title: Combined ability of chromium (Cr) tolerant plant growth promoting bacteria (PGPB) and salicylic acid (SA) in attenuation of chromium stress in maize plants.
abstract: Heavy metal contamination of agricultural soil has become a serious global problem. This study was aimed to evaluate the effects of two chromium (Cr) tolerant plant growth promoting bacteria (PGPB) in combination with salicylic acid (SA) on plant growth, physiological, biochemical responses and heavy metal uptake under Cr contamination. A pot experiment (autoclaved sand as growing medium) was performed using maize (Zea mays L.) as a test crop under controlled conditions. Cr toxicity significantly reduced plant growth, photosynthetic pigment, carbohydrates metabolism and increased H2O2, MDA, relative membrane permeability, proline and Cr contents in maize leaves. However, inoculation with selected PGPB (T2Cr and CrP450) and SA application either alone or in combination alleviated the Cr toxicity and promoted plant growth by decreasing Cr accumulation, H2O2and MDA level in maize. Furthermore, dual PGPB inoculation with SA application also improved plant performance under Cr-toxicity. Results obtained from this study indicate that PGPB inoculation and SA application enhanced Cr tolerance in maize seedlings by decreasing Cr uptake from root to shoot. Additionally, combination of both PGPB and SA also reduced oxidative stress by elevating the activities of enzymatic and non-enzymatic antioxidant, also indicated by improved carbohydrate metabolism in maize plant exposed to Cr contamination. Comparatively, alleviation effects were more pronounced in PGPB inoculated plants than SA applied plants alone. The results suggest that combined use of PGPB and SA application may be exploited for improving production potential of maize in metal (Cr) contaminated soil.
authors: Department of Environmental Sciences and Engineering, Government College University, Faisalabad 38000, Pakistan.
authors: Faisal
authors: F
authors: Islam
authors: Department of Environmental Sciences and Engineering, Government College University, Faisalabad 38000, Pakistan. Electronic address: rida_akash@hotmail.com.
authors: Tahira
authors: T
authors: Yasmeen
authors: Department of Environmental Sciences and Engineering, Government College University, Faisalabad 38000, Pakistan.
authors: Muhammad Saleem
authors: MS
authors: Arif
authors: Department of Environmental Sciences and Engineering, Government College University, Faisalabad 38000, Pakistan.
authors: Muhammad
authors: M
authors: Riaz
authors: Department of Soil and Environmental Sciences, University College of Agriculture, University of Sargodha, Sargodha 40100, Punjab, Pakistan.
authors: Sher Muhammad
authors: SM
authors: Shahzad
authors: Department of Environmental Sciences and Engineering, Government College University, Faisalabad 38000, Pakistan.
authors: Qaiser
authors: Q
authors: Imran
authors: AKHUWAT Faisalabad Institute of Research Science and Technology, Faisalabad, Pakistan.
authors: Irfan
authors: I
authors: Ali
mesh_terms: D000681:Amylases / Q000378:metabolism; D000975:Antioxidants / Q000378:metabolism; D002463:Cell Membrane Permeability / Q000187:drug effects; D002857:Chromium / Q000493:pharmacokinetics / Q000633:toxicity*; D007501:Iron / Q000493:pharmacokinetics; D015227:Lipid Peroxidation / Q000187:drug effects; D059013:Microbial Consortia / Q000187:drug effects / Q000235:genetics; D008826:Microbial Sensitivity Tests; D018384:Oxidative Stress / Q000187:drug effects; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D011188:Potassium / Q000493:pharmacokinetics; D011513:Proteus mirabilis / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D020156:Salicylic Acid / Q000378:metabolism / Q000494:pharmacology*; D064210:Secondary Metabolism / Q000187:drug effects; D012988:Soil Microbiology; D003313:Zea mays / Q000187:drug effects* / Q000254:growth & development / Q000382:microbiology*
chemical_list: D000975:Antioxidants; D002857:Chromium; D007501:Iron; D000681:Amylases; D020156:Salicylic Acid; D011188:Potassium
keywords: Antioxidant enzymes; Maize crop; Metal contamination; Oxidative stress; Rhizobacteria; Stress alleviator