Accumulation of plastid lipid-associated proteins (fibrillin/CDSP34) upon oxidative stress, ageing and biotic stress in Solanaceae and in response todrought in other species

Plastid lipid-associated proteins, also termed fibrillin/CDSP34 proteins, a re known to accumulate in fibrillar-type chromoplasts such as those of ripe ning pepper fruit, and in leaf chloroplasts from Solanaceae plants under ab iotic stress conditions. It is shown here that treatments generating active oxygen species (high light combined with low temperature, gamma irradiatio n or methyl viologen treatment) result in potato CDSP34 gene induction and protein accumulation in leaves. Using transgenic tomato plants containing t he pepper fibrillin promoter, a significant increase in promoter activity i n leaves subjected to biotic stress, namely bacterial infections, was obser ved. In WT, a higher level of the endogenous fibrillin/CDSP34 protein is al so observed after infection by E. chrysanthemi strain 3739. In addition to stress-related induction, a progressive increase in the fibrillin promoter activity is noticed during ageing in various tomato photosynthetic tissues and this increase correlates with a higher abundance of the endogenous prot ein in WT leaves. It is proposed that a mechanism related to oxidative even ts plays an essential role in the regulation of fibrillin/CDSP34 genes duri ng stress and also during development. Using a biolistic transient expressi on assay, the pepper fibrillin promoter is found to be active in various di cot species, but not in monocots. Further, substantially increased levels o f fibrillini/ CDSP34 proteins are shown in various dicotyledonous and monoc otyledonous plants in response to water deficit.