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通过水培试验,以玉米作为供试植株,研究Pb、Cu胁迫对玉米生长发育、细胞色素合成以及重金属吸收的影响。结果表明,Pb、Cu单一胁迫下玉米根长较对照组均偏低,复合胁迫下根长随着Pb、Cu复合浓度的增加而减小。玉米植株在重金属Pb、Cu单一胁迫下生物量变化不明显,但在不同水平Pb、Cu复合胁迫下,表现随着重金属胁迫浓度增加,玉米植株生物量先增加后减小。玉米叶绿素含量随着Pb胁迫浓度增加而增加、随着Cu浓度增加而降低;Pb、Cu单一胁迫下β-类胡萝卜素含量随着Pb浓度增加先降低后增加,随着Cu含量增加先增加后降低;Pb、Cu单一胁迫下花青素含量较对照组均增大,Cu胁迫下花青素含量增加更明显,最低增加0.65%,最高增加21.25%。玉米不同器官对Pb、Cu积累有一定差异,在单一重金属胁迫下Pb、Cu在玉米体内积累量与胁迫浓度呈正相关,分布顺序为根系>茎叶,根部是积累Pb、Cu主要器官。Pb、Cu复合胁迫下加剧了重金属向玉米体内的迁移累积,随着Pb、Cu复合胁迫浓度的增大,根部吸收Pb、Cu逐步增大,而茎叶吸收Pb、Cu趋于平稳。相关分析显示,玉米细胞色素的合成取决于被胁迫的重金属类型,β-类胡萝卜素含量与植株体内Pb含量显著正相关,花青素含量与Cu含量显著正相关,揭示Pb对β-类胡萝卜素诱导作用强、Cu对花青素诱导作用强。
The effects of Pb and Cu stress on the growth and development, cytochrome synthesis and heavy metal absorption of maize were studied by using hydroponic culture experiments. The results showed that under the single stress of Pb and Cu, the root length of maize was lower than that of the control, and the root length decreased with the increase of Pb and Cu concentrations under combined stress. Under the single stress of heavy metals Pb and Cu, the biomass of corn plants did not change obviously. However, under the stress of Pb and Cu, the biomass of corn plants increased first and then decreased with the increase of heavy metal stress. The content of chlorophyll of maize increased with the increase of Pb concentration and decreased with the increase of Cu concentration. The content of β-carotenoid decreased with the increase of Pb concentration and then increased with the increase of Cu concentration The content of anthocyanin increased under single stress of Pb and Cu compared with the control. The content of anthocyanin increased more obviously under Cu stress, with the minimum increase of 0.65% and the highest increase of 21.25%. There were some differences in the accumulation of Pb and Cu in different organs of maize. Under the single heavy metal stress, the accumulation of Pb and Cu in maize was positively correlated with the concentration of stress, the distribution order was root> stem and leaf, and the root was the main organ of Pb and Cu accumulation. Under the combined stress of Pb and Cu, the migration and accumulation of heavy metals to maize were aggravated. With the increase of the concentration of Pb and Cu, the absorption of Pb and Cu in root increased gradually, while the absorption of Pb and Cu in leaves and stems tended to be stable. Correlation analysis showed that the synthesis of maize cytochromes was dependent on the type of heavy metals that were intimidated. The β-carotenoid content was significantly and positively correlated with the Pb content in plants, and the anthocyanin content was positively correlated with the Cu content. Strong inducing effect of Cu, Cu on anthocyanin induction strong.