种子引发对小麦抗盐及抗旱特性影响综述

Effect of seed priming on drought and salinity tolerance of wheat: An overview

  • 摘要: 小麦是我国北方重要粮食作物, 在农业生产中经常受到干旱和盐分胁迫影响, 造成减产。种子引发是在种子萌发前用天然或人工合成试剂对种子进行处理, 从而提高植物抗逆性的一种简单而有效的方法。在干旱或高盐条件下, 利用引发剂对小麦种子引发后, 种子萌发提前, 幼苗生长发育代谢增强, 抗逆境相关生理指标提升, 作物抗旱耐盐能力增强, 最终产量及质量得到提高。本文阐述了水、有机物、植物激素、生物活性物质、生物、氧化物、无机信号物质等不同种类引发剂对小麦种子引发的作用机理和效果。并总结了种子引发的主要作用机制, 如: 减少植株对Na+的吸收, 增加对K+、Ca2+的吸收, 减少盐分对生长造成的阻碍; 促进可溶性蛋白和可溶性糖等渗透调节物质的合成和积累, 细胞内维持高渗透压, 有利于根系吸水; 诱使胁迫条件下细胞内超氧化物歧化酶、过氧化物酶、过氧化氢酶、抗坏血酸过氧化物酶等抗氧化酶的合成增多、活性增强, 有效清除活性氧, 维持细胞内氧平衡; 调节植物内源激素合成与运输从而使激素水平处于更加适应胁迫条件的平衡状态等。并讨论了引发剂与植物逆境生理研究之间相互补充、相互促进的关系, 展望了种子引发在农业方面的发展及应用前景。

     

    Abstract: Wheat is one of the most important crops in north of China. Wheat suffers from various unfavorable conditions, especially drought and high soil salinity, leading to unpredictable loss in crop production in agriculture. Seed priming is a simple and efficient technology which is the induction of a particular physiological reaction in plants by application of natural or synthetic compounds to incubate the seeds before germination. Wheat seeds treated with priming agents can reduce emergence time, enhance seeding vigor and metabolism, and improve yields and seed quality under high soil salinity or water deficit conditions. This review illustrated the mechanisms and effects of various priming agents, such as water, organics, hormones, bioactive substances, organisms, oxides, inorganic signal substance and so on. We summarized the main mechanism of seed priming. Seed priming reduced absorption of Na+ and increased absorption of K+ and Ca2+ to reducing the toxicity of single saline ion in plant. Seed priming also improved synthesizing and accumulating of osmotic regulatory substances, such as soluble protein and soluble sugar, which maintaining osmotic pressure of intracellular at a high level to benefit root uptaking water. Seed priming induced synthesis of antioxidant enzymes, such as superoxide dismutase, peroxidase, catalase, ascorbate peroxidase and so on, and enhanced the activities of those enzymes under stress conditions. The high activity of antioxidant enzymes reduced the content of reactive oxygen species effectively and maintained the oxygen balance in cells. Furthermore, seed priming also improved endogenous hormones synthesis and transportation under stressed conditions, which was important for adaptations to environmental change. We further discuss the connections of mutual complement and promotion between seed priming and adversity resistant physiology of crops. Finally, we expectate the prospect of the application and the development for seed priming in agriculture.

     

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