naa a22 4500 510788335 CHVBK 20180411083310.0 cr unu---uuuuu 180411e20130101xx s 000 0 eng 10.1007/s12298-012-0138-2 doi (NATIONALLICENCE)springer-10.1007/s12298-012-0138-2 Perspectives of genomic diversification and molecular recombination towards R -gene evolution in plants [Elektronische Daten] [Raj Joshi, Sanghamitra Nayak] Plants are under strong evolutionary pressure in developing new and noble R genes to recognize pathogen avirulence (avr) determinants and bring about stable defense for generation after generations. Duplication, sequence variation by mutation, disparity in the length and structure of leucine rich repeats etc., causes tremendous variations within and among R genes in a plant thereby developing diverse recognitional specificity suitable enough for defense against new pathogens. Recent studies on genome sequencing, diversity and population genetics in different plants have thrown new insights on the molecular evolution of these genes. Tandem and segmental duplication are important factors in R gene abundance as inferred from the distribution of major nucleotide binding site-leucine rich repeats (NBS-LRRs) type R-genes in plant genomes. Likewise, R-gene evolution is also thought to be facilitated by cluster formation thereby causing recombination and sequence exchange and resulting in haplotypic diversity. Population studies have further proven that balancing selection is responsible for the maintenance of allelic diversity in R genes. In this review, we emphasize and discuss on improved perspectives towards the molecular mechanisms and selection pressure responsible for the evolution of NBS-LRR class resistance genes in plants. Prof. H.S. Srivastava Foundation for Science and Society, 2012 R -genes nationallicence NBS-LRRs nationallicence Evolution nationallicence Diversification nationallicence Duplication nationallicence R-genes : Resistance genes nationallicence NBS : Nucleotide binding site nationallicence LRR : Leucine rich repeats nationallicence CNL : Coiled coil NBS-LRR nationallicence TNL : Toll interleukin-1 receptor NBS-LRR nationallicence Joshi Raj Centre of Biotechnology, Siksha O Anusandhan University, 751003, Bhubaneswar, India aut Nayak Sanghamitra Centre of Biotechnology, Siksha O Anusandhan University, 751003, Bhubaneswar, India aut Physiology and Molecular Biology of Plants Springer-Verlag 19/1(2013-01-01), 1-9 0971-5894 19:1<1 2013 19 12298 https://doi.org/10.1007/s12298-012-0138-2 text/html Onlinezugriff via DOI 1 review-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s12298-012-0138-2 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Joshi Raj Centre of Biotechnology, Siksha O Anusandhan University, 751003, Bhubaneswar, India aut NATIONALLICENCE 700 1- Nayak Sanghamitra Centre of Biotechnology, Siksha O Anusandhan University, 751003, Bhubaneswar, India aut NATIONALLICENCE 773 0- Physiology and Molecular Biology of Plants Springer-Verlag 19/1(2013-01-01), 1-9 0971-5894 19:1<1 2013 19 12298 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer