Biblioteca do Café
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Item Ethylene production and acc oxidase gene expression during fruit ripening of Coffea arabica L.(Brazilian Journal of Plant Physiology, 2005-09) Pereira, Luiz Filipe Protasio; Galvão, Rafaelo M.; Kobayashi, Adilson K.; Cação, Sandra Maria B.; Vieira, Luiz Gonzaga EstevesThe phytohormone ethylene is involved in several physiological and developmental processes in higher plants, including ripening of fruits, abscission of organs and tissues, senescence, wound response as well as in other abiotic stresses. The enzyme 1-aminocyclopropane-1-carboxylate oxidase (ACO) catalyzes the last step of ethylene biosynthesis. The production of ethylene and the expression of a Coffea arabica ACO gene during the last stages of fruit maturation were investigated. A rapid increase of ethylene production at the green-yellow stage of fruit ripening, after the end of endosperm formation, and a decrease of ethylene production at the cherry stage indicates a climacteric phase during ripening. An ACC oxidase (Ca-ACO) from coffee fruit cDNA was cloned and characterized using primers previously reported. The cDNA is homologous to previously described ACC oxidase cDNA in Coffea. The nucleotide and amino acid deduced sequences of the clone showed high homology with ACO from climacteric fruits. Northern blots were performed to determine the Ca-ACO transcription pattern from different tissues and from fruits at different ripening stages. Coffee fruits at an early ripening stage (green) showed the lowest level of Ca-ACO transcript accumulation. The transcript levels of Ca-ACO did not change significantly during the later stages, suggesting the presence of post- transcriptional control mechanisms. These results, taken together, strongly suggest a climacteric nature of coffee fruit ripening.Item Coffee leaf miner resistance(Brazilian Journal of Plant Physiology, 2006-06) Guerreiro Filho, OliveiroThe coffee leaf miner, Leucoptera coffeella, is a common pest of coffee plantations in Brazil. Though it is effective, chemical control substantially increases the cost of production and constitutes a significant risk for the environment. Resistant coffee cultivars have been and continue being developed through classic and molecular selection techniques. Basic knowledge about the biology of this insect, the damage it causes to the plants, the identification of sources of resistance, the development of efficient selection methods and knowledge about the genetics of resistance have contributed to the efficiency of the ongoing genetic improvement programs. Recently, coffee genomics studies have also promoted an improvement in the efficiency of the development of cultivars resistant to this insect. We present a short review of each of these aspects of the search for resistance.Item Metabolism of alkaloids in coffee plants(Brazilian Journal of Plant Physiology, 2006-06) Ashihara, HiroshiCoffee beans contain two types of alkaloids, caffeine and trigonelline, as major components. This review describes the distribution and metabolism of these compounds. Caffeine is synthesised from xanthosine derived from purine nucleotides. The major biosynthetic route is xanthosine -> 7-methylxanthosine -> 7-methylxanthine -> theobromine -> caffeine. Degradation activity of caffeine in coffee plants is very low, but catabolism of theophylline is always present. Theophylline is converted to xanthine, and then enters the conventional purine degradation pathway. A recent development in caffeine research is the successful cloning of genes of N-methyltransferases and characterization of recombinant proteins of these genes. Possible biotechnological applications are discussed briefly. Trigonelline (N-methylnicotinic acid) is synthesised from nicotinic acid derived from nicotinamide adenine nucleotides. Nicotinate N-methyltransferase (trigonelline synthase) activity was detected in coffee plants, but purification of this enzyme or cloning of the genes of this N-methyltransferase has not yet been reported. The degradation activity of trigonelline in coffee plants is extremely low.Item Bioreactors in coffee micropropagation(Brazilian Journal of Plant Physiology, 2006-06) Etienne, Hervé; Dechamp, E.; Barry-Etienne, D.; Bertrand, BernóitIn coffee, bioreactors are the most promising way for scaling-up micropropagation processes, particularly somatic embryogenesis. The availability of an efficient somatic embryogenesis process would allow the rapid mass production of heterozygous materials such as selected Coffea canephora clones and F1 Arabica hybrid varieties. For the last fifteen years, bioreactors (mechanically or pneumatically agitated bioreactors, temporary immersion bioreactors) have mostly been used on coffee to optimize the mass regeneration of somatic embryos from embryogenic tissues. This review presents the main results, obtained with several bioreactor models, concerning the different steps of the micropropagation process : i) the multiplication of embryogenic tissues, ii) the somatic embryo mass regeneration and iii) the production of pre-germinated embryos and plantlets in bioreactors. The literature shows that scaling-up can be successful, since very efficient embryo production has been achieved for both C. arabica and C. canephora. Moreover, it was proven that the pre-germinated coffee embryos - i.e. embryonic axis elongation (10-12 mm), root tip formation, cotyledon expansion and greening - obtained in temporary immersion bioreactors were photoautotrophic and able to regenerate vigorous plantlets after sowing under nursery conditions. The feasibility to apply the bioreactor technology in an industrial micropropagation procedure is also discussed in the particular socio-economic context of coffee growing.Item Impacts of drought and temperature stress on coffee physiology and production: a review(Brazilian Journal of Plant Physiology, 2006-06) DaMatta, Fábio M.; Ramalho, José D. CochichoOverall, drought and unfavourable temperatures are the major climatic limitations for coffee production. These limitations are expected to become increasingly important in several coffee growing regions due to the recognized changes in global climate, and also because coffee cultivation has spread towards marginal lands, where water shortage and unfavourable temperatures constitute major constraints to coffee yield. In this review, we examine the impacts of such limitations on the physiology, and consequently on the production of mainly Coffea arabica and C. canephora, which account for about 99 % of the world coffee bean production. The first section deals with climatic factors and the coffee plant’s requirements. The importance of controlling oxidative stress for the expression of drought and cold tolerance abilities is emphasized in the second section. In the third section, we examine the impacts of drought on cell-water relations, stomatal behaviour and water use, photosynthesis and crop yield, carbon and nitrogen metabolism, root growth and characteristics, and on drought tolerance. In the fourth section, the impacts of low positive and high temperatures on coffee physiology are discussed; some insights about effects of negative temperatures are also presented. Finally, the last section deals with shading in harsh environments as a mean of buffering climatic fluctuations, as well as of increasing environmental sustainability in coffee exploitation.Item Brazilian coffee genome project: an EST-based genomic resource(Brazilian Journal of Plant Physiology, 2006-06) Vieira, Luiz Gonzaga Esteves; Andrade, Alan Carvalho; Colombo, Carlos Augusto; Moraes, Ana Heloneida de Araújo; Metha, Ângela; Oliveira, Angélica Carvalho de; Labate, Carlos Alberto; Marino, Celso Luis; Monteiro-Vitorello, Claúdia de Barros; Monte, Damares de Castro; Giglioti, Éder; Kimura, Edna Teruko; Romano, Eduardo; Kuramae, Eiko Eurya; Lemos, Eliana Gertrudes Macedo; Almeida, Elionor Rita Pereira de; Jorge, Érika C.; Albuquerque, Érika V. S.; Silva, Felipe Rodrigues da; Vinecky, Felipe; Sawazaki, Haiko Enok; Dorry, Hamza Fahmi A.; Carrer, Helaine; Abreu, Ilka Nacif; Batista, João A. N.; Teixeira, João Batista; Kitajima, João Paulo; Xavier, Karem Guimarães; Lima, Liziane Maria de; Camargo, Luis Eduardo Aranha de; Pereira, Luiz Filipe Protasio; Coutinho, Luiz Lehmann; Lemos, Manoel Victor Franco; Romano, Marcelo Ribeiro; Machado, Marcos Antonio; Costa, Marcos Mota do Carmo; Sá, Maria Fátima Grossi de; Goldman, Maria Helena S.; Ferro, Maria Inês T.; Tinoco, Maria Laine Penha; Oliveira, Mariana C.; Sluys, Marie-Anne Van; Shimizu, Milton Massao; Maluf, Mirian Perez; Eira, Mirian Therezinha Souza da; Guerreiro Filho, Oliveiro; Arruda, Paulo; Mazzafera, Paulo; Mariani, Pilar Drummond Sampaio Correa; Oliveira, Regina L.B.C. de; Harakava, Ricardo; Balbao, Silvia Filippi; Tsai, Siu Mui; Mauro, Sonia Marli Zingaretti di; Santos, Suzana Neiva; Siqueira, Walter José; Costa, Gustavo Gilson Lacerda; Formighieri, Eduardo Fernandes; Carazzolle, Marcelo Falsarella; Pereira, Gonçalo Amarante GuimarãesCoffee is one of the most valuable agricultural commodities and ranks second on international trade exchanges. The genus Coffea belongs to the Rubiaceae family which includes other important plants. The genus contains about 100 species but commercial production is based only on two species, Coffea arabica and Coffea canephora that represent about 70 % and 30 % of the total coffee market, respectively. The Brazilian Coffee Genome Project was designed with the objective of making modern genomics resources available to the coffee scientific community, working on different aspects of the coffee production chain. We have single-pass sequenced a total of 214,964 randomly picked clones from 37 cDNA libraries of C. arabica, C. canephora and C. racemosa, representing specific stages of cells and plant development that after trimming resulted in 130,792, 12,381 and 10,566 sequences for each species, respectively. The ESTs clustered into 17,982 clusters and 32,155 singletons. Blast analysis of these sequences revealed that 22 % had no significant matches to sequences in the National Center for Biotechnology Information database (of known or unknown function). The generated coffee EST database resulted in the identification of close to 33,000 different unigenes. Annotated sequencing results have been stored in an online database at http://www.lge.ibi.unicamp.br/cafe. Resources developed in this project provide genetic and genomic tools that may hold the key to the sustainability, competitiveness and future viability of the coffee industry in local and international markets.Item Coffee seed physiology(Brazilian Journal of Plant Physiology, 2006-06) Eira, Mirian T. S.; Silva, E. A. Amaral da; Castro, Renato D. De; Dussert, Stéphane; Walters, Christina; Bewley, J. Derek; Hilhorst, Henk W. M.Considerable advances in our understanding of coffee seed physiology have been made in recent years. However, despite intense research efforts, there are many aspects that remain unclear. This paper gives an overview of the current understanding of the more important features concerning coffee seed physiology, and provides information on recent findings on seed development, germination, storage and longevity.Item Aspects of nitrogen metabolism in coffee plants(Brazilian Journal of Plant Physiology, 2006-06) Carelli, Maria Luiza Carvalho; Fahl, Joel Irineu; Ramalho, José D. CochichoCoffee plants are highly N-demanding plants. Despite the importance of N nutrition for the development, acclimation and yield of coffee plants, there are few reports concerning N metabolism in this species. In this review, our intention is to summarize the information available in the literature and to point out the influence of environmental conditions on N assimilation, as well as comment and discuss some apparently contradictory results and raise and enlighten queries about N assimilation in coffee plants.Item Cytogenetics of coffee(Brazilian Journal of Plant Physiology, 2006-06) Pinto-Maglio, Cecília A. F.The genus Coffea L. has around 100 native species distributed in tropical and subtropical areas in Africa, and the most important economic species are C. arabica and C. canephora. C. arabica is exceptional in the genus since it is the only species so far analyzed which is self-compatible, and a natural polyploid with 2n=4x=44 chromosomes; it is considered to be a segmental allopolyploid because it presents a disomic inheritance and a regular meiotic behavior. All other species in the genus are self-incompatible diploids with 2n=2x=22. Cytogenetic studies in Coffea, undertaken since 1912, have followed various phases: initial studies were limited only to establishing chromosome counts. Subsequent studies characterized the karyotypes of various species using conventional cytological techniques. As the somatic metaphase chromosomes of coffee are very small (1 - 3 µm) and morphologically symmetrical, these studies resulted in uniform karyotypes that show almost no differences among species. Since genetic improvement of coffee trees has progressed mainly by means of interspecific hybridizations involving wild species, analyses of microsporogenesis in species and hybrids were needed to establish their genetic affinity and relationships. The first successful attempts to differentiate coffee chromosomes longitudinally were made by mapping pachytene chromomeric patterns and by C and NOR banding techniques. From 1998 onwards, the use of banding techniques with the fluorochromes DAPI and CMA3, and also the cytomolecular technique FISH using rDNA probes, has increased the longitudinal differentiation of coffee chromosomes. The use of the GISH technique with total genomic DNA has revealed the parental species that originated C. arabica species.Item Selection for durable resistance to leaf rust using test-crosses on IAPAR-59 and Tupi IAC 1669-33 cultivars of Coffea arabica(Instituto de Tecnologia do Paraná - Tecpar, 2007-07) Sera, Gustavo Hiroshi; Sera, Tumoru; Ito, Dhalton Shiguer; Azevedo, José Alves de; Mata, João Siqueira da; Doi, Deisy Saori; Ribeiro Filho, ClaudionorThe aim of this study was to identify plants of the IAPAR-59 and Tupi IAC 1669-33 coffee cultivars with less defeated resistance genes by the rust races present at IAPAR (Londrina, Paraná State, Brazil) using test-crosses. Eighteen test-crosses derived from hybridizations between 'IAPAR-59' or 'Tupi IAC 1669-33' with susceptible coffee to the rust disease were evaluated. Six hybrids were used as susceptible standards originated from hybridizations between two susceptible coffee plants. Many parental plants of the 'IAPAR-59' and 'Tupi IAC 1669-33' presented more defeated resistance genes against rust races present at IAPAR than others of these cultivars or the genes were in heterozygous, because of segregant susceptible plants observed in some test-crosses. The test-crosses were very efficient to identify plants with less defeated resistance genes to the H. vastatrix. Coffee plants considered resistants would must be made test-crosses to verify which plants presented less and/or more defeated genes in homozygous.