TaCNGC-2A suppresses seed dormancy and activates pre-harvest sprouting through modulating calcium and hormonal signaling pathways

Weak seed dormancy (SD) is prone to pre-harvest sprouting (PHS), which reduces cereal yield and quality. Here, through map-based analysis, we identify TaCNGC-2A, encoding a cyclic nucleotide-gated channel protein, as a negative regulator of wheat SD. Knocking out of TaCNGC-2A enhances SD and PHS resistance, with no yield penalty. Two transcription factors, TaMYB-5B and TaMYB-5D, directly bind to the T/A mutation site of TaCNGC-2A promoter to synergistically repress its expression. The calmodulin TaCaM-3A interacts with TaCNGC-2A to jointly modulate SD and PHS resistance through influencing calcium and multiple hormonal signaling pathways. Knocking out of TaCaM-3A not only enhances SD and PHS resistance, but also increases grain weight and per-plant yield. Finally, we identify allele combinations of TaCNGC-2A and other known dormancy genes associated with strong SD. This study uncovers a regulatory mechanism underlying SD and PHS resistance and provides gene targets for breeding wheat varieties with PHS resistance. Pre-harvest sprouting (PHS) causes severe yield and quality loss in cereal crops worldwide. Here, the authors report a cyclic nucleotide-gated channel/Ca2 + -permeable channel encoding protein negatively regulate PHS and its involvement in modulating of calcium and hormonal signaling pathways in wheat.