Genetically engineering Crambe abyssinica—A potentially high‐value oil crop for salt land improvement

Abstract

Crambe abyssinica (crambe) is a new industrial oil crop that can grow on saline soil and tolerates salty water irrigation. Genetically engineered crambe in which the seed‐oil composition is manipulated for more erucic acid and less polyunsaturated fatty acid (PUFA) would be highly beneficial to industry. In this research, lysophosphatidic acid acyltransferase 2 RNA interference (CaLPAT2‐RNAi) was introduced into the crambe genome to manipulate its oil composition. The result showed in comparison with wild type, CaLPAT2‐RNAi could significantly reduce linoleic and linolenic acid content, simultaneously increasing erucic acid content. Systematic metabolism engineering was then carried out to further study CaLPAT2‐RNAi, combined with the overexpression of Brassica napus fatty acid elongase (BnFAE), Limnanthes douglasii LPAT (LdLPAT), and RNAi of endogenous fatty acid desaturase 2 (CaFAD2‐RNAi). Oil composition analysis on the tranformants' seeds showed that (a) with CaFAD2‐RNAi, PUFA content could be dramatically decreased, in comparison with BnFAE + LdLPAT + CaFAD2‐RNAi, and BnFAE + LdLPAT + CaFAD2‐RNAi + CaLPAT2‐RNAi seeds showed lower linolenic acid content; (b) BnFAE + LdLPAT + CaFAD2‐RNAi + CaLPAT2‐RNAi could increase the erucic acid content in crambe seed oil from less than 66.6% to 71.6%, whereas the highest erucic acid content of BnFAE + LdLPAT + CaFAD2‐RNAi was 79.2%; (c) although the four‐gene combination could not increase the erucic acid content of seed oil to a higher level than the others, it led to increased carbon resource deposited into C22:1 and C18:1 moieties and lower PUFA. Summarily, the present research indicates that suppression of LPAT2 is a new, promising strategy for seed‐oil biosynthesis pathway engineering, which would increase the value of crambe oil.

Towards sustainable agriculture for the salt‐affected soil

“…seedlings and got two important salt‐tolerant genes (GmNHX1 and GmNcl1), providing potential base for biotechnologically breed soybean to meet salt‐resistant planting. Nikalje, Nikam, and Suprasanna (), Nikalje et al (), and Qi et al () systemically reviewed halophytes selection, related mechanism, utilization, and added value from the angle of physiology, biochemistry, molecular biology, and biotechnology, providing insights into constructing sustainable mudflat salt‐affected agricultural ecosystem with high efficiency.…”

“…So breeding salt-tolerant crops is vital to feed the increasing population (Yamaguchi & Blumwald, 2005). Now, genetic engineering with salt-tolerant genes especially from halophytes is selected as the better strategy to raise crop salt resistance (Himabindu et al, 2016;Mishra & Tanna, 2017;Nikalje, Srivastava, Pandey, & Suprasanna, 2018;Qi et al, 2018;Tang, Mu, Shao, Wang, & Brestic, 2014).…”

“…For example, planting Jerusalem artichoke reduced the salt content of soils characterized by high and moderate salinity and also declined the soil pH to a more neutral value and improved saline-alkali soil by enriching bacterial communities, enhancing phosphatase and invertase activities, decreasing soil salinity, optimizing soil structure, and transforming the soil to loam suitable for cultivation (Long, Liu, Shao, Shao, & Liu, 2016;Wang, Tang, & Shao, 2015). Partial halophytes are crop plants including industrial crop plants and medicinal plants Jesus, Danko, Fiúza, & Borges, 2015;Kemo, Philip, William, Shen, & Shi, 2017;Liesje, John, & Jasper, 2016;Meier, Finzi, & Phillips, 2017;Mishra & Tanna, 2017;Nicole & Harro, 2016;Nikalje et al, 2018;Qi et al, 2018). Salt-tolerant mechanisms by halophytes include accumulating inorganic ions and organic solutes for osmotic regulation, keeping ion in balance by reducing Na + intake, and increasing Na + efflux as well as cellular or tissue compartmentalization, detoxification of reactive oxygen species (ROS) by antioxidant systems (Tom, Guiomar, & Paula, 2018).…”

Physical and physiological changes of Crambe abyssinica Hochst seed during maturation

“…Crambe oil contains high levels of erucic acid, which is widely used to create chemical products, plastic bags, cosmetics, detergents and other chemical compounds for industry (Qi et al, 2018) and other electrical components that this crop and its derivatives continue to gain economic importance. Studies on crambe have intensified, aiming to develop technologies to increase the knowledge about this crop, from acquisition of high quality seeds to handling and production techniques, since it is known that the crop success starts with the use of high quality seeds and that previous knowledge of the characteristics required for seed maturation is fundamental.…”

Engineering of a novel gene from a halophyte: Potential for agriculture in degraded coastal saline soil

“…The success in getting stress tolerant plant through conventional breeding has not been very encouraging. Recent advances in the tools and techniques of molecular biology have made it possible to study genetic structure, gene function, its regulation and expression, and finally culminating in transgenics for abiotic stress tolerance (Cao, Li, Liu, Kong, & Tran, ; Qi et al, ).…”