**2. Oilseed crops**

Seed oil is mainly obtained from plants recognized as oilseed crops, among them are: soybean (*Glycine max*), rapeseed/canola (*Brassica napus*), palm (*Elaeis guineensis*), mustard (*Sinapis hirta*), sunflower (*Helianthus annuus*), cottonseed (*Gossypium hirsutum*), flax (*Linum usitatissimum*), peanut (*Arachis hypogaea*), camelina (*Camelina sativa*), castor bean (*Ricinus communis*), jatropha (*Jatropha curcas*), tung tree (*Aleurites fordii*), jojoba (*Simmondsia chinensis*), sacha inchi (*Plukenetia volubilis*), niger seed (*Guizotia abyssinica*) and others [2]. Over the last decades, the adoption of these crops has been growing up significantly, reaching in 2014 more than 300 million hectares of oil crops worldwide cultivated [**Figure 1**] [3]. The main reason for this growth is due to seed oils are so attractive for industries, as mentioned in the previous paragraph, but also for the possibility to use their sub-products (metabolites) in biofuels development [4] and approaching their polyhydroxyalkanoates (PHAs) in response to petrol-based plastics waste's problems and harmful effects on the environment [5].

**Figure 1.** Total world area of oil crops harvested between 1961 and 2014 (FAOSTAT).

Seed oils applications depend on physical and chemical properties of their fatty acids composition [6]. Those oils are mainly composed of five major fatty acids, including the saturated palmitic (C16:0) and stearic (C18:0) acids, the monounsaturated oleic acid (C18:1), and the polyunsaturated LA (C18:2) and ALA (C18:3) [6]. A large variety of other less common but not less important fatty acids can be found in different species and used for various industrial applications. These fatty acids vary in the number of carbons in the chain (from 8 to 24), the number of double bonds, and the presence of epoxy, hydroxyl and other functional groups [7].

structure and composition, those oils are used as food/industrial feed [2] and as a range of product applications such as surfactants, soap, detergents, lubricants, solvents, paints, inks, chemical feedstocks and cosmetics [1]. In this study, a review about the main advances in genetic improvement of oilseed crops, starting with omics to understand metabolic routes and to find out key genes in seed oil production, and also, getting in use of modern biotechnology including genetic engineering and new breeding techniques (NBTs), a modern-breeding tool that has allowed the functional study of genes with potential application for breeding in agriculture, focusing on oilseed crop genetic improvement with high precision and less uncertainty (avoiding whole genomes crossing), and of course, in less time is presented; those scientific efforts where it was sought to upset fatty acids production or biotic tolerance will also be presented.

Seed oil is mainly obtained from plants recognized as oilseed crops, among them are: soybean (*Glycine max*), rapeseed/canola (*Brassica napus*), palm (*Elaeis guineensis*), mustard (*Sinapis hirta*), sunflower (*Helianthus annuus*), cottonseed (*Gossypium hirsutum*), flax (*Linum usitatissimum*), peanut (*Arachis hypogaea*), camelina (*Camelina sativa*), castor bean (*Ricinus communis*), jatropha (*Jatropha curcas*), tung tree (*Aleurites fordii*), jojoba (*Simmondsia chinensis*), sacha inchi (*Plukenetia volubilis*), niger seed (*Guizotia abyssinica*) and others [2]. Over the last decades, the adoption of these crops has been growing up significantly, reaching in 2014 more than 300 million hectares of oil crops worldwide cultivated [**Figure 1**] [3]. The main reason for this growth is due to seed oils are so attractive for industries, as mentioned in the previous paragraph, but also for the possibility to use their sub-products (metabolites) in biofuels development [4] and approaching their polyhydroxyalkanoates (PHAs) in response to petrol-based

plastics waste's problems and harmful effects on the environment [5].

**Figure 1.** Total world area of oil crops harvested between 1961 and 2014 (FAOSTAT).

**2. Oilseed crops**

296 Advances in Seed Biology

Despite the industry's significant interest in oil crops, it is reasonable to mention that agriculture has a challenging future. The Food and Agriculture Organization of the United Nations (FAO) in 2009 presented the big challenges facing the agricultural sector in the world for near future [8]. Human population growth, increased life expectancy, loss of biodiversity, climate change and accelerated land degradation are main factors contributing to rethink agriculture system production. Thus, there is a need to technify agricultural production systems, but without doubt, developing genetic improvement toward getting an efficient and sustainable agriculture, generating new seed qualities (new traits), such as, among others, high content of PUFAs in oilseed crops, it will be an aiming. Biotechnology will be fundamental to overcome these challenges. Genetic engineering techniques may play an important role by elevating the content of individual fatty acids or drastically changing the oil quality by the introduction of a new fatty acid,

**Figure 2.** Growing in the number of publications with the words "oildseed crops" in the title, abstract or keywords of scientific articles. Records subtracted from literature databases: Scopus (bars in grey), Web of Science (bars in black) and ScienceDirect (bars with horizontal lines).

thus increasing raw materials available for oleochemistry. In this perspective, it has came growing research efforts of scientist around the world seeking to expand the knowledge barrier on oilseed crops. **Figure 2** shows continuous growth in the number of scientific publications in this field, records subtracted from literature databases: Scopus, Web of Science, and ScienceDirect.
