Expression of terpene synthase-related genes in parents and offspring of Flammulina filiformis based on differences in volatile aroma components

Abstract

Flammulina filiformis (F. filiformis) is one of the four major edible types of fungus in the world and has been cultivated in China since 800 CE (Anno Domini). Some of the most essential criteria for evaluating the quality of F. filiformis are the types and contents of volatile components present. A focused study on screened the terpene synthase genes involved in the aroma of offspring and compared key terpenoids between parents and offspring, which is helpful for the development and application of F. filiformis. Firstly, the volatile aroma components of parent and offspring F. filiformis were extracted using two pretreatment procedures, and then were semi-quantified by an internal standard. Forty-eight, fifty-eight, and forty-eight volatile compounds were identified in parents and offspring of three different strains, and 15, 22, and 12 aroma compounds (OAVs ≥ 1) were further screened out via calculating their odor activity values (OAVs). Terpenoids, in particular linalool and eucalyptol, which contribute more to the aroma, result in the unique green and grassy aroma of the offspring. At last, the F. filiformis genome was resequenced and the coordinates of genes related to terpenoid synthase were determined. The results showed that Scaffolds, including scaffold3.t874 and scaffold9.t157 were connected to terpenoid synthesis of offspring (No. 61523). The variant genes g269 and g61 were related to terpenoid synthase sequences. This study provides a theoretical foundation for the cultivation of more diverse and unique varieties of F. filiformis.