Transgenic plants of Petunia hybrida harboring the CYP2E1 gene efficiently remove benzene and toluene pollutants and improve resistance to formaldehyde

The CYP2E1 protein belongs to the P450 enzymes family and plays an important role in the metabolism of small molecular and organic pollutants. In this study we generated CYP2E1 transgenic plants of Petunia using Agrobacterium rhizogenes K599. PCR analysis confirmed that the regenerated plants contained the CYP2E1 transgene and the rolB gene of the Ri plasmid. Southern blotting revealed the presence of multiple copies of CYP2E1 in the genome of transgenic plants. Fluorescent quantitative PCR revealed exogenous CYP2E1 gene expression in CYP2E1 transgenic plants at various levels, whereas no like expression was detected in either GUS transgenic plants or wild-types. The absorption of benzene and toluene by transgenic plants was analyzed through quantitative gas chromatography. Transgenic plants with high CYP2E1 expression showed a significant increase in absorption capacity of environmental benzene and toluene, compared to control GUS transgenic and wild type plants. Furthermore, these plants also presented obvious improved resistance to formaldehyde. This study, besides being the first to reveal that the CYP2E1 gene enhances plant resistance to formaldehyde, also furnishes a new method for reducing pollutants, such as benzene, toluene and formaldehyde, by using transgenic flowering horticultural plants

Antifungal Activity of Plant Growth Promoting Rhizobacteria Against Fusarium oxysporum and Phoma sp. of Cucurbitaceae

Cucurbitaceae is the largest group of summer vegetables which includes about 118 genera and 825 species and most of which are known to possess medicinal values. Several major pathogens are known to infect cucurbits and cause yield loss up to 70–80 %. Among them, Fusarium wilt and black rot are prevalent in and around Mysore, Karnataka, India. Plant growth promoting bacteria (PGPR) in the rhizosphere, enhances plant growth by exerting their beneficial effects through metabolites that directly or indirectly influence the plant growth. In the present study, seven bacterial isolates were isolated from the rhizosphere soils of Cucurbitaceae crops near Mysore, India. The bacterial isolates were identified based on the morphological and biochemical tests. The root rot pathogen Fusarium oxysporum and black rot causing Phoma sp. were isolated from Cucurbitaceae crops. The antifungal activity of PGPR isolates against F. oxysporum and Phoma sp. was studied by dual culture assay. All the isolates were screened for their plant growth promoting traits such as phosphate solubilisation and ability to produce—indole acetic acid (IAA), siderophore, hydrogen cyanide (HCN) and enzymes. The PGPR strains showing more than two traits also showed good antifungal activity against F. oxysporum and Phoma sp. An increase in the growth rate accompanied by decreased disease intensity was noticed in the plants treated with selected PGPR

Assessment of heavy metal tolerance and biosorptive potential of Klebsiella variicola isolated from industrial effluents

Abstract Heavy metal contamination now a day is one of the major global environmental concerns. Textile effluents of Faisalabad Pakistan are heavily contaminated with heavy metals and demands to explore native microorganisms as effective bioremediation tool. Study aimed to isolate heavy metal tolerant bacteria from textile effluents of Faisalabad Pakistan and to evaluate their biosorptive potential. Out of 30 collected samples 13 isolates having metal tolerance potential against Ni and Co were screened out. Maximum tolerable concentration and multi metal resistance was determined. A native bacterial strain showing maximum tolerance to Ni and Co and multi metal resistance against Ni, Co and Cr at different levels was selected and named as Abuzar Microbiology 1 (AMIC1). Molecular characterization confirmed it as Klebsiella variicola which was submitted in First fungal culture bank of Pakistan (FCBP-WB-0688). ICP-OES revealed that it reduced Ni (50, 49%) and Co (71, 68.6%) after 24 and 48 h, respectively. FT-IR was used to analyze functional groups and overall nature of chemical bonds. Changes in spectra of biomass were observed after absorption of Ni and Co by K. variicola. SEM revealed morphological changes in bacteria in response to metal stress. Both metals affected bacterial cell wall and created pores in it. However effect of Ni was more pronounced than Co. It was concluded that K. variicola, a native novel strain possessed significant heavy metal tolerance and bioremediation potential against Ni and Co. It may be used in future for development of bioremediation agents to detoxify textile effluents at industrial surroundings