铅、镉和锌胁迫对荷花生理生化的影响

Effect of Cd,Zn and Pb stresses on physiology and biochemistry of lotus

采用盆栽法研究荷花(Nelumbo nuciferaGaertn.)在Pb2+,Cd2+,Zn2+胁迫下,不同质量浓度处理对其生理生化特性的影响.结果表明,随着Cd2+,Zn2+质量浓度的增加,荷花叶片中的叶绿素含量呈现先升后降的趋势,而Pb2+处理下随着质量浓度的增加荷叶叶绿素下降较快,但随后又上升.3种重金属对叶绿素a含量的影响远远大于对叶绿素b含量的影响.在Pb2+,Cd2+,Zn2+胁迫下,随着质量浓度的增加荷叶的相对电导率也是呈现先上升后下降的趋势,分别在400,15和240 mg.kg-1时,相对电导率达到最高值,分别比对照高41.8%,46.6%和65.2%,之后变化趋势缓慢且有所下降;MDA含量随着质量浓度的增大而持续升高达到显著水平,最高值分别出现在400,30和240 mg.kg-1处,分别比对照高32.6%,68.0%和54.9%;随着Pb2+,Cd2+,Zn2+质量浓度的增加,溶性蛋白含量呈现先升高后下降的走势,在200,15和240 mg.kg-1,处达到最高值,分别比对照高88.2%,222.4%和106.5%;随着Pb2+,Cd2+,Zn2+胁迫质量浓度的增加,SOD,POD,CAT等保护酶的活性总体呈上升的趋势,在高质量浓度Zn2+,Pb2+处理下,SOD上升趋势减缓,在高质量浓度Zn2+处理下,CAT活性有所下降,但仍然处在较高水平.在Pb2+,Cd2+,Zn2+胁迫下,保护酶活性增强并保持较高水平,说明荷花有抵抗3种重金属污染的潜在能力.

A potted planting method is adopted to research on the influence of different processing concentrations on physiological and biochemical characteristics of lotus（Nelumbo nucifera Gaertn.） under Pb2＋,Cd2＋ and Zn2＋stress.The results show that： with the increase of Cd2＋ and Zn2＋ concentrations,the chlorophyll content in lotus leaves shows the trend of firstly increasing and then decreasing,chlorophyll content in lotus leaves is lowered more rapidly with the increase of concentration under the Pb2＋ treatment,but is increased then.The influence of the three heavy metals on the content of chlorophyll a is far greater than that on the content of chlorophyll b.Under the stress of Pb2＋,Cd2＋ and Zn2＋,with the increase of concentration,the relative conductivity of lotus leaf shows the trend of increasing firstly and lowering then,the conductivity reaches its maximum when in respectively 400,15 and 240 mg·kg-1,and is respectively higher than that of the control by 41.8%,46.6% and 65.2%,then,the change trend is slow and is lowered,the MDA content is continuously increased with the increase of concentration to achieve the prominent level,the highest values are respectively shown in 400,30 and 240 mg·kg-1,and they are respectively higher than that of the control by 32.6%,68.0% and 54.9%;With the increase of Pb2＋,Cd2＋ and Zn2＋ stress concentration,soluble protein contents show the trend of increasing firstly and lowering then,reaching the highest value in 200,15 and 240 mg·kg-1,and are respectively higher than that of the control by 88.2%,222.4% and 106.5% respectively; with the increase of Pb2＋,Cd2＋ and Zn2＋ stress concentration,the activity of SOD,POD,CAT and other protective enzymes wholly show upward trend,under the processing of high concentration of Zn2＋ and Pb2＋,the SOD upward trend slows,under the processing of high concentration Zn2＋,the CAT activity is decreased,but is still in higher level.Under the Pb2＋,Cd2＋and Zn2＋stress,activities of protective enzymes are increased and kept at high level,which indicates that the lotus has the potential ability of resisting the three heavy metal pollution.