Insights into the Novel FAD2 Gene Regulating Oleic Acid Accumulation in Peanut Seeds with Different Maturity

Abstract

AhFAD2 is a key enzyme catalyzing the conversion of oleic acid into linoleic acid. The high oleic acid characteristic of peanut mainly comes from the homozygous recessive mutation of AhFAD2A and AhFAD2B genes (aabb). However, even in high-oleic-acid varieties with the aabb genotype, the oleic acid content of seeds with different maturity varies significantly. Therefore, in addition to AhFAD2A and AhFAD2B, other FAD2 members or regulators may be involved in this process. Which FAD2 genes are involved in the regulatory processes associated with seed maturity is still unclear. In this study, four stable lines with different genotypes (AABB, aaBB, AAbb, and aabb) were used to analyze the contents of oleic acid and linoleic acid at different stages of seed development in peanut. Three new AhFAD2 genes (AhFAD2–7, AhFAD2–8, and AhFAD2–9) were cloned based on the whole-genome sequencing results of cultivated peanuts. All peanut FAD2 genes showed tissue preference in expression; however, only the expression level of AhFAD2-7 was positively correlated with the linoleic acid concentration in peanut seeds. These findings provide new insights into the regulation of oleic acid accumulation by maturity, and AhFAD2-7 plays an important role in the maturity dependent accumulation of oleic acid and linoleic acid in peanut.

The Effect of Harvest Dates on Production, Lipid Composition, Aspergillus Section Flavi Contamination, and Aflatoxin Production in High Oleic Acid Peanut Cultivars in Brazil

“…These results agree with those described in the literature since linoleic acid production is related to oleic acid. The peanut kernel produces oleic acid, and the Δ12-fatty acid desaturase catalyzes the oleic acid conversion into linoleic acid . So, as the oleic acid concentration reduces, linoleic acid concentration increases.…”

“…The peanut kernel produces oleic acid, and the Δ12-fatty acid desaturase catalyzes the oleic acid conversion into linoleic acid. 43 So, as the oleic acid concentration reduces, linoleic acid concentration increases. The results from the current study show that this conversion was stable.…”

Genotype, environment, and their interaction effects on peanut seed protein, oil, and fatty acid content variability

“…The determination of oleic and linoleic acid ratio (O/L) by FAD2A / FAD2B genes are well studied and documented in peanuts (Lópes et al., 2000; Moore & Knauft, 1989; Zhao et al., 2022). The O/L ratio from low to high is sequentially determined by four genotypes ( AABB , no mutation on both A and B genomes < aaBB , single mutation on genome A but not on genome B < AAbb , single mutation on genome B but not on genome A < aabb , double mutations on both A and B genomes) from the functional mutations of FAD2A / FAD2B genes (Wang et al., 2018).…”

Multi‐omics‐driven advances in the understanding of triacylglycerol biosynthesis in oil seeds

“…Based on whole genome sequencing of cultivated peanuts, three new AhFAD2 genes (AhFAD2-7, AhFAD2-8, AhFAD2-9) were cloned. The expression of AhFAD2-7 is positively correlated with the content of LA and the degree of peanut growth (Zhao et al, 2022).…”

“…Based on whole genome sequencing of cultivated peanuts, three new AhFAD2 genes ( AhFAD2‐7 , AhFAD2‐8 , AhFAD2‐9 ) were cloned. The expression of AhFAD2‐7 is positively correlated with the content of LA and the degree of peanut growth (Zhao et al., 2022). Recently, new mutations in the cis ‐regulatory regions of the 5′ UTR and intron of the ahFAD2 gene using CRISPR/Cas9‐mediated gene editing were created, thereby increasing the OA content in soybean seeds (Neelakandan et al., 2022).…”