Effects of nano-TiO₂ on the agronomically-relevant Rhizobium-legume symbiosis.
The impact of nano-TiO₂ on Rhizobium-legume symbiosis was studied using garden peas and the compatible bacterial partner Rhizobium leguminosarum bv. viciae 3841. Exposure to nano-TiO₂ did not affect the germination of peas grown aseptically, nor did it impact the gross root structure. However, nano-TiO₂ exposure did impact plant development by decreasing the number of secondary lateral roots. Cultured R. leguminosarum bv. viciae 3841 was also impacted by exposure to nano-TiO₂, resulting in morphological changes to the bacterial cells. Moreover, the interaction between these two organisms was disrupted by nano-TiO₂ exposure, such that root nodule development and the subsequent onset of nitrogen fixation were delayed. Further, the polysaccharide composition of the walls of infected cells of nodules was altered, suggesting that the exposure induced a systemic response in host plants. Therefore, nano-TiO₂ contamination in the environment is potentially hazardous to the Rhizobium-legume symbiosis system.
Department of Civil and Environmental Engineering, University of Delaware, Newark, DE 19716, United States; Delaware Biotechnology Institute, Newark, DE 19711, United States.
Ruimei
R
Fan
Yu Chu
YC
Huang
Michael A
MA
Grusak
C P
CP
Huang
D Janine
DJ
Sherrier
D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000633:toxicity*; D009586:Nitrogen Fixation / Q000187:drug effects; D018532:Pisum sativum / Q000187:drug effects* / Q000502:physiology; D018517:Plant Roots / Q000187:drug effects / Q000382:microbiology / Q000502:physiology; D016961:Rhizobium leguminosarum / Q000187:drug effects* / Q000502:physiology; D058441:Rhizosphere; D012989:Soil Pollutants / Q000633:toxicity*; D013559:Symbiosis / Q000187:drug effects*; D014025:Titanium / Q000633:toxicity*
D012989:Soil Pollutants; C009495:titanium dioxide; D014025:Titanium
Nano-TiO(2); Nitrogen-fixing symbiosis; Pea; Rhizobium leguminosarum bv. viciae 3841; Toxicity