细胞壁相关蛋白激酶(cell wall-associated kinase, WAK)家族成员在水稻基因组中已注释了大约130个WAK基因, 它们对于水稻的生长发育和应激响应发挥着重要作用。本研究探讨了水稻WAK16-RLK的编码基因OsWAK16对水稻种子活力和抗老化能力的调控作用及其生理机制。研究结果表明, OsWAK16突变体的种子活力在种子未老化和人工老化12 d时均显著低于野生型种子, 过表达种子的种子活力则显著高于野生型种子, 说明OsWAK16正调控种子的抗老化能力。同时, 相比野生型种子, 未老化和人工老化12 d的OsWAK16突变体种子中MDA含量以及种子浸泡液电导率显著增加, 抗氧化酶活性则显著下降; 过表达种子中的变化则正好相反。此外, 野生型, OsWAK16突变及其过表达种子在人工老化处理后OsWAK16的差异表达也引起OsPER1A、OsbZIP23、OsPIMT1、OsSdr4、OsMSRB5和OsHSP18.2等种子活力相关基因表达的协同变化。因此, 推测OsWAK16可能与其他种子活力相关基因协同作用, 行使清除细胞中活性氧的功能, 从而调控种子活力和抗老化能力。

The Cell wall-associated kinase family have annotated approximately 130 WAK genes in the genome of rice (Oryza sativa), which play an important role in rice growth and development and stress responses. Here, we investigated the regulation and physiological mechanism of OsWAK16, an encoding gene of the cell wall-associated kinase WAK16-RLK, on rice seed vigor and anti-aging ability. The results showed that before and after artificial aging, the seed vigor of OsWAK16 mutants and overexpression lines was significantly lower and higher than that of wild-type seeds, respectively, indicating that OsWAK16 positively regulates the anti-aging ability of seeds. Physiological and biochemical analyses indicated that compared with wild-type seeds before and after artificial aging treatment, malondialdehyde (MDA) content and electrical conductivity (EC) of seed soaking solution of OsWAK16 mutant seeds were significantly increased, while antioxidant enzyme activity was significantly decreased. The reverse was true in overexpression seeds. In addition, the differential expression of OsWAK16 in three types of seeds, whether artificially aged or not, also caused synergistic changes in the expression of other seed vigor-related genes OsPER1A、OsbZIP23、OsPIMT1、OsSdr4、OsMSRB5 and OsHSP18.2 etc. Therefore, it is speculated that OsWAK16 may work synergistically with other seed vigor-related genes to clear reactive oxygen species in cells, thereby regulating seed vigor and anti-aging capacity.