Seed-Specific Stable Expression of the α-AI1 Inhibitor in Coffee Grains and the Implications for the Development of the Coffee Berry Borer.

Genetic transformation of coffee ( spp.), the second most traded commodity worldwide, is an alternative approach to introducing features that cannot be introgressed by traditional crossings. The transgenic stability, heritability and quantitative and spatial expression patterns of the seed-specific promoter phytohemagglutinin (PHA-L) from were characterized in genetically modified expressing the α-amylase inhibitor-1 () gene. The α-AI1 inhibitor shows considerable activity toward digestive enzymes of the coffee berry borer (CBB) . This insect pest expends its life cycle almost entirely in coffee berries. Transgene containment in the fruit is important to meeting food and environmental safety requirements for releasing genetically modified (GM) crops. PCR analysis of T2 coffee plants showed a Mendelian single-copy segregation pattern. Ectopic transgene expression was only detected in coffee grains, as demonstrated by reverse transcription-PCR analysis of different plant tissues. An intense immunocytochemical signal associated with α-AI1 protein expression was localized to endospermic cells. In addition, a delay in the larval development of CBB was observed after challenging transgenic coffee seeds with the insect. These results indicate that the PHA-L promoter might be a useful tool in coffee for the seed-specific expression of genes related to coffee bean productivity, quality and pest protection. The biotechnological applicability of the gene for controlling CBB is also discussed. This work is the first report showing a seed-specific transgene expression in coffee plants.