Cyanamide mode of action during inhibition of onion (Allium cepa L.) root growth involves disturbances in cell division and cytoskeleton formation

Abstract

Cyanamide is an allelochemical produced by hairy vetch (Vicia villosa Roth.). Its phyotoxic effect on plant growth was examined on roots of onion (Allium cepa L.) bulbs. Water solution of cyanamide (2–10 mM) restricted growth of onion roots in a dose-dependent manner. Treatment of onion roots with cyanamide resulted in a decrease in root growth rate accompanied by a decrease in accumulation of fresh and dry weight. The inhibitory effect of cyanamide was reversed by its removal from the environment, but full recovery was observed only for tissue treated with this chemical at low concentration (2–6 mM). Cytological observations of root tip cells suggest that disturbances in cell division may explain the strong cyanamide allelopathic activity. Moreover, in cyanamide-treated onion the following changes were detected: reduction of mitotic cells, inhibition of proliferation of meristematic cells and cell cycle, and modifications of cytoskeleton arrangement.

The Allelopathic Potential of Hairy Vetch (Vicia villosa Roth.) Mulch

“…Our study showed no apparent relationship between growth habit (monocotyledonous or dicotyledonous), seed size or allelopathic effects. In the absence of soil, cyanamide in solution has been shown to affect root growth of onion in a dose-dependent manner from 2 -10 mM [34]. This coincides with the greater inhibition of radicle elongation and increased cyanamide concentration observed between the vegetative (51.36 mM) and reproductive (62.56 mM) stage hairy vetch extracts in our study, which was well above the minimum biologically active concentrations required.…”

Inhibition of tomato (Solanum lycopersicumL.) root growth by cyanamide is not always accompanied with enhancement of ROS production

“…4 Treatment of onion (Alium cepa) roots with CA at higher (6 mM) concentration had no effect on O 2 · -accumulation in short-term experiment (one day), while after additional five days, enhanced production of O 2 · -resulted in induction of death of root cells. 4 Among allelochemicals, not all act as oxidative stressors. Some have even antioxidant properties, as (±)-catechin and myrigalone A.…”

“…3 Mode of action of CA on root growth was partially examined in onion bulbs. 4 Our former studies, conducted on tomato seedlings, indicated disturbances in root tip cells division leading to reduction of length of root tip zone, as the main reason of CA-induced root growth inhibition. 5 This, in consequence, reorganized every other root zones.…”

Dynamic "Symbionts" Linked over Two Centuries: A Tribute to Lynn Margulis (1938–2011)

“…In this study we examined the effects of water solutions of CA on seed germination and post-germination growth of young seedlings of various crop and weed species. In previous work we demonstrated that water solutions of CA strongly inhibit the root growth of onion (Alium cepa L.) in a dose-dependent manner (Soltys et al, 2011). Based on that experiment, in this work we used CA at 1.2 mM and 3.0 mM concentrations, since higher concentrations (6-10 mM) induced cell death (Soltys et al, 2011).…”

“…In previous work we demonstrated that water solutions of CA strongly inhibit the root growth of onion (Alium cepa L.) in a dose-dependent manner (Soltys et al, 2011). Based on that experiment, in this work we used CA at 1.2 mM and 3.0 mM concentrations, since higher concentrations (6-10 mM) induced cell death (Soltys et al, 2011). We examined the allelopathic action of CA in two dicotyledonous annual weeds: goosegrass (Galium aparine L.), native to North America and Eurasia, and redroot pigweed (Amaranthus retroflexus L.), native to the tropical Americas but widespread as an introduced species on most continents in a great number of habitats.…”