title: The influences of Cr-tolerant rhizobacteria in phytoremediation and attenuation of Cr (VI) stress in agronomic sunflower (Helianthus annuus L.).
abstract: Chromium contamination of agronomic soil has to turn into a serious global problem. This research was pointed to assess the effects of three Cr-tolerant rhizobacteria (SS1, SS3, and SS6) on sunflower growth and heavy metal uptake under Cr smog i.e. 20, 30 and 40 ppm using K2Cr2O7. Root promotion assay and pot experiment were conducted to investigate and evaluate the effects of Cr tolerance rhizobacteria and Cr accumulation capacity of sunflower. From root promotion assay non-significant variation was observed in the root length between SS1 and SS3 compared with un-inoculated whereas SS6 enhanced the root length in the absence and presence of chromium. In addition, inoculation with rhizobacteria alleviated the Cr concentration and endorsed plant growth by enhancing Cr accumulation in sunflower. At different Cr levels, the Cr concentration in shoot was improved by each rhizobacterium though their difference was non-significant with each other, while the percentage increase was half as the Cr level doubled. Different rhizobacterium inoculation significantly (P < 0.05) affected the physiological and morphological characteristics of sunflower and increased the plant height, stem diameter, head diameter, grain yield, oil content of seeds, and total biomass, and among them, SS6 observed best followed by SS1 and SS3 comparing with un-inoculated. Our study illustrates an assessment about Cr-tolerant bacteria and their influences and recommends that these bacteria can effectively be used for crop improvement which provides a potential approach for Cr phytoremediation.
authors.affiliation: Department of Botany, Hazara University, Mansehra, Khyber Pakhtunkhwa, Pakistan; School of Life Sciences, Lanzhou University, Lanzhou 730000, China; MOE Key Laboratory of Cell Activities and Stress Adaptation, School of Life Sciences, Lanzhou University, Lanzhou 730000, China. Electronic address: ali_botanist@yahoo.com.
authors.forename: Ali
authors.initials: A
authors.lastname: Bahadur
authors.affiliation: Land Resources Research Institute, National Agricultural Research Centre, Islamabad, 45500, Pakistan.
authors.forename: Rizwan
authors.initials: R
authors.lastname: Ahmad
authors.affiliation: Department of Botany, Hazara University, Mansehra, Khyber Pakhtunkhwa, Pakistan.
authors.forename: Aftab
authors.initials: A
authors.lastname: Afzal
authors.affiliation: MOE Key Laboratory of Cell Activities and Stress Adaptation, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
authors.forename: Huyuan
authors.initials: H
authors.lastname: Feng
authors.affiliation: Plant Physiology/ Chemistry Section, Central Cotton Research Institute, Sakrand, Nawabshah, Sindh, Pakistan.
authors.forename: Vishandas
authors.initials: V
authors.lastname: Suthar
authors.affiliation: School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
authors.forename: Asfa
authors.initials: A
authors.lastname: Batool
authors.affiliation: Department of Botany, Hazara University, Mansehra, Khyber Pakhtunkhwa, Pakistan; School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
authors.forename: Aman
authors.initials: A
authors.lastname: Khan
authors.affiliation: Land Resources Research Institute, National Agricultural Research Centre, Islamabad, 45500, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Mahmood-Ul-Hassan
mesh_terms: D001673:Biodegradation, Environmental; D018533:Biomass; D002857:Chromium / Q000032:analysis / Q000494:pharmacology*; D004361:Drug Tolerance; D006368:Helianthus / Q000254:growth & development* / Q000382:microbiology; D019216:Metals, Heavy / Q000493:pharmacokinetics*; D063245:Plant Development / Q000187:drug effects; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development; D012230:Rhizobiaceae / Q000502:physiology*; D012639:Seeds / Q000187:drug effects / Q000254:growth & development; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis* / Q000494:pharmacology
chemical_list: D019216:Metals, Heavy; D012989:Soil Pollutants; D002857:Chromium
keywords: Bioaccumulation; Chromium; Contaminated soil treatment plant; Phytoremediation; Rhizobacteria