Authors: Monica A Schmidt Ken Pendarvis
Publish Date: 2016/10/22
Volume: 26, Issue: 2, Pages: 171-186
Abstract
Oilseed crops are global commodities for their oil and protein seed content We have engineered the oilseed Camelina sativa to exhibit increased protein content with a slight decrease in oil content The introduction of a phytoene synthase gene with an RNAi cassette directed to suppress the storage protein 2S albumin resulted in seeds with an 11–24 elevation in overall protein The phytoene synthase cassette alone produced enhanced βcarotene content of an average 275 ± 610 μg/g dry seed and an overall altered seed composition of 11 less protein and comparable nontransgenic amounts of both oil and carbohydrates Stacking an RNAi to suppress the major 2S storage protein resulted in seeds that contain elevated protein and slight decrease in oil and carbohydrate amounts showing that Camelina rebalances its proteome within an enlarged protein content genotype In both βcarotene enhanced seeds with/without RNAi2S suppression the seed size was noticeably enlarged compared to nontransgenic counterpart seeds Metabolic analysis of maturing seeds indicate that the enhanced βcarotene trait had the larger effect than the RNAi2S suppression on the seed metabolome The use of a GRAS generally regarded as safe βcarotene as a visual marker in a floral dip transformation system such as Camelina might eliminate the need for costly regulatory and controversial antibiotic resistance markers βcarotene enhanced RNAi2S suppressed Camelina seeds could be further developed as a rapid heterologous protein production platform in a nonfood crop leveraging its enlarged protein content and visual markerThe authors are grateful to UC Davis Proteomics Core Facility for conducting the amino acid composition analysis and to Metabolon for metabolite analysis We thank Howard Berg for photography assistance Carbohydrate analysis was performed by the Complex Carbohydrate Research Center University of Georgia supported by the Chemical Sciences Geosciences and Biosciences Division Office of Basic Energy Sciences US Department of Energy Grant DEFG0293ER20097 to Parastoo Azadi at the Complex Carbohydrate Research Center
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