Friday, October 28, 2011
Hall 1-2 (San Jose Convention Center)
Influx of carbon dioxide (CO2) into plant leaves and the efflux of water is a mechanism vital for proper plant growth and development. By taking in CO2 and transpiring water, plants obtain nutrients and carbon for production of biomass, releasing oxygen (O2) as a by-product. By examining the effects of overexpression of a stomatal density gene in poplar, we hope to genetically alter water loss from stomatal pores without hindering normal biomass accumulation and development. Our results show unaltered biomass production and decreased water loss. Using gravimetric transpiration analysis of transgenics overexpressing the EPIDERMAL PATTERNING FACTOR1 (EPF1) gene from Arabidopsis thaliana (AtEPF1) and its poplar (Populus tremula x P. alba) ortholog (PtaEPF1), numerical data confirmed decreased water loss and unaltered biomass acquisition. In addition to the improved water-use efficiency (WUE), transgenic plants demonstrated morphological changes not seen in Arabidopsis plants, such as arrested stomatal development and abnormal spacing, that may indicate an additional function of the EPF1 gene in poplar not described in Arabidopsis.