scholarly journals Gene expression patterns in shoots of Camelina sativa with enhanced salinity tolerance provided by plant growth promoting bacteria producing 1-aminocyclopropane-1-carboxylate deaminase or expression of the corresponding acdS gene

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zohreh Heydarian ◽  
Margaret Gruber ◽  
Cathy Coutu ◽  
Bernard R. Glick ◽  
Dwayne D. Hegedus
Keyword(s):  
Salt Stress ◽  
Plant Growth ◽  
Acc Deaminase ◽  
Camelina Sativa ◽  
Fine Tuning ◽  
Plant Growth Promoting Bacteria ◽  
Salt Stress Response ◽  
Expression Of Genes ◽  
Plant Growth Promoting ◽  
Growth Promoting

AbstractGrowth of plants in soil inoculated with plant growth promoting bacteria (PGPB) producing 1-aminocyclopropane-1-carboxylate (ACC) deaminase or expression of the corresponding acdS gene in transgenic lines reduces the decline in shoot length, shoot weight and photosynthetic capacity triggered by salt stress in Camelina sativa. Reducing the levels of ethylene attenuated the salt stress response as inferred from decreases in the expression of genes involved in development, senescence, chlorosis and leaf abscission that are highly induced by salt to levels that may otherwise have a negative effect on plant growth and productivity. Growing plants in soil treated with Pseudomonas migulae 8R6 negatively affected ethylene signaling, auxin and JA biosynthesis and signalling, but had a positive effect on the regulation of genes involved in GA signaling. In plants expressing acdS, the expression of the genes involved in auxin signalling was positively affected, while the expression of genes involved in cytokinin degradation and ethylene biosynthesis were negatively affected. Moreover, fine-tuning of ABA signaling appears to result from the application of ACC deaminase in response to salt treatment. Moderate expression of acdS under the control of the root specific rolD promoter or growing plants in soil treated with P. migulae 8R6 were more effective in reducing the expression of the genes involved in ethylene production and/or signaling than expression of acdS under the more active Cauliflower Mosaic Virus 35S promoter.

ACC deaminase from plant growth-promoting bacteria affects crown gall development

2007 ◽  
Vol 53 (12) ◽  
pp. 1291-1299 ◽  
Author(s):  
Youai Hao ◽  
Trevor C. Charles ◽  
Bernard R. Glick
Keyword(s):  
Plant Growth ◽  
Castor Bean ◽  
Crown Gall ◽  
Acc Deaminase ◽  
Plant Growth Promoting Bacteria ◽  
Bean Plants ◽  
Tumour Formation ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Agrobacterium Tumefaciens C58

In addition to the well-known roles of indoleacetic acid and cytokinin in crown gall formation, the plant hormone ethylene also plays an important role in this process. Many plant growth-promoting bacteria (PGPB) encode the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase, which can degrade ACC, the immediate precursor of ethylene in plants, to α-ketobutyrate and ammonia and thereby lower plant ethylene levels. To study the effect of ACC deaminase on crown gall development, an ACC deaminase gene from the PGPB Pseudomonas putida UW4 was introduced into Agrobacterium tumefaciens C58, so that the effect of ACC deaminase activity on tumour formation in tomato and castor bean plants could be assessed. Plants were also coinoculated with A. tumefaciens C58 and P. putida UW4 or P. putida UW4-acdS– (an ACC deaminase minus mutant strain). In both types of experiments, it was observed that the presence of ACC deaminase generally inhibited tumour development on both tomato and castor bean plants.

scholarly journals Alleviation of Salt Stress by Plant Growth-Promoting Bacteria in Hydroponic Leaf Lettuce

Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1523 ◽  
Author(s):  
Alessandra Moncada ◽  
Filippo Vetrano ◽  
Alessandro Miceli
Keyword(s):  
Salt Stress ◽  
Plant Growth ◽  
Leafy Vegetables ◽  
Mineral Nutrient ◽  
Plant Growth Promoting Bacteria ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Leaf Lettuce ◽  
Positive Effect ◽  
Nutrient Solutions

Mediterranean areas with intensive agriculture are characterized by high salinity of groundwater. The use of this water in hydroponic cultivations can lead to nutrient solutions with an electrical conductivity that overcomes the tolerance threshold of many vegetable species. Plant growth-promoting rhizobacteria (PGPR) were shown to minimize salt stress on several vegetable crops but the studies on the application of PGPR on leafy vegetables grown in hydroponics are rather limited and have not been used under salt stress conditions. This study aimed to evaluate the use of plant growth-promoting bacteria to increase the salt tolerance of leaf lettuce grown in autumn and spring in a floating system, by adding a bacterial biostimulant (1.5 g L−1 of TNC BactorrS13 a commercial biostimulant containing 1.3 × 108 CFU g−1 of Bacillus spp.) to mineral nutrient solutions (MNS) with two salinity levels (0 and 20 mM NaCl). Leaf lettuce plants showed a significant reduction of growth and yield under salt stress, determined by the reduction of biomass, leaf number, and leaf area. Plants showed to be more tolerant to salinity in autumn than in spring. The inhibition of lettuce plant growth due to salt stress was significantly alleviated by the addition of the bacterial biostimulant to the MNS, which had a positive effect on plant growth and fresh and dry biomass accumulation of the unstressed lettuce in both cultivation seasons, and maintained this positive effect in brackish MNS, with similar or even significantly higher values of morphologic, physiologic, and yield parameters than those recorded in control unstressed plants.

Levels of ACC and related compounds in exudate and extracts of canola seeds treated with ACC deaminase-containing plant growth-promoting bacteria

2001 ◽  
Vol 47 (4) ◽  
pp. 368-372 ◽  
Author(s):  
Donna M Penrose ◽  
Bernard R Glick
Keyword(s):  
Plant Growth ◽  
Acc Deaminase ◽  
Aminobutyric Acid ◽  
Plant Growth Promoting Bacteria ◽  
Canola Seed ◽  
Test Part ◽  
Seed Exudate ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Related Compounds

It was previously proposed that plant growth-promoting bacteria that possess 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase could utilize ACC that is present in the exudate of germinating canola seeds. The uptake and cleavage of ACC by these bacteria would lower the level of ACC, and thus ethylene within the plant, and reduce the extent of its inhibition on root elongation. To test part of the above mentioned model, ACC levels were monitored in canola seed tissues and exudate during germination. Lower amounts of ACC were present in the exudate and tissues of seeds treated with the plant growth-promoting bacterium Enterobacter cloacae CAL3, than in control seeds treated with MgSO4. The ACC-related compounds, α- and γ-aminobutyric acids, both known to stimulate ethylene production, were also measured in the canola seed exudate and tissues. Approximately the same levels of α-aminobutyric acid were present in the exudates of the bacterium-treated seeds and the control seeds, but the amount of α-aminobutyric acid was lower in the tissues of the bacterium-treated seeds than in the control seeds. Smaller quantities of γ-aminobutyric acid were seen in both the exudate and tissues of the E. cloacae CAL3-treated seeds than in the control seeds.Key words: ACC ethylene, canola, seed extract, seed exudate, plant growth-promoting bacteria.

Involvement ofgacSandrpoSin enhancement of the plant growth-promoting capabilities ofEnterobacter cloacaeCAL2 and UW4

2001 ◽  
Vol 47 (8) ◽  
pp. 698-705 ◽  
Author(s):  
Saleema S Saleh ◽  
Bernard R Glick
Keyword(s):  
Plant Growth ◽  
Pseudomonas Fluorescens ◽  
Indoleacetic Acid ◽  
Acc Deaminase ◽  
Enterobacter Cloacae ◽  
Lag Phase ◽  
Plant Growth Promoting Bacteria ◽  
Multicopy Plasmid ◽  
Plant Growth Promoting ◽  
Growth Promoting

The plant growth-promoting bacteria Enterobacter cloacae CAL2 and UW4 were genetically transformed with a multicopy plasmid containing an rpoS or gacS gene from Pseudomonas fluorescens. The transformed strains were compared with the nontransformed strains for growth, indoleacetic acid (IAA) production, antibiotic production, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, siderophore production, cell morphology, and the ability to promote canola root elongation. All transformed strains had a longer lag phase, were slower in reaching stationary phase, and attained a higher cell density than the nontransformed strains. Transformation resulted in cells that were significantly shorter than the nontransformed cells. The transformed strains also produced significantly more IAA than the nontransformed strains. Introduction of rpoS or gacS from Pseudomonas fluorescens was associated with a reduction in the production of both antibiotics, 2,4-diacetylphloroglucinol and mono-acetylphloroglucinol, produced by Enterobacter cloacae CAL2. With Enterobacter cloacae CAL2, plasmid-borne rpoS, but not gacS, increased the level of ACC deaminase activity, while introduction of rpoS in Enterobacter cloacae UW4 caused a decrease in ACC deaminase activity. Neither gacS nor rpoS significantly affected the level of siderophores synthesized by either bacterial strain. Overproduction of either GacA or RpoS in Enterobacter cloacae CAL2 resulted in a significant increase in the root lengths of canola seedlings when seeds were treated with the bacteria, and overproduction of RpoS caused an increase in canola shoot as well as root lengths.Key words: plant growth-promoting bacteria, canola, ethylene, ACC deaminase, GacS, RpoS, indoleacetic acid, siderophores, antibiotics.

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.

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