Effects of Yariv dyes, arabinogalactan-protein binding reagents, on the growth and viability of Brazilian pine suspension culture cells.

Baron Maurer, Juliana Bello; Pereira-Netto, Adaucto Bellarmino; Pettolino, Filomena Angela; Gaspar, Yolanda Maria; Bacic, Antony

Arabinogalactan-proteins (AGPs) are a family of highly glycosylated hydroxyproline-rich glycoproteins implicated in several aspects of plant growth and development. (β-D-glucosyl)3 Yariv phenylglycoside (β-GlcY), commonly known as Yariv reagent, selectively binds AGPs. We treated cell suspension cultures of Araucaria angustifolia, the Brazilian pine, with β-GlcY and observed inhibition of biomass increase in a culture medium with 50 µM β-GlcY. However, the growth was not inhibited by (α-D-galactosyl)3 Yariv phenylglycoside (α-GalY) which does not bind AGPs. Fluorescein diacetate staining of cells indicated that β-GlcY severely affected cell viability. However, cell swelling, bursting and release of cellular contents, all characteristics of necrotic cell death, were not observed in β-GlcY-treated cells. Instead, programmed cell death (PCD) structural changes such as cytoplasmic shrinkage and condensation were observed in β-GlcY-treated cells. In addition, callose accumulation, which is another marker of PCD, was also observed in β-GlcY-treated cells. The use of both, Ac-VEID-CHO, an inhibitor of caspase-like proteolytic activity related to PCD, and phenyl methyl sulphonyl fluoride (PMSF), a protease inhibitor known to suppress PCD, in the culture medium did not reverse the growth inhibition caused by β-GlcY. These data indicate that the β-GlcY-induced inhibition of Araucaria cell's growth is related to AGP perturbation, and also that this growth inhibition is due to increased cell death not driven by necrosis.

DYES & dyeing; ARABINOGALACTAN; BRAZILIAN pine; GLYCOPROTEINS; PLANT growth; PLANT development; BIOMASS

Trees: Structure & Function, 2010, Vol 24, Issue 2, p391

0931-1890

Academic Journal

10.1007/s00468-009-0408-y