外源一氧化氮对植物耐旱性与硝酸盐同化途径酶的影响——Meta分析OA

Nitric oxide(NO)has been widely reported to play an important role in regulating drought tolerance in plants.To address the controversy in the mechanism of exogenous NO in ameliorating drought stress,the ability of exogenous nitric oxide to mitigate drought as well as the factors influencing it were evaluated by collecting data from 74 relevant published papers for Meta-analysis and comparing the differences between the control group(drought)and the experimental group(drought+NO).The results showed that exogenous nitric oxide increased dry and fresh weights as well as root length and germination of plants under drought.Subfamily dry weight analysis showed that exogenous NO promoted the most significant effect on legumes under drought stress.The use of NO after drought stress resulted in better improvement compared to pretreatment.The effects of using NO in different parts of the plant on dry weight did not differ significantly,compared to the regular use of one-time application of NO,which was more significant,and the best improvement was achieved at NO content of 100 µmol·L-1.Exogenous NO also effectively promoted photosynthetic capacity,osmotic regulation and antioxidant system in plants under drought stress.In addition,exogenous NO promoted endogenous NO content as well as synthesis-associated nitrate reductase(NR)and nitrite reductase(NIR)gene expression,but the promotional effect was reduced at high content,and even inhibited the activities of NR and NIR.The rational application of exogenous NO effectively reduced drought stress damage in plants by improving plant physiological processes and regulating the nitrate reduction pathway,while too high content produced an inhibitory effect.Above results provided a basis for understanding the mechanism of NO regulation on drought tolerance in plants.