小麦对锶离子的生物强化研究

Biofortification of Triticum aestivum L. With Strontium Ions

为评价小麦对锶的富集和耐受能力,以豫表25为试验材料,设置5个锶处理浓度(0、25、100、500和1 000 mg·kg-1),培养小麦植株30 d,测定小麦生物量,锶富集浓度以及抗氧化酶活性。结果表明,小麦的根、茎和叶均能富集金属锶,表现为叶>根>茎。根冠转移系数(TLF)和生物富集系数(BCF)在各锶处理中均大于1。100 mg·kg-1锶处理下,TLF达到最大值(1.19),25 mg·kg-1锶处理下,BCF达到最大值,地上和整株BCF分别为1.86和2.61。高浓度(1 000 mg·kg-1)锶离子增加了丙二醛(MDA)含量,抑制了过氧化物酶(POD)和过氧化氢酶(CAT)活性,而超氧化物歧化酶(SOD)活性随着锶浓度的升高而增加。综上,小麦地上部分具有较强的富集锶离子能力,锶离子浓度低于500 mg·kg-1对小麦生长有促进作用,SOD活性较高,表明SOD在小麦耐受锶胁迫中发挥重要作用。本研究为小麦对锶离子的生物强化研究提供了理论依据。

Wheat（ Triticum aestivum L.） was chosen as experimental materials,with five concentrations of strontium（ 0,25,100,500 and 1 000 mg·kg-1）. Plants were cultivated for 30 days. The strontium accumulation and tolerance patterns of wheat were evaluated under five strontium concentrations. The results showed that the root,stem and leaf of wheat could absorb a certain amount of strontium,and the accumulation ability was ranked as leaf root stem. The highest translocation factor（ TLF） was 1. 19 at 100 mg·kg-1 as well as the highest bioconcentration factor of shoot（ BCFshoot） and bioconcentration factor of plant（ BCFplant） were 1. 86 and 2. 61 at 25 mg·kg-1,respectively. The high concentration（ 1 000 mg·kg-1） of strontium ions increased malonaldehyde（ MDA） content and inhibited the peroxidase（ POD） and catalase（ CAT） activity,whereas superoxide dismutase（ SOD） activity increased with strontium concentrations. In conclusion,wheat accumulates high strontium concentration in shoot,and strontium ions were benefit to wheat growth as strontium concentration was below 500 mg·kg-1 SOD plays an important role in the strontium resistance mechanism of wheat. This study provided theoretical basis for the biofortification of strontium ions.