干旱胁迫下2种内生真菌对烟草生理生化指标及NAC基因表达的影响OA北大核心CSTPCD

To investigate the effects of Piriformospora indica combined with Arbuscular mycorrhizal fungi(AMF)on drought resistance of tobacco,Yunyan 87 was inoculated with sterile water(CC),P.indica(CP),AMF(PC),P.indica and AMF(PP),and the contents of proline(Pro),superoxide dismutase(SOD),peroxidase(POD),malondialdehyde(MDA)and the expression of drought-related genes NTNAC1 and NAC4 in tobacco leav-es were determined under stress in the form of natural drought.The results showed that P.indica and AMF could promote the growth of above-ground and underground parts of tobacco,and chlorosis of leaves and symptoms of their drought were slight.After 7 days of drought stress,the contents of Pro in tobacco leaves of CP,PC and PP groups were 1.39,1.59 and 1.78 times higher than those of CC in group,respectively.The activities of SOD and POD in tobacco leaves increased first and then decreased.The activities of SOD in CP,PC and PP groups were 1.15,1.22 and 1.33 times higher than those in CC group,POD activity was 1.33,1.46 and 1.85 times higher than those of CC group,respectively.The content of MDA in tobacco leaves was decreased by 21.98％,23.98％and 24.84％in CP,PC and PP groups respectively.The expression levels of NTNAC1 and NAC4 in tobacco leaves were up-regula-ted.The expression levels of NTNAC1 in CP,PC and PP groups were 3.37,3.88 and 5.07 times higher than those in CC group,the expression levels of NAC4 gene were 3.04,3.59 and 5.56 times higher than those of CC group,re-spectively.This study indicates that P.indica and AMF showed significant synergistic effects,which could signifi-cantly improve the drought resistance of tobacco.