我们研究了基于天然多糖基质阿拉伯半乳聚糖(AG)的新型化学合成硒(Se)纳米复合材料(NCs)的作用,淀粉(ST),和κ-角叉菜胶(CAR)对植物病原体疫霉的生存力,根际细菌,田间试验和马铃薯生产力。使用透射电子显微镜(TEM),研究表明,纳米复合材料包含尺寸从20到180nm不等的纳米颗粒,具体取决于NC的类型。即使在Se/AGNC(3µg/mLSe)的最低测试浓度为50µg/mL时,所有三个研究的NC都具有杀真菌作用,Se/STNC为35µg/mL(0.5µg/mLSe),和39µg/mL的Se/CARNC(1.4µg/mLSe),包括最终悬浮液中0.000625%Se(6.25µg/mL)的浓度,用于研究硒NC对三种常见根际细菌不动杆菌细菌生长的影响,从伊尔库茨克地区生长的植物的根际中分离出的红球菌和假单胞菌,俄罗斯。基于AG的SeNC(Se/AGNC)和基于CAR的SeNC(Se/CARNC)对真菌生长的抑制作用最大,最高可达60%(300µg/mL)和49%(234µg/mL)。分别。SeNCs对植物病原体的安全使用要求它们对环境友好,而不会对根际微生物产生负面影响。在所有三种SeNCs的最终悬浮液中相同的浓度为0.000625%Se(6.25µg/mL)(对应于Se/AGNC的105.57µg/mL,Se/STNC为428.08µg/mL,Se/CARNC为170.30µg/mL)用于研究其对细菌生长的影响(杀菌,抑菌,和生物膜形成效应)。根据我们早期的研究,该浓度对导致马铃薯环腐病的植物病原细菌Clavibactersepedonicus具有抗菌作用,但在此浓度下并未对马铃薯植物的生存能力产生负面影响。在这项研究中,使用此浓度,根据细菌悬浮液的光密度,未发现所有三种SeNCs对红球红球菌的抑菌和杀菌活性。琼脂扩散,和生物膜形成的强度,但Se/CAR和Se/AGNCs抑制谷子假单胞菌的生长。在整个观察期间,细胞生长减少了15-30%,但是对于Se/CARNC观察到该细菌对生物膜形成的刺激。Se/AGNC对根际细菌Guillouiae不动杆菌也具有抑菌和抗生物膜作用。细菌生长减少2.5倍,生物膜形成减少30%,但是Se/CARNC刺激了Guilloiae的生长。根据初步现场试验结果,在块茎种植前处理后,通过在最终悬浮液中喷洒相同浓度为0.000625%(6.25µg/mL)的Se/AG和Se/CARNC,显示马铃薯生产率平均提高了30%。有关基于天然基质的SeNCs对植物的积极作用的获得和先前发表的结果为进一步研究其对根际细菌的影响以及栽培植物对胁迫因素的抗性开辟了前景。
We studied the effects of new chemically synthesized selenium (Se) nanocomposites (NCs) based on natural polysaccharide matrices arabinogalactan (AG), starch (ST), and kappa-carrageenan (CAR) on the viability of phytopathogen Phytophthora cactorum, rhizospheric bacteria, and potato productivity in the field experiment. Using transmission electron microscopy (TEM), it was shown that the nanocomposites contained nanoparticles varying from 20 to 180 nm in size depending on the type of NC. All three investigated NCs had a fungicidal effect even at the lowest tested concentrations of 50 µg/mL for Se/AG NC (3 µg/mL Se), 35 µg/mL for Se/ST NC (0.5 µg/mL Se), and 39 µg/mL for Se/CAR NC (1.4 µg/mL Se), including concentration of 0.000625% Se (6.25 µg/mL) in the final suspension, which was used to study Se NC effects on bacterial growth of the three common rhizospheric bacteria Acinetobacter guillouiae, Rhodococcus erythropolis and Pseudomonas oryzihabitans isolated from the rhizosphere of plants growing in the Irkutsk Region, Russia. The AG-based Se NC (Se/AG NC) and CAR-based Se NC (Se/CAR NC) exhibited the greatest inhibition of fungal growth up to 60% (at 300 µg/mL) and 49% (at 234 µg/mL), respectively. The safe use of Se NCs against phytopathogens requires them to be environmentally friendly without negative effects on rhizospheric microorganisms. The same concentration of 0.000625% Se (6.25 µg/mL) in the final suspension of all three Se NCs (which corresponds to 105.57 µg/mL for Se/AG NC, 428.08 µg/mL for Se/ST NC and 170.30 µg/mL for Se/CAR NC) was used to study their effect on bacterial growth (bactericidal, bacteriostatic, and biofilm formation effects) of the three rhizospheric bacteria. Based on our earlier studies this concentration had an antibacterial effect against the phytopathogenic bacterium Clavibacter sepedonicus that causes diseases of potato ring rot, but did not negatively affect the viability of potato plants at this concentration. In this study, using this concentration no bacteriostatic and bactericidal activity of all three Se NCs were found against Rhodococcus erythropolis based on the optical density of a bacterial suspension, agar diffusion, and intensity of biofilm formation, but Se/CAR and Se/AG NCs inhibited the growth of Pseudomonas oryzihabitans. The cell growth was decrease by 15-30% during the entire observation period, but the stimulation of biofilm formation by this bacterium was observed for Se/CAR NC. Se/AG NC also had bacteriostatic and antibiofilm effects on the rhizospheric bacterium Acinetobacter guillouiae. There was a 2.5-fold decrease in bacterial growth and a 30% decrease in biofilm formation, but Se/CAR NC stimulated the growth of A. guillouiae. According to the results of the preliminary field test, an increase in potato productivity by an average of 30% was revealed after the pre-planting treatment of tubers by spraying them with Se/AG and Se/CAR NCs with the same concentration of Se of 0.000625% (6.25 µg/mL) in a final suspension. The obtained and previously published results on the positive effect of natural matrix-based Se NCs on plants open up prospects for further investigation of their effects on rhizosphere bacteria and resistance of cultivated plants to stress factors.