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Muhammad Zafar-ul-Hye Tariq Shahzad Bhutta Muhammad Shaaban Shahid Hussain Muhammad Farooq Qayyum Umar Aslam Zahir Ahmad Zahir 《Phyton》2019,88(2):119-129
Soil salinity affects the growth and yield of crops. The stress of soil salinity on plants can be mitigated by inoculation of plant growth promoting bacteria (PGPR). The influence of PGPR inoculation on wheat (Triticum aestivum L.) crop productivity under salinity stress has not been properly addressed so far. Therefore, the present study was conducted to investigate the effects of various PGPR strains (W14, W10 and 6K; alone and combined) at several growth attributes of wheat plant under different soil salinity gradients (3, 6 and 9 dS m-1). The growth attributes of wheat (height, roots, shoots, spikes, grains quality, biological and economical yield, nutrients nitrogen, phosphorus and potassium in grains) were highly affected by salinity and decreased with increasing salinity level. The PGPR inoculation substantially promoted growth attributes of wheat and prominent results were observed in W14 × W10 × 6K treatment at all salinity levels. The results suggest that inoculation of PGPR is a potential strategy to mitigate salinity stress for improving wheat growth and yield. 相似文献
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Sarfraz Hussain Muhammad Arshad Muhammad Saleem Zahir Ahmad Zahir 《World journal of microbiology & biotechnology》2007,23(7):939-945
Intensive use of endosulfan has resulted in contamination of soil and water environments at various sites in Pakistan. This
study was conducted to isolate efficient endosulfan-degrading fungal strains from contaminated soils. Sixteen fungal strains
were isolated from fifteen specific sites by employing enrichment techniques while using endosulfan as a sole sulfur source,
and tested for their potential to degrade endosulfan. Among these fungal strains, Chaetosartorya stromatoides, Aspergillus terricola, and Aspergillus terreus degraded both α- and β-endosulfan upto 75% in addition to ∼20% abiotic degradation of the spiked amount (100 mg l−1) in the broth within 12 days of incubation. Biodegradation of endosulfan by soil fungi was accompanied by a substantial decrease
in pH of the broth from 7.0 to 3.2. The major metabolic product was endosulfan diol along with very low concentrations of
endosulfan ether. Maximum biodegradation of endosulfan by these selected fungal strains was found at an initial broth pH of
6, incubation temperature of 30°C and under agitation conditions. This study indicates that the isolated strains carried efficient
enzyme systems required for bioremediation of endosulfan-contaminated soil and water environments. 相似文献
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The stringent response regulator ppGpp has recently been shown by our group to inhibit the Escherichia coli inducible lysine decarboxylase, LdcI. As a follow-up to this observation, we examined the mechanisms that regulate the activities of the other four E. coli enzymes paralogous to LdcI: the constitutive lysine decarboxylase LdcC, the inducible arginine decarboxylase AdiA, the inducible ornithine decarboxylase SpeF, and the constitutive ornithine decarboxylase SpeC. LdcC and SpeC are involved in cellular polyamine biosynthesis, while LdcI, AdiA, and SpeF are involved in the acid stress response. Multiple mechanisms of regulation were found for these enzymes. In addition to LdcI, LdcC and SpeC were found to be inhibited by ppGpp; AdiA activity was found to be regulated by changes in oligomerization, while SpeF and SpeC activities were regulated by GTP. These findings indicate the presence of multiple mechanisms regulating the activity of this important family of decarboxylases. When the enzyme inhibition profiles are analyzed in parallel, a "zone of inhibition" between pH 6 and pH 8 is observed. Hence, the data suggest that E. coli utilizes multiple mechanisms to ensure that these decarboxylases remain inactive around neutral pH possibly to reduce the consumption of amino acids at this pH. 相似文献
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Ahmad Waqar Zahir Adnan Nadeem Muhammad Zia Muhammad Hano Christophe Abbasi Bilal Haider 《In vitro cellular & developmental biology. Plant》2019,55(6):710-719
In Vitro Cellular & Developmental Biology - Plant - Ipomoea turbinata Lagasca and Segura (Purple Moonflower) belongs to the largest flowering genus Ipomoea in the Convolvulaceae family. Ipomoea... 相似文献
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AIMS: This study was conducted to test the hypothesis that the bacterial strains possessing 1-aminocyclopropane-1-carboxylic acid (ACC)-deaminase activity may also promote growth of inoculated plants and could increase nodulation in legumes upon co-inoculation with rhizobia. METHODS AND RESULTS: Several rhizobacteria were isolated from maize rhizosphere through enrichment on ACC as a sole N source. Purified isolates were screened for growth promotion in maize under axenic conditions and for in vitro ACC-deaminase activity. A significant positive correlation was observed between in vitro ACC-deaminase activity of bacterial cells and root elongation. None of the isolates produced auxins. Bradyrhizobium japonicum produced less amount of auxins but did not carry ACC-deaminase activity. Results of pot experiment revealed that co-inoculation with Bradyrhizobium and plant growth promoting rhizobacteria (PGPR) isolates enhanced the nodulation in mung bean compared with inoculation with Bradyrhizobium alone. CONCLUSIONS: It is highly expected that inoculation with rhizobacteria containing ACC-deaminase hydrolysed endogenous ACC into ammonia and alpha-ketobutyrate instead of ethylene. Consequently, root and shoot growth as well as nodulation were promoted. SIGNIFICANCE AND IMPACT OF THE STUDY: The ACC-deaminase trait could be employed as an efficient tool to screen effective PGPR, which could be successfully used as biofertilizers to increase the growth of inoculated plants as well as nodulation in legumes. 相似文献
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Mathis BJ Marshall CW Milliken CE Makkar RS Creager SE May HD 《Applied microbiology and biotechnology》2008,79(1):147-155
Acquisition of nutrients by plants is primarily dependent on root growth and bioavailability of nutrients in the rooting medium.
Most of the beneficial bacteria enhance root growth, but their effectiveness could be influenced by the nutrient status around
the roots. In this study, two 1-aminocyclopropane-1-carboxylate (ACC)-deaminase containing plant-growth-promoting rhizobacteria
(PGPR), Pseudomonas fluorescens and P. fluorescens biotype F were tested for their effect on growth, yield, and nutrient use efficiency of wheat under simultaneously varying
levels of all the three major nutrients N, P, and K (at 0%, 25%, 50%, 75%, and 100% of recommended doses). Results of pot
and field trials revealed that the efficacy of these strains for improving growth and yield of wheat reduced with the increasing
rates of NPK added to the soil. In most of the cases, significant negative linear correlations were recorded between percentage
increases in growth and yield parameters of wheat caused by inoculation and increasing levels of applied NPK fertilizers.
It is highly likely that under low fertilizer application, the ACC-deaminase activity of PGPR might have caused reduction
in the synthesis of stress (nutrient)-induced inhibitory levels of ethylene in the roots through ACC hydrolysis into NH3 and α-ketobutyrate. The results of this study imply that these Pseudomonads could be employed in combination with appropriate
doses of fertilizers for better plant growth and savings of fertilizers. 相似文献
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Fatima Hamadi Hassan Latrache Hafida Zahir Jamaa Bengourram Nourreeddine Kouider Abderrahmene Elghmari Khalid Habbari 《Microbiology》2011,80(4):488-491
A simple and rapid method, Microbial adhesion to hexadecane, for estimating the cell surface charge is proposed. This method
is based on the determination of cell affinity to hexadecane at low ionic strength and at high ionic strength. The difference
between these two affinities can provide the relative cell surface charge. The application of this method for Staphylococcus aureus and Escherichia coli show that the profile of surface charge evolution as a function of pH was similar to these obtained by microelectrophoresis
method. 相似文献