无机三价砷对黄花水龙无菌苗生理生化特性的影响

EFFECT OF INORGANIC TRIVALENT ARSENIC STRESS ON PHYSIOLOGICAL AND BIOCHEMICAL CHARACTERISTICS IN STERILE IMMATURE PLANT OF JUSSIAEA STIPULACEA OHWI

采用溶液培养法研究无机三价砷胁迫对黄花水龙[Ludwigia peploides(Kunth)P.H.Raven subsp.stipulacea(Ohwi)P.H.Raven.]无菌苗的影响,通过将黄花水龙无菌苗在含不同浓度NaAsO2(0、2.5、10、50、250和500μmol/L)的1/10霍格兰溶液中培养24h,测定叶绿素、丙二醛(MDA)、可溶性蛋白、可溶性糖以及抗氧化酶SOD、POD、CAT活性的变化,以探讨无机三价砷胁迫对黄花水龙无菌苗光合特性及相关生理生化特征指标的影响。结果表明:2.5μmol/L As(Ⅲ)处理时,叶绿素a、叶绿素b和叶绿素总量达到峰值,随着处理浓度升高,叶绿素含量均有所下降;处理组MDA含量均高于对照组,且当处理浓度升高至500μmol/L显著高于对照组。可溶性蛋白含量随着砷处理浓度的升高先升后降,在As(Ⅲ)浓度为250μmol/L时显著高于对照组,当浓度高至500μmol/L时可溶性蛋白含量有所降低;可溶性糖含量随着砷浓度的升高先降后升,抗氧化酶SOD、POD、CAT活性均在低砷处理浓度下逐渐升高并到显著差异水平,但当浓度高于250μmol/L后,含量均呈下降趋势;这表明在低浓度胁迫下,黄花水龙自身会出现自我保护现象,高浓度砷对黄花水龙表现出损伤效应。研究结果为进一步研究砷胁迫下黄花水龙生理和生长变化及其培育和移植提供了一定依据。

To study the effects of inorganic trivalent arsenic stress on Ludwigia peploides(Kunth)P.H.Raven subsp.stipulacea(Ohwi)P.H.Raven,sterile immature plant of Jussiaea stipulacea Ohwi cultured in 1/2 Hoagland nutrition liquid with NaAsO2 at 0,2.5,10,50,250,500μmol/L respectively for 24h were analyzed the photosynthetic system and physiological and biochemical characteristics by measuring the contents of chlorophyll,malondialdehyde(MDA),soluble protein,soluble sugar and activity of antioxidant enzymes(SOD,POD,CAT).Results revealed that the chlorophyll a,b,and a+b contents reached their peaks at 2.5μmol/L As(Ⅲ),but the chlorophyll contents decreased gradually with the increased As(Ⅲ)concentration.As(Ⅲ)induced MDA content with the highest level at 500μmol/L that was significantly higher than that in the control group.The soluble protein content first increased and then decreased with the increased As(Ⅲ).The soluble protein content was significantly higher at 250μmol/L group than that of the control group,and it was lower at 500μmol/L group than the control group.The soluble sugar content firstly decreased and then increased with the increase of arsenic concentration.Activity of antioxidant enzymes(SOD,POD and CAT)increased gradually at low As(Ⅲ)concentration to reach significant difference,but they decreased when the As(Ⅲ)concentration was higher than 250μmol/L,suggesting that under low As(Ⅲ)concentration,Jussiaea stipulacea Ohwi itself will appear self-protection,and high As(Ⅲ)concentration will have damage effect.The results provide a basis for further study of Jussiaea stipulacea Ohwi physiology and growth change,cultivation and transplants with arsenic stress.