Fatty acid analysis of Arabidopsis thaliana seeds transformed with class 2 non-symbiotic hemoglobins

English. Biodiesel is a renewable resource that can help reduce the use of fossil fuels and climate change. The main thing holding biodiesel back is the vast quantities of plant oils needed for its production. Increasing the amount of oil produced could greatly increase the economical viability of biodiesel. One way of increasing the amount of oil produced is to increase the yield from the crops themselves. This research tries to investigate the possibility of using non-symbiotic hemoglobins to increase the oxygen transportation in the developing seeds, improving energy state and oil production. This research uses Arabidopsis thaliana as a model organism but the results gathered here should be adoptable to other oil-crops.

English. As the world’s energy demand increases, we burn more and more fossil fuels every year. This increases the amount of greenhouse gases that are released into our atmosphere, escalating global warming and changing the climate of our planet. Reducing our use of fossil fuels is therefore a necessity for stopping climate change. Using biodiesel, a possible replacement for petroleum diesel, is one possibility. Biodiesel can be produced from renewable resources such as plant oils. This results in low net carbon dioxide (CO2) emissions since the CO2 released from the fuel to the atmosphere is again trapped by the plant as it grows. So what is preventing us from using biodiesel instead of petroleum diesel right now? The answer is that we simply cannot produce enough oil from plants. So, how can we increase that oil? One way is to expand the cultivating area of oil crops. However, this is not always easy since the land is usually used for food production. But, is it possible to increase the yield in the land that is already used? Yes, by applying genetic engineering techniques that can allow us to change both the quality and the amount of oil in oil crops. Previous studies using rape seed, a commonly used oil crop, have shown that the oil production in developing seeds is limited by low oxygen concentrations. In a second study, using Arabidopsis thaliana, a plant related to rape seed used as a model organism for plant genetics studies, the plants were genetically engineered to over express a protein called class-2 non-symbiotic hemoglobin (nsHb). This Hb is believed to be an oxygen carrier that would stimulate the oil production increasing the availability of oxygen to the growing seeds. The results were very positive, and the oil content in the seeds increased by 40%. Our research builds upon these studies. We used three different lines of genetically engineered A. thaliana to investigate whether we can use Hb to increase the yield of oils. Two class-2 nsHbs were used, one from A. thaliana and one Beta vulgaris. One oxygen carrier Hb from Vitreoscilla stercoraria was also used. The genetically engineered lines were grown in a controlled environment together with a non-genetically engineered control group. The seeds from the plants were collected and their fatty acids quantified and analyzed. The results did not show a significant difference in the amount of oil between the control and the modified lines. However, differences were observed in the oil composition. These results are preliminary and more analysis needs to be done, including expression analysis. Our results are different from the previous study, but it still remains to be known if it is due to different growth conditions or expression problems in our lines.