Plant Cyclic Nucleotide Signalling

Abstract

The presence of the cyclic nucleotides 3',5'-cyclic adenyl monophosphate (cAMP) and 3',5'-cyclic guanyl monophosphate (cGMP) in plants is now generally accepted. In addition, cAMP and cGMP have been implicated in the regulation of important plant processes such as stomatal functioning, monovalent and divalent cation fluxes, chloroplast development, gibberellic acid signalling, pathogen response and gene transcription. However, very little is known regarding the components of cyclic nucleotide signalling in plants. In this addendum, the evidence for specific mechanisms of plant cyclic nucleotide signalling is evaluated and discussed.

Ca2+, cAMP, and transduction of non-self perception during plant immune responses

“…At present, it is unclear what specific gene products encode the proteins responsible for synthesis and catabolism of cAMP in plants (22). Nonetheless, cAMP has been unequivocally documented to be present in plant cells (27,40).…”

“…PAMP Signaling to NO Mediated by Endogenous cNMP. Genes encoding enzymes that synthesize (adenylyl cyclase) and break down (cNMP phosphodiesterase) cAMP in plant leaves have not yet been identified (22); translational arrest of a specific gene has not been associated with altered level of cAMP in plants. In consideration of this point, we took a pharmacological approach to manipulate endogenous cAMP.…”

“…cNMP phosphodiesterase enzymatic activity is present in plant cells (22,26,30) and acts to catabolize cAMP and maintain homeostatic levels in the cytosol after changes that occur in the level of this secondary messenger during signaling cascades (4). We hypothesized that blocking the breakdown of endogenous cAMP by inhibition of cNMP phosphodiesterase activity could therefore affect NO generation in the plant cell.…”

Novel type of adenylyl cyclase participates in tabtoxinine-β-lactam-induced cell death and occurrence of wildfire disease inNicotiana benthamiana

“…17 Nevertheless, recent study shows the presence of cAMP and AC activity in several plant species. AC activity was reported in alfalfa and tobacco.…”

“…17 For example, plant AC is closely associated with signaling cascade for pollen tube growth, 14 and cAMP have been shown to regulate Ca 2+ signaling in N. plumbaginofolia protoplasts. 20 In addition, it has been reported that self-incompatibility is associated with the level of cAMP in pistils after pollination, and the level of cAMP depends on AC activity.…”