Papaya (Carica papaya L.) and grapes (Vitis vinifera L.) are among the most important fruit crops produced in Brazil, and are cultivated in several regions around the country being of economical and social importance. Genetic engineering has great potential on the development of genetically improved fruit crops. However, intellectual property issues constantly limit the commercial use of this technology in developing countries. Thus, the present study aimed to evaluate gene promoters as alternatives to the 35S CaMV, which is the most used so far in the development of transgenic plants, but it is patented. In order to do that, the expression of the gus gene under the regulation of distinct promoters was evaluated on different papaya and grape tissues. Transient expression was evaluated on somatic embryos, leaves, stems, roots and fruits. The UBQ3 promoter, which is constitutive and is in the public domain, showed to be a real promising alternative for future work on genetic transformation of papaya but not grapes.
beta-glucuronidase; transient expression and promoters
