Project description:Soil salinity presents a notable challenge to agriculture and to increasing the use marginal lands for farming. Here we provide a detailed analysis of the physiology, chemistry and gene expression patterns in roots and shoots of Camelina sativa in response to salt stress. Salt treatment reduced shoot, but not root length. Root and shoot weight were affected by salt, as was photosynthetic capacity. Salt treatment did not alter micro-element concentration in shoots, but increased macro-element (Ca and Mg) levels. Gene expression patterns in shoots indicated that salt stress may have led to shuttling of Na+ from the cytoplasm to the tonoplast and to an increase in K+ and Ca+2 import into the cytoplasm. In roots, gene expression patterns indicated that Na+ was exported from the cytoplasm by the SOS pathway and that K+ was imported in response to salt. Genes encoding proteins involved in chelation and storage were highly up-regulated in shoots, while metal detoxification appeared to involve various export mechanisms in roots. In shoots, genes involved in secondary metabolism leading to lignin, anthocyanin and wax production were up-regulated, probably to improve desiccation tolerance. Partial genome expression partitioning was observed in roots and shoots based on the expression of homeologous genes from the three C. sativa genomes. Genome I and II were involved in the response to salinity stress to about the same degree, while about 10 % more differentially-expressed genes were associated with Genome III. This study has provided valuable information and insight into the response of camelina to salt stress. Examination of this data and comparison to similar studies in more halophytic species will allow development of even more salt-tolerant varieties of this emerging industrial crop.
