硅对平邑甜茶幼苗干旱胁迫伤害的缓解

Mitigative effect of silicon on drought stress-induced injuries in Malus hupenensis Rhed. seedling

以15%聚乙二醇(PEG)6000模拟干旱胁迫,水培平邑甜茶(Malus hupenensis Rhed.)幼苗为试验材料,硅酸钠(2 mmol/L Na2SiO3·9H2O)作为硅源,研究硅对苹果幼苗干旱胁迫伤害缓解及促进植株生长的影响。结果显示,在PEG模拟干旱胁迫下,与不施硅相比,施硅处理的平邑甜茶幼苗硅转运蛋白转录水平升高、硅含量升高、生物量提高、叶片相对含水量提高;叶片中H2O2含量、丙二醛含量及相对电渗率维持在较低水平,叶绿体结构较完整且光合作用较强。表明施硅能够通过提高Lsi1基因转录进而提高平邑甜茶幼苗体内硅的含量,缓解干旱胁迫对苹果幼苗的氧化伤害,促进植株的生长。

The study was conducted to determine the effect and mechanism of exogenous silicon (Si) on apple seedling under drought stress. Drought stress imposed by 15%( W / V ) polyethylene glycol (PEG) 6000 and Si was supplied as Na 2SiO 3·9H 2O at 2 mmol/L. The results shown Si application increased expression level of silicon transporter gene Lsi1 and silicon content in apple seedling under PEG stress, which was contributing to maintaine H 2 O 2 accumulation, malondialdehyde content and the relative electrolyte leakage at lower levels, and increased photosynthesis by protecting the chloroplast structure. In conclusion, exogenous silicon could increase silicon content in plant by enhance the expression level of Lsi1 , and then alleviate oxidative damage of drought stress and improve the growth of apple seedlings.