不同类型钠盐胁迫对玉米自交系B73萌发的影响OA

The germination stage is the most sensitive phase of maize(Zea mays L.)in response to salt stress,and elucidating its salt tolerance mechanisms is of great significance for stress-resistant breed-ing in maize.Using the maize inbred line B73 as the material,the germination indicators,physiologi-cal characteristics,and expression changes of salt stress-responsive genes were analyzed under treat-ments with different concentrations of neutral salts(NaCl,Na2SO4)and alkaline salts(NaHCO3,Na2CO3).The results showed that the germination indicators of maize changed significantly with in-creasing salt concentrations.Seed germination was markedly inhibited under 150 mmol/L stress for all sodium salts,with Na2CO3 exhibiting the most prominent inhibitory effect.The germination vigor,germination percentage,and germination index decreased to 86.3％,81.8％,and 84.7％of the con-trol,respectively,and the salt injury index increased to 85％.The activities of antioxidant enzymes in the radicle and plumule displayed distinct tissue specificity and salt dependency;the activities of SOD,POD,CAT,and APX in the radicle were significantly inhibited,with alkaline salt stress being the most pronounced.Overall,alkaline salt stress caused significantly greater damage to plants than neu-tral salt stress,and different types of sodium salts at 150 mmol/L showed significant differences com-pared with the control.Expression analysis of salt stress-related genes revealed that ZmSOD3 was highly significantly upregulated under NaCl and NaHCO3 stress,ZmPOD,ZmPOD44,ZmPRX1,and ZmCAT1 were highly significantly upregulated under NaHCO3 stress,ZmGT61 WTBZ and ZmMAPK4 were significantly upregulated under Na2CO3 stress,and ZmMAC39 and ZmMAC82 were significantly downregulated under salt treatments.In conclusion,the inhibition of maize seed germination by sodium salt stress was concentration-dependent,with Na2CO3 stress exhibiting the most significant effect,and gene expression regulation was specific to different sodium salt stresses.