5-Aminolevulinic acid ameliorates cadmium-induced morphological, biochemical, and ultrastructural changes in seedlings of oilseed rape
5-Aminolevulinic acid ameliorates cadmium-induced morphological, biochemical, and ultrastructural changes in seedlings of oilseed rape
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DOI：
10.1007/s11356-013-1735-5
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发表时间：
2013-10-01
影响因子：
5.8
通讯作者：
Zhou, W. J.
中科院分区：
文献类型：
--
作者：
Ali, Basharat;Huang, C. R.;Zhou, W. J.
油菜生长旺盛，可作为镉污染土壤的植物修复材料。利用植物生长调节剂对抗重金属胁迫是目前研究人员的主要目标之一。研究了5-氨基乙酰丙酸（ALA、0、0.4、2和10 mg/l）对油菜生长的促进作用。Cd胁迫（0、100和500亩）下zs758幼苗的生长发育。结果表明，Cd胁迫通过降低根茎和下胚轴长度、地上部和根部生物量、叶绿素含量和抗氧化酶活性来抑制幼苗生长。另一方面，Cd胁迫增加了茎部丙二醛（MDA）水平、H2O2产量和Cd积累。对叶片叶肉细胞的显微研究表明，镉的毒性完全破坏了整个细胞结构，并在显微镜下出现了镉的积累。低剂量ALA （2 mg/l）对幼苗生长和生物量有促进作用。结果表明：2 mg/l ALA显著提高Cd胁迫下叶绿素含量，降低地上部Cd含量；ALA降低了子叶中MDA和H2O2的含量。Cd胁迫下，2 mg/l ALA处理显著提高了抗坏血酸过氧化物酶、过氧化物酶、过氧化氢酶、谷胱甘肽还原酶和超氧化物歧化酶的活性。本研究还表明，较高的ALA浓度（10 mg/l）对油菜的生长有不利影响。显微研究表明，ALA的施用减轻了Cd对叶肉细胞的毒性作用，改善了细胞结构。用2 mg/l ALA在500亩M Cd下使用效果更好，该剂量下细胞结构清晰，细胞壁和细胞膜明显，细胞核大，核仁发育良好，有两个或多个核仁。叶绿体几乎呈圆形，含有类囊体膜和颗粒，但与其他处理相比，叶绿体中没有淀粉粒。综上所述，ALA具有促进Cd胁迫下植物存活的作用。
Due to its prolific growth, oilseed rape (Brassica napus L.) can be grown successfully for phytoremediation of cadmium (Cd)-contaminated soils. Nowadays, use of plant growth regulators against heavy metals stress is one of the major objectives of researchers. The present study evaluates the ameliorate effects of 5-aminolevulinic acid (ALA, 0, 0.4, 2, and 10 mg/l) on the growth of oilseed rape (B. napus L. cv. ZS 758) seedlings under Cd stress (0, 100, and 500 mu M). Results have shown that Cd stress hampered the seedling growth by decreasing the radical and hypocotyls length, shoot and root biomass, chlorophyll content, and antioxidants enzymes. On the other hand, Cd stress increased the level of malondialdehyde (MDA) and production of H2O2 and accumulation of Cd in the shoots. The microscopic study of leaf mesophyll cells showed that toxicity of Cd totally destroyed the whole cell structure, and accumulation of Cd also appeared in micrographs. Application of ALA at lower dosage (2 mg/l) enhanced the seedling growth and biomass. The results showed that 2 mg/l ALA significantly improved chlorophyll content under Cd stress and decreased the level of Cd contents in shoots. Application of ALA reduced the MDA and H2O2 levels in the cotyledons. The antioxidants enzymes (ascorbate peroxidase, peroxidase, catalase, glutathione reductase, and superoxide dismutase) enhanced their activities significantly with the application of 2 mg/l ALA under Cd stress. This study also indicated that higher dosage of ALA (10 mg/l) imposed the negative effect on the growth of oilseed rape. Microscopic study showed that application of ALA alleviated the toxic effects of Cd in the mesophyll cell and improved the cell structure. Use of 2 mg/l ALA under 500 mu M Cd was found to be more effective, and under this dosage, cell structure was clear, with obvious cell wall and cell membrane as well as a big nucleus, which was found with well-developed two or more nucleoli. Chloroplast was almost round in shape and contained thylakoids membranes and grana, but starch grains were not found in chloroplast comparatively to other treatments. On the basis of our results, we can conclude that ALA has a promotive effect which could improve plant survival under Cd stress.