Plants synthetize a large spectrum of secondary metabolites with substantial structural and functional diversity, making them a rich reservoir of new biologically active compounds. Among different plant lineages, the evolutionarily ancient branch of non-vascular plants (Bryophytes) is of particular interest as these organisms produce many unique biologically active compounds with highly promising antibacterial properties. Here, we characterized antibacterial activity of metabolites produced by different ecotypes (strains) of the model mosses Physcomitrium patens and Sphagnum fallax. Ethanol and hexane moss extracts harbor moderate but unstable antibacterial activity, representing polar and non-polar intracellular moss metabolites, respectively. In contrast, high antibacterial activity that was relatively stable was detected in soluble exudate fractions of P. patens moss. Antibacterial activity levels in P. patens exudates significantly increased over four weeks of moss cultivation in liquid culture. Interestingly, secreted moss metabolites are only active against a number of Gram-positive, but not Gram-negative, bacteria. Size fractionation, thermostability and sensitivity to proteinase K assays indicated that the secreted bioactive compounds are relatively small (less than <10 kDa). Further analysis and molecular identification of antibacterial exudate components, combined with bioinformatic analysis of model moss genomes, will be instrumental in the identification of specific genes involved in the bioactive metabolite biosynthesis.

Telomere length has been implicated in the organismal response to stress, but the underlying mechanisms are unknown. Here we examine the impact of telomere length changes on Arabidopsis thaliana responses to three contrasting abiotic environments, and measure 31 fitness, development, physiology and leaf-level anatomy traits. We report that telomere length in wild type and short telomere mutants is resistant to abiotic stress, while elongated telomeres in ku70 mutants are more plastic. We also detect significant pleiotropic effects of telomere length on flowering time and key leaf physiology and anatomical traits. Furthermore, our data reveal a significant genotype by environment (GxE) interaction for reproductive fitness, with the benefits and costs to performance depending on the growth conditions. These results imply that life-history tradeoffs between flowering time and reproductive fitness are impacted by telomere length variation. We postulate that telomere length in plants is subject to natural selection imposed by different environments.

Telomere length has been implicated in the organismal response to stress, but the underlying mechanisms are unknown. Here we examine the impact of telomere length changes on Arabidopsis thaliana responses to three contrasting abiotic environments, and measure 31 fitness, development, physiology and leaf-level anatomy traits. We report that telomere length in wild type and short telomere mutants is resistant to abiotic stress, while elongated telomeres in ku70 mutants are more plastic. We also detect significant pleiotropic effects of telomere length on flowering time and key leaf physiology and anatomical traits. Furthermore, our data reveal a significant genotype by environment (GxE) interaction for reproductive fitness, with the benefits and costs to performance depending on the growth conditions. These results imply that life-history tradeoffs between flowering time and reproductive fitness are impacted by telomere length variation. We postulate that telomere length in plants is subject to natural selection imposed by different environments.