Abstract
Seed storage proteins are synthesized on rough endoplasmic reticulum as larger precursors. The precursors are transported to protein storage vacuoles (PSVs) by vesicle-mediated machinery, and then are processed into their mature forms. Recently, we identified AtVSR1 as a vacuolar sorting receptor for seed storage proteins in Arabidopsis (1). Storage protein precursors are accumulated in the extracellular space in the seeds of AtVSR1-deficient mutant. To identify the factors responsible for the receptor-dependent vacuolar sorting of storage proteins in maturing seeds, we applied reverse genetic approach with various T-DNA inserted lines of Arabidopsis. We characterized the storage proteins patterns accumulated in their mutant seeds by immunoblot analysis with specific antibodies against storage proteins. We screened some mutants that accumulated storage protein precursors in the seeds.
1) T. Shimada et al. Proc. Natl. Acad. Sci. USA, 100, 16095 (2003)