An Integrated Metabolomic and Gene Expression Analysis of ‘Sachinoka’ Strawberry and Its Somaclonal Mutant Reveals Fruit Color and Volatiles Differences

Plant tissue culture produces a wide range of genetic variations which are useful for quality improvement of the plant species. However, the differences in metabolic components and the key genes responsible for the difference in metabolic components between somaclonal variation and the original parent are still largely unknown. In this study, a mutant named ‘Mixue’ was identified with somaclonal variation of the ‘Sachinoka’ strawberry. The contents of pelargonidin-3-O-glucoside and cyanidin-3-O-glucoside in the red fruit of ‘Mixue’ were significantly decreased compared with ‘Sachinoka’. In comparison with ‘Sachinoka’, the expression levels of FaMYB10, FaMYB11.2, FaWD40 and FaTT19 in the turning fruit of ‘Mixue’ were significantly down-regulated, while the expression of FaMYB1 was significantly up-regulated in the red fruit. ‘Sachinoka’ and ‘Mixue’ fruits were found to have 110 volatile components. Among them, 15 volatile components in the red fruit of ‘Mixue’ were significantly increased compared with ‘Sachinoka’, such as nerolidol, benzaldehyde, ethyl hexanoate, ethyl isovalerate, which led to an enhanced aroma in ‘Mixue’ and might result from the up-regulated expression of FaNES1, FaCNL and FaAATs in ‘Mixue’. These results provide useful information on the effect of somaclonal variation on metabolic components of strawberry fruit and lay the foundation for the improvement in quality of strawberry.