Department of Plant Sciences and Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran.
Department of Microbiology and Immunology, Clinical and Diagnostic Immunology, KU Leuven, Leuven, Belgium.
BMC Plant Biol. 2022 Jul 26;22(1):367. doi: 10.1186/s12870-022-03702-w.
Maize (Zea mays) growth performance has been hindered due to the high soil salinity. Salinity is one of the most severe abiotic stresses that has led to growth imbalance and profitability of harvests in arid and semi-arid regions. Plants have taken advantage of salt-tolerant bacteria as plant growth-promoters to enhance growth and reduce the adverse effects of salinity through the regulation of some biochemical, physiological, and molecular features. Preferences for non-chemical, eco-friendly, and economical approaches have caused the inquiry of the Bacillus genus as a joint group of plant growth-promoting rhizobacteria known to alleviate salt-stress impacts. In the present study, halotolerant Bacillus strains were isolated from salt-marshland soil and characterized for their physiological, molecular, and biochemical properties. Twenty-four bacterial isolates collected from high saline fields of salt marshland were analyzed by MALDI-TOF MS proteome analysis, which confirmed the taxonomic affiliation with Bacillus cereus, Bacillus subtilis, Bacillus atrophaeus, and Bacillus thorngiensis. Applying the isolates on maize plants as bio-inoculant bacteria obviously increased the growth parameters (P < 0.01). Pot experiments showed that isolates 74 and 90 were the most prominent strains to minimize the harmful effects of salinity. Its effects are heightening the potassium/sodium ratio and K-Na selectivity in shoots and roots measured by flame atomic absorption photometry (AAS). Accordingly, Bacillus cereus isolate 74 showed a maximum increase in dry weights of the shoot (133.89%), root (237.08%), length of the shoot (125%), and root (119.44%) compared to the control condition. Our findings suggest that bacteria isolated from marshland may be an economical and simple means to increase plant growth and resistance to high salinity soil conditions.
由于土壤盐分过高，玉米（Zea mays）的生长性能受到了阻碍。盐度是最严重的非生物胁迫之一，导致干旱和半干旱地区的作物生长失衡和收成减少。植物利用耐盐细菌作为植物生长促进剂，通过调节一些生化、生理和分子特征，来增强生长并减少盐分的不利影响。由于人们偏爱非化学、环保和经济的方法，因此人们对芽孢杆菌属进行了研究，该属是一种联合的植物促生根际细菌群，已知可以减轻盐胁迫的影响。在本研究中，从盐沼土壤中分离出耐盐芽孢杆菌菌株，并对其生理、分子和生化特性进行了表征。通过 MALDI-TOF MS 蛋白质组分析对从盐沼高盐田收集的 24 个细菌分离株进行了分析，这证实了与蜡样芽孢杆菌、枯草芽孢杆菌、萎缩芽孢杆菌和苏云金芽孢杆菌的分类归属。将分离株作为生物接种细菌应用于玉米植物上，明显增加了生长参数（P < 0.01）。盆栽试验表明，分离株 74 和 90 是减轻盐害最显著的菌株。其作用是通过火焰原子吸收分光光度法（AAS）提高钾/钠比和 shoot 和 root 中的 K-Na 选择性。因此，与对照条件相比，蜡样芽孢杆菌分离株 74 使 shoot（133.89%）、root（237.08%）、shoot 长度（125%）和 root 长度（119.44%）的干重增加最多。我们的研究结果表明，从沼泽地分离的细菌可能是一种经济且简单的方法，可以增加植物的生长和对高盐土壤条件的抗性。
