scholarly journals Seed treatment with chitosan synergizes plant growth promoting ability ofPseudomonas aeruginosa-P17 in sorghum (Sorhum bicolorL.)

2019 ◽  
Author(s):  
G. Praveen Kumar ◽  
Suseelendra Desai ◽  
Bruno M. Moerschbacher ◽  
Nour Eddine-El Gueddari

AbstractInoculation of crop plants with PGPR has in a large number of investigations resulted in increased plant growth and yield both in the greenhouse and in the field. This plant growth promoting effect of bacteria could be due to net result of synergistic effect of various pgpr traits that they exert in the rhizosphere region of the plant. Four (04) bacterial strain of fluorescent Pseudomonas spp. viz. P1, P17, P22 and P28 were identified previously for their plant growth promoting nature and abiotic stress tolerance and selected further to assess their chitinolytic activity and growth promotion on sorghum in combination with chitosans of low and high degree of acetylation. It was found that P1 has no chitin degrading nature and rest of the three strains have this property. When studied for their ability to grow in presence of chitosans of DA 1.6, 11, 35 and 56% all the strains showed growth in presence of chitosans. Seed bacterization of sorghum seeds with 04 bacterial strains in the presence and absence of chitosans (both low and high DA) and assessment of plant growth promotion after 15 days of sowing showed that P17+DA 56% chitosan combination showed higher growth of seedlings in plant growth chamber with highest root length of 25.9 cm, highest shoot length of 32.1 cm and dry mass of 132.7 mg/ plant. In P17+DA 56% chitosan treated seedlings various defence enzymes and PR-proteins were found to be present in highest quantities as compared to P1 and un-inoculated controls. Since this strain showed highest growth promotion of sorghum seedlings chitin-chitosan modifying enzyme (CCME) of this strain was partially characterized using different proteomic tools and techniques. CCME of P17 had one active polypeptide with a Pi in the range of 3.0-4.0. The digestion pattern of acetylated and deacetylated chitosans showed that P17 enzyme has endochitinase activity. Substrate specificity assay showed that the enzyme had more specificity towards highly acetylated chitosans. Two dimensional PAGE and MS analysis of the protein revealed similarities of this enzyme with protein of Pseudomonas aeruginosa chitinase PA01 strain of GenBank. In conclusion, the study established the option of opening new possibilities for developing bacterial-chitosan (P17+DA 56% chitosan) product for plant growth promotion and induced systemic resistance in sorghum.

2019 ◽  
Vol 116 (31) ◽  
pp. 15735-15744 ◽  
Author(s):  
Anna Koprivova ◽  
Stefan Schuck ◽  
Richard P. Jacoby ◽  
Irene Klinkhammer ◽  
Bastian Welter ◽  
...  

Plants in their natural ecosystems interact with numerous microorganisms, but how they influence their microbiota is still elusive. We observed that sulfatase activity in soil, which can be used as a measure of rhizosphere microbial activity, is differently affected by Arabidopsis accessions. Following a genome-wide association analysis of the variation in sulfatase activity we identified a candidate gene encoding an uncharacterized cytochrome P450, CYP71A27. Loss of this gene resulted in 2 different and independent microbiota-specific phenotypes: A lower sulfatase activity in the rhizosphere and a loss of plant growth-promoting effect by Pseudomonas sp. CH267. On the other hand, tolerance to leaf pathogens was not affected, which agreed with prevalent expression of CYP71A27 in the root vasculature. The phenotypes of cyp71A27 mutant were similar to those of cyp71A12 and cyp71A13, known mutants in synthesis of camalexin, a sulfur-containing indolic defense compound. Indeed, the cyp71A27 mutant accumulated less camalexin in the roots upon elicitation with silver nitrate or flagellin. Importantly, addition of camalexin complemented both the sulfatase activity and the loss of plant growth promotion by Pseudomonas sp. CH267. Two alleles of CYP71A27 were identified among Arabidopsis accessions, differing by a substitution of Glu373 by Gln, which correlated with the ability to induce camalexin synthesis and to gain fresh weight in response to Pseudomonas sp. CH267. Thus, CYP71A27 is an additional component in the camalexin synthesis pathway, contributing specifically to the control of plant microbe interactions in the root.


2021 ◽  
Vol 22 (3) ◽  
pp. 441-449
Author(s):  
Pradeep Kumar ◽  
Sandeep Kumar ◽  
R.C. Dubey

Plant growth-promoting bacterial strains (LEP1-LEP31) were isolated from rhizosphere of Lycopersicon esculentum L. (Tomato) and screened for their plant growth promoting (PGP) activities. On the basis of morphological, physiological, biochemical, carbon source utilization and molecular characterization, these strains were identified as Pseudomonas sp., Azotobacter sp. and Bacillus sp. For antagonistic activities all the strains were subject to the chitinase activities by the development of clear halo around the inoculated bacterial spots when loaded on chitin (0.2%) supplemented mediumBased on pot and field trial results of individual strains and consortium application, it may be concluded that all the three strains i.e. Pseudomonas sp. LEP17, Azotobacter sp. strain LEP21 and Bacillus sp. strain LEP25 showed plant growth promoting effects. The growth promotion provided by these strains was apparently related to improve shoot and root development, which resulted in better nutrient uptake capability and suppression of plant pathogen. All these three strains were superior in this regard because they provided the best and most consistent effects on growth and yield of L. esculentum. All these strains Pseudomonas sp. LEP17, Azotobacter sp. strain LEP21, Bacillus sp. strain LEP25 and their consortium seems to be suitable for use as a plant growth promoting and improvement of growth and yield


2021 ◽  
Vol 11 (5) ◽  
pp. 2233
Author(s):  
Maria J. Ferreira ◽  
Angela Cunha ◽  
Sandro Figueiredo ◽  
Pedro Faustino ◽  
Carla Patinha ◽  
...  

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.


Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 888
Author(s):  
Giorgia Novello ◽  
Patrizia Cesaro ◽  
Elisa Bona ◽  
Nadia Massa ◽  
Fabio Gosetti ◽  
...  

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.


2021 ◽  
Vol 16 (8) ◽  
pp. 75-80
Author(s):  
Pitchaiah Pelapudi ◽  
Sasikala Ch ◽  
Swarnabala Ganti

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.


2015 ◽  
Vol 9 (3) ◽  
pp. 24-37 ◽  
Author(s):  
Mohammed Faisal Ansari ◽  
Devayani R. Tipre ◽  
Shailesh R. Dave

Organic farming is gaining popularity where bio-inoculants could play a key role in promoting the growth of plants. The liquid biofertilizers concept is new to farmers and developed recently. Lots of liquid biofertilizers formulations and field efficiency were shown in the past by various researchers, but the plant growth promoting (PGP) efficiency of the liquid biofertilizers isolates were not reported till date. In the present work 6 different commercially available liquid biofertilizers were used to isolate the organism. These isolated cultures were used to study their PGP efficiency with respect to phosphate solubilization and production of EPS, IAA, siderophore, ammonia, chitinase, ACC-deaminase and HCN. The phosphate solubilization was shown up to 303 g/ml by APS isolate. EPS production was shown by using different C sources and production up to 24 g/l was shown by studied isolated. Most of the organisms studied were able to produce IAA and highest production was shown up to 20 g/ml. More than 65% studied isolates showed siderophore and ACC-deaminase production. The present study shows that the commercial liquid biofertilizer isolates possess multiple traits of plant growth promotion. DOI: http://dx.doi.org/10.3126/ijls.v9i3.12463   International Journal of Life Sciences 9 (3): 2015; 24-37


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Kanza Batool ◽  
Fatima tuz Zahra ◽  
Yasir Rehman

Arsenic (As) is a well-known toxic metalloid found naturally and released by different industries, especially in developing countries. Purple nonsulfur bacteria (PNSB) are known for wastewater treatment and plant growth promoting abilities. As-resistant PNSB were isolated from a fish pond. Based on As-resistance and plant growth promoting attributes, 2 isolates CS2 and SS5 were selected and identified as Rhodopseudomonas palustris and Rhodopseudomonas faecalis, respectively, through 16S rRNA gene sequencing. Maximum As(V) resistance shown by R. faecalis SS5 and R. palustris CS2 was up to 150 and 100 mM, respectively. R. palustris CS2 showed highest As(V) reduction up to 62.9% (6.29±0.24 mM), while R. faecalis SS5 showed maximum As(III) oxidation up to 96% (4.8±0.32 mM), respectively. Highest auxin production was observed by R. palustris CS2 and R. faecalis SS, up to 77.18±3.7 and 76.67±2.8 μg mL−1, respectively. Effects of these PNSB were tested on the growth of Vigna mungo plants. A statistically significant increase in growth was observed in plants inoculated with isolates compared to uninoculated plants, both in presence and in absence of As. R. palustris CS2 treated plants showed 17% (28.1±0.87 cm) increase in shoot length and 21.7% (7.07±0.42 cm) increase in root length, whereas R. faecalis SS5 treated plants showed 12.8% (27.09±0.81 cm) increase in shoot length and 18.8% (6.9±0.34 cm) increase in root length as compared to the control plants. In presence of As, R. palustris CS2 increased shoot length up to 26.3% (21.0±1.1 cm), while root length increased up to 31.3% (5.3±0.4 cm), whereas R. faecalis SS5 inoculated plants showed 25% (20.7 ± 1.4 cm) increase in shoot length and 33.3% (5.4 ± 0.65 cm) increase in root length as compared to the control plants. Bacteria with such diverse abilities could be ideal for plant growth promotion in As-contaminated sites.


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