Screening of reference genes in Siraitia grosvenorii and spatio-temporal expression analysis of 3-hydroxy-3-methylglutaryl coenzyme A / 中草药

ABSTRACT

Objective: To screen the reference genes of Siraitia grosvenorii for gene expression analysis, and to study the spatio-temporal expression characteristics of 3-hydroxy-3-methylglutaryl coenzyme A (HMGR) which was the key enzyme of mogroside V biosynthesis. Methods: In this study, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), microtubule associated protein (α-tubulin), actin (β-actin), and ubiquitin (UBQ5) fragments of S. grosvenorii were cloned, and the stabilities of the four housekeeping genes were evaluated in different positions (leaves, stems, and fruits) and different periods of fruit development. In addition, the spatio-temporal expression of HMGR gene was analyzed. Results: UBQ5 was the most suitable reference gene for spatio-temporal expression analysis in S. grosvenorii; The relative expression of HMGR was low in leaves, and that in stems and fruits was higher; The relative expression quantity of HMGR in fruits showed the fluctuation changes that increased firstly and then decreased, then increased and decreased again; The highest expression of HMGR was at 70 d of fruit development period, followed by 5, 30, 10, and 50 d. Conclusion: UBQ5 is the most suitable reference gene in S. grosvenorii. The relative expression of HMGR changes significantly in leaves, stems, and fruits. The relative expression quantity of HMGR in fruits shows the fluctuation changes, which is similar to synthetic accumulation pattern of mogroside V.