Abstract
Low temperature affects rice growth and yield. Receptor-like protein kinases play an important role in plant growth and development. In order to reveal the role of a leucine-rich receptor like kinase LRK2 in low temperature stress and growth and development of rice. In this study, we used the obtained LRK2 overexpressing plants for experiments and the results show that the cold tolerance and yield of LRK2 overexpressing plants were higher than that of wild type. LRK2 has high homology with the phytosulfokine receptors (PSKRs) gene of different species, and LRK2 gene is responsive to phytosulfokine (PSK). In addition, we observed that the proline content of LRK2 overexpressing plants was significantly higher than that of the wild-type at low temperature, while the malondialdehyde content was significantly lower than that of the wild-type. Yeast two-hybrid screening and bimolecular fluorescence complementary analysis showed that LRK2 interacts with rice growth hormone response factor 24 (OsARF24) in vitro. These results suggest that LRK2 gene may be involved in the regulation of cold stress response and yield in rice. These findings will help us understand PSKR signaling in other grasses and support improvements in rice genetics.