Cross Talk Between Cyclic Nucleotides and Calcium Signaling Pathways in Plants–Achievements and Prospects

Abstract

A variety of plant cellular activities are regulated through mechanisms controlling the level of signal molecules, such as cyclic nucleotides (cNMPs, e.g., cyclic adenosine 3′:5′-monophosphate, cAMP, and cyclic guanosine 3′:5′- monophosphate, cGMP) and calcium ions (Ca2+). The mechanism regulating cNMP levels affects their synthesis, degradation, efflux and cellular distribution. Many transporters and the spatiotemporal pattern of calcium signals, which are transduced by multiple, tunable and often strategically positioned Ca2+-sensing elements, play roles in calcium homeostasis. Earlier studies have demonstrated that while cNMPs and Ca2+ can act separately in independent transduction pathways, they can interact and function together. Regardless of the context, the balance between Ca2+ and cNMP is the most important consideration. This balance seems to be crucial for effectors, such as phosphodiesterases, cyclic nucleotide gated channels and cyclase activity. Currently, a wide range of molecular biology techniques enable thorough analyses of cellular cross talk. In recent years, data have indicated relationships between calcium ions and cyclic nucleotides in mechanisms regulating specific signaling pathways. The purpose of this study is to summarize the current knowledge on nucleotide-calcium cross talk in plants.

Brachypodium distachyon ERECTA-like1 protein kinase is a functional guanylyl cyclase

“…Previous reports have shown that the activity of plant transmembrane GCs called moonlight proteins can be modulated by calcium ions [28][29][30]. In vitro experiments have shown that the GC activity of the phytosulfokine receptor AtPSKR1 is significantly enhanced by calcium at physiological levels (0.1-10 µM), and more impor-tantly, the same concentration of Ca 2+ that activates GC activity also exerts an inhibitory effect on kinase activity [31].…”

“…7A). In plants, calcium may directly or indirectly regulate protein kinases [30,40], while bioinformatics and in vitro analyses have also revealed the presence of a calmodulin-binding motif within the kinase domains of AtPSKR1 and AtBRI1; thus, it is conceivable that calcium may modulate the cyclase/kinase activities indirectly via CaM isoforms [23,31]. However, although Ca 2+ significantly inhibited the kinase activity of BdERL1, there was no significant difference in its activity with the addition of calcium alone or with the addition of both calcium and calmodulin, as both of these conditions inhibited the kinase to a similar extent (Fig.…”

Dynamic Expression, Differential Regulation and Functional Diversity of the CNGC Family Genes in Cotton

“…In plants, calcium 2 of 31 is an essential nutrient, and intracellular changes in free Ca 2+ levels act as regulators in many growth and developmental processes and coordinate responses to developmental cues and environmental stimuli [5,6]; in contrast, recent advances support that cAMP (and cGMP) constitutes an important component of the complex signaling network, including key pathways mediated by hormones, lipid, sugar, Ca 2+ , K + , nitrate, etc. [7][8][9][10][11][12]. Thus, it is anticipated that CNGCs may play pivotal roles during growth and development in plants.…”

Links between Regulatory Systems of ROS and Carbohydrates in Reproductive Development

“…Furthermore, NO, a negative chemoattractant of pollen tube guidance, together with ROS, a positive regulator of tip growth, were shown to be required for the pollen tube elongation to the right direction [ 19 , 20 ]. These findings, together with multitasked feature of ROS, Ca 2+ , and NO [ 2 , 21 , 22 , 23 , 24 ], suggest that these signaling molecules might govern the reproductive development by regulating various other pathways.…”