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| 多年生黑麦草对镉和砷复合胁迫的响应及酶学机理 |
| Response and enzymatic mechanisms of Lolium perenne L. to combined cadmium and arsenic stress |
| 投稿时间：2024-06-23 |
| DOI：10.13254/j.jare.2024.0450 |
| 中文关键词: Cd-As复合胁迫，光合作用，酶学机理，转运蛋白 |
| 英文关键词: Cd-As combined stress, photosynthesis, enzymatic mechanism, transporter |
| 基金项目:国家自然科学基金项目（32260314） |
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| 摘要点击次数: 205 |
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| 中文摘要: |
| 单一有毒微量元素对牧草的影响已受到广泛关注，但关于多年生黑麦草对Cd-As复合胁迫响应研究较少。为探讨Cd-As复合胁迫对多年生黑麦草的生长特征、光合作用、酶学机理和转运蛋白的影响，本研究在温室种植多年生黑麦草（品种为“大瀑布”和“维纳斯”），设置对照组（Cd 0 mg·kg-1，As 0 mg·kg-1）、Cd3As60（Cd 3 mg·kg-1，As 60 mg·kg-1）、Cd3As120（Cd 3 mg·kg-1，As 120 mg·kg-1）、Cd3As180（Cd 3 mg·kg-1，As 180 mg·kg-1）处理组，研究Cd-As复合胁迫对多年生黑麦草累积特征的影响及其酶学机理。结果表明：与Cd3As60相比，高浓度Cd-As胁迫下“大瀑布”和“维纳斯”地上部丙二醛（MDA）含量均显著增加（12.93%~24.73%和16.02%~29.98%），抗氧化系统活性增强，叶绿体基质类囊体排列紊乱，细胞壁变薄，细胞核变形，光合作用受阻，使植株株高缩短（15.12%~28.32%和1.75%~7.20%）、生物量降低（36.22%~54.56%和2.96%~17.82%）；“大瀑布”地上部和根部Lsi1（硅转运蛋白）含量均显著增加（12.23%~20.06%和13.39%~15.64%），As在地上部和根部可溶组分中的占比增加（2%~11%和1%~12%），细胞受到的As毒害减轻；与Cd3As60相比，高浓度Cd-As胁迫下对“维纳斯”的毒害增强，根部细胞受损严重，谷胱甘肽（GSH）、植物络合素（PCs）、非蛋白巯基（NPT）含量和CAX（阳离子/H+交换体）、Nramp（天然抗性巨噬细胞蛋白）含量减少，Cd在地上部和根部的累积（8.96%~13.18%和9.47%~18.59%）及其在可溶组分中的占比减少（1%~9%和0%~2%）。研究表明，Cd-As胁迫引起多年生黑麦草氧化胁迫和细胞膜结构受损，非酶物质和转运蛋白含量降低，导致多年生黑麦草对Cd、As的累积降低。 |
| 英文摘要: |
| The impact of single toxic trace elements on forage grass has received widespread attention, but studies on the response of Lolium perenne L. to Cd-As combined stress are scarce. To investigate the effects of Cd-As combined stress on the growth characteristics, photosynthesis, enzyme mechanism and transporter of perennial ryegrass, in this study, L. perenne ‘Nicaragua’and L. perenne ‘Venus’ were grown in a greenhouse with the following treatment groups：control group（Cd 0 mg·kg-1, As 0 mg·kg-1）, Cd3As60（Cd 3 mg·kg-1, As 60 mg·kg-1）, Cd3As120（Cd 3 mg·kg-1, As 120 mg·kg-1）, and Cd3As180（Cd 3 mg·kg-1, As 180 mg·kg-1）. The accumulation characteristics of Cd and As in L. perenne, as well as their enzymatic mechanisms, were analyzed. The results showed that compared with Cd3As60, under high-concentration Cd-As stress, the content of MDA in the shoots of‘Nicaragua’and‘Venus’significantly increased （12.93%-24.73% and 16.02%-29.98%）, the activity of antioxidant system was enhanced. The chloroplast stroma thylakoid arrangement was disordered, the cell wall thinned, and the nucleus deformed, resulting in inhibited photosynthesis, which led to shorter plants（15.12%-28.32% and 1.75%-7.20%）and reduced biomass（36.22%-54.56% and 2.96%-17.82%）. The content of Lsi1 protein in the shoot and root of‘Nicaragua’significantly increased by（12.23% - 20.26%）and（13.39% - 15.64%）, which increased the proportion of As in the soluble fractions（2% - 11% and 1% - 12%）, thereby the As toxicity to cells was alleviated. Compared with Cd3As60, under high-concentration Cd-As stress, with the increase of soil As content, the toxicity to‘Venus’increased, the root cells were severely damaged, the contents of GSH, PCs, NPT, CAX and Nramp reduced, which decreased the accumulation of Cd in shoots and roots（8.96%-13.18% and 9.47%-18.59%）and its proportion in soluble fractions（1%-9% and 0%-2%）. Cd-As stress could induce oxidative stress and cell membrane structure damage, decrease the content of thiol substances and transport proteins, resulting in reduced accumulation of Cd and As in L. perenne. |
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