Multigene Engineering of Triacylglycerol Metabolism Boosts Seed Oil Content in Arabidopsis    

Abstract

Increasing the yield of oilseed crops is an important objective for biotechnologists. A number of individual genes involved in triacylglycerol metabolism have previously been reported to enhance the oil content of seeds when their expression is altered. However, it has yet to be established whether specific combinations of these genes can be used to achieve an additive effect and whether this leads to enhanced yield. Using Arabidopsis (Arabidopsis thaliana) as an experimental system, we show that seed-specific overexpression of WRINKLED1 (a transcriptional regulator of glycolysis and fatty acid synthesis) and DIACYLGLYCEROL ACYLTRANSFERASE1 (a triacylglycerol biosynthetic enzyme) combined with suppression of the triacylglycerol lipase SUGAR-DEPENDENT1 results in a higher percentage seed oil content and greater seed mass than manipulation of each gene individually. Analysis of total seed yield per plant suggests that, despite a reduction in seed number, the total yield of oil is also increased.

Genome Wide Analysis of Fatty Acid Desaturation and Its Response to Temperature

“…At the onset of flowering, about five plants of each genotype were transferred to controlledenvironment chambers set to the same photoperiod, photosynthetic photon flux density, and relative humidity but different constant temperatures ranging from 10°C to 30°C. Plants in 7-cm 2 pots were bagged to retain all seeds as described previously (van Erp et al, 2014). At maturity, seeds were harvested from either individual plants in 7-cm 2 pots or pools of approximately five plants for each genotype in P40 trays and used for further analysis.…”

“…Seed oil and moisture contents were measured by low-resolution time domain NMR spectroscopy using a Minispec MQ20 device (Bruker) fitted with a robotic sample-handling system (Rohasys) as described previously (van Erp et al, 2014). The total fatty acid composition of seeds was measured by gas chromatography analysis after combined digestion and fatty acid methyl ester formation using the method described by Browse et al (1986).…”

Phospholipase Dζ Enhances Diacylglycerol Flux into Triacylglycerol

“…Therefore, there is considerable effort to increase the oil quality and yield in plants through breeding and application of biotechnology (Tan et al, 2011;Shi et al, 2012;Haslam et al, 2013;Vanhercke et al, 2013;van Erp et al, 2014;Li et al, 2015a). Though many of the involved genes have been cataloged and enzyme activities measured, a better understanding of the coordinated metabolic network ( Fig.…”

Ectopic expression of WRI1 affects fatty acid homeostasis in Brachypodium distachyon vegetative tissues

“…The Arabidopsis wri1 mutant has an 80% reduction of seed oil content (Focks and Benning, 1998), whereas overexpression of WRI1 increases seed oil content by 10% to 20% (Cernac and Benning, 2004). WRI1 orthologs from maize (Zea mays), rape (Brassica napus), and oil palm (Elaeis guineensis) have been shown to be involved in TAG production in embryos or fruit mesocarps, and their overexpression leads to increased seed oil content (Liu et al, 2010;Shen et al, 2010;Pouvreau et al, 2011;Ma et al, 2013;van Erp et al, 2014). Ectopic expression of WRI1 has also been used to stimulate oil production in nonseed tissues in both Arabidopsis and tobacco (Nicotiana tabacum; Cernac and Benning, 2004;Sanjaya et al, 2011;Dussert et al, 2013;Kelly et al, 2013;Vanhercke et al, 2014;Grimberg et al, 2015;Ma et al, 2015).…”