**5. Conclusion**

in increasing oil composition and content which was demonstrated in some experiments in transgenic yeast. This report shows an important way for further studies due to LPAAT genes that are involved in natural cottonseed oil content and variation which should open a possible strategy in development of genetically modified cotton crops with improvement of seed oil

Peanut (*Arachis hypogaea*) is grown worldwide as an oilseed crop. In many countries, peanut seeds do an important contribution to the people diet because they are a good source of proteins and lipids for human nutrition. [85] determined that peanut seeds which are rich in oil (about 50% of seed composition) and oleic acid (18:1), linoleic acid (18:2), palmitic acid (16:0), behenic acid (22:0), eicosenoic acid (20:1), stearic acid (18:0), arachidic (20:0) and lignoceric acid (24:0) are presented (sorted from highest to lowest content). However, the fatty acid composition of peanut oil varies depending on the seed maturity, genotype, growth location,

Research about transgenic peanut crops has been undertaken for the development of fungi resistant. This crop is susceptible to many types of pathogens including those caused by fungi. Chenaulr et al. [87] reported the development of transgenic peanuts which were introduced two hydrolase genes, a glucanase from alfalfa (*Medicago sativa* L.), and a chitinase from rice (*Oryza sativa* L.) into somatic embryos using biolistic. Although the study focused on seedlings characterization (found up to 37% of hydrolase activity in transgenic lines), these authors assume that transgenic lines obtained could be promising due to high transgene expression what would exhibit some level of resistance to a broad range of fungal pathogens. Following with the same modified peanut lines, Chenault et al. [88] developed an assay under greenhouse conditions where these lines were tested for resistance to *Sclerotinia minor* by inoculation with a mycelial plug. There were lines up to 84% of resistance to the pathogen. On the other hand, the peanut lines considered more resistance kept going in race and were tested for *S. minor* resistance under field conditions [89]. In that report, three transgenic lines showed a significant resistance to the pathogen compared with the wild-type cultivar. Finally, Jonnala et al. [90] determined the oil composition of the best three transgenic lines obtained in the previous report. This author reported similar oil content of all transgenic peanut lines to that wild-type lines, indicating that genetic modification did not cause substantial unintentional changes in peanut chemical composition. In the same way, Ng et al. [91] examined chemical characteristics, volatile components, and olfactory characteristics of those three GM peanut lines (previously tested at field conditions) using gas chromatograph/mass spectrometer (GC/MS) equipped with an olfactory detector. These authors reported minimal variations in nutritional composition between GM peanuts and wild type, indicating that

Olive oil production and consumption are increasing in importance around the world. Spain is the largest producer with an average 1 million tons per year, followed by Italy and Greece

content and composition.

308 Advances in Seed Biology

**4.7. Peanuts (***Arachis hypogaea***)**

climatic conditions, and they together [86].

genetic modifications did not cause significant change in peanut.

**4.8. Olive (***Olea europaea* **L.)**

As it was seen throughout the review, last three decades, for these oilseed crops: soybean (*Glycine max*), sunflower (*Helianthus annuus*), canola (*Brassica napus*), palm (*Elaeis guineensis*), castor bean (*Ricinus communis*), cotton (*Gossypium* spp.), peanut (*Arachis hypogaea*) and olive (*Olea europaea*), it has been evidenced a strong development supported by modern biotechnology, and there should be no doubt that, carefully undertaken, genetic engineering represents a very safe, fast and, low-cost method to enrich important oilseed crops for essential nutritional contents. Ongoing and future research will have to face big challenges in agriculture.
