Cyclic nucleotides and nucleotide cyclases in plants under stress

Abstract

Cyclic nucleotides, cAMP and cGMP, are important signaling molecules that control a range of cellular functions and modulate different reactions. The level of the cyclic nucleotides is elevated and decreased by nucleotide cyclases and phosphodiesterases, respectively. The adenylate and guanylate cyclases synthesize cAMP and cGMP from ATP and GTP, respectively, while phosphodiesterases hydrolyze the cyclic nucleotides to AMP and GMP. An important aspect of cyclic nucleotide signal transduction has been identified and characterized during research on their receptors, such as cyclic nucleotide-dependent protein kinases and cyclic nucleotide-gated ion channels. It was proved that these receptors are involved in mediation of many effects of cyclic nucleotides. In the last decade, the participation of cyclic nucleotides in plant resistance to abiotic and biotic stresses has been extensively studied. The results of this research have shown that cAMP and cGMP are involved in signal transduction in response to various environmental stresses.