Xinyu Li Ye Deng Qi Li Caiyan Lu Jingjing Wang Huiwen Zhang Jianguo Zhu Jizhong Zhou and Zhili He. Shifts of functional gene representation in wheat rhizosphere microbial communities under elevated ozone. The ISME Journal 2012 doi:10.1038-ismej.2012.120.

Abstract

Although the influence of ozone (O₃) on plants has been well studied in agroecosystems little is known about the effect of elevated O₃ (eO₃) on soil microbial functional communities. Here we used a comprehensive functional gene array (GeoChip 3.0) to investigate the functional composition and structure of rhizosphere microbial communities of Yannong 19 (O₃-sensitive) and Yangmai 16 (O₃-relatively sensitive) wheat (Triticum aestivum L.) cultivars under eO₃. Compared with ambient O₃ (aO₃) eO₃ led to an increase in soil pH and total carbon (C) percentages in grain and straw of wheat plants and reduced grain weight and soil dissolved organic carbon (DOC). Based on GeoChip hybridization signal intensities although the overall functional structure of rhizosphere microbial communities did not significantly change by eO₃ or cultivars the results showed that the abundance of specific functional genes involved in C fixation and degradation nitrogen (N) fixation and sulfite reduction did significantly (P<0.05) alter in response to eO₃ and-or wheat cultivars. Also Yannong 19 appeared to harbor microbial functional communities in the rhizosphere more sensitive in response to eO₃ than Yangmai 16. Additionally canonical correspondence analysis suggested that the functional structure of microbial community involved in C cycling was largely shaped by soil and plant properties including pH DOC microbial biomass C C-N ratio and grain weight. This study provides new insight into our understanding of the influence of eO₃ and wheat cultivars on soil microbial communities.