Chlorophyll a fluorescence transient analysis of transgenic potato overexpressing D-galacturonic acid reductase gene for salinity stress tolerance

L-Ascorbate plays a vital role in the alleviation of salinity stress in crop plants. Overexpression of the ascorbate pathway enzyme D-galacturonic acid reductase in transgenic potato plants confers improved tolerance to various abiotic stresses. These transgenic potato plants were further studied for their primary photosynthetic performances under salinity stress. The changes in primary photochemistry of PSII induced by salinity stress were studied using JIP-test. Analysis of the fast phase chlorophyll a fluorescence transients indicated that there was a differential effect of salinity stress on different sites of the photosynthetic machinery. The transgenic potato leaves exhibited a gain in the ability for restraining the energy loss when they were imposed by salinity stress. These observations suggest that under salinity stress, the photosynthetic energy conservation in the transgenic plants was more effective than in the wild-type plants.