AgNPs的绿色合成及其对杨树组培苗生长的影响

Green synthesis of AgNPs and its effect on the growth of poplar tissue culture in vitro

纳米银(AgNPs)因在植物快繁中表现出的积极作用而备受关注.为探究AgNPs对杨树离体再生的影响,以硝酸银溶液为前驱体,奇异变形杆菌YC801(Proteus mirabilis YC801)菌液上清为还原剂和封端剂于胞外进行AgNPs的绿色合成,在优化AgNPs合成条件的基础上,进一步探究了AgNPs对杨树(Populus L.)组培苗不定根形成及其幼苗生长的影响.研究结果表明将培养24 h的YC801菌液上清与浓度为10 mmo l·L^(-1)AgNO_(3)溶液在100℃、pH=10的条件下混合反应10 min时AgNPs的合成效率最高,浓度最大可达0.8484 mg·mL^(-1).合成的AgNPs在430 nm左右有特征吸收峰,其粒径分布在20~60 nm范围内,颗粒呈球形或伪球形,且分散性良好.在杨树离体再生中的研究发现,不同浓度的AgNPs对杨树组培苗的株高、不定根长、侧根数以及长势均有不同程度的促进作用.其中,1.0 mg·L^(-1)AgNPs的促进效果最佳,与CK相比,株高、不定根长度和侧根数显著提高,分别增加了43.95%,42.42%和104.53%,根系活力提高了42.69%.AgNPs在提高杨树叶绿素含量和促进光合效率方面发挥着显著效果,与CK相比,SPAD和PS II的最大光化学效率F_(v)/F_(m)分别提高了17.66%和5.33%.综上所述,通过研究高效绿色合成的AgNPs在杨树离体再生中发挥的积极作用,为AgNPs在植物的离体快繁中的应用提供了重要的技术支撑.研究结果表明,上述绿色合成的纳米银在杨树等植物离体快繁研究中具有潜在的应用价值.

Silver nanoparticles(AgNPs)has attracted much attention because of its positive role in plant rapid propagation.In order to investigate the effect of AgNPs on the regeneration of poplar trees in vitro,green synthesized AgNPs was carried out extracellularly using silver nitrate solution as the precursor and the supernatant of Proteus mirabilis YC801 as the reducing and capping agent,and the synthesis conditions of AgNPs were optimized in the present study.On this basis,the effects of AgNPs on adventitious root formation and seedling growth of poplar(Populus L.)tissue culture were further studied.The results showed that when the supernatant of YC801 bacterium cultured for 24 h was mixed with 10 mmol·L^(-1)AgNO_(3)solution at 100℃and pH=10 for 10 min,the synthesis efficiency of AgNPs was the highest,and the maximum concentration was 0.8484 mg·mL^(-1).The synthesized AgNPs had a characteristic absorption peak at about 430 nm,with the particle size distribution was 20-60 nm.The particles were spherical or pseudo-spherical with good dispersion.In the process of regeneration of poplars in vitro,it was found that AgNPs with different concentrations could promote the seedingheight,adventitious root length,and lateral root numbers of poplar tissue culture seedlings.Among the treatments,the promoting effect of 1.0 mg·L^(-1)AgNPs was the best.Compared with CK,the plant height increased by 43.95%,the adventitious root length and the number of lateral root increased by 42.42%and 104.53%,respectively,and root vitality increased by 42.69%.Further study indicated that AgNPs played a significant role in increasing chlorophyll content and photosynthetic efficiency of poplar.Compared with CK,SPAD and the maximum photochemical efficiency F_(v)/F_(m)of PS II increased by 17.66%and 5.33%,respectively.In summary,the green synthetic AgNPs has potential application in the plant rapid propagation in vitro.