Effect of temperature on polyunsaturated fatty acid accumulation in soybean seeds

Abstract

Soybean oil contains around 60 % of polyunsaturated fatty acids, which are responsible for the low oxidative stability of soy-derived products. Soybean lines with low linolenic acid content can be obtained by genetic manipulation; however, a high proportion of the variation in fatty acids content is due to environmental factors. This work aimed to determine the effect of temperature on oil composition and on the activity of the enzymes CDP-choline:1,2-diacylglycerolcholine phosphotransferase (CPT) and acyl-CoA:lysophosphatidylcholine acyltransferase (LPCAT), responsible for maintenance of polyunsaturated fatty acids in the cytoplasmic acyl-CoA pool, that is used for oil synthesis in the seeds. CAC-1, a soybean variety with linolenic acid content of about 8 % and CC4, a BC3F4 CAC-1 derived line, with about 4 % linolenic acid, were used. The lines were cultivated under two temperature: 34/28ºC or 22/13ºC - day/night. The seeds were collected along seven development stages, according to their fresh weight. Fatty acid analysis was carried out by gas chromatography and CPT and LPCAT activities were determined by measuring the radioactivity incorporated in their products, phosphatidyl-[14C]choline and phosphatidylcholine-[14C]oleoyl, respectively. Linolenic acid contents were 3.89 and 6.92 % for line CC4 and 7.39 and 12.49 % for variety CAC-1, when submitted to high and low temperature conditions, respectively. Both enzymes were more active, in the development stages analyzed, in seeds produced under low temperature. Kinetics characterization of CPT and LPCAT were conducted previously.

Regional Distribution of Protein and Oil Compositions of Soybean Cultivars in China

“…Hurburgh et al (1987) studied soybean samples from grain elevators in four states of the United States. Lannal et al (2005) reported that the content of linolenic acid increased when soybean was cultivated at lower temperatures. They also found that the decrease of protein content was greater than the increase of oil in the hot drier regions.…”

In silico characterization of 1,2-diacylglycerol cholinephosphotransferase and lysophospha­tidylcholine acyltransferase genes in Glycine max L. Merrill

“…As these genes have been studied for the improvement of soybean oil quality (Lanna et al, 2005;Lima, 2005;Martins, 2007;Sousa, 2007), the presence of at least one seed-specific gene model was expected. However, this was not observed, and the gene models were shown to be expressed in different tissues.…”

“…LPCAT activity affects the incorporation of fatty acids into the sn-2 position of PC where polyunsaturated fatty acids are formed; therefore, it indirectly influences the composition of seed TAGs (Fukurawa-Stoffer et al, 2003). The exchange of acyl groups between CoA and acyl-phosphatidylcholine is important for regulating the quality of polyunsaturated fatty acids in the acyl-CoA pool for oil synthesis in developing seeds (Lanna et al, 2005).…”

Contribution of the universities to the development of field crop cultivars

“…In the 1980s, UFV included in the objectives of its breeding program the quality improvement of soybeans for human consumption, including better taste, levels of oil and protein, elimination of antinutritional factors, reduction of polysaccharides, altered levels of unsaturated fatty acids and others (Pereira et al 1992, Araújo et al 1997, Moreira et al 1997, Utumi et al 1998, Chiari et al 2004, Lanna et al 2005, Sediyama et al 2005, Moraes et al 2006, Barros et al 2008, Teixeira et al 2012. Simultaneously, the use of biotechnology tools became part of the routine in the work of soybean breeding (Alzate-Marin et al 1996, Moreira et al 1997, Schuster et al 2001, Moraes et al 2006.…”