The genus Leucas belongs to Lamiaceae, and has attained more attention due to the presence of unusual allenic fatty acids called laballenic and phlomic acid in majority of its species. This genus has been known since traditional medicinal times and has numerous economical, nutritional, and industrial properties. So far genetic, molecular and biochemical analyses of lipid metabolism and fatty acid biosynthetic pathway in Leucas has not been reported. The objective of this study is to identify, isolate, analyze expression profiles, and functionally characterize the membrane-associated desaturases responsible for unsaturated fatty acid accumulation in Leucas cephalotes. Full-length LcFAD2 and LcFAD3 cDNAs were isolated and expressed in Saccharomyces cerevisiae BY4741 for functional characterization. Substrate feeding assay using S. cerevisiae confirmed that the LcFAD2 enzyme catalyzes desaturation of both palmitoleic (16:1∆⁹) and oleic (18:1∆⁹) acids to form palmitolinoleic (16:2∆^9,12) and linoleic (18:2∆^9,12) acids respectively. As a contrast, the heterologous activity of LcFAD2 enzyme in S. cerevisiae led to the synthesis of palmitolinoleic (16:2∆^9,12) acid, an unusual fatty acid that is not found naturally in Leucas cephalotes. While the LcFAD3 enzyme catalyzed linoleic acid (18:2∆^9,12) into α-linolenic acid (18:3∆^9,12,15). Furthermore, transcript abundance of LcFAD2 and LcFAD3 cDNAs were estimated from various plant parts such as roots, shoots, leaves, petals and developing seeds. Our results have shown that the differential transcriptional activity of LcFAD2 and LcFAD3 desaturase genes differs significantly in developing seeds, petals, leaves, stems, and roots of L. cephalotes. Furthermore, for the industrial production of these essential fatty acids, namely, linoleic and α-linolenic acid, FAD2 and FAD3 enzyme activity could be exploited from this upcoming significant oil plant, Leucas cephalotes.

Leucas属属于唇形科，由于在其大多数物种中存在称为拉巴烯酸和韧皮酸的不寻常的烯属脂肪酸，因此受到了更多的关注。该属自传统药用时代就已为人所知，并具有许多经济、营养和工业特性。迄今为止，尚未报道Leucas中脂质代谢和脂肪酸生物合成途径的遗传、分子和生化分析。本研究的目的是鉴定、分离、分析表达谱，并在功能上表征负责Leucas cephalotes中不饱和脂肪酸积累的膜相关去饱和酶。全长LcFAD2和LcFAD3 cDNA 被分离并在酿酒酵母BY4741 中表达以进行功能表征。使用S. cerevisiae进行的底物补料试验证实 LcFAD2 酶催化棕榈油酸 (16:1Δ ⁹ ) 和油酸 (18:1Δ ⁹ ) 去饱和形成棕榈油酸 (16:2Δ ^9,12 ) 和亚油酸 (18 :2∆ ^9,12 ) 酸。相比之下，酿酒酵母中 LcFAD2 酶的异源活性导致棕榈油酸 (16:2Δ ^{9,12 ) 酸的合成，这是一种在}Leucas cephalotes中天然不存在的不寻常脂肪酸. ^而LcFAD3酶催化亚油酸 (18:2∆ ^9,12 ) 转化为 α-亚麻酸 (18:3∆ 9,12,15 )。此外，LcFAD2和LcFAD3 cDNA 的转录本丰度是从植物的各个部分（如根、芽、叶、花瓣和发育中的种子）中估算出来的。我们的研究结果表明，LcFAD2和LcFAD3去饱和酶基因的差异转录活性在L. cephalotes的种子、花瓣、叶、茎和根的发育过程中存在显着差异。此外，对于这些必需脂肪酸的工业生产，即亚油酸和α-亚麻酸，FAD2和FAD3酶活性可以从这种即将到来的重要石油植物Leucas cephalotes中得到利用。