scholarly journals Genomic Mining and Physiological Characterization of new Halophilic Plant Growth Promoting Bacilli

2021 ◽  
Author(s):  
Claudia Petrillo ◽  
Stefany Castaldi ◽  
Mariamichela Lanzilli ◽  
Matteo Selci ◽  
Angelina Cordone ◽  
...  
Keyword(s):  
Plant Growth ◽  
Crop Production ◽  
Growth Promotion ◽  
Biological Activities ◽  
Gene Clusters ◽  
Plant Growth Promoting Bacteria ◽  
Dual Culture ◽  
Whole Genome Analysis ◽  
Plant Growth Promoting ◽  
Growth Promoting

Massive application of chemical fertilizers and pesticides has been the main strategy used to cope with the rising crop demands in the last decades. The indiscriminate use of chemicals while providing a temporary solution has led to a decrease in crop productivity and an increase in the environmental impact of modern agriculture. A sustainable alternative to the use of chemicals for crop production is the use of microorganisms naturally capable of enhancing plant growth and protecting crops from pests, known as Plant-Growth-Promoting Bacteria (PGPB). The aim of the present study was to isolate and characterize PGPB from salt-pans sand samples able to ameliorate plant fitness. To survive high salinity, salt-tolerant microbes produce a broad range of compounds with heterogeneous biological activities that are potentially beneficial for plant growth. We have isolated and screened in vitro a total of 20 halophilic spore-forming bacteria for phyto-beneficial traits and compared the results with two rhizosphere Bacilli recently isolated from the rhizosphere of the same collection site and recently characterized as potential biocontrol agents. Whole-genome analysis on five selected halophilic strains confirmed the presence of numerous gene clusters with PGP and biocontrol functions and of novel secondary-metabolite biosynthetic genes potentially involved in plant growth promotion and protection. The predicted biocontrol potential was confirmed in dual culture assays against several phytopathogenic fungi and bacteria. Interestingly, the absence of predicted gene clusters with known biocontrol functions in some of the isolates was not predictive of the in vivo results, supporting the need of combining laboratory assays and genome mining in PGPB identification for future applications.

scholarly journals Genomic and Physiological Characterization of Bacilli Isolated From Salt-Pans With Plant Growth Promoting Features

2021 ◽  
Vol 12 ◽  
Author(s):  
Claudia Petrillo ◽  
Stefany Castaldi ◽  
Mariamichela Lanzilli ◽  
Matteo Selci ◽  
Angelina Cordone ◽  
...  
Keyword(s):  
Plant Growth ◽  
Biological Activities ◽  
Gene Clusters ◽  
Plant Growth Promoting Bacteria ◽  
Dual Culture ◽  
Whole Genome Analysis ◽  
Salt Pans ◽  
Plant Growth Promoting ◽  
Growth Promoting

Massive application of chemical fertilizers and pesticides has been the main strategy used to cope with the rising crop demands in the last decades. The indiscriminate use of chemicals while providing a temporary solution to food demand has led to a decrease in crop productivity and an increase in the environmental impact of modern agriculture. A sustainable alternative to the use of agrochemicals is the use of microorganisms naturally capable of enhancing plant growth and protecting crops from pests known as Plant-Growth-Promoting Bacteria (PGPB). Aim of the present study was to isolate and characterize PGPB from salt-pans sand samples with activities associated to plant fitness increase. To survive high salinity, salt-tolerant microbes produce a broad range of compounds with heterogeneous biological activities that are potentially beneficial for plant growth. A total of 20 halophilic spore-forming bacteria have been screened in vitro for phyto-beneficial traits and compared with other two members of Bacillus genus recently isolated from the rhizosphere of the same collection site and characterized as potential biocontrol agents. Whole-genome analysis on seven selected strains confirmed the presence of numerous gene clusters with PGP and biocontrol functions and of novel secondary-metabolite biosynthetic genes, which could exert beneficial impacts on plant growth and protection. The predicted biocontrol potential was confirmed in dual culture assays against several phytopathogenic fungi and bacteria. Interestingly, the presence of predicted gene clusters with known biocontrol functions in some of the isolates was not predictive of the in vitro results, supporting the need of combining laboratory assays and genome mining in PGPB identification for future applications.

scholarly journals Plant growth promoting rhizobacteria isolated from halophytes and drought-tolerant plants: genomic characterisation and exploration of phyto-beneficial traits

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Kleopatra Leontidou ◽  
Savvas Genitsaris ◽  
Anastasia Papadopoulou ◽  
Nathalie Kamou ◽  
Irene Bosmali ◽  
...  
Keyword(s):  
Plant Growth ◽  
Crop Production ◽  
Growth Promotion ◽  
Plant Growth Promoting Rhizobacteria ◽  
Gene Clusters ◽  
Stress Factors ◽  
Wild Plant ◽  
Whole Genome Analysis ◽  
Plant Growth Promoting ◽  
Growth Promoting

Abstract Plant growth promoting rhizobacteria (PGPR) are able to provide cross-protection against multiple stress factors and facilitate growth of their plant symbionts in many ways. The aim of this study was to isolate and characterize rhizobacterial strains under natural conditions, associated with naturally occurring representatives of wild plant species and a local tomato cultivar, growing in differently stressed Mediterranean ecosystems. A total of 85 morphologically different rhizospheric strains were isolated; twenty-five exhibited multiple in vitro PGP-associated traits, including phosphate solubilization, indole-3-acetic acid production, and 1-aminocyclopropane-1-carboxylate deaminase activity. Whole genome analysis was applied to eight selected strains for their PGP potential and assigned seven strains to Gammaproteobacteria, and one to Bacteroidetes. The genomes harboured numerous genes involved in plant growth promotion and stress regulation. They also support the notion that the presence of gene clusters with potential PGP functions is affirmative but not necessary for a strain to promote plant growth under abiotic stress conditions. The selected strains were further tested for their ability to stimulate growth under stress. This initial screening led to the identification of some strains as potential PGPR for increasing crop production in a sustainable manner.

scholarly journals Efficacy of Plant Growth-Promoting Bacteria Bacillus cereus YN917 for Biocontrol of Rice Blast

2021 ◽  
Vol 12 ◽  
Author(s):  
Hu Zhou ◽  
Zuo-hua Ren ◽  
Xue Zu ◽  
Xi-yue Yu ◽  
Hua-jun Zhu ◽  
...  
Keyword(s):  
Disease Prevention ◽  
Plant Growth ◽  
Bacillus Cereus ◽  
Rice Blast ◽  
Growth Promotion ◽  
Gene Clusters ◽  
Plant Growth Promoting Bacteria ◽  
Detached Leaf ◽  
Plant Growth Promoting ◽  
Growth Promoting

Bacillus cereus YN917, obtained from a rice leaf with remarkable antifungal activity against Magnaporthe oryzae, was reported in our previous study. The present study deciphered the possible biocontrol properties. YN917 strain exhibits multiple plant growth-promoting and disease prevention traits, including production of indole-3-acetic acid (IAA), ACC deaminase, siderophores, protease, amylase, cellulase, and β-1,3-glucanase, and harboring mineral phosphate decomposition activity. The effects of the strain YN917 on growth promotion and disease prevention were further evaluated under detached leaf and greenhouse conditions. The results revealed that B. cereus YN917 can promote seed germination and seedling plant growth. The growth status of rice plants was measured from the aspects of rice plumule, radicle lengths, plant height, stem width, root lengths, fresh weights, dry weights, and root activity when YN917 was used as inoculants. YN917 significantly reduced rice blast severity under detached leaf and greenhouse conditions. Genome analysis revealed the presence of gene clusters for biosynthesis of plant promotion and antifungal compounds, such as IAA, tryptophan, siderophores, and phenazine. In summary, YN917 can not only be used as biocontrol agents to minimize the use of chemical substances in rice blast control, but also can be developed as bio-fertilizers to promote the rice plant growth.

scholarly journals The Root Microbiome of Salicornia ramosissima as a Seedbank for Plant-Growth Promoting Halotolerant Bacteria

2021 ◽  
Vol 11 (5) ◽  
pp. 2233
Author(s):  
Maria J. Ferreira ◽  
Angela Cunha ◽  
Sandro Figueiredo ◽  
Pedro Faustino ◽  
Carla Patinha ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
Growth Promotion ◽  
Cultivated Plants ◽  
Plant Growth Promoting Bacteria ◽  
Crop Cultivation ◽  
Halotolerant Bacteria ◽  
Salicornia Ramosissima ◽  
Plant Growth Promoting ◽  
Growth Promoting

Root−associated microbial communities play important roles in the process of adaptation of plant hosts to environment stressors, and in this perspective, the microbiome of halophytes represents a valuable model for understanding the contribution of microorganisms to plant tolerance to salt. Although considered as the most promising halophyte candidate to crop cultivation, Salicornia ramosissima is one of the least-studied species in terms of microbiome composition and the effect of sediment properties on the diversity of plant-growth promoting bacteria associated with the roots. In this work, we aimed at isolating and characterizing halotolerant bacteria associated with the rhizosphere and root tissues of S. ramosissima, envisaging their application in saline agriculture. Endophytic and rhizosphere bacteria were isolated from wild and crop cultivated plants, growing in different estuarine conditions. Isolates were identified based on 16S rRNA sequences and screened for plant-growth promotion traits. The subsets of isolates from different sampling sites were very different in terms of composition but consistent in terms of the plant-growth promoting traits represented. Bacillus was the most represented genus and expressed the wider range of extracellular enzymatic activities. Halotolerant strains of Salinicola, Pseudomonas, Oceanobacillus, Halomonas, Providencia, Bacillus, Psychrobacter and Brevibacterium also exhibited several plant-growth promotion traits (e.g., 3-indole acetic acid (IAA), 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, siderophores, phosphate solubilization). Considering the taxonomic diversity and the plant-growth promotion potential of the isolates, the collection represents a valuable resource that can be used to optimize the crop cultivation of Salicornia under different environmental conditions and for the attenuation of salt stress in non-halophytes, considering the global threat of arable soil salinization.

scholarly journals The Effects of Plant Growth-Promoting Bacteria with Biostimulant Features on the Growth of a Local Onion Cultivar and a Commercial Zucchini Variety

Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 888
Author(s):  
Giorgia Novello ◽  
Patrizia Cesaro ◽  
Elisa Bona ◽  
Nadia Massa ◽  
Fabio Gosetti ◽  
...  
Keyword(s):  
Plant Growth ◽  
Growth Promotion ◽  
Global Market ◽  
Plant Growth Promoting Bacteria ◽  
Bacterial Strains ◽  
Mineral Concentration ◽  
Positive Effects ◽  
Plant Growth Promoting ◽  
Onion Cultivar ◽  
Growth Promoting

The reduction of chemical inputs due to fertilizer and pesticide applications is a target shared both by farmers and consumers in order to minimize the side effects for human and environmental health. Among the possible strategies, the use of biostimulants has become increasingly important as demonstrated by the fast growth of their global market and by the increased rate of registration of new products. In this work, we assessed the effects of five bacterial strains (Pseudomonas fluorescens Pf4, P. putida S1Pf1, P. protegens Pf7, P. migulae 8R6, and Pseudomonas sp. 5Vm1K), which were chosen according to their previously reported plant growth promotion traits and their positive effects on fruit/seed nutrient contents, on a local onion cultivar and on zucchini. The possible variations induced by the inoculation with the bacterial strains on the onion nutritional components were also evaluated. Inoculation resulted in significant growth stimulation and improvement of the mineral concentration of the onion bulb, induced particularly by 5Vm1K and S1Pf1, and in different effects on the flowering of the zucchini plants according to the bacterial strain. The present study provides new information regarding the activity of the five plant growth-promoting bacteria (PGPB) strains on onion and zucchini, two plant species rarely considered by the scientific literature despite their economic relevance.

Isolation, identification and characterization of native plant growth promoting bacteria and their plant growth promotion in Zea mays

2021 ◽  
Vol 16 (8) ◽  
pp. 75-80
Author(s):  
Pitchaiah Pelapudi ◽  
Sasikala Ch ◽  
Swarnabala Ganti
Keyword(s):  
Plant Growth ◽  
Plant Growth Promotion ◽  
Root Length ◽  
Growth Promotion ◽  
Shoot Length ◽  
Root Weight ◽  
Plant Growth Promoting Bacteria ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Shoot Weight

In the present rapid growing world, need for a sustainable agricultural practice which helps in meeting the adequate food demand is much needed. In this context, plant growth promoting bacteria were brought into the spot light by the researchers. Though the plant growth promoting bacteria have several beneficial applications, due to some of the disadvantages in the field conditions, they lagged behind. In the current research work, native PGPR were isolated from the rhizosphere soil samples of maize with an aim to isolate the nitrogen fixing, phosphate solubilising and potash solubilising bacteria. Out of the several isolates, potent PGPR isolates viz., Paenibacillus durus PCPB067, Bacillus megaterium PCBMG041 and Paenibacillus glucanolyticus PCPG051 were isolated and identified by using the 16 S rRNA gene sequencing studies. Genomic DNA sequences obtained were deposited in the NCBI Genbank and accession numbers were assigned as MW793452, MW793456 and MW843633. In order to check the efficacy of the PGPR isolates, pot trials were conducted by taking maize as the host plant. Several parameters viz. shoot length, shoot weight, root length, root weight and weight of the seeds were tested in which PGP treatment showed good results (shoot length - 187±3.5 cm, shoot weight - 31±4 g, root length - 32±3.6 cm, root weight - 17±2 g, yield- 103.3±6.1 g) when compared to the chemical fertilizer treatment (shoot length - 177±3.5 cm, shoot weight - 25±3.6 g, root length - 24±3.5 cm, root weight - 14.6±1.52 g, yield- 85.6±7.6 g). Based on the results, it can be stated that these native PGPR isolates can be effectively used in the plant growth promotion of maize.

scholarly journals Variovorax sp. Has an Optimum Cell Density to Fully Function as a Plant Growth Promoter

2019 ◽  
Vol 7 (3) ◽  
pp. 82 ◽  
Author(s):  
Oyungerel Natsagdorj ◽  
Hisayo Sakamoto ◽  
Dennis Santiago ◽  
Christine Santiago ◽  
Yoshitake Orikasa ◽  
...  
Keyword(s):  
Plant Growth ◽  
Cell Density ◽  
Growth Promotion ◽  
Growth Promoter ◽  
Plant Growth Promoting Bacteria ◽  
Biochemical Tests ◽  
Green Pepper ◽  
Plant Growth Promoter ◽  
Plant Growth Promoting ◽  
Growth Promoting

Utilization of plant growth-promoting bacteria colonizing roots is environmentally friendly technology instead of using chemicals in agriculture, and understanding of the effects of their colonization modes in promoting plant growth is important for sustainable agriculture. We herein screened the six potential plant growth-promoting bacteria isolated from Beta vulgaris L. (Rhizobium sp. HRRK 005, Polaromonas sp. HRRK 103, Variovorax sp. HRRK 170, Mesorhizobium sp. HRRK 190, Streptomyces sp. HRTK 192, and Novosphingobium sp. HRRK 193) using a series of biochemical tests. Among all strains screened, HRRK 170 had the highest potential for plant growth promotion, given its ability to produce plant growth substances and enzymes such as siderophores and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, respectively, concomitantly with active growth in a wider range of temperatures (10–30 °C) and pH (5.0–10.0). HRRK 170 colonized either as spots or widely on the root surface of all vegetable seedlings tested, but significant growth promotion occurred only in two vegetables (Chinese cabbage and green pepper) within a certain cell density range localized in the plant roots. The results indicate that HRRK 170 could function as a plant growth promoter, but has an optimum cell density for efficient use.

scholarly journals Isolation and selection of plant growth-promoting bacteria associated with sugarcane

2016 ◽  
Vol 46 (2) ◽  
pp. 149-158 ◽  
Author(s):  
Ariana Alves Rodrigues ◽  
Marcus Vinicius Forzani ◽  
Renan de Souza Soares ◽  
Sergio Tadeu Sibov ◽  
José Daniel Gonçalves Vieira
Keyword(s):  
Plant Growth ◽  
Growth Promotion ◽  
Vital Role ◽  
Plant Growth Promoting Bacteria ◽  
Biotic And Abiotic Stress ◽  
Phosphate Solubilizers ◽  
Chitinase A ◽  
Plant Growth Promoting ◽  
Promote Plant Growth ◽  
Growth Promoting

ABSTRACT Microorganisms play a vital role in maintaining soil fertility and plant health. They can act as biofertilizers and increase the resistance to biotic and abiotic stress. This study aimed at isolating and characterizing plant growth-promoting bacteria associated with sugarcane, as well as assessing their ability to promote plant growth. Endophytic bacteria from leaf, stem, root and rhizosphere were isolated from the RB 867515 commercial sugarcane variety and screened for indole acetic acid (IAA) production, ability to solubilize phosphate, fix nitrogen and produce hydrogen cyanide (HCN), ammonia and the enzymes pectinase, cellulase and chitinase. A total of 136 bacteria were isolated, with 83 of them presenting some plant growth mechanism: 47 % phosphate solubilizers, 26 % nitrogen fixers and 57 % producing IAA, 0.7 % HCN and chitinase, 45 % ammonia, 30 % cellulose and 8 % pectinase. The seven best isolates were tested for their ability to promote plant growth in maize. The isolates tested for plant growth promotion belong to the Enterobacteriaceae family and the Klebsiella, Enterobacter and Pantoea genera. Five isolates promoted plant growth in greenhouse experiments, showing potential as biofertilizers.

Colonization and persistence of a plant growth-promoting bacterium Pseudomonas fluorescens strain CS85, on roots of cotton seedlings

2004 ◽  
Vol 50 (7) ◽  
pp. 475-481 ◽  
Author(s):  
Chunxia Wang ◽  
Daoben Wang ◽  
Qi Zhou
Keyword(s):  
Plant Growth ◽  
Pseudomonas Fluorescens ◽  
Growth Promotion ◽  
Lateral Roots ◽  
Marker Genes ◽  
Original Strain ◽  
Plant Growth Promoting Bacteria ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Root Surfaces

Pseudomonas fluorescens CS85, which was previously isolated from the rhizosphere of cotton seedlings, acts as both a plant growth-promoting bacterium and a biocontrol agent against cotton pathogens, including Rhizoctonia solani, Colletotrichum gossypii, Fusarium oxysporum f sp. vasinfectum, and Verticillium dahliae. Strain CS85 was labeled separately with luxAB and gusA. The labeled strains were stably maintained and had high levels of expression of the marker genes, luxAB and gusA, after successive transfers on nonselective medium, long-term preservation, and after recovery from soil. The labeled strains displayed similar biocontrol characteristics (e.g., antibiosis, effects of growth -promotion and disease -control) to the original strain. The labeled strains colonized all surfaces of the young plant root zones, such as roots hairs and lateral roots, although the distribution of the labeled strains on the root surfaces was not uniform. Moreover, the population densities of the labeled strains on the root surface were stably maintained at high levels during the first 2 weeks of plant growth in the native soil, so that about 107–108 CFU/g root were detected, then decreased gradually. Nevertheless, approximately 106 CFU/g root of the labeled strains were observed on the root surfaces 35 d after planting.Key words: plant growth-promoting bacteria, luxAB, gusA, root colonization.

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