The FAD2 Gene in Plants: Occurrence, Regulation, and Role

Abstract

Vegetable oils rich in oleic acid are more desirable than oils rich in polyunsaturated and saturated fatty acids. The biological switch of oleic acid to linoleic acid is facilitated by fatty acid desaturase 2 enzyme that is further classified into FAD2-1, FAD2-2, FAD2-3, and FAD2-4. The genes coding these enzymes have high sequence similarity, but differ mostly in their expression patterns. The seed-type FAD2 genes had evolved independently after segregation by duplication from constitutively expressed FAD2 genes. Temperature, light and wounding effectively regulate FAD2 expression in plants. FAD2 genes are expressed differently in different tissues of the plant, and the over-expression of FAD2 modifies physiological and vegetative characteristics. The activity of FAD2 leads to an increase in the content of dienoic fatty acids, and hence increases the resistance toward cold and salt stress. The thorough study of the FAD2 gene is important for understanding the expression, regulation and mechanism that will help in improving the quality of oil and stress resistance in plants.

Impact of Microclimate on Fatty Acids and Volatile Terpenes in “Kerman” and “Golden Hills” Pistachio (Pistacia vera) Kernels

“…This inverse relationship has also been found in other cultivars and countries (Pantano et al., ; Tsantili et al., ). Different values for heat accumulation in both locations studied could have impacted the activity of the enzymes involved in the synthesis of linoleic acid from oleic acid (Dar, Choudhury, Kancharla, & Arumugam, ). Golden Hills’ oleic acid peaked between 18‐Aug and 1‐Sept with 2013 to 2249 TU in Parlier, and 2178 to 2423 TU in Lost Hills accumulating from bloom, while for Kerman the concentration increased throughout all the study to 1‐Sept with 2249 TU in Parlier and 2282 TU in Lost Hills, indicating that the concentration of these compounds in the pistachio kernel could be cultivar dependent.…”

A novel quantitative trait locus on chromosome A9 controlling oleic acid content in Brassica napus

“…To date, most high oleic acid germplasms reported are based on the mutation of FAD2 genes in Brassica species (Long et al ., ; Peng et al ., ; Wells et al ., ). Such a narrow gene resource may lead to decreased genetic variation and thus compromise the improvement of yield and stress resistance, as illustrated in previous studies (Bai et al ., ; Dar et al ., ; Kinney, ; Miquel, ; Shi et al ., ). The problem has also been noted in other oil crops, such as peanut and maize (Belo et al ., ; Janila et al ., ; Mikkilineni and Rocheford, ; Wang et al ., , ).…”

Molecular mechanisms involved in postharvest chilling tolerance of pomegranate fruit

“…Delta 12 fatty acid desaturase 2 (FAD2) are membrane-modifying enzymes known to participate in adaptation to low temperatures through acyl chain modifications and their ability to increase membrane unsaturated fatty acids. 51 The mRNA levels of FAD2-3 and FAD2-4 were shown to increase under cold stress in cotton. 52 Furthermore, fad2 mutants in Arabidopsis were shown to be chilling sensitive, 53 and in contrast, overexpression of FAD2 in transgenic rice plants improved chilling resistance.…”

“…Amongst the lipid metabolism‐related transcripts were three transcripts encoding fatty acid desaturase enzymes: delta (12) oleic acid desaturase 2, delta(8)‐fatty‐acid desaturase 2, and omega‐3 fatty acid desaturase (Table ). Delta 12 fatty acid desaturase 2 (FAD2) are membrane‐modifying enzymes known to participate in adaptation to low temperatures through acyl chain modifications and their ability to increase membrane unsaturated fatty acids . The mRNA levels of FAD2‐3 and FAD2‐4 were shown to increase under cold stress in cotton .…”