| Abstract Detail
Coffee Genomics - Morning Privat, Isabelle [1], Chenwei, Lin [2], Tanksley, Steve [3], Mc Carthy, James [1]. Sucrose metabolism during coffee bean maturation : from genes to enzymatic activities. SUCROSE is a major contributor of free reducing sugars involved in the Maillard reaction that occurs during the roasting of coffee grain, and therefore, it is widely believed to be an important coffee flavor precursor molecule in the green grain. Consistent with this idea, the highest quality Arabica grain have appreciably higher levels of sucrose (between 7.3 and 11.4 %) than the lowest quality Robusta grain (between 4 and 5 %). Because of the clear correlation between the level of sucrose in the grain and coffee flavor and so quality, understanding the underlying genetic basis for variations in the sucrose metabolism and carbon partitioning in coffee grain is important. Here we present for the first time the isolation and characterization of cDNA encoding key enzymes involved in sucrose metabolism in Coffea Canephora i.e. sucrose synthase (CcSS2), sucrose phosphate synthase (CcSPS1), sucrose phosphatase (CcSP1), as well as cell-wall (CcInv1), vacuolar (CcInv2) and cytoplasmic (CcInv3) invertases. Experiments were conducted to determine key enzymes activities in sucrose metabolism during coffee bean maturation in one Arabica (CCCA12) and one Robusta (FRT05). These two genotypes are characterized by a difference of sucrose content in green bean, CCCA12 accumulating 30 % more than FRT05. Quantitative RT-PCR has been also carried out to determine if there is a correlation between transcript accumulation and the corresponding enzymatic activity. The results presented here, provide genetic and biochemical tools for the selection of coffee varieties with higher sucrose content in mature coffee beans.
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1 - Nestle, Plant Science and Technology, 101 avenue Gustave Eiffel, Notre Dame d\'Oe, 37390, France
2 - Cornell University, Plant Breeding, 248 Emerson Hall, Ithaca, NY, 14853, USA
3 - Cornell University, Plant Breeding and Genetics, 248 Emerson Hall - Cornell University, Ithaca, NY, 14853, USA
Keywords:
coffee bean maturation
sucrose
Quality.
Session: SAT01-13
Location: Hall of Ideas Room G/Monona Terrace
Date: Wednesday, July 26th, 2006
Time: 11:20 AM
Abstract ID:188 |
