Developing double mutant Arabidopsis plants deficient in fatty acid desaturase 7 and a salicylic acid pathway regulator, NPR1-1

Salicylic acid (SA) is one of several molecules whose accumulation is known to stimulate the synthesis of defense genes in Arabidopsis thaliana as well as in other green plants. Fatty acid desaturase 7 is a cytoplasmic desaturase that introduces double bonds into fatty acids. In previous experiments on both Arabidopsis thaliana and tomato (Solanum lycopersicum), it was observed that a loss of function mutation in FAD7 coincided with an increase in SA accumulation in plant cells. Additionally, in those experiments, plants displaying the fad7-1 mutation displayed increased resistance when challenged with aphids as compared to WT Arabidopsis possessing functional FAD7. However, the mechanism whereby increased resistance was mediated was not concluded from the studies. It has been hypothesized that a SA-dependent mechanism was responsible for the displayed increased resistance due to the high SA levels observed. If this is the case, then a regulator of SA pathways, NPR1, is also important in mediating increased resistance. However, plants have not yet been synthesized to specifically test whether fad7-1 mediates increased resistance via a SA pathway and NPR1 or not. Therefore, in this project, double mutant Arabidopsis plants were generated from single mutant Arabidopsis parental plants. After three generations of pollination, double mutant plants were obtained and plentiful seed was collected from them. Future experiments will utilize the seed collected from this project to test the potential role that fad7-1 has in mediating increased plant resistance via a SA-dependent mechanism and NPR1, an important SA pathway regulator