1-Aminocyclopropane-1-carboxylic acid deaminase mutants of the plant growth promoting rhizobacterium Pseudomonas putida GR12-2 do not stimulate canola root elongation

1994 ◽  
Vol 40 (11) ◽  
pp. 911-915 ◽  
Author(s):  
Bernard R. Glick ◽  
Christian B. Jacobson ◽  
Melinda M. K. Schwarze ◽  
J. J. Pasternak
Keyword(s):  
Carboxylic Acid ◽  
Plant Growth ◽  
Pseudomonas Putida ◽  
Root Elongation ◽  
Acc Deaminase ◽  
Plant Growth Promoting Rhizobacteria ◽  
Wild Type ◽  
Ethylene Concentration ◽  
Plant Growth Promoting ◽  
Growth Promoting

The plant growth promoting rhizobacterium Pseudomonas putida GR12-2 was mutagenized with nitrosoguanidine and three separate mutants that were unable to utilize 1-aminocyclopropane-1-carboxylic acid (ACC) as a sole nitrogen source were selected. These mutants are devoid of the ACC deaminase activity that is present in wild-type P. putida GR12-2 cells. Only wild-type cells, but not any of the ACC deaminase mutants, promoted root elongation of developing canola seedlings under gnotobiotic conditions. These results are interpreted in terms of a model in which P. putida GR12-2 promotes root elongation by binding to germinating seeds and sequesters and hydrolyzes some of the unbound ACC, thereby lowering the level of ACC and hence the endogenous ethylene concentration, allowing the roots to grow longer.Key words: 1-aminocyclopropane-1-carboxylate, ACC, plant growth promoting rhizobacteria, PGPR, ACC deaminase, bacterial fertilizer.

Determination of 1-aminocycopropane-1-carboxylic acid (ACC) to assess the effects of ACC deaminase-containing bacteria on roots of canola seedlings

2001 ◽  
Vol 47 (1) ◽  
pp. 77-80 ◽  
Author(s):  
Donna M Penrose ◽  
Barbara A Moffatt ◽  
Bernard R Glick
Keyword(s):  
Carboxylic Acid ◽  
Plant Growth ◽  
Root Elongation ◽  
Acc Deaminase ◽  
Plant Growth Promoting Bacteria ◽  
Psychrophilic Bacterium ◽  
Ethylene Inhibitor ◽  
Seedling Roots ◽  
Plant Growth Promoting ◽  
Growth Promoting

Previously, it was proposed that plant growth-promoting bacteria that possess the enzyme, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, can reduce the amount of ethylene produced by a plant and thereby promote root elongation. To test this model, canola seeds were imbibed in the presence of the chemical ethylene inhibitor, 2-aminoethoxyvinyl glycine (AVG), various strains of plant growth-promoting bacteria, and a psychrophilic bacterium containing an ACC deaminase gene on a broad host range plasmid. The extent of root elongation and levels of ACC, the immediate precursor of ethylene, were measured in the canola seedling roots. A modification of the Waters AccQ*Tag Amino Acid Analysis Method(tm) was used to quantify ACC in the root extracts. It was found that, in the presence of the ethylene inhibitor, AVG, or any one of several ACC deaminase-containing strains of bacteria, the growth of canola seedling roots was enhanced and the ACC levels in these roots were lowered.

Response of spring rape (Brassica napus var. oleifera L.) to inoculation with plant growth promoting rhizobacteria containing 1-aminocyclopropane-1-carboxylate deaminase depends on nutrient status of the plant

2002 ◽  
Vol 48 (3) ◽  
pp. 189-199 ◽  
Author(s):  
Andrei A Belimov ◽  
Vera I Safronova ◽  
Tetsuro Mimura
Keyword(s):  
Brassica Napus ◽  
Plant Growth ◽  
Pseudomonas Putida ◽  
Ethylene Production ◽  
Root Elongation ◽  
Plant Growth Promoting Rhizobacteria ◽  
Nutrient Status ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Stimulation Of

Responses of rape (Brassica napus var. oleifera L.) to inoculation with plant growth promoting rhizobacteria, Pseudomonas putida Am2, Pseudomonas putida Bm3, Alcaligenes xylosoxidans Cm4, and Pseudomonas sp. Dp2, containing 1-aminocyclopropane-1-carboxylate (ACC) deaminase were studied using growth pouch and soil cultures. In growth pouch culture, the bacteria significantly increased root elongation of phosphorus-sufficient seedlings, whereas root elongation of phosphorus-deficient seedlings was not affected or was even inhibited by the bacteria. Bacterial stimulation of root elongation of phosphorus-sufficient seedlings was eliminated in the presence of a high ammonia concentration (1 mM) in the nutrient solution. Bacterial effects on root elongation of potassium-deficient and potassium-sufficient seedlings were similar. The bacteria also decreased inorganic phosphate content in shoots of potassium- and phosphorus-sufficient seedlings, reduced ethylene production by phosphorus-sufficient seedlings, and inhibited development of root hairs. The effects of treatment with Ag+, a chemical inhibitor of plant ethylene production, on root elongation, ethylene evolution, and root hair formation were similar to bacterial treatments. The number of bacteria on the roots of phosphorus-deficient seedlings was not limited by phosphorus deficiency. In pot experiments with soil culture, inoculation of seeds with bacteria and treatment with aminoethoxyvinylglycine, an inhibitor of ethylene biosynthesis in plants, increased root and (or) shoot biomass of rape plants. Stimulation of plant growth caused by the bacteria was often associated with a decrease in the content of nutrients, such as P, K, S, Mo, and Ba, in shoots, depending on the strain used. The results obtained show that the growth-promoting effects of ACC-utilizing rhizobacteria depend significantly on the nutrient status of the plant.Key words: 1-aminocyclopropane-1-carboxylate deaminase, Brassica napus, PGPR, phosphorus uptake, plant-bacteria interaction, ethylene, Pseudomonas.

Characterization of plant growth promoting rhizobacteria isolated from polluted soils and containing 1-aminocyclopropane-1-carboxylate deaminase

2001 ◽  
Vol 47 (7) ◽  
pp. 642-652 ◽  
Author(s):  
Andrei A Belimov ◽  
Vera I Safronova ◽  
Tatyana A Sergeyeva ◽  
Tatyana N Egorova ◽  
Victoria A Matveyeva ◽  
...  
Keyword(s):  
Plant Growth ◽  
Root Elongation ◽  
Indian Mustard ◽  
Acc Deaminase ◽  
Plant Growth Promoting Rhizobacteria ◽  
Sand Culture ◽  
Bacterial Strains ◽  
Pot Experiments ◽  
Plant Growth Promoting ◽  
Growth Promoting

Fifteen bacterial strains containing 1-aminocyclopropane-1-carboxylate (ACC) deaminase were isolated from the rhizoplane of pea (Pisum sativum L.) and Indian mustard (Brassica juncea L.) grown in different soils and a long-standing sewage sludge contaminated with heavy metals. The isolated strains were characterized and assigned to various genera and species, such as Pseudomonas brassicacearum, Pseudomonas marginalis, Pseudomonas oryzihabitans, Pseudomonas putida, Pseudomonas sp., Alcaligenes xylosoxidans, Alcaligenes sp., Variovorax paradoxus, Bacillus pumilus, and Rhodococcus sp. by determination of 16S rRNA gene sequences. The root elongation of Indian mustard and rape (Brassica napus var. oleifera L.) germinating seedlings was stimulated by inoculation with 8 and 13 isolated strains, respectively. The bacteria were tolerant to cadmium toxicity and stimulated root elongation of rape seedlings in the presence of 300 µM CdCl2 in the nutrient solution. The effect of ACC-utilising bacteria on root elongation correlated with the impact of aminoethoxyvinylglycine and silver ions, chemical inhibitors of ethylene biosynthesis. A significant improvement in the growth of rape caused by inoculation with certain selected strains was also observed in pot experiments, when the plants were cultivated in cadmium-supplemented soil. The biomass of pea cv. Sparkle and its ethylene sensitive mutant E2 (sym5), in particular, was increased through inoculation with certain strains of ACC-utilising bacteria in pot experiments in quartz sand culture. The beneficial effect of the bacteria on plant growth varied significantly depending on individual bacterial strains, plant genotype, and growth conditions. The results suggest that plant growth promoting rhizobacteria containing ACC deaminase are present in various soils and offer promise as a bacterial inoculum for improvement of plant growth, particularly under unfavourable environmental conditions.Key words: ACC deaminase, cadmium, ethylene, Indian mustard, pea, phytoremediation, rape, rhizobacteria.

Partial purification and characterization of 1-aminocyclopropane-1-carboxylate deaminase from the plant growth promoting rhizobacterium Pseudomonas putida GR12-2

1994 ◽  
Vol 40 (12) ◽  
pp. 1019-1025 ◽  
Author(s):  
Christian B. Jacobson ◽  
J. J. Pasternak ◽  
Bernard R. Glick
Keyword(s):  
Plant Growth ◽  
Pseudomonas Putida ◽  
Molecular Mass ◽  
Acc Deaminase ◽  
Plant Growth Promoting Rhizobacteria ◽  
Partial Purification ◽  
Ph Optimum ◽  
Native Form ◽  
Plant Growth Promoting ◽  
Growth Promoting

The plant growth promoting rhizobacterium Pseudomonas putida GR12-2 can utilize 1-aminocyclopropane-1-carboxylate (ACC) as a sole nitrogen source because it possess the unusual enzyme ACC deaminase, which hydrolyzes ACC to ammonia and α-ketobutyrate. This enzyme, which is thought to be intimately involved in the mechanism that the bacterium uses to promote root elongation in developing canola seedlings, was partially purified and characterized. The native form of the enzyme is a trimer with a molecular mass of 105 kDa and a subunit molecular mass of 35 kDa. ACC deaminase activity is found in the cytoplasm of the bacterium, is induced by low levels (i.e., 100 nM) of ACC, and has a temperature optimum at approximately 30 °C and a pH optimum of 8.5. These properties are very similar to those reported for ACC deaminase from another soil bacterium, Pseudomonas sp. strain APC.Key words: 1-aminocyclopropane-1-carboxylate, ACC, plant growth promoting rhizobacteria, PGPR, ACC deaminase, bacterial fertilizer.

Biological consequences of plasmid transformation of the plant growth promoting rhizobacterium Pseudomonas putida GR12-2

1991 ◽  
Vol 37 (10) ◽  
pp. 796-799 ◽  
Author(s):  
Yuwen Hong ◽  
J. J. Pasternak ◽  
Bernard R. Glick
Keyword(s):  
Nitrogen Fixation ◽  
Plant Growth ◽  
Pseudomonas Putida ◽  
Root Elongation ◽  
Plant Growth Promoting Rhizobacteria ◽  
Siderophore Production ◽  
Broad Host Range ◽  
Metabolic Load ◽  
Plant Growth Promoting ◽  
Growth Promoting

Pseudomonas putida GR12-2, a plant growth promoting rhizobacterium, was transformed with the broad host range plasmid pGSS15. The presence of the plasmid caused (i) a decrease in cell generation times, (ii) an altered pattern of cell proteins, (iii) an inhibition of the enhancement of canola root elongation, (iv) impairment of nitrogen fixation, and (v) a decrease in siderophore production. Strains that were cured of pGSS15, on the other hand, re-established growth rates, levels of siderophore production, and canola root elongation capabilities equivalent to nontransformed P. putida GR12-2. Thus, the transforming plasmid imposes a metabolic load on the recipient bacteria that impacts on a number of different energy-dependent processes. Key words: plant growth promoting rhizobacteria, nitrogen fixation, Pseudomonas, transformation, metabolic load.

ROOT ELONGATION IN VARIOUS AGRONOMIC CROPS BY THE PLANT GROWTH PROMOTING RHIZOBACTERIUM PSEUDOMONAS PUTIDA GR12–2

1996 ◽  
Vol 44 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Jeremy A. Hall ◽  
David Peirson ◽  
Sibdas Ghosh ◽  
Bernard Glick R.
Keyword(s):  
Plant Growth ◽  
Pseudomonas Putida ◽  
Root Elongation ◽  
Ethylene Biosynthesis ◽  
Control Treatment ◽  
Wild Type Plant ◽  
Wild Type ◽  
Agronomic Crops ◽  
Plant Growth Promoting ◽  
Growth Promoting

Seeds of canola, lettuce, tomato, barley, wheat, and oats were inoculated with either the wild-type plant growth promoting rhizobacterium (PGPR),Pseudomonas putidaGR12–2, or the mutantP. putidaGR 12–2lacd68 (deficient in the activity of the enzyme 1-aminocyclopropane-1-carboxylate deaminase) alone and in conjunction with either an inhibitor of ethylene biosynthesis, L-α-(aminoethoxyvinyl)-glycine (AVG), or the chemical ethylene generator, (2-chloroethyl) phosphonic acid (ethophon). For the different treatments, variations in root length under gnotobiotic conditions were compared. Canola, lettuce, tomato, and wheat responded to all of the treatments in a similar manner: The root lengths increased when seeds were treated withP. putidaGR 12–2 and/or AVG but not with the mutant strain, in comparison with a MgSO4control treatment, while the ethophon treatment inhibited root elongation. With barley and oat, none of the treatments had any effect on root lengths; however, when the ethophon concentration was increased, root elongation of these two plants was also inhibited. These observations are consistent with a model in which promotion of root growth byP. putidaGR 12–2 is a consequence of inhibition of ethylene production within the developing seedling.

Persistence in soil of the plant growth promoting rhizobacterium Pseudomonas putida GR12-2 and genetically manipulated derived strains

1995 ◽  
Vol 41 (6) ◽  
pp. 445-451 ◽  
Author(s):  
Weizhen Tang ◽  
J. J. Pasternak ◽  
Bernard R. Glick
Keyword(s):  
Plant Growth ◽  
Pseudomonas Putida ◽  
Soil Bacteria ◽  
Plant Growth Promoting Rhizobacteria ◽  
Broad Host Range ◽  
Wild Type ◽  
Soil Persistence ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Genetically Manipulated

Transformation of the plant growth promoting rhizobacterium Pseudomonas putida GR12-2 with broad-host-range vectors can affect the growth of the bacterium, its ability to promote root elongation of canola seedlings under gnotobiotic conditions, and its persistence in soil. Plasmid transformants, and a transposon-mutagenized derivative of P. putida GR12-2, fell into two classes with respect to these three attributes: strains that were clearly diminished in these capabilities and strains that behaved like the nontransformed wild type. These differences can be accounted for by the imposition of a metabolic load that is created by some types of genetic modification that results in a physiological impairment of the modified bacterium and decreases its ability to function as a plant growth promoting rhizobacterium.Key words: plant growth promoting rhizobacteria, PGPR, bacterial fertilizer, soil bacteria, soil persistence, microcosm.

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