外源SNP对干旱胁迫下不同马铃薯品种叶片抗氧化酶活性的影响

Sodium Nitroprusside Role on Antioxidant Enzymes Activities in Leaves of Different Potato Cultivars under Drought Stress

以正常水分状态、轻度干旱胁迫、中度干旱胁迫和重度干旱胁迫下的马铃薯抗旱品种‘底西瑞’和干旱敏感品种‘大西洋’植株为材料,于现蕾期采用0(对照)和0.01mmol·L-1 SNP分别喷施各处理植株,对不同处理下2个品种的植株形态、叶片超氧阴离子和H_2O_2含量以及抗氧化酶活性进行比较分析,探讨外源SNP对干旱状态下马铃薯的生理应答机制,为马铃薯的抗旱栽培提供新的技术理论支持。结果显示:(1)SNP喷施对重度水分胁迫下马铃薯植株的正常生长具有一定的保护作用。(2)在干旱胁迫条件下,马铃薯叶片POD活性在品种‘底西瑞’中增加而在品种‘大西洋’中降低,超氧阴离子含量和H_2O_2含量以及CAT和APX活性在各品种中均增加,但超氧阴离子含量和H_2O_2含量增加程度与胁迫程度无关。(3)抗旱品种‘底西瑞’在干旱胁迫下的超氧阴离子含量低于干旱敏感品种‘大西洋’,而其POD、CAT和APX活性则高于‘大西洋’;0.01mmol·L-1SNP处理未改变马铃薯叶片中超氧阴离子和H_2O_2含量随土壤水分的变化趋势,但改变了‘大西洋’叶片中SOD、POD、CAT活性以及‘底西瑞’叶片中APX活性的变化趋势。(4)外源喷施0.01mmol·L-1SNP降低了‘底西瑞’在中度和重度胁迫下以及‘大西洋’在轻度和中度胁迫下超氧阴离子含量,提高了干旱胁迫下‘底西瑞’和‘大西洋’的POD和APX活性。研究表明,POD、CAT和APX可作为马铃薯水分胁迫下的应答以及品种抗旱性的筛选指标,外源SNP可通过诱导增强干旱胁迫下马铃薯的抗氧化酶活性来提高其抗旱性。

In order to elucidate effect of SNP on the parameters response to drought and relate to drought resistance of cultivars and to supply the new method and theory for drought resistant cultivation in processed potato,we firstly treated drought-resistant potato cv.‘Desiree＇and drought-sensitive potato cv.‘Atlantic＇with 0（control）and 0.01mmol·L-1SNP at bud,and then analyzed plant morphology,the contents of superoxide anion and H_2O_2,as well as activities of antioxidant enzymes under normal water,light water-stress,medium water-stress and heavy water-stress,respectively.The results showed that：（1）SNP treatment could maintain the normal growth of potato under heavy water-stress.（2）The contents of superoxide anion and H_2O_2,as well as activities of CAT and APX increased under water stress,but increases of superoxide anion content and H_2O_2 content were not related to the levels of stress.（3）The activity of PODrose in Desiree but lowered in Atlantic under drought stress.Compared with Atlantic drought resistant cultivar of Desiree possessed low content of superoxide anion and high activities of POD,CAT and APX under drought stress.Along with the levels of stress 0.01mmol·L-1 SNP treatment did not change the tendency of superoxide anion content and H_2O_2 content but changed the tendency of SOD,POD and CAT activities in Atlantic and of APX activity in Desiree.（4）The content of superoxide anion decreased in Desiree under normal water and heavy drought stress and in Atlantic under light drought stress and heavy drought stress by 0.01mmol·L-1 SNP.Additionally,SNP increased activities of POD and APX in both Desiree and Atlantic under drought stress.In conclusion,the parameters responsed to drought and drought resistance cultivars in potato were POD,CAT and APX activities.SNP could enhance the drought resistance of potato under drought stress.