title: Novel Alleviation Mechanisms of Aluminum Phytotoxicity via Released Biosilicon from Rice Straw-Derived Biochars.
abstract: Replacing biosilicon and biocarbon in soil via biochar amendment is a novel approach for soil amelioration and pollution remediation. The unique roles of silicon (Si)-rich biochar in aluminum (Al) phytotoxicity alleviation have not been discovered. In this study, the alleviation of Al phytotoxicity to wheat plants (root tips cell death) by biochars fabricated from rice straw pyrolyzed at 400 and 700 °C (RS400 and RS700) and the feedstock (RS100) were studied using a slurry system containing typical acidic soils for a 15-day exposure experiment. The distributions of Al and Si in the slurry solution, soil and plant root tissue were monitored by staining methods, chemical extractions and SEM-EDS observations. We found that the biological sourced silicon in biochars served dual roles in Al phytotoxicity alleviation in acidic soil slurry. On one hand, the Si particles reduced the amount of soil exchangeable Al and prevented the migration of Al to the plant. More importantly, the Si released from biochars synchronously absorbed by the plants and coordinated with Al to form Al-Si compounds in the epidermis of wheat roots, which is a new mechanism for Al phytotoxicity alleviation in acidic soil slurry by biochar amendment. In addition, the steady release of Si from the rice straw-derived biochars was a sustainable Si source for aluminosilicate reconstruction in acidic soil.
authors.affiliation: Department of Environmental Science, Zhejiang University, Hangzhou 310058, China.|Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, Jiangsu Province, China.
authors.forename: Linbo
authors.initials: L
authors.lastname: Qian
authors.affiliation: Department of Environmental Science, Zhejiang University, Hangzhou 310058, China.|Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou 310058, China.
authors.forename: Baoliang
authors.initials: B
authors.lastname: Chen
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, Jiangsu Province, China.
authors.forename: Mengfang
authors.initials: M
authors.lastname: Chen
mesh_terms: D000535:Aluminum / Q000378:metabolism / Q000633:toxicity*; D002606:Charcoal; D008855:Microscopy, Electron, Scanning; D012275:Oryza / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects; D012825:Silicon / Q000378:metabolism*; D012989:Soil Pollutants / Q000378:metabolism / Q000633:toxicity*; D013052:Spectrometry, X-Ray Emission
chemical_list: D012989:Soil Pollutants; C540010:biochar; D002606:Charcoal; D000535:Aluminum; D012825:Silicon