title: Silicon-mediated alleviation of Cr(VI) toxicity in wheat seedlings as evidenced by chlorophyll florescence, laser induced breakdown spectroscopy and anatomical changes.
abstract: Silicon (Si)-mediated alleviation of Cr(VI) toxicity was examined in wheat seedlings using an in vivo approach that involves chlorophyll fluorescence, laser induced breakdown spectroscopy (LIBS) and anatomical changes. Exposure to Cr(VI) significantly reduced the growth and photosynthetic activities (chlorophyll fluorescence) in wheat which was accompanied by remarkable accumulation of this element in tissues. However, addition of Si to the growth medium alleviated the effects of Cr(VI). The LIBS spectra were used as a fingerprint of the elemental compositions in wheat seedlings, which showed a reduction in Cr accumulation following Si addition. Nutrient element levels (Ca, Mg, K and Na) declined in wheat following the addition of Cr (VI), as recorded by LIBS and inductively coupled plasma atomic emission spectroscopy (ICAP-AES). However, addition of Si along with Cr(VI) increased the contents of nutrient elements in wheat. LIBS, ICAP-AES and AAS showed a similar distribution pattern of elements measured in wheat. Anatomical observations of leaf and root revealed that Cr(VI) affected internal structures while Si played a role in protection from toxic effects. The results showed the suitability of chlorophyll fluorescence as a parameter and appropriateness of LIBS technique and anatomical procedures to elucidate Si-mediated alleviation of Cr(VI) toxicity. Furthermore, our results suggest that the measured parameters and techniques can be used non-invasively for monitoring the growth of crops under different environmental conditions.
authors.affiliation: Center of Advance Studies, Department of Botany, Banaras Hindu University, Varanasi 221005, India. Electronic address: dktripathiau@gmail.com.
authors.forename: Durgesh Kumar
authors.initials: DK
authors.lastname: Tripathi
authors.affiliation: Govt. RamanujPratap Singhdev Post Graduate College, Baikunthpur, Korea-497335, Chhattisgarh, India. Electronic address: vijaypratap.au@gmail.com.
authors.forename: Vijay Pratap
authors.initials: VP
authors.lastname: Singh
authors.affiliation: Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of Allahabad, Allahabad 211002, India. Electronic address: profsmprasad@gmail.com.
authors.forename: Sheo Mohan
authors.initials: SM
authors.lastname: Prasad
authors.affiliation: D.D. Pant Interdisciplinary Research Laboratory, Department of Botany, University of Allahabad, Allahabad 211002, India. Electronic address: dkchauhanau@yahoo.com.
authors.forename: Devendra Kumar
authors.initials: DK
authors.lastname: Chauhan
authors.affiliation: Center of Advance Studies, Department of Botany, Banaras Hindu University, Varanasi 221005, India. Electronic address: nkdubeybhu@gmail.com.
authors.forename: Nawal
authors.initials: N
authors.lastname: Kishore Dubey
authors.affiliation: Laser Spectroscopy Research Lab, Department of Physics, University of Allahabad, Allahabad, India. Electronic address: awadheshkrai@rediffmail.com.
authors.forename: Awadhesh Kumar
authors.initials: AK
authors.lastname: Rai
mesh_terms: D002734:Chlorophyll / Q000737:chemistry / Q000378:metabolism; D002857:Chromium / Q000378:metabolism / Q000633:toxicity*; D004347:Drug Interactions; D004785:Environmental Pollutants / Q000633:toxicity*; D007834:Lasers; D010788:Photosynthesis / Q000187:drug effects; D018515:Plant Leaves / Q000033:anatomy & histology / Q000187:drug effects; D018517:Plant Roots / Q000033:anatomy & histology / Q000187:drug effects; D036226:Seedlings / Q000033:anatomy & histology / Q000187:drug effects / Q000378:metabolism; D012825:Silicon / Q000378:metabolism / Q000494:pharmacology*; D013054:Spectrophotometry, Atomic; D013057:Spectrum Analysis / Q000295:instrumentation; D014908:Triticum / Q000033:anatomy & histology / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism
chemical_list: D004785:Environmental Pollutants; D002857:Chromium; D002734:Chlorophyll; C074702:chromium hexavalent ion; D012825:Silicon
keywords: Anatomy; Chlorophyll fluorescence; Chromium toxicity; ICAP-AES; LIBS; Silicon