transcriptomics of the chilling stress response in Rhizophora apiculata

Low temperatures largely determine the geographic limits of plant species by reducing plant survival and growth. Mangroves are primarily tropical with some species extending their range into the cooler subtropics. Interspecific differences in the geographic distribution of mangrove species have been associated with cold tolerance, with exclusively tropical species being highly cold-sensitive and subtropical species being relatively cold-tolerant. To identify species-specific adaptations to low temperatures, we studied the chilling stress response of the widespread Indo-West Pacific mangrove species Rhizophora apiculata (tropical range limit). For this species, we measured the maximum photochemical efficiency of photosystem II (Fv/Fm) as a proxy for the physiological condition of the plants and examined gene expression profiles at a pre-chilling temperature of 28C, during chilling at 15C and 5C, and during post-chilling recovery at 28C.