Two trials to activate a defensive response pathway and observe FAD2 mRNA quantities in wounded zucchini leaves were conducted resulting in similar findings. The northern blot with the labeled RNA showed an equal intensity of hybridizing bands at all three times. A third experiment was also run to compare possible differences in FAD2 expression between dark and light-grown plants and in different tissues. However comparison of FAD2 expression in root and leaf samples suggested equal steady state mRNA levels. If increased mRNA accumulation occurred in response to wounding, we would have expected to see an increase in the intensity of the FAD2 hybridizing bands over time after wounding.
Plants have many fatty acid desaturase genes with similar sequences.
High stringency was used in probe hybridization, however and we believe that the bands strictly display the mRNA associated with FAD2. The results that we are observing are preliminary results that still can be confirmed. Future study of the FAD2 gene might include a longer wounding experiment or possibly focus on the systemic amounts of mRNA as opposed to the local wounding we performed. Further investigation into how zucchini plant responses and gene sequences are different from other plants studied could be yet another follow-up of this project. This research was supported by M. J. Murdock Charitable Trust.