Alleviation of salt stress by plant growth regulators and IAA producing bacteria in wheat

Acta Physiologiae Plantarum (Impact Factor: 1.52). 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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    • "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.
    Saudi Journal of Biological Sciences 05/2015; 1. DOI:10.1016/j.sjbs.2015.04.019
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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.
    Archives of Agronomy and Soil Science 03/2015; DOI:10.1080/03650340.2015.1036044
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    • "We recently reported that OsSUV3 over expression in rice functions in salt tolerance, it also improved growth performance in terms of plant height, number of tillers/ plant, number of panicle/plant, number of filled grain/ panicle, number of non-chaffy grains/panicle, straw dry weight, 100 grain weight, root length, root dry weight, leaf area, root and shoot lengths when compared to control plants (Tuteja et al. 2013). Much attention is now focused on the plant hormones for their crucial roles in stress responses and adaptation (Kuppu et al. 2013) and exploitation of different plant hormones for reducing the negative effects of salinity in growth parameters (Egamberdieva 2009). In the present study, OsSUV3 rice transgenic T 1 and T 2 lines maintained higher endogenous content of GA 3 , zeatin and IAA under 200 mM NaCl as compared to the control plants. "
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    ABSTRACT: Background The SUV3 (suppressor of Var 3) gene encodes a DNA and RNA helicase, which is localized in the mitochondria. Plant SUV3 has not yet been characterized in detail. However, the Arabidopsis ortholog of SUV3 (AT4G14790) has been shown to be involved in embryo sac development. Previously, we have reported that rice SUV3 functions as DNA and RNA helicase and provides salinity stress tolerance by maintaining photosynthesis and antioxidant machinery. Here, we report further analysis of the transgenic OsSUV3 rice plants under salt stress. Findings The transgenic OsSUV3 overexpressing rice T1 lines showed significantly higher endogenous content of plant hormones viz., gibberellic acid (GA3), zeatin (Z) and indole-3-acetic acid (IAA) in leaf, stem and root as compared to wild-type (WT), vector control (VC) and antisense (AS) plants under salt (200 mM NaCl) stress condition. A similar trend of endogenous plant hormones profile was also reflected in the T2 generation of OsSUV3 transgenic rice under defined parameters and stress condition. Conclusions In response to stress, OsSUV3 rice plants maintained plant hormone levels that regulate the expression of several stress-induced genes and reduce adverse effects of salt on plant growth and development and therefore sustains crop productivity.
    Rice 07/2014; 7(1). DOI:10.1186/s12284-014-0017-2
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