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Brasília, Brazil

Santos G.C.,Federal University of Lavras | von Pinho E.V.R.,Federal University of Lavras | Rosa S.D.V.F.,Embrapa Cafe
Genetics and Molecular Research | Year: 2013

Coffee (Coffea arabica L.) seeds are sensitive to desiccation and oxidative stress during drying processes. We investigated the effect of drying and moisture levels on germination-related gene expressions associated with enzymatic systems that prevent oxidative stress in coffee seeds. Coffee seeds collected at physiological maturity were subjected to slow and quick drying to 40, 30, 20, and 12% moisture levels (wet basis), and as the control, seeds without drying were used. The seeds' physiological quality was calculated as percentage of normal seedlings at 15 and 30 days, normal vigorous seedlings at 30 days, and cotyledonary leaves at 45 days. The isoenzymes esterase, catalase (CAT), peroxidase (POX), and endo-β-mannanase expressions were electrophoretically analyzed. CAT and POX expressions were analyzed using RT-qPCR with specific primers constructed from the target gene sequences from the Brazilian Coffee Genome Database. Slow drying showed better physiological quality for seeds at 40 and 12% moisture levels, while quick drying was the most effective for seeds with 20% moisture. Sensitivity to water loss was confirmed by quick drying and activation of enzymes. CAT and POX transcriptions reduced during drying. RT-qPCR revealed a complex gene-expression pattern during the oxidative process, with high gene expression in wet seeds. © FUNPEC-RP. Source

Zanella L.,Federal University of Lavras | Borem R.A.T.,Federal University of Lavras | Souza C.G.,Federal University of Lavras | Alves H.M.R.,Embrapa Cafe | Borem F.M.,Federal University of Lavras
Natureza a Conservacao | Year: 2012

The goals of this research were to analyze the fragmentation of the Atlantic Forest and to create landscape management scenarios for the municipality of Carmo de Minas, MG, Brazil. We used landscape metrics to analyze the fragmentation process of the study area, which was historically exploited for agropastoral activities. Future scenarios were modeled to represent the potential restoration of the environment based on the behavior of the natural vegetation units. The natural vegetation in the study area is highly fragmented, and the environmental integrity of its remnants is severely threatened. The management scenarios showed how the restored natural units behave in the landscape as well as the isolation and connectivity between them. Using these models, future dynamics of the landscape can be predicted. Two important actions for the conservation of the remaining natural vegetation were identified: the maintenance of secondary forest and the restoration of permanent preservation areas. © 2012 ABECO. Source

de Oliveira A.C.B.,Embrapa Cafe | Pereira A.A.,Empresa de Pesquisa Agropecuaria Minas Gerais Epamig | da Silva F.L.,Empresa de Pesquisa Agropecuaria Minas Gerais Epamig | de Rezende J.C.,Epamig | And 2 more authors.
Crop Breeding and Applied Biotechnology | Year: 2011

Gains from selection for yield were estimated in Arabica coffee progenies carrying rust-resistance genes. The experiment in augmented block design was installed in Três Pontas, state of Minas Gerais. Three blocks were established with six plants per plot, spaced 3.50 × 0.90 m, in 96 regular (F 2 progenies) and two control treatments. The plant response to rust was evaluated on a grade scale in 2008. Yield (bags per hectare) was estimated in the growing seasons 2005 to 2008. Significant differences between treatments for yield were observed in all harvests, except 2005. The presence of genetic variability among progenies allowed significant gain from selection for yield. Under the experimental conditions of this study, selection for yield can be performed in the first high-yield year, without major losses compared to genetic gain from selection for yield when based on the mean of four harvests. Source

dos Santos T.B.,Instituto Agronomico do Parana IAPAR | Budzinski I.G.F.,Instituto Agronomico do Parana IAPAR | Marur C.J.,Instituto Agronomico do Parana IAPAR | Petkowicz C.L.O.,Federal University of Parana | And 2 more authors.
Plant Physiology and Biochemistry | Year: 2011

Galactinol synthase (EC; GolS) catalyzes the first step in the synthesis of raffinose family oligosaccharides (RFOs). Their accumulation in response to abiotic stresses implies a role for RFOs in stress adaptation. In this study, the expression patterns of three isoforms of galactinol synthase (CaGolS1-2-3) from Coffea arabica were evaluated in response to water deficit, salinity and heat stress. All CaGolS isoforms were highly expressed in leaves while little to no expression were detected in flower buds, flowers, plagiotropic shoots, roots, endosperm and pericarp of mature fruits. Transcriptional analysis indicated that the genes were differentially regulated under water deficit, high salt and heat stress. CaGolS1 isoform is constitutively expressed in plants under normal growth conditions and was the most responsive during all stress treatments. CaGolS2 is unique among the three isoforms in that it was detected only under severe water deficit and salt stresses. CaGolS3 was primarily expressed under moderate and severe drought. This isoform was induced only at the third day of heat and under high salt stress. The increase in GolS transcription was not reflected into the amount of galactinol in coffee leaves, as specific glycosyltransferases most likely used galactinol to transfer galactose units to higher homologous oligosaccharides, as suggested by the increase of raffinose and stachyose during the stresses. © 2011 Elsevier Masson SAS. Source

de Campos M.K.F.,Instituto Agronomico Do Parana | de Carvalho K.,Instituto Agronomico Do Parana | de Souza F.S.,Instituto Agronomico Do Parana | Marur C.J.,Instituto Agronomico Do Parana | And 3 more authors.
Environmental and Experimental Botany | Year: 2011

In this study we investigated the effects of the high endogenous proline level on water relations, gas exchange and antioxidant enzymatic activity in leaves of transgenic 'Swingle' citrumelo rootstocks transformed with the P5CSF129A gene coding for the key-enzyme for proline synthesis, under water deficit. Leaf total water, osmotic and pressure potentials, stomatal conductance, photosynthetic rates and xylem sap flow were evaluated in non-transformed control and transgenic plants during water deficit treatment. Malondialdehyde (MDA) content, catalase (CAT; EC, superoxide dismutase (SOD; EC and ascorbate peroxidase (APX; EC activities were quantified in leaves collected based on their total water potential, representing the following conditions: irrigated (Ψw=-1.3MPa), moderate stress (Ψw=-2.3 to -2.5MPa), severe stress (Ψw=-3.8 to -3.9MPa) and recovery (24h after re-irrigation: Ψw=-1.3 to -1.9MPa). Osmotic adjustment was observed in transgenic plants until 11 days after withholding water, while pressure potential in non-transformed controls was close to zero after nine days of water deprivation. This superior maintenance of turgor pressure in leaves of transgenic plants led to higher stomatal conductance, photosynthetic and transpiration rates when compared to non-transgenic plants. Drought caused a significant decrease in APX and SOD activities in control plants, followed by an increase after re-watering. On the other hand, CAT was more active in control than in transgenic plants under irrigated condition and both stress levels. Our results suggest that transgenic plants were able to cope with water deficit better than non-transformed controls since the high endogenous proline level acted not only by mediating osmotic adjustment, but also by contributing to gas exchange parameters and ameliorating deleterious effects of drought-induced oxidative stress. © 2011 Elsevier B.V. Source

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