Paper Title
USE OF ANTARCTIC ENDOPHYTES TO IMPROVE LETTUCE AND CHARD PRODUCTION

Abstract
Abstract - Climate variations are one of the most important factors for global food security. Considering current models of climate change, the decrease in soil water availability will be one of the main constraints for native plant communities and crops worldwide. Therefore, lands under osmotic stress (due to salinity and/or drought) are expected to increase during this century, negatively affecting food production. For centuries, the growth and survival of plants has been subject, on many occasions, to their ability to adjust their physiology to tolerate the impacts of different types of stress, whether biotic or abiotic, as well as mutualistic interactions with beneficial microbes associated with their roots (such as mycorrhizal fungi, root endophytes, and rhizosphere bacteria). Recent studies show that functional symbiosis, is one of the most important strategies to improve crop production or yield. In this study, we conducted trials in which lettuce and chard plants (N=100) were inoculated with spores of Antarctic endophytes isolated from two native plants of Antarctica, Colobanthusquitens and Deschamsia antarctica, which were subsequently identified using molecular biology and morphological approaches. The strains selected for this study were Penicillium chrysogenum and Penicillium brevicompactum, as they had the highest hydrolytic enzyme activities and enzymatic activities involved in the breakdown of carbohydrates or proteins and phosphorus solubilization. Our results show that lettuce and chard plants, in the presence of endophytes and with 25% less water, achieve yields close to those of plants with 100% water without endophyte addition. Likewise, inoculated plants with 100% water obtained yields about 15% higher than plants with the same amount of irrigation water without inoculation. Our findings suggest that root endophytes play a pivotal ecological role not only in their ability to decompose different sources of nutrients but also in accelerating nitrogen mineralization, improving nutrient acquisition, and promoting plant growth in soils under water stress. ACKNOWLEDGMENT - ANID through Project ID22I10300 and DICREA-UBB. BIOGRAPHY S Acuña-Nelson has completed his PhD in Chemical Engineering from Universidad de Concepción, Chile. He has published more than 25 papers in reputed journals and have been a reviewer of several renowned scientific journals. Currently, he is an associate professor in the Food Engineering Department at the Universidad del Bío-Bío, Chile.