MgO纳米颗粒对油菜子叶外植体的影响

Effects of MgO nanoparticles on the cotyledon explants from Brassica napus L. in vitro

MgO纳米颗粒(MgO NPs)是在药剂、污染修复、涂料及半导体等中得到广泛应用的无毒环保材料,以油菜(Brassica napusL.)品种‘宁油12’培养于MS培养基上4—5 d的子叶外植体为供体材料,在添加0—10.0 mmol∕L MgO NPs的油菜不定芽再生培养基(MS+4.5 mg∕L 6-BA)上培养21 d。结果表明:1.5 mmol∕L MgONPs处理的子叶外植体不定芽再生频率和单个外植体平均不定芽数均达最高值,分别为83.33%和19.33个,显著高于对照;0.5—1.5 mmol∕L MgO NPs处理显著提高了子叶不定根的再生频率;超过2.0 mmol∕L,对外植体有明显抑制效应;超过8.0 mmol∕L,外植体完全失去再生能力。但在4.0 mmol∕L时,从子叶不定根再生频率以及外植体质量上看,较2.0 mmol∕L时的活力有明显提高,可能存在纳米颗粒团聚效应降低了高浓度MgO NPs对外植体再生的抑制效应。以上结果表明:低浓度MgO NPs处理对油菜子叶外植体再生有显著促进作用,但超过2.0 mmol∕L表现出明显的毒害效应。低浓度MgO NPs亦可作为组培上值得尝试的价廉环保的添加剂。

Magnesium oxide nanoparticles(MgO NPs)have wide uses in pharmaceuticals,toxic waste remediation,toxic gas removal,paint and semiconductors,but at present,there are not studies on plant growth and development with MgO NPs.This study investigated effects of MgO NPs on the cotyledons of rape(Brassica napus L.)variety‘Ningyou 12’.The cotyledons of 4-5 d rape seedlings on MS media were cut and transferred to the rape adventitions bud regeneration media(MS+4.5 mg∕L 6-BA)added 0-10.0 mmol∕L MgO NPs for 21 d.Compared with negative control,the rate of adventitious buds was increased significantly on 1.5 mmol∕L MgO NPs media from 36.67%to 83.33%,but inhibited obviously by MgO NPs with the concentration over 2.0 mmol∕L,and the regeneration ability of cotyledons was suppressed completely by the MgO NPs over 8.0 mmol∕L.However,the adventitions bud regeneration rate and the number of adventitious buds each cotyledon were not obviously different between 2.0 mmol∕L and 4.0 mmol∕L MgO NPs,but the root regeneration rate and weight of cotyledon explants with 4.0 mmol∕L MgO NPs treatment were better than that of 2.0 mmol∕L.It was possible that aggregation effect of nanoparticles decreased the inhibition function on rape cotyledon explants.These results showed that low concentration of MgO NPs(1.5 mmol∕L)could increase the regeneration ability of rape cotyledon explants,but over 2.0 mmol∕L,MgO NPs could cause toxic effects obviously.In addition,MgO NPs could be tried to use on the plant tissue culture as a kind of nontoxic and cheap additive.