School of Biosciences, Mahatma Gandhi University, PD Hills (PO), Kottayam, Kerala, 686 560, India.
Curr Microbiol. 2019 Apr;76(4):503-509. doi: 10.1007/s00284-019-01649-0. Epub 2019 Feb 25.
Rhizosphere provides unique space for intensive chemical conversation between plant and microorganisms. The common rhizobacterial mechanisms which have been demonstrated to promote plant growth include production of phytohormones, nitrogen fixation, synthesis of 1-aminocyclopropane-1-carboxylate deaminase (ACC deaminase) and phosphate solubilization. The microbially produced phytohormone indole-3-acetic acid (IAA) is considered to have significant role in interaction between plant and bacteria. Hence any substance with modulatory effect on rhizobacterial IAA production can expect to have its impact on plant-microbe interaction. With the advent of nanotechnology, nanoparticles are being used for diverse applications. However, applications of nanotechnology in agriculture have not been studied in detail. In the study, rhizospheric Pseudomonas monteilii was selected to investigate the concentration-dependent effect of biogenic gold nanoparticles (AuNPs) on its IAA production. For this, AuNPs synthesized by Bacillus subtilis SJ15 were characterized by UV-Vis spectroscopy, FT-IR, TEM and EDS. The results showed AuNPs to have spherical, hexagonal and triangular shapes with a size range of 12-32 nm and absorption peak at 545 nm. Further, various concentrations of AuNPs were used to identify its impact on IAA production by P. monteilii. From this, enhanced production of IAA by P. monteilii was found to take place in the presence of 50 µg/mL AuNPs. When Vigna unguiculata seedlings were grown in presence of 50 µg/mL of AuNPs, increased growth was observed. The results of the study thus showed the ability of AuNPs to augment the IAA-producing potential of P. monteilii.
根际为植物和微生物之间的密集化学交流提供了独特的空间。已证实促进植物生长的常见根际细菌机制包括植物激素的产生、固氮作用、1-氨基环丙烷-1-羧酸脱氨酶（ACC 脱氨酶）和磷酸盐溶解的合成。微生物产生的植物激素吲哚-3-乙酸（IAA）被认为在植物与细菌之间的相互作用中具有重要作用。因此，任何对根际细菌 IAA 产生具有调节作用的物质都有望对植物-微生物相互作用产生影响。随着纳米技术的出现，纳米粒子被用于各种应用。然而，纳米技术在农业中的应用尚未得到详细研究。在这项研究中，选择了根际假单胞菌来研究生物源金纳米粒子（AuNPs）对其 IAA 产生的浓度依赖性影响。为此，通过枯草芽孢杆菌 SJ15 合成的 AuNPs 通过紫外可见光谱、傅里叶变换红外光谱、TEM 和 EDS 进行了表征。结果表明 AuNPs 具有球形、六方和三角形形状，尺寸范围为 12-32nm，吸收峰在 545nm。此外，使用不同浓度的 AuNPs 来确定其对 P. monteilii 产生 IAA 的影响。结果发现，在 50µg/mL AuNPs 的存在下，P. monteilii 的 IAA 产量增加。当豇豆幼苗在 50µg/mL 的 AuNPs 存在下生长时，观察到生长增加。因此，该研究结果表明 AuNPs 能够增强 P. monteilii 的 IAA 产生潜力。
