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Selected Development Project
Project Title

Effects of Rhizobacteria on the Tolerance, Uptake and Speciation of Arsenic in Rice

Principal Investigator Dr LI Wai Chin
Area of Research Project
Science and Environmental Studies
Project Period
From 01/2015 To 12/2017
  • Investigate the effects of isolated As-tolerant plant growth-promoting rhizobacteria (PGPR) on rice growth and their plant growth promoting mechanisms
  • Examine the effects of PGPR on As uptake, accumulation and speciation in rice
  • Investigate the effects of Fe-oxidising bacteria (FeOB) on Fe plaque formation on rice roots and accumulation of As in rice
  • Explore the feasibility of combing rhizobacteria (PGPR and FeOB) to enhance the As tolerance of rice and reduce As accumulation in rice grains
Methods Used
  • Isolation of As tolerant PGPR and FeOB
  • Uptake kinetics, accumulation and transformation of different species of As in rice with PGPR
  • Effects of FeOB on accumulation of As in rice and induced Fe plaque formation on rice roots
  • Effects of combining PGPR and FeOB on As tolerance, accumulation and speciation in rice - field trial
Summary of Findings
  • Rhizobacteria from As contaminated sites exhibit high metal tolerance
  • Rhizobacteria influence the uptake, accumulation and speciation of As in rice
  • Microbially induced Fe oxidation contributes to the precipitation of Fe oxides that
  • Function as a barrier to sequester As on the root surface
  • The results of this study will contribute to the understanding of the mechanisms of As uptake in rice
  • A better understanding of the interactions amongst plant-toxic metal/loids-rhizobacteria can then be achieved.
  • The findings are expected to be of critical importance in setting the directions for the development of practical mitigation measures of As accumulation in rice to minimize health risks in food production and maintain good yields even in contaminated paddy fields.
Selected Publications Related to the Study
  1. Li WC*, Chow CF. 2017. Adverse child health impacts resulting from food adulterations in the Greater China Region. Journal of the Science of Food and Agriculture (Accepted)
  2. He HD, Li WC*, Yu RQ, Ye ZH. 2017. Illumina-based Analysis of Bulk and Rhizosphere Soil Bacteria Communities in Rice Paddy Fields under the Influence of Mixed Heavy Metal Contamination. Pedosphere (accepted)
  3. Xiao AW, Ouyang Y, Li WC*, Ye ZH*. 2017. Effect of organic manure on Cd and As accumulation in brown rice and grain yield in Cd-As-contaminated paddy fields. Environ Sci Pollut Res 24(10): 9111–9121
  4. He HD, Tam NFY, Yao AJ, Qiu RL, Li WC, Ye ZH*. 2016. Effects of alkaline and bioorganic amendments on Cd, Pb, Zn, and nutrient accumulation in brown rice and grain yield in acidic paddy fields contaminated with a mixture of heavy metals. Environ Sci Pollut Res 23(23), 23551-23560
  5. Li WC*, Tse H F. 2015. Health risk and significance of mercury in the environment. Environ Sci Pollut R 22(1), 192-201.
  6. Li WC, Deng H, Wong MH. 2015. Metal solubility and speciation under the influence of waterlogged condition and the presence of wetland plants. Geoderma 270: 98-108
  7. Li WC*, Law FY, Chan YHM. 2015. Biosorption studies on copper (II) and cadmium (II) using pretreated rice straw and rice husk. Environ Sci Pollut Res 24(10): 8903-8915
  8. Chan WF, Li WC, Wong MH. 2015. The Uptake Kinetics of Arsenic in Upland Rice Cultivar Zhonghan 221 Inoculated with Arbuscular Mycorrhizal Fungi. Int J Phytoremediation 17(11):1073-80
  9. Li WC, Ouyang Y, Ye ZH. 2014. Accumulation of Hg and Cd in rice from paddy soil near a Hg mine. Environ Toxicol Chem 33(11):2438-47.
Biography of Principal Investigator

Dr Li received his B. Sc. in Applied Biology (Major in Environmental Science) and Ph.D. from Hong Kong Baptist University. After graduation, he was a lecturer and course coordinator at Hong Kong Baptist University during 2007-2012. Currently he is working as an Assistant Professor in the Department of Science and Environmental Studies, Faculty of Liberal Arts and Social Sciences, Education University of Hong Kong. Dr Li’s current research mainly focuses on soil pollution.

Funding Source

Early Career Scheme