• ISSN 1008-505X
  • CN 11-3996/S

农业土壤−植物系统中新型硒生物强化技术研究进展

Research progress on novel selenium biofortification technologies in agricultural soil-plant systems

  • 摘要: 硒是人体和动物所必需的微量元素,在抗氧化、免疫调节、维持甲状腺功能以及保障生殖健康等方面发挥着不可替代的生理作用。植物硒是人体和动物获取硒的最主要来源,而植物中硒含量主要取决于土壤有效硒含量及植物对硒吸收累积能力。世界绝大多数土壤缺硒,硒缺乏问题十分普遍。常规植物硒生物强化通常是通过土壤基施或叶面喷施硒酸盐或亚硒酸盐来实现,但由于这两种硒盐易发生淋溶迁移,且植物对它们的吸收利用效率较低,因此存在对土壤及地下水造成二次污染的风险。为此,多种新型硒生物强化措施被研究和开发利用。本文总结了土壤−植物系统中几类主要硒新型生物强化技术的研究进展。从提高植物硒吸收积累的途径区分,新型硒生物强化技术主要包括:利用基因工程手段提高植物对硒的吸收利用和积累能力;利用纳米技术制备高效吸收的纳米硒制剂(肥);利用功能性微生物活化土壤中的硒元素,促进硒协同吸收;利用富硒区域工农业生产副产品,生产硒含量高的有机肥。基因工程技术主要通过改变植物原有的遗传特性,使植物具备更强的硒吸收与积累能力,并能将富硒性状稳定遗传给后代;纳米硒生物强化技术则主要借助纳米技术提升硒的生物利用度,同时降低其毒性,该技术具有合成周期短、安全剂量范围宽的特点,具备替代传统无机硒肥的潜力;微生物协同强化技术包含两方面内容:一是利用功能微生物的硒转化能力,增加土壤−植物系统中可利用形态硒的含量,进而提高硒的生物有效性;二是利用微生物菌肥增强根系对硒的吸收能力;富硒有机物料缓释硒肥则充分利用高硒或硒污染地区生长的富硒植物及其副产物来制作缓释硒肥,这不仅能提高作物的硒含量,还能提升资源回收利用率。为尽快实现这些新型硒强化技术的落地,未来应聚焦于以下几个方面:1) 深入探究作物硒吸收和转移的遗传机制,以及选育富硒作物品种;2) 优化纳米硒生物肥制备方法,提高其稳定性和生物活性;3)筛选并鉴定具有硒转化微生物,并探讨其转化机理;4) 推进富硒缓释有机肥的研发与应用,并研究如何调控硒释放速率,以匹配植物生长周期的需求。

     

    Abstract: Selenium (Se) is an essential trace element for humans and animals, and adequate Se nutrition heavily relies on sufficient Se in plants. Plants acquire Se predominantly through root uptake from soil, however, large areas in the world are deficient in Se. To increase the Se absorption and accumulation in plants, selenate and selenite have traditionally been applied. Nevertheless, these chemicals are highly soluble and prone to loss via runoff and leaching, posing risks of secondary soil and water contamination and exhibiting low utilization efficiency by plants.Various novel Se biofortification techniques are emerging to address these challenges. This study summarized the progress in the researches of current Se biofortification technologies within soil-plant systems. Distinguished by the approaches to enhancing Se uptake and accumulation in plants, novel Se biofortification technologies encompass several strategies. These include utilizing genetic engineering to enhance plants' capacity for Se uptake, utilization, and accumulation; employing nanotechnology to produce highly efficient nano-selenium formulations (fertilizers); leveraging functional microorganisms to activate Se in soil, thereby synergizing Se uptake; and producing organic fertilizers with high Se content from the by-products of industrial and agricultural activities in Se-rich regions. Genetic engineering techniques primarily aim to modify the inherent genetic traits of plants, enabling them to possess greater Se absorption and accumulation capabilities and to stably transmit Se-enriched traits to subsequent generations. Nano-selenium biofortification mainly harnesses nanotechnology to improve Se bioavailability and reduce its toxicity, featuring a relatively short synthesis cycle and a broad safe dosage range, thus holding the potential to replace traditional inorganic Se fertilizers. Microbial-assisted biofortification exploits microorganisms’ ability to transform Se, increasing the available Se forms in the soil-plant system and facilitating Se uptake by plants, thereby elevating Se content. The slow-release Se fertilizers derived from Se-rich organic materials fully utilize Se-rich plants and their by-products grown in Se-rich or Se-contaminated areas to produce slow-release Se fertilizers, which not only enhance crop Se content but also improve resource recycling and utilization efficiency. To expedite the practical application of these novel Se-enrichment technologies, future research should focus on the following areas: 1) investigating the genetic mechanisms underlying Se uptake and transformation in crops and breeding Se-rich crop varieties; 2) optimizing the preparation methods of nano-selenium biofertilizers to enhance their stability and bioactivity; 3) screening and identifying microorganisms capable of Se transformation and exploring their transformation mechanisms; 4) developing and applying Se-rich slow-release organic fertilizers, as well as determining how to regulate Se release rates to align with the demands of plant growth cycles.

     

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