Journal of Pure and Applied MicrobiologyVol. 9 No. Special Edition May. 2015

Morphological and Lethal Effects of D-Leu on the Xanthomonas citri subsp. citri

Yulong Chen1, Zhongkang Wang1, Zhenji Wang2, Qinyan Xia1 and Youping Yin1*

1Genetic Engineering Research Center, School of Life Science, Chongqing University, Chongqing, 400030, China. 2Department of Chemistry and Life Science, Chuxiong Normal University, Chuxiong, 675000, China.

Received on 19 March 2015 and accepted on 07 May 2015

 

ABSTRACT

D-amino acids exist in many bacteria, fungi and insects, but little investigation into their function has been performed. In this study, we determined the antibacterial effect of D-Leu on Xanthomonas citri subsp. citri (Xcc), a plant pathogen that is extremely detrimental to the production of Citrus fruit. Our results showed that 2 mM D-Leu morphologically altered Xcc strain 101 from rod to chain form and 7 mM D-Leu caused Xcc strain 101 to lose pathogenicity and/or die. Electro-microscopic examination revealed that the bacterial chain was formed by many bacteria own some cell membrane, and the cellular membrane broken and protoplasm prolapse out. This discovery has the potential to provide a new preventative strategy against bacterial diseases of plants and to screen for biocontrol bacteria.

Keywords : D-amino acids; plant pathogenic bacteria;  morphological change; killing effect;Xanthomonas citri subsp. Citri