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以小麦‘西旱3号’为材料,分析了PTIO(NO清除剂)、过氧化氢酶(CAT,H2O2清除剂)和DPI(质膜NADPH氧化酶抑制剂)对NaCl胁迫下小麦幼苗元素含量、根一氧化氮(NO)水平和质外体活性氧(ROS)产生的影响。结果显示,50和150mmol·L-1 NaCl均诱导小麦根、叶的Na含量增加而Ca含量减少,但50 mmol·L-1 NaCl胁迫诱导根K含量减少而叶K含量增多,根叶K/Na比减少。PTIO、CAT和DPI的加入导致150 mmol·L-1 Na Cl胁迫的小麦根Na和Ca含量减少而叶中的含量增多;PTIO和CAT处理增加根K量而DPI降低其含量,这三种试剂均增加150 mmol·L-1 NaCl胁迫下幼苗叶K含量。进一步研究发现,根的NO荧光强度在150 mmol·L-1 NaCl胁迫下显著增强,50 mmol·L-1 NaCl胁迫的根中一氧化氮合酶(NOS)类似蛋白活性降低约19%,而150 mmol·L-1 NaCl胁迫诱导酶活性升高约30%。PTIO或CAT减弱了150 mmol·L-1 NaCl胁迫下根的NO荧光,却刺激了NOS类似蛋白活性,而NaCl+DPI处理诱导小麦根最大的NO荧光强度和最高的NOS类似蛋白活性。此外,Na Cl胁迫的根质外体H2O2、O2·–和·OH含量增加。与150 mmol·L-1 NaCl单独胁迫相比,添加PTIO可减少根质外体H2O2和O2·–含量,却增加·OH含量,添加CAT只提高了质外体O2·–含量,而DPI的加入使根质外体H2O2和·OH增加而O2·–减少。这表明,不同的盐浓度使小麦幼苗对Na、K和Ca吸收发生了变化;盐胁迫促进小麦根NO及质外体ROS的积累,它们之间相互影响,可能共同调控植物在盐胁迫响应过程中根对Na、K和Ca的吸收及其向地上部分的转运。
The wheat seedlings ’Xidan 3’ were used as materials to analyze the effects of PTIO (NO scavenger), catalase (CAT, H2O2 scavenger) and DPI (plasma membrane NADPH oxidase inhibitor) , Root nitric oxide (NO) and the production of reactive oxygen species (ROS). The results showed that both 50 and 150 mmol·L -1 NaCl induced the increase of Na content and the decrease of Ca content in the roots and leaves of wheat, however, the K content decreased but the K content increased in 50 mmol·L -1 NaCl stress. The K / Na ratio decreased. The addition of PTIO, CAT and DPI led to the decrease of Na and Ca content in wheat roots with 150 mmol·L-1 NaCl stress and the increase of the content in leaves. PTIO and CAT treatments increased root K and DPI decreased the content of these three agents Increased the K content of seedling leaves under 150 mmol·L-1 NaCl stress. Further studies showed that the NO fluorescence intensity of root increased significantly under the stress of 150 mmol·L-1 NaCl, and the activity of nitric oxide synthase (NOS) -like protein decreased by about 19% in roots of 50 mmol·L-1 NaCl 150 mmol·L-1 NaCl induced about 30% increase in enzyme activity. PTIO or CAT attenuated the NO fluorescence of roots under 150 mmol·L -1 NaCl stress, but stimulated the activity of NOS-like proteins. However, NaCl + DPI treatment induced the highest NO fluorescence intensity and highest NOS-like protein activity in wheat roots. In addition, the contents of H2O2, O2 · - and · OH in NaCl-treated root exudates increased. Compared with 150 mmol·L-1 NaCl alone, the addition of PTIO reduced the content of H2O2 and O2 · -, but increased the content of · OH, while the addition of CAT increased the content of O2 · - Adding H2O2 and · OH increased the root exosomes and O2 · - decreased. This indicated that different salt concentrations changed the absorption of Na, K and Ca in wheat seedlings. The salt stress promoted the accumulation of NO and the extracellular ROS in wheat seedlings. The interaction between them affected the salt stress response Middle root absorbs Na, K and Ca and translocates to the aerial part.