Browsing by Subject "Stomata"

Stomata are microscopic pores; surrounded by a pair of guard cells; they play a crucial role in minimizing the trade-off between conservation of water and photosynthetic efficiency. SLAC1, a stomatal anion channel protein mediates stomatal closure in response to elevated CO2 concentration. Genetic evidence suggested that Populus SLAC1 might have lost its function. In this study hybrid aspen (P. tremula L. × P. tremuloides Michx.) clone 51 was transformed by introducing Arabidopsis thaliana SLAC1 gene regulated by either SLAC1 or GC1 promoter. The aim was to find out guard cell specific promoter and to select transgenic lines that showed rapid stomatal closure in response to elevated CO2 concentration. Histochemical GUS assay suggested that the SLAC1 promoter is more guard cell specific than GC1 promoter. The gas exchange experiment showed an overall decrease in stomatal conductance in transgenic lines with the increasing CO2 concentration compared to wild type plants. However, it was difficult to select the strongest transgenic lines, as all the replicates of independent lines did not show clear response of stomatal closure; in response to elevated CO2 concentration.