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Department of Biology

Faculty Haiping Cheng

E-mail address:
Phone Number: 718-960-7190
Office: Science Hall 3408 (Lab: Science Hall 3411, 718-960-7227)
Rank: Professor
Degrees and Sources of Degrees: B.A, M.A., Fudan Univ., China; Ph.D., Univ. of Mass., Amherst; Postdoc., Mass. Institute of Technology

Research Interests

We are currently focusing on a NIH-support research project that studies the molecular switch that controls the transformation of Gram negative bacterium Sinorhizobium meliloti from free living form to attached and invading form of cells. In the process, the production of flagella required for motility is shut down and the production exopolysaccharide succinoglycan is up-regulated. The presence of succinoglycan is essential for the invasion of plant host alfalfa by S. meliloti cells. The molecular switch consists of at least ExoR, ExoS, and ChvI proteins. ExoS is the periplasmic sensor of the ExoS/ChvI two-component regulatory system. ExoR functions in periplasm and forms ExoR-ExoS protein complex to regulated sensing activities of ExoS and indirectly regulates expression of hundreds of genes regulated by the ExoS/ChvI system. The expression of these hundreds of genes are likely required to the support either free living or invasion into its hosts.

ExoR, ExoS, and ChvI have been found in more than 100 different bacteria including animal and plant pathogens, and plant symbionts, suggesting they might be part of common molecular switch controling the transformation of bacterial cells from free living form to those invade and infect hosts.

The molecular control consist of ExoR, ExoS, and ChvI also plays an critial role the establishment of the nitrogen fixing symbiosis between Sinorhizobium meliloti and its plant host alfalfa, which is the long-term research project of the lab. The nitrogen fixing symbiosis is not only an excellent model system to study interorganismic signal exchanges but also represents an alternative approach to improving agriculture production while saving energy and improving environment.


  • Eliza M. Wiech, Hai-Ping Cheng, and Shaneen M. Singh. 2015 Computational analyses of the Sinorhizobium meliloti Rm1021 ExoR protein. Protein Chem. 24(3):319-327. [PDF]

  • Mary Ellen Heavner, Wei-Gang Qiu, and Hai-Ping Cheng. 2015 Phylogenetic Co-Occurrence of ExoR, ExoS, and ChvI, Components of the RSI Bacterial Invasion Switch, Suggests a Key Adaptive Mechanism Regulating the Transition between Free-Living and Host-Invading Phases in Rhizobiales. PLoS One. 2015  26;10(8):e0135655.  [PDF]

  • Myrthala M Verástegui-Valdés; Yu-Jing Zhang; Flor N Rivera-Orduña; Hai-Ping Cheng; Xin-Hua Sui; En-Tao Wang. 2014.  Microsymbionts of Phaseolus vulgaris in acid and alkaline soils of Mexico.  Systematic and Applied Microbiology. 37: 605-612.   [PDF]

  • Hai-Yang Lu, Li Luo, Meng-Hua Yang, and Hai-Ping Cheng. 2012. Sinorhizobium meliloti ExoR is the target of periplasmic proteolysis. J. Bacteriology. 194(15): 4029-4040 [PDF]

  • Hai-Yang Lu and Hai-Ping Cheng. 2010. Autoregulation of Sinorhizobium meliloti exoR gene expression. Microbiology 156: 2092-2101 [PDF]

  • Shi-Hua Shen, Feng Chi, Kuixian Ji, Yu-xiang Jing, Ming-Feng Yang, Hai-Ping Cheng, Frank B. Dazzo. 2010. New ecological dynamics of GFP-tagged rhizobia after inoculation of tobacco plants. Journal of Microbiology and Biotechnology, 20(2): 238-244 [PDF]

  • Ming-Sheng Qi, Li Luo, Hai-Ping Cheng, Jia-Bi Zhu, Guan-Qiao Yu. 2008. Characteristics of the LrhA subfamily of transcriptional regulators from Sinorhizobium meliloti. Acta Biochim Biophys Sin (Shanghai). 2008 Feb;40(2):166-73 [PDF]

  • Xue-Song Zhang and Hai-Ping Cheng. 2006. Identification of Sinorhizobium meliloti early symbiotic genes by use of a positive functional screen. Applied Environmental Microbiology. 72:2738-2748 [PDF]

  • Feng Chi, Shi-Hua Shen, Hai-Ping Cheng, Yu-Xiang Jing and Frank B. Dazzo. 2005. Ascending migration of endophytic rhizobia, from roots to leaves, inside rice plants and assessment of benefits to rice growth physiology. Applied Environmental Microbiology, 71:7271-7278 [PDF]

  • Li Luo, Shi-Yi Yao, Anke Becker, Silvia Ruberg, Guan-Qiao Yu, Jia-Bi Zhu, and Hai-Ping Cheng. 2005. Identification of two new Sinorhizobium meliloti lysR like transcriptional regulators required for nodulation. J. Bacteriology, 187: 4562-4572 [PDF]

  • Li Luo, Ming-Sheng Qi, Shi-Yi Yao, Hai-Ping Cheng, Jia-Bi Zhu, Shan-Jiong Shen, and Guan-Qiao Yu. 2005. Characterization of OxyR homolog from Sinorhizobium meliloti Rm1021 regulating the expression of catalase genes. Acta Biochimica et Biophysica Sinica, 37: 421-428 [PDF]

  • Shi-Yi Yao, Li Luo, Katherine Har, Anke Becker, Silvia Ruberg, Guan-Qiao Yu, Jia-Bi Zhu, and Hai-Ping Cheng. 2004. The Sinorhizobium meliloti ExoR and ExoS proteins regulate both succinoglycan and flagella production. J. Bacteriology, 186:6042-6049 [PDF]

  • Hai-Ping Cheng and Shi-Yi Yao. 2004. The promoters of the Sinorhizobium meliloti exoY gene and their expression during nodulation. FEMS. Microbiology Letters, 231:131-136 [PDF]

  • Brett Pellock, Hai-Ping Cheng, and Graham C. Walker. 2000. Alfalfa root nodule invasion efficiency is dependent on Sinorhizobium meliloti. J. Bacteriology, 182:4310-4318 [PDF]

  • Hai-Ping Cheng and Graham C. Walker. 1998. Succinoglycan production of Rhizobium meliloti 1021 is regulated by the ExoS/ChvI two-component regulatory system. J. Bacteriology. 180: 20-26 [PDF]

  • Hai-Ping Cheng and Graham C. Walker. 1998. Succinoglycan is required for the formation of infection threads during the nodulation of alfalfa by Rhizobium meliloti 1021. J. Bacteriology. 180: 5183-5191 [PDF]

  • Anke Becker, S. Ruber, H. Kuster, A.A. Roxlau, M. Keller, T. Ivashina, Hai-Ping Cheng, G.C. Walker, and A. Pulher. 1997. The 32-Kilobase exp gene cluster of Rhizobium meliloti directing the biosynthesis of galactoglucan: genetic organization and properties of the encoded gene products. J. Bacteriology. 179:1375-1384. [PDF]

  • Hai-Ping Cheng and Thomas G. Lessie. 1994. Multiple replicons constituting the genome of Pseudomonas cepacia 17616. J. Bacteriology.176:4034-4342 [PDF]

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