关键词: SAPK2, 水稻, 钾元素, 缺钾胁迫, K⁺代谢相关基因

Abstract: In order to reveal the function and mechanism of SAPK2(osmotic stress/ABA-activated protein kinase 2) involved in rice(Oryza sativa L.) response to K deficiency,the sapk2 mutants constructed by CRISPR/Cas9(clustered regularly interspaced short palindromic repeats/Cas9) technology and wild type rice seeds were used to study SAPK2 expression profiles, germination, growth of seedling and the expression levels of K⁺metabolism-related genes under K deficiency condition. The results showed that the N,P and K deficiency treatments caused a significant decrease in the expression level of SAPK2 in rice;compared with the wild type, the germination of the sapk2 mutants was significantly delayed, the germination rate was significantly reduced,and the seedling growth was severely inhibited under the K deficiency condition; compared with wild-type,the expression levels of K⁺ metabolism-related genes such as OsKAT1(potassium channel gene1),OsKAT2(potassium channel gene 2),OsAKT1(shaker K⁺channel1) and OsHAK1 (high-affinity potassium transporter1) in sapk2 mutants were significantly downregulated.These results indicated that SAPK2 played an important positive regulatory role in the process of seed germination and seedling vegetative growth of rice under K deficiency environment,and the mechanism may be that SAPK2 directly or indirectly regulated the expression level of K⁺ metabolismrelated genes to participate in the K deficiency response.

Key words: SAPK2, Rice, K, K deficiency stress, K⁺metabolism-related genes