Article

Alleviation of salt stress by plant growth regulators and IAA producing bacteria in wheat. Acta Phys Plant

Acta Physiologiae Plantarum (Impact Factor: 1.58). 07/2009; 31(4):861-864. DOI: 10.1007/s11738-009-0297-0

ABSTRACT

The action of phytohormone producing bacteria and plant growth regulators on germination and seedling growth of wheat under saline conditions were studied. Seed dormancy enforced by salinity (100 mM NaCl) was substantially alleviated and the germination was promoted by gibberellin, auxin, zeatin, and ethephon from 54 to 97%. The IAA producing bacterial strains Pseudomonas aureantiaca TSAU22, Pseudomonas extremorientalis TSAU6 and Pseudomonas extremorientalis TSAU20 significantly increased seedling root growth up to 25% in non-salinated conditions and up to 52% at 100 mM NaCl, compared to control plants. It is concluded that growth regulators considerably alleviated salinity-induced dormancy of wheat seeds. The facts mentioned above make it possible to recommend root colonizing bacteria that produce phytohormone to alleviate salt stress of wheat grown under conditions of soil salinity.

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    • "Indole acetic acid (IAA) is the most abundant naturally occurring plant hormone, well known for its regulating function in plant growth and development (Rout 2006). Indole acetic acid is a type of auxin that stimulates growth through cell elongation and lateral root formation which probably support more absorption of minerals (Egamberdieva 2009). Research work with IAA on growth, yield attributes and fruit yield of tomato is scanty. "
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    ABSTRACT: Abstract The experiment was conducted at research field and laboratory of the Department of Crop Physiology and Ecology, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh during the period of December 2013 to April 2014. The experiment was laid out in two factors randomized complete block design with three replications including three concentrations of Indole Acetic Acid (0, 100 and 200 ppm) and three tomato varieties (BARI tomato 7, Manik and Ratan). Plant height, number of leaves and number of branches, days required for first flower initiation, days required for 50% flowering, days required for fruit setting, fruit cluster plant-1, fruit plant-1, weight tomato-1, yield plant-1, yield plot-1 and yield hectare-1 were significant influenced by the combined application of IAA and varieties of tomato. BARI Tomato-7 had the highest fruit yield with 100 ppm IAA and the lowest yield was observed in Ratan with 0 ppm IAA. IAA treated plots showed better performance for growth parameters and yield compared to control condition and 100 ppm IAA was more suitable than the 200 ppm IAA for higher yield of tomato cultivation. Among the treatment combinations, BARI Tomato-7 with 100 ppm IAA was superior, Ratan with 0 ppm IAA was inferior and BARI Tomato-7 with 200 ppm IAA, Manik with 200 ppm IAA and Ratan with 200 ppm IAA treated plots showed the intermediate results for yield and yield components.
    Full-text · Article · Jun 2015
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    • "According to Iqbal and Ashraf (2010) and Alqarawi et al. (2014b), salinity perturbs the hormonal balance of plants; therefore, hormonal homeostasis under salt stress might be one possible mechanism of phytohormone induced plant salt tolerance. The exogenous application of phytohormones such as gibberellins (Afzal et al., 2005), auxins (Egamberdieva, 2009), and cytokinins (Gül et al., 2000) mitigate salt stress and stimulate plant root and shoot growth under stress. The content of phytohormones in plants may also be affected by root-associated microorganisms (Turan et al., 2014). "
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    ABSTRACT: Abiotic stresses cause changes in the balance of phytohormones in plants and result in inhibited root growth and an increase in the susceptibility of plants to root rot disease. The aim of this work was to ascertain whether microbial indole-3-acetic acid (IAA) plays a role in the regulation of root growth and microbially mediated control of root rot of cotton caused by Fusarium solani. Seed germination and seedling growth were improved by both NaCl and Mg2SO4 (100 mM) solutions when treated with root-associated bacterial strains Pseudomonas putida R4 and P. chlororaphis R5, which are able to produce IAA. These bacterial strains were also able to reduce the infection rate of cotton root rot (from 70 to 39%) caused by F. solani under gnotobiotic conditions. The application of a low concentration of IAA (0.01 and 0.001 μg/ml) stimulated plant growth and reduced disease incidence caused by F. solani (from 70 to 41-56%, respectively). Shoot and root growth and dry matter increased significantly and disease incidence was reduced by bacterial inoculants in natural saline soil. These results suggest that bacterial IAA plays a major role in salt stress tolerance and may be involved in induced resistance against root rot disease of cotton.
    Full-text · Article · May 2015 · Saudi Journal of Biological Sciences
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    • "Similarly , bacterial IAA has also been shown to alleviate salt stress of plants grown under conditions of soil salinity . For instance , halotolerant bacteria have been reported to enhance the growth by improving the osmotic stress tolerance in plants ( Egamberdieva 2009 ; Tiwari et al . 2011 ; Kim et al . "
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    ABSTRACT: Abstract Salt-tolerant strains of Enterobacter asburiae, Bacillus thuringiensis, Moraxella pluranimalium and Pseudomonas stutzeri were evaluated for their ability to alleviate salt stress of wheat (Triticum aestivum L.) seedlings. 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity of P. stutzeri S-80 and B. thuringiensis S-26 was 190 and 183 nmol h-1, respectively. Maximum levels of auxin were recorded with P. stutzeri S-80 (107 μg ml-1) and E. asburiae S-24 (143 μg ml-1) under normal and salt-stressed conditions (0.25 M NaCl), respectively with 500 μg ml-1 L-tryptophan. Auxin response mediated by rhizobacteria was also demonstrated by microscopically assaying the transgenic auxin-responsive reporter DR5::GUS expression tomato (Solanum lycopersicum L. cv. MicroTom). In pot trials, seedlings fresh and dry biomass witnessed highly significant improvements of 1 and 2.2 folds, Downloaded by [University of the Punjab] at 06:18 14 April 2015 Accepted Manuscript respectively, with M. pluranimalium S-29 (at 100 mM NaCl) and E. asburiae S-24 (150 mM NaCl), over control. At final harvest, maximum increase in number of tillers (up to 94%) and seed weight (up to 40%) were recorded with E. asburiae S-24 and M. pluranimalium S-29 at 200 mM salt stress. In conclusion, newly isolated strains of M. pluranimalium S-29, E. asburiae S-24 and P. stutzeri S-80 enhanced the growth of T. aestivum by mitigating the salt stress of plants.
    Full-text · Article · Mar 2015 · Archives of Agronomy and Soil Science
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