NcSnRK1and NcRbohC1 regulate pollen germination on waterlily stigma after pollination

Pre-fertilization barrier is the primary cause of intersubgeneric hybridization barrier in waterlily. The research results indicate that reactive oxygen species (ROS) are involved in regulating the germination process of pollen on the stigma of waterlily after pollination, and candidate genes NcSnRK1 and NcRbohC1 have been identified; Transient transgenic experiments were used to validate the functions of NcSnRK1 and NcRbohC1 on the waterlily stigma. Through yeast two-hybrid assays, luciferase complementation, and Pull-down experiments, the interaction between NcSnRK1 and NcRbohC1 was confirmed. The above results indicate that NcSnRK1 may phosphorylate certain N-terminal sites of NcRbohC1 after pollination in waterlily, thereby activating ROS burst in the stigmatic papilla cells, disrupting ROS homeostasis on stigma of waterlily, and consequently inhibiting pollen germination on the stigma. The research results can provide theoretical basis for taking effective measures to overcome pre-fertilization barrier and germplasm innovation in waterlily.