Bioinformatics and Biotechnology

Electronic Journal of Biotechnology ISSN: 0717-3458 Vol. 11 No. 4, Issue of October 15, 2008
© 2008 by Pontificia Universidad Católica de Valparaíso -- Chile Received March 4, 2008 / Accepted August 20, 2008
DOI: 10.2225/vol11-issue4-fulltext-11

Cloning and characterization of resistance gene analogs from under-exploited plant species

Ramasubramanian Thirumalaiandi
Division of Crop Protection
Central Research Institute for Jute and Allied Fibres
Indian Council of Agricultural Research
Barrackpore, Kolkata, 700 120, India
Tel: 91 33 2535 6121/6122. Ext. 220
Fax: 91 33 25350415

Michael Gomez Selvaraj
Department of Plant and Soil Science
Texas Tech University
Texas, USA
Tel: 8067466101
Fax: 8067466528

Raghu Rajasekaran
Dipartimento di Scienze del Mare
Università Politecnica delle Marche
60131 Ancona, Italy
Tel: 39 071 220 4659
Fax: 39 71 220 4650

Mohankumar Subbarayalu*#
Department of Plant Molecular Biology and Biotechnology
Centre for Plant Molecular Biology
Tamil Nadu Agricultural University
Coimbatore, 641 003, Tamil Nadu, India
Fax: 91-4222431672

*Corresponding author

Keywords: Adenanthera pavonina, Clitoria ternatea, NBS-LRR, Pongamia glabra, resistance gene analogs; solanum trilobatum.

Present addresses:  #Agricultural Research Station, Vaigaidam, Tel: 91-4546244112.


RGAs: resistance gene analogs
R-genes: resistance genes

Abstract   Full Text

Genomic DNA sequences sharing homology with NBS region of resistance gene analogs were isolated and characterized from Pongamia glabra, Adenanthera pavonina, Clitoria ternatea and Solanum trilobatum using PCR based approach with primers designed from conserved regions of NBS domain. The presence of consensus motifs viz., kinase 1a, kinase 2, kinase 3a and hydrophobic domain provided evidence that the cloned sequences may belong to the NBS-LRR gene family. Conservation of tryptophan as the last residue of kinase-2 motif further confirms their position in non-TIR NBS-LRR family of resistance genes. The Resistance Gene Analogs (RGAs) cloned from P. glabra, A. pavonina, C. ternatea and S. trilobatum clustered together with well- characterized non-TIR-NBS-LRR genes leaving the TIR-NBS-LRR genes as a separate cluster in the average distance tree constructed based on BLOSUM62. All the four RGAs had high level of identity with NBS-LRR family of RGAs deposited in the GenBank. The extent of identity between the sequences at NBS region varied from 29% (P. glabra and S. trilobatum) to 78% (A. pavonina and C. ternatea), which indicates the diversity among the RGAs.

Supported by UNESCO / MIRCEN network