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Cell death induction and nitric oxide biosynthesis in white poplar ( Populus alba ) suspension cultures exposed to alfalfa saponins
Author(s) -
Balestrazzi Alma,
Agoni Valentina,
Tava Aldo,
Avato Pinarosa,
Biazzi Elisa,
Raimondi Elena,
Macovei Anca,
Carbonera Daniela
Publication year - 2011
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.2010.01436.x
Subject(s) - saponin , aglycone , nitric oxide , chemistry , programmed cell death , botany , chromatography , glycoside , biochemistry , biology , apoptosis , medicine , alternative medicine , organic chemistry , pathology
The present work reports on the biological activity of alfalfa ( Medicago sativa ) saponins on white poplar ( Populus alba , cultivar ‘Villafranca’) cell suspension cultures. The extracts from alfalfa roots, aerial parts and seeds were characterized for their saponin content by means of thin layer chromatography (TLC) and electrospray ionisation coupled to mass spectrometry. The quantitative saponin composition from the different plant extracts was determined considering the aglycone moieties and determined by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) analyses. Only soyasapogenin I was detected in the seed extract while several other saponins were found in the root and leaf extracts. Actively proliferating white poplar cell cultures were challenged with the different saponin extracts. Only alfalfa root saponins, at 50 µg ml −1 , induced significant cell death rates (75.00 ± 4.90%). Different cell subpopulations with peculiar cell death morphologies were observed and the programmed cell death (PCD)/necrosis ratio was reduced at increasing saponin concentrations. Enhancement of nitric oxide (NO) production was observed in white poplar cells treated with root saponins (RSs) at 50 µg ml −1 and release of reactive oxygen species (ROS) in the culture medium was also demonstrated. Saponin‐induced NO production was sensitive to sodium azide and N G ‐monomethyl‐ l ‐arginine, two specific inhibitors of distinct pathways for NO biosynthesis in plant cells.