopies. The data were consistent with the formation of square planar nickel(II) complexes with mixed ligands, what was confirmed by single crystal X-ray diffraction studies on compounds 2f and 2h. These complexes present intramolecular Ni H C anagostic interactions. All complexes inhibited the germination of Hemileia vastatrix and Phakopsora pachyrhizi , the causal agents of devastating diseases on soybean and coffee cultures. The most active compounds presented IC 90 values as low as 405 µM against H. vastatrix , and 280 μM against P. pachyrhizi. Thus, the title compounds are target molecules for the development of new agrochemicals against the Asian soybean rust and Coffee leaf-rust diseases. [ABSTRACT FROM AUTHOR]

Occurrence and intensity coffee leaf rust (Hemileia vastatrix) depend mainly on the irrigation system, soil fertility and plant nutrition. The aim of this study was to evaluate the spatial distribution of coffee leaf rust relative to soil fertility and plant nutrition in coffee plantations irrigated by drip and center pivot using geostatistics. The experiment was installed in two experimental areas, with a drip and center pivot irrigation system of 11 and 17 ha and 52 and 50 georeferenced sampling points, respectively. The incidence of the disease, soil fertility and plant nutritional status were evaluated at each point. For the drip system, there was no significant correlation between disease incidence and leaf contents of N, P, K, and Ca. Regarding fertility, there was a positive correlation only for P and the disease incidence. For the center pivot system, there was a positive correlation between coffee leaf rust and Ca, P, and K, and negative for P and K in the leaves, varying according to the assessment date. In soil, only Ca correlated negatively whereas K positively correlated with incidence. The spatial distribution of the disease and nutrients varied over the years, being observed a gradient from foci in the kriging maps elaborated after the adjustment of the exponential model. [ABSTRACT FROM AUTHOR]

Coffee (Coffea arabica L.) is one of the most important agricultural products in the world, since more than 56 countries are dedicated to its cultivation and it is the main agricultural commodity since the period 1962-1989 and coffee orange rust (Hemileia vastatrix Berkeley & Broome) is the most devastating disease for this crop. In Central America, the losses caused by this pathogen were up to 50% in the 2011-2012 production cycle. Coffee production in the state of Veracruz decreased by 8% since 2011 due to rust infestations, consequently research has been carried out on beneficial microorganisms that provide tolerance to the pathogen, whose obtaining and application does not represent a risk of deterioration of the soil resource. Therefore, the endomycorrhizal meet these requirements, however it is necessary to know the diversity and conditions of association with the agricultural species of interest so that the management is effective. The objective was to characterize endomycorrhic populations present in coffee plants (C. arabica L.) Typica variety with and without signs of rust infection in Ixhuatlán del café, Veracruz. We identified 37 species that correspond to 14 genera of endomycorrhizal, being the most common Acaulospora and Rhizophagus, the latter being the most frequent in plants without signs of rust infection. A higher percentage of root colonization and spore density was also found in plants without signs of infection (7.70% and 661.68 spores / 100 g of soil, respectively) but the Shannon (H) diversity index and the Simpson (D) does not indicate that the endomycorrhizal populations found are diverse. These results show that the plants that interact in symbiosis with mycorrhiza are able to tolerate better the biotic and abiotic stress, besides the prevalence of certain endomycorrhizal genera in coffee plants with particular physiological characteristics gives a guideline to deepen the study of the established differential symbiosis between plants and microorganisms. [ABSTRACT FROM AUTHOR]

Brazil is the major coffee producer in the world, with 2 million hectares cropped, with 75% of this area with Coffea arabica and 25% with Coffea canephora. Coffee leaf rust (CLR) is one of the main diseases that cause yield losses by reducing healthy leaf area. As CLR is highly influenced by weather conditions, this study aimed to determine the best linearization model to estimate the CLR apparent infection rate, to correlate CLR infection rates with weather variables, and to develop and assess the performance of weather-based infection rate models to be used as a disease warning system. The CLR epidemic was analyzed for 88 site-seasons, while progress curves were assessed by linear, monomolecular, logistic, Gompertz, and exponential linearization models for apparent infection rate determination. Correlations between CLR infection rates and weather variables were conducted at different periods. From these correlations, multiple linear regressions were developed to estimate CLR infection rates, using the most weather-correlated variables. The Gompertz growth model had the best fit with CLR progress curves. Minimum temperature and relative humidity were the weather variables most correlated to infection rate and, therefore, chosen to compose a CLR forecast system. Among the models developed, the one for the condition of high coffee yield at a narrow row spacing was the best, with only 9.4% of false negative occurrences for all the months assessed. [ABSTRACT FROM AUTHOR]

Cultivar IAC Obatã 4739 was derived from a cross between coffee tree IAC 1669-20-1 and cultivar Catuaí Amarelo IAC 62. It is short and high-yielding, rust-resistant, has large and yellow fruits, medium to late maturation, excellent cup quality, and responds effectively to irrigation. [ABSTRACT FROM AUTHOR]

Summary: Coffee leaf rust, caused by Hemileia vastatrix (Hv), represents the biggest threat to coffee production worldwide and ranks amongst the most serious fungal diseases in history. Despite a recent series of outbreaks and emergence of hypervirulent strains, the population evolutionary history and potential of this pathogen remain poorly understood. To address this issue, we used restriction site‐associated DNA sequencing (RADseq) to generate ∼19 000 single nucleotide polymorphisms (SNPs) across a worldwide collection of 37 Hv samples. Contrary to the long‐standing idea that Hv represents a genetically unstructured and cosmopolitan species, our results reveal the existence of a cryptic species complex with marked host tropism. Using phylogenetic and pathological data, we show that one of these lineages (C3) infects almost exclusively the most economically valuable coffee species (tetraploids that include Coffea arabica and interspecific hybrids), whereas the other lineages (C1 and C2) are severely maladapted to these hosts, but successfully infect diploid coffee species. Population dynamic analyses suggest that the C3 group may be a recent ‘domesticated’ lineage that emerged via host shift from diploid coffee hosts. We also found evidence of recombination occurring within this group, which could explain the high pace of pathotype emergence despite the low genetic variation. Moreover, genomic footprints of introgression between the C3 and C2 groups were discovered and raise the possibility that virulence factors may be quickly exchanged between groups with different pathogenic abilities. This work advances our understanding of the evolutionary strategies used by plant pathogens in agro‐ecosystems with direct and far‐reaching implications for disease control. [ABSTRACT FROM AUTHOR]

IAC 125 RN was derived from a cross between the coffee cultivar Villa Sarchí and the Hibrido de Timor CIFC 832/2. The coffee trees are short and resistant to races 1 and 2 of the nematode Meloidogyne exigua and to all races of coffee rust, Hemileia vastatrix, present in Brazil. Brazil. [ABSTRACT FROM AUTHOR]

Coffee leaf rust (CLR) caused by the fungus Hemileia vastarix is a devastating disease in almost all coffee producing countries and remote sensing approaches have the potential to monitor the disease. This study evaluated the potential of Sentinel-2 band settings for discriminating CLR infection levels at leaf levels. Field spectra were resampled to the band settings of the Sentinel-2, and evaluated using the random forest (RF) and partial least squares discriminant analysis (PLS-DA) algorithms with and without variable optimization. Using all variables, Sentinel-2 Multispectral Imager (MSI)-derived vegetation indices achieved higher overall accuracy of 76.2% when compared to 69.8% obtained using raw spectral bands. Using the RF out- of- bag (OOB) scores, 4 spectral bands and 7 vegetation indices were identified as important variables in CLR discrimination. Using the PLS-DA Variable Importance in Projection (VIP) score, 3 Sentinel-2 spectral bands (B4, B6 and B5) and 5 vegetation indices were found to be important variables. Use of the identified variables improved the CLR discrimination accuracies to 79.4 and 82.5% for spectral bands and indices respectively when discriminated with the RF. Discrimination accuracy slightly increased through variable optimization for PLS-DA using spectral bands (63.5%) and vegetation indices (71.4%). Overall, this study showed the potential of the Sentinel 2 MSI band settings for CLR discrimination as part of crop condition assessment. Nevertheless further studies are required under field conditions. [ABSTRACT FROM AUTHOR]

Taxonomy and History Hemileia vastatrix Berk. and Broome (Basidiomycota, Pucciniales) was described in 1869 in eastern Africa and Ceylon as the agent of coffee leaf rust and has spread to all coffee cultivation areas worldwide. Major disease outbreaks in Asia, Africa and America caused and continue to cause severe yield losses, making this the most important disease of Arabica coffee, a cash crop for many tropical and sub-tropical countries. Life cycle and Disease symptoms Hemileia vastatrix is a hemicyclic fungus with the urediniosporic life cycle as its most important (if not only) source of inoculum. Chlorotic spots are the first macroscopic symptoms, preceding the differentiation of suprastomatal, bouquet-shaped, orange-coloured uredinia. The disease can cause yield losses of up to 35% and have a polyetic epidemiological impact on subsequent years. Disease control Although the use of fungicides is one of the preferred immediate control measures, the use of resistant cultivars is considered to be the most effective and durable disease control strategy. The discovery of 'Híbrido de Timor' provided sources of resistance that have been used in several breeding programmes and that have been proven to be effective and durable, as some have been in use for more than 30 years. Genetic diversity and Molecular pathogenicity Although exhibiting limited genetic polymorphism, the very large genome of H. vastatrix ( c. 797 Mbp) conceals great pathological diversity, with more than 50 physiological races. Gene expression studies have revealed a very precocious activation of signalling pathways and production of putative effectors, suggesting that the plant-fungus dialogue starts as early as at the germ tube stage, and have provided clues for the identification of avr genes. [ABSTRACT FROM AUTHOR]

Coffee leaf rust caused by the fungus Hemileia vastatrix (Berk and Br.) is a major disease occurring in coffee plantations. Although the rust fungus exists in different physiological races, the genetic difference between them is meagrely understood. In this study, genetic diversity of 14 identified and two unidentified leaf rust races was determined by sequence-related amplified polymorphism ( SRAP) markers. Of 48 SRAP primer pairs tested, 35 primers are polymorphic and generated 347 distinct scorable fragments. The number of fragments ranged from 4 to 18 with a mean of 9.97 fragments per primer combination. Of the total 347 amplified fragments, 185 fragments (53.31%) are polymorphic with an average of 5.41 fragments per primer combination. The average resolving power (Rp) and the average polymorphism information content ( PIC) of the 35 SRAP primer combinations were 13.60 and 0.356, respectively. Of 35 SRAP primer pairs, 15 primer pairs were more informative and generated 25 unique fragments, which are useful for race discrimination. The study demonstrated the existence of genetic variability among various leaf rust races and this information will be helpful in coffee breeding programmes. [ABSTRACT FROM AUTHOR]

The Pucciniomycete fungus Hemileia vastatrix causes leaf rust on coffee trees. The pathogen is responsible for considerable yield losses in susceptible coffee cultivars if appropriate management strategies are not implemented. Rapid spread and epidemics of rust fungi are usually associated with the emergence of new races of the pathogen that overcome resistance or with the emergence of more aggressive populations of the pathogen. In Brazil, coffee production is dominated by susceptible cultivars of Coffea arabica and Coffea canephora. We assessed aggressiveness in 46 populations of H. vastatrix from Minas Gerais and Espírito Santo, two of the most important coffee-producing states in Brazil. We observed a significant difference in the incubation period between the populations from Minas Gerais and Espírito Santo when 183 single-pustule isolates were inoculated onto Catuaí Vermelho IAC 44, a susceptible C. arabica cultivar. Variation in aggressiveness components was observed between and within localities. Isolates with longer incubation periods also tended to have longer latent periods, although there was only a low correlation between these two aggressiveness components ( r2 = 0.34, P = 2.2 × 10−16). Low-sporulating isolates also had significantly longer incubation and latent periods. The H. vastatrix population from Minas Gerais and Espírito Santo is structured by the formation of groups of individuals with differential level of aggressiveness. Our results indicate that the variation in aggressiveness of the Brazilian H. vastatrix population may be associated with the geographic coffee-producing areas. [ABSTRACT FROM AUTHOR]

•A number of genes that confer resistance to coffee leaf rust (SH1-SH9) have been identified within the genus Coffea, but despite many years of research on this pathosystem, the complementary avirulence genes of Hemileia vastatrix have not been reported. • After identification of H. vastatrix effector candidate genes (HvECs) expressed at different stages of its lifecycle, we established an assay to characterize HvEC proteins by delivering them into coffee cells via the type-three secretion system (T3SS) of Pseudomonas syringae pv. garcae (Psgc). • Employing a calmodulin-dependent adenylate cyclase assay, we demonstrate that Psgc recognizes a heterologous P. syringae T3SS secretion signal which enables us to translocate HvECs into the cytoplasm of coffee cells. Using this Psgc-adapted effector detector vector (EDV) system, we found that HvEC-016 suppresses the growth of Psgc on coffee genotypes with the SH1 resistance gene. Suppression of bacterial blight symptoms in SH1 plants was associated with reduced bacterial multiplication. By contrast, HvEC-016 enhanced bacterial multiplication in SH1-lacking plants. • Our findings suggest that HvEC-016 may be recognized by the plant immune system in a SH1-dependent manner. Thus, our experimental approach is an effective tool for the characterization of effector/avirulence proteins of this important pathogen. [ABSTRACT FROM AUTHOR]

Selecting superior genotypes is facilitated by marker-assisted selection (MAS), which is particularly suitable for transferring disease resistance alleles because it nullifies environmental effects and allows selection of resistant individuals in the absence of the pathogen or race, enabling preventive breeding. Molecular markers linked to two major genes (S3 and S?), conferring resistance to coffee rust, and those linked to the Ck-1 gene, conferring resistance to coffee berry disease (CBD), have previously been identified. These markers were validated and used in a progeny of crosses between Indian selections with Coffea arabica cultivars. Eleven resistant individuals homozygous for S3 were identified by MAS. Of these, seven carry S? from Híbrido de Timor and the gene introduced from Coffea liberica (S3). S? was characterized as derived from Coffea canephora. Thus, it was possible to identify C. arabica genotypes carrying important genes for rust resistance introgressed from other coffee species. MAS also allowed identification of sources of CBD resistance for use in preventive breeding for resistance to this serious disease. Using two validated molecular markers, two coffee plants carrying Ck-1 were identified: the UFV 328-60 genotype (F) was resistant and homozygous based on both molecular markers but exhibited no markers related to S3 and S?, and the UFV 317-12 genotype (F) was resistant and homozygous but resistant and heterozygous based on CBD-Sat207 and CBD-Sat235, respectively. Along with possessing Ck-1, the latter carries S?. Overall, plants carrying different genes for resistance to rust and CBD were identified. These plants are important sources for gene pyramiding in breeding programs aimed at multiple and durable resistance. [ABSTRACT FROM AUTHOR]

Phosphites (Phi) are inorganic salts of phosphorous acid that have been used as resistance elicitors to activate mechanisms underlying plant defence. This study assessed the effectiveness of manganese phosphite (MnPhi) for the management of rust ( Hemileia vastatrix) on coffee seedlings. The effect of this compound on the induction of resistance was also measured by the expression of defence-related genes such as POX (peroxidase) , CAT (catalase) , GLU ( β-1.3-glucanase) and PAL (phenylalanine ammonia-lyase) and by the activity of defence enzymes such as ascorbate peroxidase ( APX), superoxide dismutase ( SOD) and polyphenol oxidase ( PPO). Foliar sprayings of MnPhi on coffee seedlings provided 63% control of rust severity. This compound induced defence responses in seedlings with increased transcription of genes POX, CAT, GLU and PAL in non-inoculated plants and increased activity of APX, SOD and PPO enzymes in plants inoculated with H. vastatrix and in non-inoculated plants. It is suggested that MnPhi can induce resistance in coffee seedlings. [ABSTRACT FROM AUTHOR]

Hemileia vastatrix caused a severe epidemic in Central America in 2012-13. The gradual development of that epidemic on nearly a continental scale suggests that dispersal at different scales played a significant role. Shade has been proposed as a way of reducing uredospore dispersal. The effect of shade (two strata: Erythrina poeppigiana below and Chloroleucon eurycyclum above) and full sun on H. vastatrix dispersal was studied with Burkard traps in relation to meteorological records. Annual and daily patterns of dispersal were observed, with peaks of uredospore capture obtained during wet seasons and in the early afternoon. A maximum of 464 uredospores in 1 day (in 14.4 m ³ of air) was recorded in October 2014. Interactions between shade/full sun and meteorological conditions were found. Rainfall, possibly intercepted by tree cover and redistributed by raindrops of higher kinetic energy, was the main driver of uredospore dispersal under shade. Wind gusts reversed this effect, probably by inhibiting water accumulation on leaves. Wind gusts also promoted dispersal under dry conditions in full sun, whereas they had no effect under shaded conditions, probably because the canopy blocked the wind. Our results indicate the importance of managing shade cover differentially in rainy versus dry periods to control the dispersal of airborne H. vastatrix uredospores. [ABSTRACT FROM AUTHOR]

Melampsora larici-populina(Mlp) is a parasitic fungus causing poplar leaf rust, a disease that threatens poplar plantations worldwide. Like other phytopathogens,Mlptranslocates specialized proteins, called effectors, into host tissues and cells to eventually divert host resources. 124202 is a hypotheticalMlpeffector selected through anin silicosecretome analysis. It shares about 30% identity with theM. liniAvrM effector. Using heterologous systems, the objectives of this work were to assess if 124202 could mitigateArabidopsisdefence or potentiatePseudomonasvirulence and investigate its putative interaction partners in plants. Yeast two-hybrid screens identified three potential 124202 interactors in plants: lipoxygenase 2, synaptotagmin A and quinolinate synthase. Expression of a fluorescently tagged 124202 protein inNicotiana benthamianaandArabidopsis thalianashowed that it could be associated with membranes but may also be found in the cytoplasm of host cells. Bacterial infection assays in wild-type and 124202-expressingArabidopsislines indicate that 124202 does not alter the susceptibility ofArabidopsistoPseudomonas syringaepv.tomatoDC3000. Overall, our results suggest that the function of 124202 might involve vesicle-mediated trafficking but is unlikely to quantifiably contribute to the suppression of plant immunity. [ABSTRACT FROM AUTHOR]

Brazilian arabica coffee production is based on a set of highly productive cultivars sexually propagated. All of them are susceptible to coffee leaf miner, Leucoptera coffeella, and most of them are also susceptible to coffee leaf rust, Hemileia vastatrix. Aiming to reduce the selection process of cultivars with multiple resistances to both biotic constraints, the Coffea arabica clones 760, 1059, 1064 and 1215 were evaluated under field conditions. The mean yield of four C. arabica clones was not statistically different from the experimental controls; however, the yield of clone 1059 was 21% higher than the control cultivar Obatã IAC 1669-20. Leaf miner resistance level in all the evaluated clones remained the same as the mother plant's. However, the same did not occur for resistance to H. vastatrix, due to the emergence of new pathogen races. In summary, it is potentially feasible the adoption of clone 1059 as a new clonal cultivar resistant to coffee leaf miner. [ABSTRACT FROM AUTHOR]

Coffee production is affected by coffee leaf rust, a plant disease caused by Hemileia vastatrix Berk. et Br. As an alternative for the chemical control of this pathogen, we evaluated the effect of three hydrophobic deep eutectic solvents (HDES) of menthol:pyruvic acid (M:PA), thymol:pyruvic acid (T:PA) and thymol:menthol (T:M) on the urediospore germination of H. vastatrix collected in Teocelo, Ver. Méx. When HDES were characterized by IR spectroscopy, hydrogen bonds were observed between the components. When the effect on urediospores was evaluated, significantly lower germination was observed with the four concentrations considered (2, 1.5, 1, and 0.1 mg/mL) for the three HDES with respect to the negative control (p = 0.0001), except with T:M at 1 mg/mL. The most active HDES at the lowest concentration was T:AP at 1 mg/mL, with an effect comparable to the observed with copper oxychloride at 5 mg/mL (positive control, commercial fungicide). Thus, these HDES can be considered as a potential alternative for the chemical control of coffee leaf rust. [ABSTRACT FROM AUTHOR]