Regulation and enhancement of lipid accumulation in oil crops: The use of metabolic control analysis for informed genetic manipulation

Abstract

Plant oils are a very valuable agricultural commodity. They are currently mainly used (>80%) for food and animal feed but, increasingly, they have utility as renewable sources of industrial feedstocks or biofuel. Because of finite agricultural land, the best way to increase availability (in order to match demand) is by improving productivity. To do this requires a knowledge of metabolism and its regulation. Various methods have been used to provide information but only systems biology can yield quantitative data about complete metabolic pathways. We have used metabolic control analysis to provide information about major oil crops such as oilseed rape, oil palm, olive, and soybean. Such knowledge has then been used to inform genetic manipulation for crop improvement.Abbreviations: MCA, metabolic control analysis; QTL, quantitative trait loci Eur.

Properties and Biotechnological Applications of Acyl‐CoA:diacylglycerol Acyltransferase and Phospholipid:diacylglycerol Acyltransferase from Terrestrial Plants and Microalgae

“…TAG can also be synthesized through acyl-CoAindependent pathways via the catalytic action of PDAT, which catalyzes the transfer of an acyl moiety from the sn-2 position of phosphatidylcholine (PtdCho) to the sn-3 position of sn-1, 2-DAG to yield TAG (Dahlqvist et al, 2000;Ståhl et al, 2004). Both DGAT and PDAT play crucial roles in determining the flux of carbon into TAG (Aznar-Moreno and Harwood et al, 2013;Zhang et al, 2009). They also contribute to the routing of modified fatty acids from PtdCho into TAG in some plant species, such as flax (Linum usitatissimum), castor (Ricinus communis), tung tree (Vernicia fordii), and ironweed (Vernonia galamensis), which produce relatively high levels of polyunsaturated or unusual fatty acids in their seed oils (Kim et al, 2011;Kroon et al, 2006;Li et al, 2010a;Pan et al, 2013;Shockey et al, 2006;van Erp et al, 2011).…”

“…DGAT1 is considered to play a critical role in determining the flux of carbon into seed TAG in some species (Harwood et al, 2013). In oilseed crops such as canolatype B. napus and safflower (Carthamus tinctorius), the level of DGAT activity was found to be coordinated with oil accumulation during seed development (Tzen et al, 1993;Weselake et al, 1993).…”

Preferred carbon precursors for lipid labelling in the heterotrophic endosperm of developing oat (Avena sativa L.) grains

“…Therefore, our data suggest that one reason to the higher oil content in the HO cultivar is a more efficient transfer of formed FAs from PL into TAG (Stymne and Stobart, 1987). To further elucidate which specific enzymes in acyl lipid metabolism that exert a strong influence in the flow of acyl groups from PL to TAG, one approach could be to use metabolic control analysis (Harwood et al, 2013), but also classical biochemistry. There is a number of enzymes involved in this process, such as phospholipid:diacylglycerol acyltransferase (PDAT), acyl-CoA:lysophosphatidylcholine acyltransferase (LPCAT), and phospholipases (Bates et al, 2013).…”

Inspiré par les lipides (Médaille Chevreul 2014)

“…Il y a diverses manières d'obtenir des informations sur la régulation de l'accumulation d'huile dans la graine oléagi-neuse (voir Harwood et al, 2013). Parmi ces méthodes, nous avons utilisé l'analyse de contrôle pour obtenir des informations quantitatives.…”

“…Quand ces graines transgéniques ont été plantées pour des essais de plein champ sur deux années successives, une augmentation de 8 % du rendement en huile a été observée (Taylor et al, 2009). Ce résultat rassurant a montré l'utilité d'utiliser l'analyse de contrôle de flux pour sous-tendre des tentatives futures d'utiliser une modification génétique pour accroître les rendements en huile (Harwood et al, 2013). Un point mérite d'être ajouté concernant la manipulation de la culture.…”