Title : Cyclic nucleotide-gated ion channel 14 and 16 promote basal tolerance to heat and chilling in rice seedlings
Calcium signaling has been postulated to be critical for both heat and chilling tolerance in plants, but the molecular events in calcium signaling in response to neither of the temperature stresses are fully understood. Here, we investigated the function of two cyclic nucleotide gated calcium channel (CNGC) proteins OsCNGC14 and OsCNGC16 in temperature stress tolerance in rice by examining the loss of function mutants of these two genes generated by genome editing. These mutants have reduced survival rate, higher accumulation of hydrogen peroxide and heightened cell death under heat and chilling. The OsCNGC16 mutant also has a lower induction of the heat shock pathway as shown by transcriptome profiling. Furthermore, the loss of either OsCNGC14 or OsCNGC16 reduces or abolishes cytosol calcium signals induced by either heat or chilling. Therefore, OsCNGC14 and OsCNGC16 play important roles in heat tolerance and chilling tolerance in rice and are important regulators of calcium signals in response to temperature stress. This study also reveals for the first time a critical role of CNGC in chilling tolerance in plants and suggests an overlapping molecular mechanisms in calcium signaling in responses to heat stress and chilling stress.