IAA-producing rhizobacteria from chickpea (Cicer arietinumL.) induce changes in root architecture and increase root biomass

2014 ◽  
Vol 60 (10) ◽  
pp. 639-648 ◽  
Author(s):  
Rosario Alicia Fierro-Coronado ◽  
Francisco Roberto Quiroz-Figueroa ◽  
Luz María García-Pérez ◽  
Enrique Ramírez-Chávez ◽  
Jorge Molina-Torres ◽  
...  

Rhizobacteria promote and have beneficial effects on plant growth, making them useful to agriculture. Nevertheless, the rhizosphere of the chickpea plant has not been extensively examined. The aim of the present study was to select indole-3-acetic acid (IAA) producing rhizobacteria from the rhizosphere of chickpea plants for their potential use as biofertilizers. After obtaining a collection of 864 bacterial isolates, we performed a screen using the Salkowski reaction for the presence of auxin compounds (such as IAA) in bacterial Luria–Bertani supernatant (BLBS). Our results demonstrate that the Salkowski reaction has a greater specificity for detecting IAA than other tested auxins. Ten bacterial isolates displaying a wide range of auxin accumulation were selected, producing IAA levels of 5 to 90 μmol/L (according to the Salkowski reaction). Bacterial isolates were identified on the basis of 16S rDNA partial sequences: 9 isolates belonged to Enterobacter, and 1 isolate was classified as Serratia. The effect of BLBS on root morphology was evaluated in Arabidopsis thaliana. IAA production by rhizobacteria was confirmed by means of a DR5::GFP construct that is responsive to IAA, and also by HPLC–GC/MS. Finally, we observed that IAA secreted by rhizobacteria (i) modified the root architecture of A. thaliana, (ii) caused an increase in chickpea root biomass, and (iii) activated the green fluorescent protein (GFP) reporter gene driven by the DR5 promoter. These findings provide evidence that these novel bacterial isolates may be considered as putative plant-growth-promoting rhizobacteria modifying root architecture and increasing root biomass.

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1894
Author(s):  
Supriya P. Kusale ◽  
Yasmin C. Attar ◽  
R. Z. Sayyed ◽  
Roslinda A. Malek ◽  
Noshin Ilyas ◽  
...  

Bacteria that surround plant roots and exert beneficial effects on plant growth are known as plant growth-promoting rhizobacteria (PGPR). In addition to the plant growth-promotion, PGPR also imparts resistance against salinity and oxidative stress and needs to be studied. Such PGPR can function as dynamic bioinoculants under salinity conditions. The present study reports the isolation of phytase positive multifarious Klebsiella variicola SURYA6 isolated from wheat rhizosphere in Kolhapur, India. The isolate produced various plant growth-promoting (PGP), salinity ameliorating, and antioxidant traits. It produced organic acid, yielded a higher phosphorous solubilization index (9.3), maximum phytase activity (376.67 ± 2.77 U/mL), and copious amounts of siderophore (79.0%). The isolate also produced salt ameliorating traits such as indole acetic acid (78.45 ± 1.9 µg/mL), 1 aminocyclopropane-1-carboxylate deaminase (0.991 M/mg/h), and exopolysaccharides (32.2 ± 1.2 g/L). In addition to these, the isolate also produced higher activities of antioxidant enzymes like superoxide dismutase (13.86 IU/mg protein), catalase (0.053 IU/mg protein), and glutathione oxidase (22.12 µg/mg protein) at various salt levels. The isolate exhibited optimum growth and maximum secretion of these metabolites during the log-phase growth. It exhibited sensitivity to a wide range of antibiotics and did not produce hemolysis on blood agar, indicative of its non-pathogenic nature. The potential of K. variicola to produce copious amounts of various PGP, salt ameliorating, and antioxidant metabolites make it a potential bioinoculant for salinity stress management.


2006 ◽  
Vol 17 (7) ◽  
pp. 3009-3020 ◽  
Author(s):  
Johan-Owen De Craene ◽  
Jeff Coleman ◽  
Paula Estrada de Martin ◽  
Marc Pypaert ◽  
Scott Anderson ◽  
...  

The endoplasmic reticulum (ER) contains both cisternal and reticular elements in one contiguous structure. We identified rtn1Δ in a systematic screen for yeast mutants with altered ER morphology. The ER in rtn1Δ cells is predominantly cisternal rather than reticular, yet the net surface area of ER is not significantly changed. Rtn1-green fluorescent protein (GFP) associates with the reticular ER at the cell cortex and with the tubules that connect the cortical ER to the nuclear envelope, but not with the nuclear envelope itself. Rtn1p overexpression also results in an altered ER structure. Rtn proteins are found on the ER in a wide range of eukaryotes and are defined by two membrane-spanning domains flanking a conserved hydrophilic loop. Our results suggest that Rtn proteins may direct the formation of reticulated ER. We independently identified Rtn1p in a proteomic screen for proteins associated with the exocyst vesicle tethering complex. The conserved hydophilic loop of Rtn1p binds to the exocyst subunit Sec6p. Overexpression of this loop results in a modest accumulation of secretory vesicles, suggesting impaired exocyst function. The interaction of Rtn1p with the exocyst at the bud tip may trigger the formation of a cortical ER network in yeast buds.


2011 ◽  
Vol 55 (5) ◽  
pp. 2438-2441 ◽  
Author(s):  
Zeynep Baharoglu ◽  
Didier Mazel

ABSTRACTAntibiotic resistance development has been linked to the bacterial SOS stress response. InEscherichia coli, fluoroquinolones are known to induce SOS, whereas other antibiotics, such as aminoglycosides, tetracycline, and chloramphenicol, do not. Here we address whether various antibiotics induce SOS inVibrio cholerae. Reporter green fluorescent protein (GFP) fusions were used to measure the response of SOS-regulated promoters to subinhibitory concentrations of antibiotics. We show that unlike the situation withE. coli, all these antibiotics induce SOS inV. cholerae.


2016 ◽  
Vol 82 (8) ◽  
pp. 2240-2246 ◽  
Author(s):  
Alex I. Kanno ◽  
Cibelly Goulart ◽  
Henrique K. Rofatto ◽  
Sergio C. Oliveira ◽  
Luciana C. C. Leite ◽  
...  

ABSTRACTThe expression of many antigens, stimulatory molecules, or even metabolic pathways in mycobacteria such asMycobacterium bovisBCG orM. smegmatiswas made possible through the development of shuttle vectors, and several recombinant vaccines have been constructed. However, gene expression in any of these systems relied mostly on the selection of natural promoters expected to provide the required level of expression by trial and error. To establish a systematic selection of promoters with a range of strengths, we generated a library of mutagenized promoters through error-prone PCR of the strong PL5promoter, originally from mycobacteriophage L5. These promoters were cloned upstream of the enhanced green fluorescent protein reporter gene, and recombinantM. smegmatisbacteria exhibiting a wide range of fluorescence levels were identified. A set of promoters was selected and identified as having high (pJK-F8), intermediate (pJK-B7, pJK-E6, pJK-D6), or low (pJK-C1) promoter strengths in bothM. smegmatisandM. bovisBCG. The sequencing of the promoter region demonstrated that it was extensively modified (6 to 11%) in all of the plasmids selected. To test the functionality of the system, two different expression vectors were demonstrated to allow corresponding expression levels of theSchistosoma mansoniantigen Sm29 in BCG. The approach used here can be used to adjust expression levels for synthetic and/or systems biology studies or for vaccine development to maximize the immune response.


2001 ◽  
Vol 153 (3) ◽  
pp. 503-516 ◽  
Author(s):  
Kyeong Han Yoon ◽  
Miri Yoon ◽  
Robert D. Moir ◽  
Satya Khuon ◽  
Frederick W. Flitney ◽  
...  

The properties of keratin intermediate filaments (IFs) have been studied after transfection with green fluorescent protein (GFP)-tagged K18 and/or K8 (type I/II IF proteins). GFP-K8 and -K18 become incorporated into tonofibrils, which are comprised of bundles of keratin IFs. These tonofibrils exhibit a remarkably wide range of motile and dynamic activities. Fluorescence recovery after photobleaching (FRAP) analyses show that they recover their fluorescence slowly with a recovery t1/2 of ∼100 min. The movements of bleach zones during recovery show that closely spaced tonofibrils (<1 μm apart) often move at different rates and in different directions. Individual tonofibrils frequently change their shapes, and in some cases these changes appear as propagated waveforms along their long axes. In addition, short fibrils, termed keratin squiggles, are seen at the cell periphery where they move mainly towards the cell center. The motile properties of keratin IFs are also compared with those of type III IFs (vimentin) in PtK2 cells. Intriguingly, the dynamic properties of keratin tonofibrils and squiggles are dramatically different from those of vimentin fibrils and squiggles within the same cytoplasmic regions. This suggests that there are different factors regulating the dynamic properties of different types of IFs within the same cytoplasmic regions.


2008 ◽  
Vol 191 (1) ◽  
pp. 231-237 ◽  
Author(s):  
Michael C. Konopka ◽  
Kem A. Sochacki ◽  
Benjamin P. Bratton ◽  
Irina A. Shkel ◽  
M. Thomas Record ◽  
...  

ABSTRACT Facile diffusion of globular proteins within a cytoplasm that is dense with biopolymers is essential to normal cellular biochemical activity and growth. Remarkably, Escherichia coli grows in minimal medium over a wide range of external osmolalities (0.03 to 1.8 osmol). The mean cytoplasmic biopolymer volume fraction (〈φ〉) for such adapted cells ranges from 0.16 at 0.10 osmol to 0.36 at 1.45 osmol. For cells grown at 0.28 osmol, a similar 〈φ〉 range is obtained by plasmolysis (sudden osmotic upshift) using NaCl or sucrose as the external osmolyte, after which the only available cellular response is passive loss of cytoplasmic water. Here we measure the effective axial diffusion coefficient of green fluorescent protein (D GFP) in the cytoplasm of E. coli cells as a function of 〈φ〉 for both plasmolyzed and adapted cells. For plasmolyzed cells, the median D GFP ( \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(D_{GFP}^{m}\) \end{document} ) decreases by a factor of 70 as 〈φ〉 increases from 0.16 to 0.33. In sharp contrast, for adapted cells, \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(D_{GFP}^{m}\) \end{document} decreases only by a factor of 2.1 as 〈φ〉 increases from 0.16 to 0.36. Clearly, GFP diffusion is not determined by 〈φ〉 alone. By comparison with quantitative models, we show that the data cannot be explained by crowding theory. We suggest possible underlying causes of this surprising effect and further experiments that will help choose among competing hypotheses. Recovery of the ability of proteins to diffuse in the cytoplasm after plasmolysis may well be a key determinant of the time scale of the recovery of growth.


2011 ◽  
Vol 77 (22) ◽  
pp. 8193-8196 ◽  
Author(s):  
Lucja M. Jarosz ◽  
Bastiaan P. Krom

ABSTRACTWe propose a screening method for compounds affecting growth and germination inCandida albicansusing a real-time PCR thermocycler to quantify green fluorescent protein (GFP) fluorescence. Using PACT1-GFPand PHWP1-GFPreporter strains, the effects of a wide range of compounds on growth and hyphal formation were quantitatively assessed within 3 h after inoculation.


2016 ◽  
Vol 3 (1) ◽  
pp. 105-113 ◽  
Author(s):  
Mohammad Mosharraf Hossain ◽  
Keshob Chandra Das ◽  
Sabina Yesmin ◽  
Syfullah Shahriar

Plant growth promoting rhizobacteria (PGPR) are beneficial bacteria that colonize plant roots and enhance plant growth by a wide variety of mechanisms. Ten isolates of bacteria designated as SS01, SS02, SS03, SS04, SS05, SS06, SS07, SS08, SS09 and SS10 were successfully isolated and morphologically and biochemically characterized. Subsequently to investigate the effect of PGPR isolates on the growth of chickpea, a pot culture experiment was conducted in 2013 at National Institute Biotechnology, Bangladesh net house. Prior to seeds grown in plastic pots, seeds were treated with PGPR isolates and seedlings were harvested after 21 days of inoculation. All the isolates were gram negative in reaction, catalase positive, produced indole acetic acid (IAA) as well as performed phosphate solubilization, able to degrade cellulose and have the adaptability in wide range of temperature and showed positive growth pattern in medium. Most of isolates resulted in a significant increasing of shoot length, root length and dry matter production of shoot and root of chickpea seedlings. Application of PGPR isolates significantly improves the percentage of seed germination under saline conditions. The present study, therefore suggested that the use of PGPR isolates SS04, SS10 and SS08 as inoculants biofertilizers might be beneficial for chickpea cultivation in saline conditionRes. Agric., Livest. Fish.3(1): 105-113, April 2016


2016 ◽  
Vol 15 (27) ◽  
pp. 1452-1463 ◽  
Author(s):  
Agossou Noumavo Pac ocirc me ◽  
Adouk egrave Agbodjato Nad egrave ge ◽  
Baba Moussa Farid ◽  
Adjanohoun Adolphe ◽  
Baba Moussa Lamine

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