(800-52) Built Better: Evaluating Field Performance of Inducible vs Constitutive Promoters Controlling Stress Response Transgenes in Hybrid 717-1B4 Populus tremula x alba
Graduate Research Assistant West Virginia University Morgantown, West Virginia
Body of Abstract: Plant biomass conversion into biofuels is one route to renewable energy, and highly productive sustainable feedstock plants are crucial for the transition away from fossil fuels. High stress tolerance is necessary in feedstocks used for large scale plantations that will be installed on marginal lands to avoid competition with agricultural production. To improve performance under stress conditions a Poplar hybrid species, Populus tremula x alba, has been transformed with drought, salt, and heat stress response transgenes paired with both constitutive and inducible promoters making up 25 transgenic lines that are currently being evaluated in a field study. Environmental and soil monitoring data paired with the physiological and growth data of ~400 individual trees is being collected in two randomized block design fields. Height and SPAD are measured every two weeks, as well as porometer and fluorometer data measured using an LI-600 to track physiological responses to moisture changes during periods of high and low soil moisture. Differences in stomatal activity and transpiration can be seen between promoter types as well as within transgenic lines, and continuous growth monitoring shows the impacts of these differences on biomass production. Preliminary data shows low growth rates in constitutive heat response line HSFA8 compared to other constitutive heat response lines and their inducible counterparts, suggesting individual transgene expression may have more impact on field behavior than promoter type.