Isolation of endophytic bacteria from <i>Rehmannia glutinosa</i> Libosch and their potential to promote plant growth

Abstract

In order to study the growth promoting potential of endophytic bacteria from Rehmannia glutinosa Libosch, a total of 25 different bacteria belonging to 7 genera were identified by 16S rRNA gene sequencing, including Bacillus, Micrococcus, Lysinibacillus, Brevibacterium, Halomonas, Kocuria and Terribacillus. In this study, thirteen bacterial strains were found to solubilize inorganic phosphate, with the isolate Kocuria rosea (EH15) having the highest phosphorus dissolution activity (3.70 µ µ µ µ µg/mL). Twelve isolates were positive for nitrogen fixation abilities. Twenty-two strains produced indole-3-acetic acid (IAA) in the presence of L-tryptophan, and eleven of the twenty-two isolates synthesized IAA in the absence of L-tryptophan. The strain K. rosea (EH15) was capable of producing the highest IAA amount (15.36 and 7.98 mg/L) in Luria Bertani (LB) broth containing 0.2% L-tryptophan and lacking L-tryptophan, respectively. Ten isolates had siderophore production abilities with Bacillus amyloliquefacieus EH10 (0.26) and Brevibacterium frigoritolerans EH13 (0.32) showing high siderophore production characteristics. Five bacteria endogenous were selected to evaluate the growth parameters of Brassica napus L. and all isolates exhibited a significantly greater increase in seedling height, root length, fresh weight and dry weight, than the control plants. The greatest improvement appeared in the case of co-inoculation of EH10 and EH15, except in dry weight, and the biggest enhancement in dry weight occurred in the strain EH15. In general, these endophytic bacteria indicate a potential as microbial fertilizers to promote the growth of R. glutinosa Libosch.

By Modulating the Hormonal Balance and Ribonuclease Activity of Tomato Plants Bacillus subtilis Induces Defense Response against Potato Virus X and Potato Virus Y

“…In recent years, the mechanisms of increasing plant growth by PGPM, including endophytic bacteria, have been studied by many researchers. Bacteria can influence plant growth by producing phytohormones, such as indole acetic acid [ 63 , 64 , 65 , 66 ], cytokinins and gibberellins [ 47 , 65 , 66 , 67 ]. There is a lot of information in the literature on the ability of endophytic microorganisms to synthesize IAA.…”

Termite Nest Associated Bacillus siamensis YC-9 Mediated Biocontrol of Fusarium oxysporum f. sp. cucumerinum

“…The preliminary preparation of the experiment is the same as that in the “ In vivo Antifungal Activity in a Pot Experiment” section. After 30 days of inoculation with YC-9 or sterile water, the plant growth characteristics were measured by the modified method developed by Wang et al (2020) . The heights of the aerial and underground parts were measured as the plant and root height, respectively.…”

Culturable Bacterial Endophytes of Wild White Poplar (Populus alba L.) Roots: A First Insight into Their Plant Growth-Stimulating and Bioaugmentation Potential

“…K. rosea (s12 and s17) has been previously described as an endophyte of Rehmannia glutinosa [112], ryegrass (Lolium perenne) [113], and annual wormwood (Atremisia annua) [114].…”