Clone BRS Research Articles

Sensory description of beverages of intervarietal hybrids of Conilon and Robusta: Natural and fermented coffees

AbstractThis study describes the sensory profile of beverages of Coffea canephora hybrids (clones BRS 2314 and BRS 2357) in natural (N) and fermented (F) versions. Flash Profile and Temporal Dominance of Sensations were performed; physicochemical characteristics were evaluated. Increase in total titratable acidity and reduction in pH was observed with fermentation. BRS 2314 beverages had higher contents of 5‐caffeoylquinic acid and caffeine. Natural coffees were described as having brown/coffee color, coffee aroma and flavor, roasted aroma and flavor, sweet aroma, and sour taste, and presenting dominance of coffee and tobacco flavors, and bitter and sour tastes. Fermented coffees were described as full‐bodied and having non‐characteristic, fermented and herbal aromas, astringent sensation, bitter taste and bitter aftertaste, and residual flavors, with the dominance of chocolate, fermented and roasted flavors, and bitter taste. BRS 2357 beverages were characterized by bitter taste and bitter aftertaste. BRS 2314N beverage presented attributes considered positive for quality.Practical ApplicationsThe results are relevant for the coffee production chain and consumers. Intervarietal hybrids of Conilon and Robusta are grown in an area characterized by family farming and with great prospects for sustainable production (in the Rondônia/BR state, Western Amazon) and are developed to express the best characteristics of both botanical varieties, as the high potential of Robusta coffees for fine cup beverages. The hybrid clones were successfully evaluated by experts, but the results do not necessarily correspond to the consumers' insights into coffee brew quality. In addition, fermentation allows to produce beverages with different nuances. The joint use of quick methodologies for static (Flash Profile) and temporal (Temporal Dominance of Sensations) sensory descriptions provided a closer representation of the consumers' perception of those products. This information brings new market perspectives for high‐yield Coffea canephora coffees that are now going through a moment of breaking paradigms regarding quality.

Beverage quality of Coffea canephora genotypes in the western Amazon, Brazil

This study aimed to evaluate the beverage quality of Coffea canephora genotypes in different environments of the western Amazon to assist plant selection and new cultivar development. To analyze beverage quality, samples of cherry coffee beans were collected separately for each genotype from clonal competition trials installed in the municipalities of Ouro Preto do Oeste, Alta Floresta do Oeste, Porto Velho, and Ariquemes in Rondônia State and Rio Branco in Acre State (Brazil). The beverage quality was assessed using the Robusta Cupping Protocol, which attribute to each genotype a score in a range from 0 to 100, highlighting nuances. Analysis of variance and principal components using reference points were used to quantify genotype x environment interaction (G x E). The analysis of variance indicated that genotypic and G x E interaction effects were significant (p < 0.01). By using a centroid dispersion method, we could identify four clones of low, eight of specific (to favorable or unfavorable environments), and seven of broad adaptability to the environments. The clones BRS 2314, 11, and 17 had average quality scores above 80 in all environments, with potential for specialty coffee production. The clones BRS 1216, BRS 3220, and BRS 3193 presented unstable behavior, with beans of higher quality in some of the evaluated environments. Such inconsistency in clone behavior is caused by unpredictable changes in plant performance in different environments. Our results indicate that both genotypic (clones) and G x E interaction effects are important for the expression of coffee beverage quality. However, the clones BRS 3213, BRS 3210, and BRS 2299 had less prominent nuances, with lower potential for specialty coffee production.

Reaction of Sweet Cassava Genotypes to Xanthomonas phaseoli pv. manihotis From Three Regions of Brazil

Xanthomonas phaseoli pv. manihotis (Xpm) is the causal agent of Cassava Bacterial Blight (CBB), one of the most important cassava diseases. The aim of this study was to evaluate the susceptibility of sweet cassava genotypes to strains of Xpm from three different geographic regions of Brazil in greenhouse conditions. The inoculation of 14 genotypes of cassava was made by cutting leaflets using scissors previously soaked in a bacterial suspension with 1 × 108 UFC ml-1 and also by inserting a soaked toothpick into the bud of the oldest leaf. The results showed significant differences when the cassava genotypes were individually evaluated in relation to the Xpm strains used; however, the relationship between cassava genotypes and Xpm strains was significant for wilt symptom. The UnB 1111 strain was more aggressive than the UnB 1386 strain based on the average value of the reaction grade, showing the variation that exists between the bacterial isolates from different regions. Considering the reaction of cassava germplasm’s resistance to the three strains used in the study, the BGMC 434 genotype was the only one classified as resistant based on the average reaction grade. The genotypes BGMC 753, BGMC 1289, BGMC 982 and the elite clones BRS 396, BRS 397, BRS 398, 259/08 and BRS 399 were classified as moderately resistant, which indicates the possibility of recommending them for disease favorable regions.

HYDROPHILIC POLYMER CHANGES THE WATER DEMAND IN THE IMPLEMENTATION OF A DWARF CASHEW ORCHARD

Abstract: Important losses of dwarf cashew seedlings during the establishment of orchards in the Brazilian semiarid are related to the relatively short rainy season. This study aimed to evaluate biochar and hydrophilic polymer as soil amendments to increase water retention and reduce plant death in the first year. An experiment was conducted at the Curu Station, Paraipaba, CE, Brazil, using the clone BRS 226. The experimental design consisted of randomized blocks, with amounts of 0.5, 1.0, 2.0, and 4.0 kg of cashew wood biochar and 20, 40, 60, 80 g of hydrophilic polymer applied per pit, as well as a control treatment (no soil amendment). Seedlings were submitted to an irrigation regime to avoid water stress (5 L water seedling-1 when the tensiometer installed at a depth of 0.15 m reached 60 kPa). The variables of plant development number of leaves, plant height, stem diameter, and canopy diameter were evaluated up to 374 days after transplanting to the field. The analysis of variance showed no treatment effect on plant development. However, minimum water consumption was observed when 29.56 g of hydrophilic polymer was applied per pit, providing 100.0% seedling survival.

Sampling of cashew nuts from cashew tree clones

Abstract The aim of this work was to estimate sample sizes to assist the genetic improvement of the cashew tree (Anacardium occidentale L.). Stratified sampling, comprising five strata (S5, S4, S3, S2, and S1) of five cashew clones (BRS 274, BRS 275, BRS 226, BRS 189 and CCP 76), was effective for estimating the different sample sizes of the nut. Sample size for each clone depends on the weight-nut variance, the margin of error B permitted in the estimates and the desired precision of the results. The increases in sample size with clone variance, lowered the permitted margin of error B, and increased the desired precision of the results. These clones required different sample sizes for a morphological study of the nuts. Larger nuts require larger samples for the same margin of error B. For an error B of 0.2g, the sample size for clones S5, S4 and S3 were n5 = 84, n4 = 49 and n3 = 37 nuts. For clones BRS 274 (S5) and BRS 275 (S4), with better nut classification, the mean weights were respectively 16.79 and 12.78g. Clones BRS 189 (S2) and CCP 76 (S1), with smaller nuts, have a smaller variances, s22 = 0.7638 and s12 = 1.0712, where the mean weight was 8.29 and 7.81g respectively.

Reaction of commercial clones of cashew to powdery mildew in northeastern Brazil

Cashew powdery mildew, caused by Erysiphe quercicola, is one of the main disease problems of cashew trees in Brazil. Thus, research to study the reaction of commercial cashew clones under different epidemiological stages of the disease is very important for identifying resistant clones. The objective of this research was to evaluate the reaction of commercial clones of cashew to powdery mildew by monitoring the disease during three disease cycles. The study was carried out at Embrapa Agroindústria Tropical, Pacajus Experimental Field, Ceará, Brazil, during 2012, 2013 and 2014 using eleven commercial clones of cashew (CCP 09, CCP 76, CCP 100, CCP 06, EMBRAPA 51, EMBRAPA 50, BRS 265, BRS 189, BRS 274, BRS 275 and BRS 226). Powdery mildew severity on inflorescences was estimated using a descriptive scale of severity consisting of scores ranging from 0 to 4. The transformed data were used to estimate the area under the disease progression curve (AUDPC) and the rate of infection. Based on similarities in disease severity estimates with time, clones were clustered using multivariate clustering analysis. Epidemics of cashew powdery mildew differed between the three cycles in terms of duration and severity. The clones were classified into four clusters of similar clones, defined by the graphical analysis on the basis of the powdery mildew severity. Clones BRS 274, BRS 275, CCP 1001 and BRS 226 attained lower AUDPC and clones BRS 189 and CCP 06 showed higher AUDPC. The results show evidence of partial resistance to powdery mildew among commercially grown cashew clones. Clones BRS 274, BRS 275, BRS 226 and CCP 1001 were the most resistant, while CCP 06 and BRS 189 clones were the most susceptible to powdery mildew. The AUDPC seems to be suitable for discriminating between genotypes, whereas the rate of disease progression may be used for establishing a threshold in the evaluation of other control methods, as it does not clearly differentiate between disease reactions.

Agronomic characteristics and nutritive value of elephant grass clones managed under rotational stocking during the dry period

This study aimed to evaluate the agronomic characteristics and nutritional value of two clones of elephant grass (CNPGL 00-1-3 and BRS Kurumi) operating under rotational stocking in the dry season. A completely randomized design with repeated measures (grazing cycles) and three replicates (paddocks) was used. Clones were managed under rotational stocking with a defoliation interval of 24 days and four days of occupation of paddocks, using Holstein x Gyr heifers with mean body weight of 150 kg. The evaluations were conducted in April/May, May/June, June/July and July/August 2010. Green forage mass was influenced by clone and grazing cycle, with higher mean value observed for CNPGL 03-01-00, which was 17% higher than the value observed for BRS Kurumi, and there was decreased of dry mass of green forage with the advance of grazing cycles. Leaf mass was influenced only by grazing cycle, with gradual reduction from the first to the third cycle. However, in fourth cycle was increase in biomass of leaves, which did not differ from that observed in the second cycle. There was interaction for dry matter production of stem, being observed differences in the first and third cycles for the clones. There was no effect of the factors studied for the production of senescent material. The leaf:stem ratio was influenced by grazing cycles, with interaction of the factors studied. The clone BRS Kurumi kept the leaf:stem ratio stable over the cycles, while clone CNPGL 1-3-00 presented a decrease in leaf:stem ratio from first until to third cycle. The content of crude protein (PB) was not influenced by the factors studied, with average values of 15.3% and 15.8% PB for the CNPGL 00-1-3 and BRS Kurumi clones. Neutral detergent fiber (NDF) and the in vitro dry matter digestibility (IVDMD) were affected only by grazing cycles. The highest values of NDF were observed in the three first grazing cycles, with values of 55.5%, 56.0% and 55.7% from the first to the third grazing cycle, respectively, while in the fourth cycle was obtained the value of 50.5%. There was a decrease in the IVDMD until the third cycle. In the fourth cycle the IVDMD values were similar to the first cycle. The clones did not differ in relation to biomass production, morphological composition and nutritional value, during the dry season.

QUALITY OF ACEROLA (Malpighia emarginata) TREATED WITH GIBBERELIC ACID AND STORED UNDER REFRIGERATION

ABSTRACT The goal of this study was study the postharvest quality of acerola clone BRS 236 (Malpighia emarginata D.C.) which was harvested at physiological maturity and submitted to four treatments under immersion during 5 minutes at 25 °C, which are: control (water), 60 mg L-1; 120 mg L-1 and 180 mg L-1. After treatment the fruits were packed in polystyrene trays and placed with polyethylene film and then stored at 10 ± 2 °C and 85 ± 5% RH for 12 days. Were analyzed in three days intervals (0, 3, 6, 9 and 12 days): skin color, firmness, pH, titratable acidity, soluble solids, SS/TA ratio, vitamin C and yellow flavonoids. Vitamin C, anthocyanins and yellow flavonoids were not influenced by treatments with GA3 at the end of 12-day of cold storage at 10 ºC. The exogenous application of 120 mg L-1 of GA3 resulted in retention of red color and content of anthocyanins of acerola fruits BRS 236 clone 12-day storage at 10 °C.

Caracterização da forragem e da extrusa de clones de capim elefante anão sob lotação intermitente

The objective of this trial was to evaluate the behavior ingestive of crossbred heifers and chemical characteristics of the material from two clones of dwarf elephant grass (BRS Kurumi ‘and CNPGL 01/03/00) submitted to different management strategies through sampling of forage (whole plant extrusa and manual hand plucking. The experiment was conducted at Embrapa Dairy Cattle, Coronel Pacheco, MG. We used a completely randomized design with factorial (2x2x2) with three replications. The treatments consisted of two clones of elephant grass (BRS Kurumi ‘and CNPGL 01/03/00), two light interception at the entrance of the animals (90 and 95%) and two heights of post-grazing residue (30 and 50 cm) with three replications. The chemical analysis showed that the methodology manual grazing simulation enables an acceptable estimate of the forage selected by grazing animals and the sampling of the whole plant is not selected by the animal diet. To harvest extrusa rate evaluation and mass bit, fractions and chemical composition of the plant of the ingested material was taken. Characteristics, structural and nutritional value of clone BRS ‘Kurumi’ facilitated greater forage intake by the animal, suggesting its use in grazing systems.

Proteomic analysis of responsive stem proteins of resistant and susceptible cashew plants after Lasiodiplodia theobromae infection.

Gummosis caused by Lasiodiplodia theobromae, a necrotrophic fungus, is the major disease of cashew plants in the semi-arid conditions of northeastern Brazil. Although various studies were carried out on this pathosystem, there is no information available on the molecular mechanisms of plant defense related to the incompatible interaction of cashew with L. theobromae. Therefore, this original study comprises a differential proteomic analysis of cashew stems from: (i) resistant dwarf clone BRS 226 mock-inoculated (control) and artificially inoculated with L. theobromae; and (ii) cashew plants bearing resistant and susceptible traits to gummosis, originated from open pollination of BRS 226 in a commercial orchard with high disease incidence. The contribution of the reprogrammed proteins to molecular events triggered in cashew plants challenged by L. theobromae has a great relevance in the identification of the host candidate proteins linked to biological pathways that respond to L. theobromae infection. Furthermore this study may contribute to improve breeding programs aimed at selecting resistant/tolerant cashew clones toward this pathogen.

Economic analysis of cashew early dwarf Crop BRS - 189 depending on water levels and doses of potassium fertilization

Water and fertilizer among the production factors are the elements that most restrict the production of cashew. The precise amount of these factors is essential to the success of the crop yield. This research aimed to determine the best factor-product ratio and analyze technical and economic indicators, of productivity of the cashew clone BRS 189 (Anacardium occidentale) to production factors water and potassium. The experiment was conducted from May 2009 to December 2009 in an experimental area of 56.0 m x 112.0 m in the irrigated Curu - Pentecoste, located in the municipality of Pentecoste, Ceará, Brazil. Production factors water (W) and potassium (K) were the independent variables and productivity (Y), the dependent variable. Ten statistical models that have proven satisfactory for obtaining production function were tested. The marginal rate of substitution was obtained through the ratio of the potassium marginal physical product and the water marginal physical product. The most suited model to the conditions of the experiment was the quadratic polynomial without intercept and interaction. Considering that the price of the water was 0.10 R$ mm -1, the price of the potassium 2.19 R$ kg -1 and the price of the cashew 0.60 R$ kg-1, the amounts of water and K2O to obtain the maximum net income were 6,349.1 L plant-1 of water and 128.7 g plant -1year, -1 respectively. Substituting the values obtained in the production function, the maximum net income was achieved with a yield of 7,496.8 kg ha-1 of cashew.

Bioactive compounds and total antioxidant capacity of cashew apples (Anacardium occidentale L.) during the ripening of early dwarf cashew clones

Lately, tropical fruit consumption has increased due to a higher knowledge of its nutritional and therapeutic value. The aim of this work was to evaluate the antioxidant potential of cashew apples from different early dwarf clones during their ripening. The clones analyzed included: CCP 76, CCP 09, BRS 189 and BRS 265 in seven ripening stages. They were analyzed for vitamin C, total carotenoid, total anthocyanin, yellow flavonoids and polyphenol content and total antioxidant capacity. Clone BRS 265 ripe cashew apple presented the highest vitamin C content (279.37 mg x 100 g-1). The ripe BRS 189 cashew apple is colored bright red, and its total anthocyanin content was the highest (21.16 mg x 100 g-1). The yellow flavonoids content was higher for ripe CCP 76 and BRS 189 cashew apples with 56.32 and 50.75 mg x 100 g-1, respectively. The highest levels of extrable polyphenols and antioxidant capacity were observed in CCP 09 in the first five ripening stages. The antioxidant activity of cashew apples (Anacardium occidentale L.) is mainly attributed to polyphenol content (r = 0.90; p < 0.01), and, therefore, they may be considered relevant sources of antioxidant compounds, which are necessary for human health. Cashew apples are consumed fresh which confers direct benefits for human health and present high potential for the development of new products with functional properties.

QUALITY CHANGES AND ANTHOCYANIN AND VITAMIN C DECAY RATES OF FROZEN ACEROLA PURÉE DURING LONG-TERM STORAGE

This study aimed at evaluating the quality changes and decay rate of antioxidant compounds during long-term storage (330 days) of frozen puree from different acerola clones: BRS 235, BRS 236, BRS 237, BRS 238, II47/1 and BRS 152. The soluble solids/titrable acidity ratio was relatively stable during storage. All clones, except BRS 236, showed great loss of anthocyanin after 180 days of storage; although in general, they presented high levels of anthocyanins. For most clones, there was a direct correlation between vitamin C and anthocyanin decay rates and for these, it is possible that the decay in anthocyanin content is linked to the reaction between anthocyanin and vitamin C or, most probably, by-products of vitamin C degradation. Overall, processing of acerola purees resulted in alternative products with good quality and clones BRS 238 and II 47/1 had the best performances. PRACTICAL APPLICATIONS Acerola is a rich source of antioxidants such as ascorbic acid and anthocyanins and, as most tropical fruits, it has a very short postharvest life. Thus, processing acerola pulp and storing it at low temperatures are fundamental for extending storage life and preventing decay. This research describes original and important information on the kinetics of degradation of anthocyanin and vitamin C, both nutritionally relevant compounds, during the storage of frozen fruit pulp. This study has potential application in the fruit processing industry as a valuable tool for the optimization of conservation and for the attainment of a better quality product.

Germinação e desenvolvimento inicial de clones de cajueiro comum sob irrigação com água salina

A maioria dos pomares de cajueiro no Brasil está localizada no trópico semiárido, onde a água é escassa e apresenta problemas de salinidade. Desta forma, este trabalho objetivou avaliar o efeito da salinidade na germinação e no desenvolvimento inicial de mudas de cajueiro BRS 274 e BRS 275. Os tratamentos foram dispostos em esquema fatorial 5 x 2 com quatro repetições, referentes a soluções salinas ajustadas para as condutividades elétricas (CEa) (0, 3,0, 6,0, 9,0 e 12 dS m-1), e dois clones de cajueiro (BRS 274 e BRS 275). As variáveis avaliadas foram: porcentagem de emergência (PE), índice de velocidade de emergência (IVE), tempo médio de emergência (TME), altura da plântula (AP), diâmetro da plântula (DP), número de folhas (NF), área foliar (AF), massa seca das folhas (MSF), massa seca do caule (MSC) e massa seca da raiz (MSR) obtidos 30 dias após a emergência. Houve efeito de interação entre os clones e a salinidade da água de irrigação para as variáveis PE e IVE. Por sua vez, todas as variáveis estudadas foram influenciadas pela salinidade da água de irrigação e o clone BRS 275 apresentou resultados superiores para as variáveis PE, IVE, TME, AF e MSF em comparação com o clone BRS 274.

The influence of processing and long-term storage on the antioxidant metabolism of acerola (Malpighia emarginata) purée

This study evaluated the effect of the processing and long-term storage on the antioxidant potential and activity of antioxidant enzymes of frozen purées from six acerola clones. Ripe acerolas from clones BRS 235, BRS 236, BRS 237, BRS 238, II47/1 and BRS 152 were harvested; the pulp was processed, packed in sealed polyethylene plastic bags and stored in a domestic freezer at -18°C for 11 months. Samples of each clone were analyzed on harvest/processing day and every 30 days after for bioactive antioxidant compounds, antioxidant enzyme activity and total antioxidant activity. Acerola purées presented a decrease of non-enzyme antioxidants and an increase of antioxidant enzymes activities, indicatives of a compensatory mechanism between enzymatic and non-enzymatic antioxidants. In acerola purée, anthocyanin and polyphenols are strongly correlated to soluble solids content and vitamin C seems a major contributor to total antioxidant activity. Clone II47/1 had an outstanding performance regarding the antioxidant potential of its purée and the best storage period at -18ºC would be 150 days, for all clones studied.

Desenvolvimento inicial do clone brs 275 de cajueiro sob irrigação com diferentes níveis salinos

Most cashew orchards in Brazil is located in semi-arid tropics, where water is scarce and has salinity problems. Based on this fact, this study aimed to evaluate the effect of salinity on early development of seedlings of cashew BRS 275. The experiment was conducted in a greenhouse at Embrapa Fortaleza - CE, Brazil. Seeds of BRS 275 were sown in containers containing vermiculite. The treatments were saline solutions with different electrical conductivity (ECw) 3, 6, 9 and 12 dS m-1, being the distilled water used as control (0 dS m-1). The experiment was a completely randomized design with four replications of five seedlings per plot. Evaluated it seedling height (AP) diameter of the seedling (DP), number of leaves (NF), leaf area (AF), dry matter of leaf (MSF), dry matter of stem (MSC), dry matter of root (MSR) and the substrate conductivity (CEs), obtained 15 days after emergence of seedling. The irrigation with saline water showed a linear effect for all variables of plantets, except for DP that showed no significance and the MSC had a quadratic effect. The increasing salt concentration reduced the early development of seedlings of cashew, clone BRS 275.

Spatial-temporal Analysis of Gummosis in Three Cashew Clones at Northeastern Brazil

The cashew gummosis caused by the fungus Lasiodiplodia theobromae is one of the most important disease of cashew in the northeast of Brazil. The lack of studies about method of early detection, pathogen dissemination, host predisposition, mechanisms of attack and defence and efficient control measures assures this disease as a limiting factor as to growing of cashew under semi-arid conditions. Therefore, the characterization of spatial patterns of gummosis development under commercial orchards may provide important insights into the mechanisms involving in dissemination and disease progress of this disease, as well as in the understanding of dynamic of host, pathogen and environmental interactions for this pathossystem. This work aimed to characterize gummosis temporal and special dynamics in three commercial orchards of cashew clones of cashew with different levels of susceptibility by studying the special arrangement of diseased plants. Disease incidence and severity, quantified determined by a descriptive scale in clones BRS 226 (resistant), Embrapa 51 (slightly resistant) and Faga 11 (susceptible) in a commercial orchard located in Pio IX district (Piaui state, Brazil), were monitored and mapped. Data were collected within three blocks of 90 plants for each clone. Indices of dispersion were estimated to study the spatial dynamic. The dynamics and structure of gummosis foci were also analysed. As expected, data showed different degrees of gummosis incidence and severity for the three clones. Even under different levels of disease, a random dispersion pattern model of dispersion could be observed at the beginning of epidemic for all clones. However, as disease develops, a clustered model is likely to fit. The increase in disease incidence resulted from the increasing in both focus number and size.

Beta-caroteno, ácido ascórbico e antocianinas totais em polpa de frutos de aceroleira conservada por congelamento durante 12 meses

The objective of the work was to evaluate b-carotene, ascorbic acid and total anthocyanins alterations in fruit pulp of acerola tree clones conserved by the cold. The fruit clones BRS 152 (Sertaneja), BRS 235 (Apodi), BRS 236 (Cereja), BRS 237 (Roxinha), BRS 238 (Frutacor) and II 47/1 were harvested in a commercial maturation stage (ripe red) in Limoeiro do Norte, Ceara, Brasil, carried to Planta Piloto de Processamento de Frutos da Embrapa Agroindustria Tropical, unpulped, the pulp was storaged in polietilin bags (100 g), frozen, kept in a freezer at -20 °C, and evaluated every 30 days for 12 months. The experiment was carried out with experimental delineament totally casualized in a factorial scheme 6 x 13 (clones x time), with 3 repetitions. The concentration of b-carotene in the Cereja clone was stable, while the other ones were decreased during the whole time of the experiment. There was a small decrease in the ascorbic acid level in all the clones in the study during the storage, probably due to the high acidity of the pulp, which helps maintain its nutrient. The total anthocyanins level were stable in the Frutacor and Sertaneja clones, however, it decreased in the other ones. The II 47/1 clone was, among all the studied clones, the one that presented the highest levels of ascorbic acid C and total anthocyanins, keeping these characteristics during the whole storage. In conclusion, the clones that presented the lowest level of b-carotene, showed the highest concentrations of total anthocyanins.

Efficient gene transfer in C. elegans: extrachromosomal maintenance and integration of transforming sequences : C.C. Mello, J.M. Kramer, D. Stinchcomb and V. Ambros EMBO J. 10, 3959–3970

Gummosis is an aggressive disease caused by the necrotrophic fungus Lasiodiplodia theobromae (Pat.) Griffon & Maubl that threatens commercial cashew orchads in Brazil. To study the molecular mechanisms involved in the cashew response to L. theobromae, a proteomic analysis of stems from the commercial cashew clone BRS 226 (resistant) was conducted at early times post-artificial infection. In addition, changes in the stem proteome profiles of gummosis resistant and susceptible cashew plants grown under field condition and naturally exposed to pathogen were also compared. After two-dimensional gel electrophoresis (2D-PAGE), 73 proteins showed statistically significant differences in spot abundance. Of these, 31 spots were identified in BRS 226 stems compared with mock-inoculated controls and 32 in stems collected from field-grown resistant and susceptible cashew plants. L. theobromae-responsive proteins were mainly involved in energy metabolism pathways, stress and defense, cell signaling and protein metabolism indicating modulation of various cellular functions upon fungal infection. As stress-inducing factors seem to be important for susceptibility to disease, the change in the abundance relative these proteins may possibly indicate an attempt to maintain cellular homeostasis, as resistance determinant factor, related with a possible role in the regulation of oxidative burst. These findings provide the first information about the cellular mechanisms acting in the Anacardium occidentale genotypes associated with the pathophysiological state of infection with L. theobromae.Gummosis caused by Lasiodiplodia theobromae, a necrotrophic fungus, is the major disease of cashew plants in the semi-arid conditions of northeastern Brazil. Although various studies were carried out on this pathosystem, there is no information available on the molecular mechanisms of plant defense related to the incompatible interaction of cashew with L. theobromae. Therefore, this original study comprises a differential proteomic analysis of cashew stems from: (i) resistant dwarf clone BRS 226 mock-inoculated (control) and artificially inoculated with L. theobromae; and (ii) cashew plants bearing resistant and susceptible traits to gummosis, originated from open pollination of BRS 226 in a commercial orchard with high disease incidence. The contribution of the reprogrammed proteins to molecular events triggered in cashew plants challenged by L. theobromae has a great relevance in the identification of the host candidate proteins linked to biological pathways that respond to L. theobromae infection. Furthermore this study may contribute to improve breeding programs aimed at selecting resistant/tolerant cashew clones toward this pathogen.