• ISSN 1008-505X
  • CN 11-3996/S

油菜素甾醇信号响应养分和重金属胁迫的生理分子机制

Physiological and molecular mechanisms of brassinosteroid signaling in response to nutrient and heavy metal stresses

  • 摘要: 植物生长发育需要吸收利用各种必需营养元素及有益元素维持植物整个生命活动。土壤中营养元素含量过低或有毒重金属元素过量均能抑制植物的生长发育和产量品质的形成,积累的重金属还能通过食物链迁移而危害人体健康。植物激素油菜素甾醇作为一种促生激素不仅参与了植物生长发育的各个阶段,也在应对各种生物和非生物胁迫中发挥了重要作用。本文在阐述植物油菜素甾醇合成、运输、代谢和信号传导的主要过程及其关键基因的基础上,综述了油菜素甾醇参与调控氮、磷、硼、铁等必需营养元素胁迫所涉及的分子机制,以及参与缓解镉、砷、铅和铬等有毒重金属胁迫的生理分子机制。当植物遭遇营养胁迫时,油菜素甾醇信号途径核心转录因子BES1/BZR1的表达模式发生改变,进而影响下游靶基因的表达以适应营养胁迫过程。在重金属胁迫下,外源喷施油菜素甾醇可以降低体内重金属的积累,减少其对植物生长的不利影响,提高重金属胁迫下植物的光合能力,增强抗氧化酶活性以应对活性氧的爆发,增强对各种重金属胁迫的耐受能力。在农业生产中外源喷施油菜素甾醇类化合物作为植物生长调节剂,有利于植物生长发育,增强对逆境条件的抗性,具有低投入、高产出的效果。因此,在提高农作物抗逆能力实现高产稳产中,油菜素甾醇具有广阔的应用前景。

     

    Abstract: Plants absorb and utilize various essential and beneficial elements to complete the whole life cycles. Inefficient nutritional elements or excessive toxic heavy metals in soil will inhibit plant growth, development, and the formation of yield and crop quality. The heavy metals existed in crops may even damage human health through food chain migration. Phytohormone brassinosteroid, as a growth-promoting hormone, involves in various procession of plant growth and development, and plays an important role in coping with biotic and abiotic stresses. The paper reviews the main processes and key genes involved in the synthesis, transport, metabolism and signal transduction of brassinosteroid in plants, and the molecular mechanism of brassinosteroid involved in the regulation of nutrient stress such as nitrogen, phosphorus, boron, and iron, and the physiological and molecular mechanisms of brassinosteroid involved in alleviating the stress of toxic heavy metals such as cadmium, arsenic, lead and chromium. BES1/BZR1, the key transcription factors in brassinosteroid signaling, will change their expression patterns when plants are subjected to nutrient stress, and then affect the expression of downstream target genes to adapt to the nutrient stress. Under heavy metal stress, exogenous spraying of brassinosteroid can reduce the accumulation of heavy metals in plants, reduce the adverse effects on plant growth, improve the photosynthetic capacity, increase the activity of antioxidant enzymes to cope with the outbreak of reactive oxygen species, and then enhance the tolerance to heavy metal stresses. Exogenous application of brassinosteroid in agricultural production is also found beneficial to plant growth and development, and high resistance to adverse conditions, therefore, showing broad prospects in agricultural production in improving crop stress resistance and achieving high and stable yield.

     

/

返回文章
返回