Over-expression of AtPAP2 in <it>Camelina sativa </it>leads to faster plant growth and higher seed yield

<p>Abstract</p> <p>Background</p> <p>Lipids extracted from seeds of <it>Camelina sativa </it>have been successfully used as a reliable source of aviation biofuels. This biofuel is environmentally friendly because the drought resistance, frost tolerance and low fertilizer requirement of <it>Camelina sativa </it>allow it to grow on marginal lands. Improving the species growth and seed yield by genetic engineering is therefore a target for the biofuels industry. In <it>Arabidopsis</it>, overexpression of purple acid phosphatase 2 encoded by <it>Arabidopsis </it>(<it>AtPAP2</it>) promotes plant growth by modulating carbon metabolism. Overexpression lines bolt earlier and produce 50% more seeds per plant than wild type. In this study, we explored the effects of overexpressing AtPAP2 in <it>Camelina sativa</it>.</p> <p>Results</p> <p>Under controlled environmental conditions, overexpression of AtPAP2 in <it>Camelina sativa </it>resulted in longer hypocotyls, earlier flowering, faster growth rate, higher photosynthetic rate and stomatal conductance, increased seed yield and seed size in comparison with the wild-type line and null-lines. Similar to transgenic <it>Arabidopsis</it>, activity of sucrose phosphate synthase in leaves of transgenic <it>Camelina </it>was also significantly up-regulated. Sucrose produced in photosynthetic tissues supplies the building blocks for cellulose, starch and lipids for growth and fuel for anabolic metabolism. Changes in carbon flow and sink/source activities in transgenic lines may affect floral, architectural, and reproductive traits of plants.</p> <p>Conclusions</p> <p>Lipids extracted from the seeds of <it>Camelina sativa </it>have been used as a major constituent of aviation biofuels. The improved growth rate and seed yield of transgenic <it>Camelina </it>under controlled environmental conditions have the potential to boost oil yield on an area basis in field conditions and thus make <it>Camelina</it>-based biofuels more environmentally friendly and economically attractive.</p>