不同濃度鈣?鋅抑制劑對煙草鎘積累及亞細胞分布的影響

宋曉慧 秦仕華 陸引罡

摘要[目的]探討鈣鋅互作對鎘元素在煙草體內亞細胞分布的影響。[方法]以煙草南江三號為研究材料，通過添加不同濃度鈣、鋅2種抑制劑，采用土培盆栽試驗，研究煙草鎘的亞細胞分布。[結果]煙草葉部和根部的整個亞細胞中，鎘含量分布大小順序為胞液、細胞壁、葉綠體、線粒體。土壤中鎘濃度為1 mg/kg時，加入鈣抑制劑100 mg/kg，煙草根部葉綠體、細胞器和胞液的鎘含量均下降，而細胞壁中的鎘含量增加；加入鋅抑制劑 50 mg/kg，煙草所有亞細胞中的鎘含量均有所下降，說明加入鋅抑制劑50 mg/kg比加入鈣抑制劑100 mg/kg的效果好。土壤鎘濃度為5 mg/kg時，煙草根部和葉部細胞器的鎘含量都有所上升，其余3個亞細胞中的鎘含量減少。[結論]煙草中鎘在胞液中的分布多于細胞壁，葉綠體和線粒體鎘含量少，在不同濃度鈣、鋅處理下煙草對鎘的耐性加強，鎘在煙草體內結合在細胞壁上，通過主動運輸進入胞液，胞液區室化作用明顯，可能是煙草耐鎘的主要機制，減少煙葉鎘含量的重要途徑。

關鍵詞鈣/鋅；煙草；鎘；吸收；亞細胞分布

中圖分類號X503.231文獻標識碼

A文章編號0517-6611（2017）10-0008-03

Effects of Different Concentrations of Calcium and Zinc Inhibitors on Accumulation and Subcellular Distribution of Cadmium in Tobacco

SONG Xiaohui1，QIN Shihua2，LU Yingang2*（1.College of Resources and Environmental Engineering，Anshun University，Anshun，Guizhou 561000；2.Guizhou University，Guiyang，Guizhou 550025）

Abstract[Objective] The aim was to explore effects of different concentrations of calcium and zinc inhibitors on cadmium accumulation and subcellular distribution in tobacco.[Method] Taking Nanjiang 3 as material，we studied the subcellular distribution of cadmium in tobacco by soil culture pot experiment with adding different concentrations of calcium and zinc inhibitors.[Result] The cadmium content in whole subcellular of leaves and roots of tobacco was in order of cytosol，cell wall，chloroplast and mitochondria.When the concentration of cadmium in soil was 1 mg/kg，and the concentration of calcium inhibitor was 100 mg/kg，the cadmium decreased in cytosol，chloroplast and organelles of tobacco root，but increased in cell wall；when the concentration of cadmium in soil was 1 mg/kg，and the concentration of zinc inhibitor was 50 mg/kg，the cadmium decreased in all subcellular of tobacco，which indicated that adding 50 mg/kg zinc inhibitor had better effect than adding 100 mg/kg calcium inhibitor.When the concentration of cadmium in soil was 5 mg/kg，the concentration of cadmium in organelles of tobacco leaves and roots all increased，while the concentration of cadmium in the other 3 subcellular decreased.[Conclusion] The cadmium in cytosol is more than that in cell wall，and the cadmium in chloroplast and mitochondria was little.The tolerance of tobacco under different concentrations of calcium and zinc is strengthened.The cadmium in tobacco is combined on cell wall，and then transported into cytosol，and the cytosol has strong chamber，which may be main mechanism and important way to reduce cadmium in tobacco.

Key wordsCalcium and zinc；Tobacco；Cadmium；Absorption；Subcellular distribution

鎘（Cd）是常見的化學污染物，其毒性對生物各個器官及組織有嚴重的損傷[1]。煙草是一種生物量較高的經濟作物，對鎘有較強的富集和向上運輸能力，且有75%～81%的鎘轉運在葉子中，具有超積累植物的主要特征，在土壤鎘污染的植物修復方面有較大的應用潛力[2-4]。鈣（Ca）、鋅（Zn）是植物生長的必需營養元素，并且均能在煙草吸收鎘的過程中起到競爭作用，從而減輕甚至抑制鎘對植物的損傷[5-10]。……