小肽Ospep5对水稻耐镉性的影响OA

Cadmium(Cd)stress is one of the major heavy metal stresses which causes serious impacts on plant growth and de-velopment.Although studies have shown that plant small peptides have a mitigating effect on stress,research on their tolerance to cadmium toxicity in rice is limited.In previous studies,a few peptides were identified through translatome,transcriptome,and proteome analysis,among which Ospep5 was found to significantly improve salt tolerance in rice.In this study,the effects of Ospep5 on the growth of rice seedlings under cadmium stress were investigated using the japonica cultivar Nipponbare,Ospep5 overexpressing line Ospep5-OX,and the CRISPR/Cas9 mutant ospep5-3 as the experimental materials.The results showed that 500 µmol L-1 CdCl2 significantly inhibited the morphological growth and chlorophyll content of rice seedlings,while the activities of superoxide dismutase(SOD),contents of proline(Pro),malondialdehyde(MDA),and cadmium ion content were significantly increased.Compared to cadmium stress alone,exogenous application of synthetic Ospep5 effectively alleviated the inhibition of cadmium stress on the morphological growth of rice seedlings.Furthermore,SOD activity was significantly increased,and MDA content,Pro content,and cadmium ion content were significantly reduced.And the relative expression level of cadmium tolerance genes(OsHMA2,OsHMA3,OsCAL1)were upregulated.In conclusion,Ospep5 improves the tolerance of rice seedlings to cad-mium stress by regulating various physiological and biochemical reactions and the expression of cadmium tolerance genes.