纳米氧化锌对玉米种子萌发及根系碳代谢的影响

Effects of ZnO nanoparticles on seed germination and root carbon metabolism in maize(Zea mays L.)

作为一种纳米金属氧化物,纳米氧化锌(ZnO nanoparticles,ZnO NPs)因其独特的物理性质和较大的比表面积,逐渐在农业领域得到应用。为了探究纳米氧化锌对玉米生长的影响,设置了7个不同浓度的纳米氧化锌悬浮液(10 mg·L^-1、20 mg·L^-1、50 mg·L^-1、100 mg·L^-1、200 mg·L^-1、500 mg·L^-1和1000 mg·L^-1),采用震荡浸种的方法,研究了纳米氧化锌对种子萌发及玉米碳代谢的影响。结果表明,低浓度(20 mg·L^-1、50 mg·L^-1和100 mg·L^-1)纳米氧化锌缩短了种子发芽的时间,提高了种子的平均发芽速度,其中,浓度为50 mg·L^-1时,平均发芽速度最快。玉米种子的发芽率、发芽势、发芽指数及活力指数均随着纳米氧化锌浓度的升高呈先升高后降低的趋势,并在50 mg·L^-1时达到最高;低浓度(50 mg·L^-1和100 mg·L^-1)的纳米氧化锌显著增加了根系及胚芽的生长和伸长,这有利于生物量的积累。此外,纳米氧化锌(50 mg·L^-1)显著增加了根系己糖激酶和脲苷二磷酸葡萄糖焦磷酸化酶活性,降低了醛缩酶活性,为种子萌发生长提供代谢产物和能量。50 mg·L^-1纳米氧化锌震荡浸种促进了糖酵解代谢和细胞壁的生物合成过程,有利于促进种子萌发,提高幼苗活力。

As a metal nanoparticles,ZnO nanoparticles(ZnO NPs)has been applied in agricultural production gradually due to its unique physical properties and larger specific surface area.In order to understand the effects of ZnO NPs on maize growth,seven different concentrations of ZnO NPs(10 mg·L^-1,20 mg·L^-1,50 mg·L^-1,100 mg·L^-1,200 mg·L^-1,500 mg·L^-1,1000 mg·L^-1)with shake immersion method were used to investigate their effects on seed germination and root carbon metabolism in maize.The results showed that lower concentration(20 mg·L^-1,50 mg·L^-1,100 mg·L^-1)ZnO NPs shortened the germination time and increased the germination rate;the germination rate with 50 mg·L^-1 treatment was the fastest.The total germination,germination energy,germination index and seed vigor index increased and then decreased with the ZnO NPs concentration increasing;and all indexes with 50 mg·L^-1 treatment reached maximum values.Low concentrations(50 mg·L^-1,100 mg·L^-1)ZnO NPs significantly increased root and shoot growth and elongation,favorable to biomass accumulation.In addition,ZnO NPs(50 mg·L^-1)significantly increased the activities of hexokinase and UDP-glucose pyrophosphorylase while reduced the aldolase activity,providing metabolites and energy for seed germination and growth.Therefore,50 mg·L^-1 ZnO NPs promoted glycolysis and cell wall biosynthesis,which would be conductive to enhancing seed germination and seedling vigor.