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

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

Actinidia DRM1 - An intrinsically disordered protein whose mRNA expression is inversely correlated with spring budbreak in kiwifruit

Intrinsically disordered proteins (IDPs) are a relatively recently defined class of proteins which, under native conditions, lack a unique tertiary structure whilst maintaining essential biological functions. Functional classification of IDPs have implicated such proteins as being involved in various physiological processes including transcription and translation regulation, signal transduction and protein modification. Actinidia DRM1 (Ade DORMANCY ASSOCIATED GENE 1), represents a robust dormancy marker whose mRNA transcript expression exhibits a strong inverse correlation with the onset of growth following periods of physiological dormancy. Bioinformatic analyses suggest that DRM1 is plant specific and highly conserved at both the nucleotide and protein levels. It is predicted to be an intrinsically disordered protein with two distinct highly conserved domains. Several Actinidia DRM1 homologues, which align into two distinct Actinidia-specific families, Type I and Type II, have been identified. No candidates for the Arabidopsis DRM1-Homologue (AtDRM2) an additional family member, has been identified in Actinidia