Se胁迫条件下EDDS对彩叶草生长和生理指标及Se含量的影响

Effects of EDDS on growth,physiological indexes and Se content of Coleus blumei under Se stress

采用室内水培法,研究了在1.0 mg.L-1Se胁迫条件下添加0.0(CK)、0.5、1.0、1.5、2.5和5.0 mmol.L-1乙二胺二琥珀酸(EDDS)对彩叶草(Coleus blumei Benth.)鲜质量及部分生理指标的影响,并对相同条件下彩叶草各器官的Se含量以及Se富集系数和转运系数进行了分析。分析结果表明:在1.0 mg.L-1Se胁迫条件下,添加0.5～1.5 mmol.L-1EDDS,彩叶草根、茎和叶的鲜质量均明显高于对照;而添加2.5和5.0 mmol.L-1EDDS,各器官的鲜质量均低于对照;总体上,随EDDS浓度的提高,彩叶草根、茎、叶的鲜质量逐渐下降。随着EDDS浓度的提高,彩叶草根中的MDA含量逐渐增加但均显著低于对照;而随EDDS浓度的提高,叶中的SOD、CAT和APX活性均呈低浓度时降低、高浓度时升高的趋势,而GSH含量、POD和GSH-Px活性则呈低浓度时升高、高浓度时降低的趋势。添加1.0 mmol.L-1EDDS,彩叶草叶片中的SOD、CAT和APX活性均降至最低且显著低于对照,而GSH含量、POD和GSH-Px活性则达到最高值且显著高于对照。随EDDS浓度的提高,彩叶草根、茎和叶中的Se含量以及Se富集系数和转运系数均呈低浓度时升高、高浓度时降低的趋势;各处理组彩叶草根中的Se含量明显高于茎和叶,茎中的Se含量则略高于叶;添加1.0 mmol.L-1EDDS,根、茎和叶中的Se含量以及富集系数和转运系数均达到最高值且显著高于对照。实验结果表明:添加适宜浓度的EDDS可增加彩叶草对Se的吸收及富集能力,有利于Se污染土壤的修复,且对彩叶草的生长及代谢无明显影响。

Effects of adding 0. 0 （CK）, 0. 5, 1. 0, 1. 5, 2. 5 and 5. 0 mmol . L-1[S,S]- ethylenediamine disuccinic acid （EDDS） on fresh weight and some physiological indexes of Coleus blumei Benth. under 1.0 mg .L-1 Se stress were studied by indoor solution culture method, and Se contents in different organs and Se enrichment or translocation coefficients of C. blumei were analyzed under the same experimental conditions. The results show that when adding 0.5-1.5 mmol . L-x EDDS under 1.0 mg . L-1 Se stress, fresh weights of root, stem and leaf of C. blumei are obviously higher than those of the control, while, when adding 2.5 and 5.0 mmol . L-1 EDDS, fresh weights of organs are all lower than those of the control. Generally, fresh weights of root, stem and leaf of C. blumei decrease gradually with rising of EDDS concentration. With rising of EDDS concentration, MDA contents in root of C. blumei increase gradually but all are significantly lower than those of the control. With rising of EDDS concentration, activities of SOD, CAT and APX in leaf of C. blumei appear the trend of decreasing at low concentration and increasing at high concentration, while GSH content and activities of POD and GSH-Px appear the trend of increasing at low concentration and decreasing at high concentration. Under condition of adding 1.0 mmol . L-1 EDDS, activities of SOD, CAT and APX in leaf of C. blumei all reach thelowest and are significantly lower than those of the control, while GSH content and activities of POD and GSH-Px reach the highest and are significantly higher than those of the control. With rising of EDDS concentration, Se contents in root, stem and leaf of C. blumei and Se enrichment and translocation coefficients all appear the trend of increasing at low concentration and decreasing at high concentration. And Se content in root is obviously higher than that in stem and leaf, but that in stem is slightly higher than that in leaf. Under condition of adding 1.0 mmol .L-1 EDDS, Se contents in root, stem and leaf and Se enrichment and translocation coefficients reach the highest and all are significantly higher than those of the control. It is suggested that adding EDDS with suitable concentration may enhance the ability of C. blumei to uptake and enrichment Se and is beneficial to repair soil contaminated by Se, and has no obvious influence on growth and metabolism of C. blumei.