Ultrastructural and biochemical study of Berberis parvifolia root meristem and cell cultures

Abstract

Electron-microscopic examination of Berberis parvifolia cells of the seedling root apical meristem revealed a dense cytoplasm with many organelles and small vacuoles. Inside the small vacuoles, electron-dense precipitates, or small vesicular formations (0.1 – 1.0 μm) were found. Small vesicles (0.1 – 1.0 μm) filled with an osmiophilic precipitate were also found in the cytoplasm. The analysis of the alcoholic extracts obtained from the root apex demonstrated that the cells of the primary meristem contain the protoberberine alkaloids jatrorrhizine, palmatine and berberine. The vesicular formations, as well as the electron-dense precipitates detected in the meristematic cells, were also identified in the B. parvifolia cell cultures, These components are characteristic for all B. parvifolia cells cultivated in vitro, no matter at which stage of the cellular growth cycle they are, or whether they belong to high- or low-producing cell lines. The ultrastructural differences between cells are mostly quantitative and regard the abundance of cytoplasm, the number of mitochondria, or the number of amyloplasts. Between the alkaloid and starch syntheses there is a negative correlation.