서강대학교

초록/요약

In Antarctic landscape, mosses constitute the dominant flora. Polytrichastrum alpinum (Hedw.) G.L.Sm., also known as alpine haircap moss, is distributed over large area of arctic, sub-arctic and montane temperate regions. In order to understand and investigate the functional benefits of P. alpinum genetic resources, we generated and characterized the transgenic Arabidopsis plants overexpressing two different P. alpinum genes. These genes include PaMBF1c and PaFKBP12 with high homology to a multiprotein bridging factor1c and a peptidyl prolyl isomerase FKBP12 (FKBP12), respectively. The overexpression of PaMBF1c in Arabidopsis showed enhanced tolerance against salt, osmotic, ionic stresses as well as temperature stresses. More specifically, salt tolerance in PaMBF1c overexpressing lines was even higher than the AtMBF1c overexpressing lines. RNA-sequencing data demonstrated that ten of salt stress-induced genes were already upregulated in PaMBF1c overexpressing lines under normal growth conditions. Improved salt tolerant phenotypes and the RNA-sequencing results together suggest that given the salt-enriched conditions in the Antarctic, MBF1c from P. alpinum might have evolved to obtain an improved salt stress tolerance than MBF1c from Arabidopsis. Overexpression of PaFKBP12 resulted in cell size reduction accompanied with increase of the seed number per silique in both Arabidopsis thaliana and Brassica napus transgenic lines. The constitutive expression of PaFKBP12 in Arabidopsis conferred enhanced tolerance to heat stress. In addition to this, the PaFKBP12 overexpressing lines, compared to the wild type, showed hyposensitive phenotypes to ABA at seedling stage as evidenced by biomass increase, root length, and higher chlorophyll retention under treatments with higher ABA concentrations. PaFKBP12-OE lines also able to afford severe dehydration conditions at least in part because of reduced stomatal aperture, decreased water loss and increased expression of stress responsive genes compared to wild type under drought stress conditions. Overall, our findings demonstrate explicit roles of moss genes in bestowing multiple abiotic stress tolerance in transgenic lines. Our study potentiates the importance of genetic resources from extremophytes such as polar moss in improving stress tolerances in agriculturally important plants.