Department of Microbiology and Molecular Genetics, The Women University, Multan, Pakistan.
Department of Microbiology and Molecular Genetics, University of the Punjab, Lahore, Pakistan.
PLoS One. 2022 Feb 4;17(2):e0262932. doi: 10.1371/journal.pone.0262932. eCollection 2022.
Drought accompanied with reduced precipitation is one of the key manacles to global agricultural throughput and is expected to escalate further hence posing major challenges to future food safety. For a sustainable agricultural environment, drought resistant plant growth promoting rhizobacteria (PGPR) are new encouraging prospect, which are inexpensive and have no side effects, as those of synthetic fertilizers. In the present study, five strains of Pseudomonas aeruginosa, the strain MK513745, strain MK513746, strain MK513747, strain MK513748, and strain MK513749 were used as drought tolerant PGPR with multiple traits of IAA production, N fixation, P solubilization, siderophore producing capabilities. The strain MK513745 and strain MK513749 produced higher quantities of indole acetic acid (116±0.13 and 108±0.26 μg ml-1). MK513749 yielded 12 different indole compounds in GCMS analysis. The strain MK513748 yielded maximum S.I. (3.33mm) for phosphate solubilizing test. Maximum nitrogen concentration was produced (0.18 μg ml-1) by strain MK513746. Percent siderophore units ranged from 2.65% to 2.83% as all five pseudomonas strains were siderophore positive. In all growth experiments of plant microbe interaction two varieties of Vigna radiata (AZRI-06, NM-11) plants inoculated with P. aeruginosa strains under drought stress responded significantly (P<0.05) better than control stressed plants. Maximum shoot length was enhanced up-to 125%, pod/plant 172%, number of grains 65%, 100 seed weight 95%, 100 seed straw weight 124% and total yield 293% were recorded in plants inoculated with drought stress tolerant PGPR in both varieties as compared to respective stressed control plants. Photosynthetic activity, membrane stability (45%), water content (68%) and antioxidant efficacy (19%) were improved with PGPR inoculations. The variety NM-11 (V2) was more tolerant to drought stress with inoculations of Pseudomonas strains than AZRI-06 (V1). Inoculations with these indole acetic acid producing strains would be suitable for plant growth promotion in areas facing water deficiency.
干旱伴随着降水减少是全球农业产量的关键制约因素之一，预计未来还会进一步加剧，从而对未来的食品安全构成重大挑战。为了实现可持续的农业环境，具有多种特性的耐旱植物促生根际细菌（PGPR）是一种有希望的新方法，它们价格低廉，没有副作用，不像合成肥料那样有副作用。在本研究中，使用了 5 株铜绿假单胞菌，分别为菌株 MK513745、菌株 MK513746、菌株 MK513747、菌株 MK513748 和菌株 MK513749，作为具有 IAA 生产、固氮、解磷、产铁载体能力的耐旱 PGPR。菌株 MK513745 和菌株 MK513749 产生了更高数量的吲哚乙酸（116±0.13 和 108±0.26μg ml-1）。MK513749 在 GCMS 分析中产生了 12 种不同的吲哚化合物。菌株 MK513748 在磷酸盐溶解测试中产生的 S.I.（3.33mm）最大。菌株 MK513746 产生的最大氮浓度为 0.18μg ml-1。5 株假单胞菌的铁载体单位百分比范围为 2.65%至 2.83%，均为铁载体阳性。在植物-微生物相互作用的所有生长实验中，在干旱胁迫下接种铜绿假单胞菌的 2 个豇豆品种（AZRI-06、NM-11）的植物比对照应激植物反应明显（P<0.05）更好。与各自的应激对照植物相比，接种耐旱性 PGPR 的植物的最大茎长增加了 125%，荚/株增加了 172%，粒数增加了 65%，100 粒重增加了 95%，100 粒秸秆重增加了 124%，总产增加了 293%。与相应的应激对照植物相比，在具有光合作用、膜稳定性（45%）、含水量（68%）和抗氧化功效（19%）提高的条件下，接种 PGPR 后，植株的光合活性也得到了改善。与 AZRI-06（V1）相比，接种假单胞菌的 NM-11（V2）品种对干旱胁迫更具耐受性。在缺水地区，接种这些产生吲哚乙酸的菌株将有利于促进植物生长。
