Nuclear-Localised Cyclic Nucleotide Gated Channels Mediate Symbiotic Calcium Oscillations

Charpentier M, Sun J, Martins TV, Radhakrishnan GV, Findlay K, Soumpourou E, Thouin J, Véry AA, Sanders D, Morris RJ, Oldroyd GED, 27 MAY 2016, Science : 1102-1105


Nuclear-associated Ca2+ oscillations mediate plant responses to beneficial microbial partners—namely, nitrogen-fixing rhizobial bacteria that colonize roots of legumes and arbuscular mycorrhizal fungi that colonize roots of the majority of plant species. A potassium-permeable channel is known to be required for symbiotic Ca2+ oscillations, but the calcium channels themselves have been unknown until now. We show that three cyclic nucleotide–gated channels in Medicago truncatula are required for nuclear Ca2+oscillations and subsequent symbiotic responses. These cyclic nucleotide–gated channels are located at the nuclear envelope and are permeable to Ca2+. We demonstrate that the cyclic nucleotide–gated channels form a complex with the postassium-permeable channel, which modulates nuclear Ca2+ release. These channels, like their counterparts in animal cells, might regulate multiple nuclear Ca2+ responses to developmental and environmental conditions.