外源ABA与盐胁迫对银边吊兰生长及生理特性的影响

Effects of ABA and Salt Stress on the Growth and Physiological Characteristics of Chlorophytum comosum var.variegatum

【目的】通过探究外源ABA与不同浓度盐胁迫对银边吊兰生长及生理特性的影响,为盐渍化土壤中园林草本植物的耐盐适应奠定一定的理论基础。【方法】以水培条件下生长健壮的银边吊兰为材料,设置3个盐浓度梯度处理1个月(分别为S0(0 mmol/L)、S1(100 mmol/L)、S2(200 mmol/L)及2个ABA喷施处理(喷施与不喷施)),对其叶片形态、生物量、净光合速率(Pn)和蒸腾速率(T_(r))、光合色素含量、渗透调节物质含量和抗氧化酶活性等进行测定与分析。【结果】(1)盐胁迫下银边吊兰生物量、叶绿素、类胡萝卜素、可溶性糖含量显著降低;光合速率(P_(n))和蒸腾速率(T_(r))显著下降;膜脂过氧化产物丙二醛(MDA)含量显著增加,表明盐胁迫显著影响了银边吊兰的生长及营养物质积累,抑制了其光合特性,加剧了其氧化胁迫。盐胁迫下银边吊兰通过提高根冠比以提高对逆境的耐受性,增加脯氨酸含量以应对渗透胁迫,增强过氧化物酶(POD)和抗坏血酸过氧化物酶(APX)活性以应对氧化胁迫。表明银边吊兰通过调节其生长生理特性对盐胁迫做出了积极响应。(2)喷施外源ABA使盐胁迫下银边吊兰的生物量、根冠比、叶绿素和类胡萝卜素含量显著增加,表明外源ABA缓解了盐胁迫对其生长、营养物质积累和光合特性的影响;同时,外源ABA增加了盐胁迫下银边吊兰的脯氨酸和可溶性糖含量,缓解了其渗透胁迫;而膜脂过氧化产物丙二醛(MDA)含量显著降低,POD和APX活性显著升高,表明外源ABA通过调节银边吊兰的抗氧化酶活性缓解了盐胁迫对其造成的氧化胁迫。【结论】盐胁迫显著抑制了银边吊兰的生长。银边吊兰通过增加其根冠比、提高渗透调节物质脯氨酸含量和抗氧化酶活性以积极应对。喷施外源ABA可进一步增加盐胁迫下植株的根冠比、渗透调节物质含量和抗氧化酶的活性,降低蒸腾速率,有效缓解盐胁迫对银边吊兰的伤害,提高其抗盐性。

[Objective]By exploring the effects of exogenous ABA and different concentrations of salt stress on the growth and physiological characteristics of Chlorophytum comosum var.variegatum,this paper can provide a certain theoretical foundation for the adaptability of garden herbs to salinized soil.[Method]The mature plant of Chlorophytum comosum var.variegatum with robust growth was used as the test materials.Under hydroponics conditions,3 salt concentration gradient treatments(0 mmol/L,100 mmol/L,200 mmol/L)×2 ABA spraying treatments(spraying or no spraying)were set.After treatment with one month,the leaf morphology,biomass,net photosynthetic rate(P_(n))and transpiration rate(T_(r)),photosynthetic pigment content,osmotic regulation substance content and antioxidant enzyme activities under different treatments were examined[Result](1)Under salt stress,the contents of biomass,chlorophyll,carotenoid and soluble sugar were significantly reduced.Photosynthetic rate(P_(n))and transpiration rate(T_(r))decreased significantly.The content of malondialdehyde(MDA)of membrane lipid peroxidation product increased significantly,indicating that salt stress significantly affected the growth and nutrient accumulation of Chlorophytum comosum var.variegatum,inhibited its photosynthetic characteristics,and aggravated its oxidative stress.Under salt stress,the tolerance to adversity was improved by increasing root/shoot ratio,proline content was increased to cope with osmotic stress,and the activities of peroxidase(POD)and ascorbic peroxidase(APX)were enhanced to cope with oxidative stress.The results showed that the Chlorophytum comosum var.variegatum responded positively to salt stress by regulating its physiological characteristics.(2)Exogenous ABA significantly increased the biomass,root/shoot ratio,the contents of chlorophyll and carotenoid of Chlorophytum comosum var.variegatum under salt stress,indicating that exogenous ABA alleviated the effects of salt stress on its growth,nutrient accumulation and photosynthetic characteristics.At the same time,ABA increased the contents of proline and soluble sugar under salt stress and alleviated the osmotic stress.The content of MDA was decreased significantly,and POD and APX activities were increased significantly under ABA application treatments,indicating that exogenous ABA alleviated the oxidative stress caused by salt stress by regulating the activities of antioxidant enzyme of Chlorophytum comosum var.var⁃iegatum.[Conclusion]Salt stress significantly inhibited the growth and changed the physiological characteristics of Chlorophytum comosum var.variegatum plants.On the other hand,the plants can positively respond to salt stress by increasing its root/shoot ratio,osmotic regulation substance proline content and antioxidant enzyme activities.Exogenous ABA treatment can effectively alleviate the damage caused by salt stress on Chloro⁃phytum comosum var.variegatum and improve its salt resistance by reducing transpiration rate,increasing the root/shoot ratio,the osmotic regulation substance contents and antioxidant enzyme activities further.