Effect of Genetic Modification of Catalase Activity on the Dormancy and the Sprouting of Potato Mini Tubers (Solanum Tuberosum L.)

In several vegetable species a relationship between the metabolism of active oxygen species and breakage of dormancy has been established. However, scarce information is available on the role of oxidative stress in potato tubers. The purpose of this investigation is to study the effect of CAT genetic modification on the dormancy break of potato tubers. A transgenic approach with partial repression of CAT activity in cv. Desirée was applied. The genes coding for the CAT 2 of Nicotiana plumbaginifolia (Cat 2AS) and of Gossypium hirsutum (GH) were used according to "antisense" and "co-suppression" strategies. The repression of CAT activity was associated with Ascorbate peroxidase (APX) accumulation and a decrease in the Hydrogen peroxide (H2O2) in potato tubers. The sprouting of transgenic tubers was accelerated as compared to the non-transformed control and was associated with a decrease of CAT activity and H2O2 contents. Keywords— Catalase, Dormancy, Hydrogen peroxide, Solanum tuberosum L. Abbreviations: EDTA: (Ethylene-diamine-tetra-acetic); H2O2: Hydrogen peroxide; NBT: (Nitroblue tetrazolium); SDS: (Sodium dodecyl sulphate); PAGE: (Polyacrylamide gel); PVPP: (Polyvinylpolypyrrolidone); TEMED: (Tetramethyl–ethylen-diamine).