New insights into the accumulation of vitamin B3 in Torreya grandis nuts via ethylene induced key gene expression

Vitamin B-3, derived primarily from plant sources, is an essential nutrient for humans. Torreya grandis is rich in vitamin B-3, however, the mechanism underlying the biosynthesis and regulation of vitamin B-3 in T. grandis remains unclear. A systematic transcriptomic investigation was thus conducted to identify the gene expression pattern of vitamin B-3 biosynthesis in 10 T. grandis cultivars. The findings suggest that biosynthesis occurs mainly via the aspartate pathway. Expression and correlation analyses indicate that aspartate oxidase (AOX) and quinolinate synthase (QS) may play important roles in vitamin B-3 accumulation. Furthermore, co-expression network and ethephon treatments indicate that the ethylene response factor (ERF) may be involved in the regulation of vitamin B-3 biosynthesis in T. grandis nuts. Our findings not only help to elucidate the biosynthesis of vitamin B-3, but also provide valuable resource material for future genomic research and molecular-assisted breeding to develop genotypes with higher vitamin B-3 levels.

Automated summary

Systematic transcriptomic analysis revealed that vitamin B-3 biosynthesis in Torreya grandis nuts mainly occurs via the aspartate pathway, with aspartate oxidase and quinolinate synthase playing important roles in its accumulation. Ethylene response factor may be involved in the regulation of vitamin B-3 biosynthesis.