为了研究多胺参与植物应答气体甲醛胁迫的生理特性,以模式植物烟草为实验材料分析了在气体甲醛胁迫下分别采用100μmol/L精胺和200μmol/L亚精胺预处理对烟草叶片甲醛吸收效率、叶绿素含量、过氧化生理指标、抗氧化酶系统活性及甲醛代谢的影响。结果表明:(1)精胺和亚精胺预处理可以显著提高烟草对1、3和5 mg/m~3气体甲醛的吸收效率,且精胺的效果好于亚精胺。(2)在气体甲醛胁迫下,精胺和亚精胺预处理延缓了烟草叶片中叶绿素b降解,且对过氧化氢(Hydrogen peroxide,H_2O_2)和丙二醛(Malondialdehyde,MDA)的积累有抑制作用。此外,精胺和亚精胺预处理不同程度提高了气体甲醛胁迫下过氧化物酶(Peroxidase,POD)、过氧化氢酶(Catalase,CAT)、抗坏血酸过氧化物酶(Ascorbate peroxidase,APX)和超氧化物歧化酶(Superoxide dismutase,SOD)的活性。(3)精胺与亚精胺预处理对烟草代谢气体甲醛没有促进作用。
This work is to investigate the role and the mechanism of polyamine during the plants response to gaseous formaldehyde stress.With pretreatment of 100 μmol/L spermine and 200 μmol/L spermidine to model plant tobacco,the formaldehyde absorption of tobacco leaves,chlorophyll content,physiological indexes of peroxidation,formaldehyde metabolism,and the activities of the four main antioxidant enzymes(POD,CAT,APX and SOD)under gaseous formaldehyde stress were determined. The results showed that :1)The absorption efficiencyof tobacco under 1,3 and 5 mg/m~3 gaseous formaldehyde significantly increased by the pretreatment with spermine and spermidine,and theeffect by spermine was better than that by spermidine. 2)Under gaseous formaldehyde stress,the pretreatment of spermine and spermidinedelayed the degradation of chlorophyll b,and the accumulations of H_2O_2 and MDA in tobacco leaves were also inhibited. Besides,the activitiesof POD,CAT,APX and SOD were enhanced at varied degree with the pretreatment of spermine and spermidin under gaseous formaldehydestress. 3)The pretreatment of spermine and spermidine presented no promotion on the metabolism of gaseous formaldehyde in tobacco.