Inheritance of high oleic acid content in new sourcesof groundnut (Arachis hypogaea L.)

In view of growing importance of oil quality, an understanding of the inheritance of high oleic acid is essential to breed for high oleate groundnuts. Hence an investigation was undertaken to infer genes governing the high oleic acid in newly identified sources of groundnut. Number of crosses studied were one with low × medium (TAG 24 × TPG 41), two with low × high (TAG 24 × ICG 2381 and TAG 24 × 104 P51) and with one medium × high oleic acid (TPG 41 × 104 P 56) cross combinations during post rainy season of 2010 at Main Agricultural Research Station of University of Agricultural Sciences, Dharwad, India. Individuals in F2 generation segregated in the ratio 3:1 in the crosses of low × medium and medium × high crosses and 15:1 in low × high cross combinations suggesting duplicative recessive genes governing the high oleate trait.

Differential Lipotoxic Effects of Palmitate and Oleate in Activated Human Hepatic Stellate Cells and Epithelial Hepatoma Cells

Background/Aims: Nonalcoholic fatty liver disease (NAFLD) progression to fibrosis, cirrhosis and hepatocellular carcinoma, alters the cellular composition of this organ. During late-stage NAFLD, fibrotic and possibly cancerous cells can proliferate and, like normal hepatocytes, are exposed to high concentrations of fatty acids from both surrounding tissue and circulating lipid sources. We hypothesized that primary human activated hepatic stellate cells and epithelial hepatoma (HepG2) cells respond differently to lipotoxic conditions, and investigated the mechanisms involved. Methods: Primary activated hepatic stellate cells and HepG2 cells were exposed to pathophysiological concentrations of fatty acids and comparative studies of lipid metabolic and stress response pathways were performed. Results: Both cell types remained proliferative during exposure to a combination of palmitate plus oleate reflective of the general saturated versus unsaturated fatty acid composition of western diets. However, exposure to either high palmitate or high oleate alone induced cytotoxicity in activated stellate cells, while only palmitate caused cytotoxicity in HepG2 cells. mRNA microarray and biochemical comparisons revealed that stellate cells stored markedly less fatty acids as neutral lipids, and had reduced capacity for beta-oxidation. Similar to previous observations in HepG2 cells, palmitate, but not oleate, induced ER stress and actin stress fiber formation in activated stellate cells. In contrast, oleate, but not palmitate, induced the inflammatory signal TXNIP, decreased cytoskeleton proteins, and decreased cell polarity preceding cell death in activated stellate cells. Conclusions: Palmitate-induced lipotoxicity was associated with ER stress pathways in both primary activated hepatic stellate cells and epithelial hepatoma cells, whereas high oleate caused lipotoxicity only in activated stellate cells, possibly through a distinct mechanism involving disruption of cytoskeleton components. This may have implications for optimal dietary fatty acid compositions during various stages of NAFLD.

Effect of Production Environment on Seed Quality of Normal and High-Oleate Large Seeded Virginia-Type Peanut (Arachis hypogaea L.)

ABSTRACT Six Virginia-type peanut (Arachis hypogaea L.) cultivars and their paired backcross-derived high-oleate lines were grown during 2003 and 2004 in North Carolina to compare standard germination (SG), cool germination (CG), and electrical conductivity (EC) of seed. Oleic acid level had no influence on SG but did alter CG and EC compared to the corresponding normal oleate cultivars. Averaged across background genotypes, high-oleate lines had lower seed vigor than their paired lines with normal oleic content. The high-oleate lines of three of the six pairs had lower CG and higher EC. Planting and harvest date affected all the seed quality traits measured. Standard germination of both normal and high-oleate lines was reduced in 2004 when harvest was delayed, but was not affected in 2003. In 2003, CG of the high-oleate lines was lower than that of normal lines in three of the four production environments; EC was higher in the high-oleate lines in all planting date and harvest date combinations. In 2004, there was no difference between the CG of normal and high-oleate lines, but EC was higher in the high-oleate lines for three of the four environments. In the greenhouse, the Virginia-type cultivars NC-V 11 and Gregory, along with their paired backcross-derived high-oleate lines were compared at 22/18 C, 26/22 C and 30/26 C day/night temperature regimes. Seed oleic to linoleic acid (O/L) ratio of normal peanut grown in 30/26 C, 26/22 C, and 22/18 C, measured 1.9, 1.5, and 1.3, respectively. The O/L ratio for their high-oleate pairs decreased from 24.7 when grown in 30/26 C to 15.9 in 26/22 C and to 13.7 in 22/18 C. Temperature did not affect the fatty acid composition of axis total lipid or phospholipid fractions. The high-oleate trait was expressed in the axis lipids. The average O/L ratio of axes from normal peanut was 1.1 while that of high-oleate lines was 4.6. Likewise, axis phospholipids for normal and high-oleate lines were 1.0 and 5.9. A lower production environment temperature decreased the O/L ratio of seed oil of high-oleic peanut lines, and the high-oleate trait expressed in peanut seed storage lipids is also expressed in axis membrane lipids to a lesser degree.

Predicting Main Fatty Acids, Oil and Protein Content in Intact Single Seeds of Groundnut by near Infrared Reflectance Spectroscopy

Eighty-four, 61 and 105 groundnut seeds, including high oleate genotypes and F2 seeds of normal oleate × high oleate crosses, genotypes with high or low oil and F2 seeds from high oil × low oil crosses, and randomly selected samples representing various origins, different seed sizes, and varied seed coat color and protein content, were used to develop the NIRS models for main fatty acids, oil and protein. For oleic, linoleic and palmitic acid, the optimized spectrum pretreatment method was first derivative plus multiplicative scattering correction; for stearic acid and the four bad fatty acids, first derivative plus vector normalization. The Rcal2 and RMSECV for oleic acid were 97.20% and 2.65%; for linoleic acid, 96.90% and 2.40%; and for palmitic acid, 93.39% and 0.53%, respectively. The best spectrum pretreatment method for oil and protein was first derivative plus multiplicative scattering correction and min-max normalization. For oil and protein, the Rcal2 was 89.06% and 91.45%, and RMSECV, 0.89% and 0.78%, respectively. The NIRS models can be used to develop groundnut cultivars both with high oil and with high oleate to cater the growing need for biodiesel production.