Abstract
Flavonoid is one of the major groups of second metabolites in plants. Many Arabidopsis mutants with defects of the flavonoid accumulation, which are called transparent testa mutants from white color of their seed coats, have been reported. Analyses of these mutants revealed the major pathway of flavonoid synthesis. However, the mechanism of the final step of the incorporation of flavonoids into vacuoles is not known.
To elucidate the relationship between the flavonoid accumulation and vacuolar sorting system, we screened a mutant seeds with white seed coats from the library of gfs (green-fluorescent seeds) mutants, which have a defect in vacuolar protein sorting (1). The isolated mutant gfs9 had pale-brown seed coat and was defective in the transport of seed storage proteins into protein storage vacuoles. Our findings suggest that GFS9 is a novel protein involved in both the flavonoid accumulation and the vesicle transport.
(1) Fuji et al. (2008) Plant Cell, 19, 320-332.
