Cyclic nucleotide-gated channels: Essential signaling components in plants for fertilization and immunity responses

Abstract

The Cyclic Nucleotide-Gated Channels (CNGCs) in plants are responsible for conducting mono and divalent cations such as Ca2+, Pb2+, Na+ , and K+ . The CNGCs have been identifi ed in different plant species, namely, Arabidopsis thaliana where 20 have been genetically identifi ed. They express during different developmental stages of the plant organ, tissue, or cell indicating the specifi city in their function. The CNGCs have been implicated in diverse responses in plants from stress tolerance (both biotic and abiotic) to transpiration and fertilization. These responses in plants are due to the presence of complex signaling network of which CNGCs are a part. Thus far CNGCs were implicated in the hormone-mediated pathways (GA, IAA, ABA, JA) leading to developmental responses, NO-mediated pathways leading to plant defense and immunity responses, and cyclic nucleotides monophosphates (cNMPs) and Calmodulin-mediated pathways leading to regulation of cation conduction into the cell. The cNMPs and calcium acts as the secondary messenger in these signaling pathways transducing the signal from the environment into the cell.