Genetic diversity and plant growth-promoting activity of the dominant bacteria from canola plants in Western Iran

Abstract

Background Plant growth-promoting bacteria (PGPB) can be used as a safe and sustainable agricultural measure to increase plant yield. In this study, cultivable rhizospheric, endophytic, and epiphytic bacteria associated with canola were isolated on nutrient agar medium. The SDS-PAGE method was used for grouping the bacterial strains. Bacterial strains with more than 80% similarity in their protein patterns were placed in the same species and selected as a representative for partial 16S rRNA encoding gene sequence analysis. Results It was found that the bacteria used in this study belonged to Pseudomonas, Frigoribacterium, Sphingomonas, Sphingobacterium, Microbacterium, Bacillus, and Rhodococcus genera. Three PGP bioactivities including siderophore production, nitrogen fixation ability, and phosphate solubilization were evaluated for 18 Pseudomonas representative strains. All tested strains were able to produce siderophore, although only 5 strains could fix nitrogen and none was able to solubilize phosphate. Greenhouse experiments showed that 4 bacterial strains (i.e., 8312, 642, 1313W, and 9421) significantly affected canola seed germination and seedling growth. Bacterial strain 8312, which was identified as Pseudomonas sp., showed the highest effect on the growth of the canola plant. These results indicated the potential of strain 8312 to be used as a biofertilizer in canola cultivation. Conclusions The results of this research indicated that canola-related bacteria were diverse during the flowering stage. One isolate had a significant effect on all canola plant growth factors in the greenhouse. Hence, it is recommended to investigate this strain further in field infestation experiments.

Identification of Canola Roots Endophytic Bacteria and Analysis of Their Potential as Biofertilizers for Canola Crops with Special Emphasis on Sporulating Bacteria

“…At present, there is growing interest in bacterial endophytes since they can exert a positive effect on plant growth, but those of canola plants have rarely been studied, and their identification has been carried out primarily through rrs gene sequence analysis [11][12][13][14][15][16]. In this work, we applied, for the first time, MALDI-TOF MS for the identification of canola root endophytes, as it is a rapid and reliable methodology for bacterial identification [28,32,33].…”

“…These biofertilizers are commonly formulated with plant growth-promoting bacteria (PGPB) [7], which include bacterial endophytes with a high potential for biofertilization [8][9][10]. Nevertheless, few studies to date have addressed the isolation and identification of canola endophytes, which is an essential step in the design of biofertilizers for this crop [11][12][13][14][15][16].…”

“…The identification of endophytic bacteria isolated from canola roots has primarily been performed through rrs gene sequence analysis [11][12][13][14][15][16]. This methodology, together with MALDI-TOF MS (matrix-assisted laser desorption/ionization time-of-flight mass spectrometry) form the current basis of "culturomics", a term introduced in works concerning the human gut microbiome [17,18] that has also been used in works aiming to achieve the isolation and identification of plant endophytic bacteria [19].…”

Plant growth–promoting rhizobacteria: Peribacillus frigoritolerans 2RO30 and Pseudomonas sivasensis 2RO45 for their effect on canola growth under controlled as well as natural conditions

“…Whereas Pseudomonas sp. strain, which was able to produce siderophores and fix nitrogen, affected canola seeds germination and seedlings growth ( Jamalzadeh et al., 2021 ). Ecological applications of Pseudomonas and Bacillus species as bioinoculants are crucial for maintaining food security ( Sah et al., 2021 ; Etesami et al., 2023 ).…”

Rhizospheric microbial consortium of Lilium lancifolium Thunb. causes lily root rot under continuous cropping system

“…The composition of the rhizospheric bacterial community is affected by changes in environmental factors such as soil humidity, soil pH, and organic compounds content, which differ across soil types ( Cao et al, 2018 ; Lei et al, 2021 ; Khmelevtsova et al, 2022 ). In addition, the rhizospheric bacterial community is also affected by plant genotypes ( Jamalzadeh et al, 2021 ; Kaushal et al, 2021 ; He et al, 2022 ), implying a degree of host selectivity on the establishment of these communities.…”