Transcriptomic Analysis Reveals Key Genes Involved in Oil and Linoleic Acid Biosynthesis during Artemisia sphaerocephala Seed Development

Artemisia sphaerocephala seeds are rich in polysaccharides and linoleic acid (C18:2), which have been widely used as traditional medicine and to improve food quality. The accumulation patterns and molecular regulatory mechanisms of polysaccharides during A. sphaerocephala seed development have been studied. However, the related research on seed oil and C18:2 remain unclear. For this study, A. sphaerocephala seeds at seven different development stages at 10, 20, 30, 40, 50, 60, and 70 days after flowering (designated as S1~S7), respectively, were employed as experimental samples, the accumulation patterns of oil and fatty acids (FA) and the underlying molecular regulatory mechanisms were analyzed. The results revealed that oil content increased from 10.1% to 20.0% in the early stages of seed development (S1~S2), and up to 32.0% in mature seeds, of which C18:2 accounted for 80.6% of the total FA. FA and triacylglycerol biosynthesis-related genes jointly involved in the rapid accumulation of oil in S1~S2. Weighted gene co-expression network analysis showed that transcription factors FUS3 and bHLH played a critical role in the seed oil biosynthesis. The perfect harmonization of the high expression of FAD2 with the extremely low expression of FAD3 regulated the accumulation of C18:2. This study uncovered the gene involved in oil biosynthesis and molecular regulatory mechanisms of high C18:2 accumulation in A. sphaerocephala seeds; thus, advancing research into unsaturated fatty acid metabolism in plants while generating valuable genetic resources for optimal C18:2 breeding.

MONOSOMIC ANALYSIS OF FATTY ACID COMPOSITION IN EMBRYO LIPIDS OF ZEA MAYS L

ABSTRACT The effects of monosomy of specific chromosomes on the fatty acid composition of maize embryos were studied. A novel technique was developed to obtain fatty acid profiles of single embryos without reducing the viability of the sampled kernels. Monosomic 2 embryos had significantly more oleic acid and significantly less linoleic acid than diploid control embryos. Since the conversion of oleic acid to linoleic acid is a single-enzyme-mediated reaction, we suggest that a gene involved in linoleic acid biosynthesis is located on chromosome 2. Additional consistent variations were found in other monosomic types. This study demonstrates that monosomic analysis can be used to study gene dosage effects at the biochemical level.