摘要
以烟草(Nicotiana tabacum L.)为材料,采用不同浓度镉胁迫(0、5、25、50mg/L)的水培试验,分别用电感耦合等离子体光谱仪、紫外分光光度计、酶联免疫法、光合作用仪、叶绿素荧光分析仪研究了镉胁迫3d对叶内镉含量、生长素氧化酶(IAAO)活性、生长素(IAA)、脱落酸(ABA)、赤霉素(GA3)、玉米素(Z)的含量、光合特性及荧光特性的影响。结果显示烟草叶内镉含量随着胁迫浓度增加而显著增加;IAAO活性在镉为5mg/L时下降,然后随着镉浓度增加而显著上升;IAA含量在镉为5mg/L时上升,但随着镉浓度增加而显著下降;ABA含量随着镉浓度上升而增加;GA3含量在5mg/L时上升,然后随着镉浓度增加而显著下降;Z含量随着镉浓度增加而显著下降;叶绿素a、叶绿素b和类胡萝卜素含量均随镉胁迫浓度增大而显著减少;光合参数中的净光合速率(Pn)、气孔导度(Gs)、细胞间隙CO2浓度(Ci)、蒸腾速率(Tr)及荧光参数中的PSⅡ潜在光化学效率(Fv/Fo)、PSⅡ最大光化学效率(Fv/Fm)、PSⅡ实际光化学效率(ФPSⅡ)、光化学猝灭系数(qP)均随镉胁迫浓度增大而下降。由此可见,镉胁迫打破了烟草激素的平衡,降低了光合能力。
Tobacco（Nicotiana tabacum L.） seedlings were used to evaluate the effects of exogenous Cd2＋ on hormone levels,photosynthetic and fluorescent characteristics.Seedlings with six leaves and same height were hydroponically cultivated in Hoagland′s nutrient solution for 15 d.The seedlings were aerated 3 h per day and the nutrient solution was renewed every 5 d.Afterwards,Cd（NO3）2 was added to the nutrient solution at 0,5,25 and 50 mg/L,respectively（calculated as pure Cd2＋）.After Cd2＋ treatment for 3 d,the Cd2＋ contents in leaves were determined with inductively coupled plasma atomic emission spectrometer.The levels of endogenous phytohormones including indoleacetic acid（IAA）,gibberellic acid（GA3）,abscisic acid（ABA） and zeatin（Z）,were assayed with enzyme-linked immunosorbent assay（ELISA）.The activities of indoleacetic acid oxidase（IAAO）,photosynthetic performance and chlorophyll fluorescent characteristics were measured.Our results showed that the contents of Cd2＋ in leaves significantly increased with the increase of exogenous Cd2＋ concentration,the activities of IAAO decreased at Cd2＋ 5 mg/L,but increased at higher concentrations of exogenous Cd2＋.At Cd2＋ 50 mg/L,the activity of IAAO increased by 101.71% comparison with the control.Both of the contents of IAA and GA3 increased at Cd2＋ 5 mg/L,but decreased with the increase of exogenous Cd2＋ concentration.At 50 mg/L Cd2＋,the contents of IAA decreased by 34.10%,the contents of GA3 decreased by 39.69%,while the contents of ABA gradually increased with Cd2＋ concentration increase.At 50 mg/L Cd2＋,the contents of ABA increased by 61.84% comparison with the control.However,the contents of Z sharply decreased with the increase of Cd2＋ concentration,and the contents of Z decreased by 75.35% at 50 mg/L Cd2＋.Moreover,the contents of chlorophyll a and b and carotenoid decreased significantly with the increase of exogenous Cd2＋ contents.At 50 mg/L Cd2＋,chlorophyll a and b and carotenoid declined by 34.80%,5
出处
《生态学报》
CAS
CSCD
北大核心
2011年第16期4517-4524,共8页
Acta Ecologica Sinica
基金
河南省教育厅自然基金项目(2006180012)
河南省重大公益项目(091100910500)
关键词
镉
烟草
叶
激素
光合特性
荧光特性
cadmium
tobacco leaves
phytohormones
photosynthetic performance
fluorescent characteristics
