Abstract Detail

Phylogenomics

Andersen, Ethan [4], Nepal, Madhav P. [1], Reese, R. Neil [2], Ali, Shaukat [3], Neupane, Surendra [4].

Evolutionary Divergence of Disease Resistance Genes in Six Monocot Species.

Disease resistance genes (R-genes) in plants encode important receptor proteins that are an integral part of the plants’ defense against pathogens. The main objectives of this study were to 1) identify R-genes in six monocot species (Aegilops tauschii, Triticum urartu, barley, foxtail millet, wheat, and banana), and 2) elucidate their evolutionary divergence. We performed a Hidden Markov Model (HMM) search for CNL members of the R- genes in each of the six genomes and analyzed conserved motifs within the NB-ARC region, namely the P-Loop, Kinase-2, and GLPL motifs. Phylogenetic analyses were performed to study their evolutionary relationships within and between genomes and structural variation and chromosomal clustering were visualized. The A. tauschii and T. urartu genomes were closely compared to wheat, since they are likely the contributors of the wheat D and A genomes, respectively. We identified 442, 334, 175, 242, 618, and 55 CNL genes in Aegilops tauschii, Triticum urartu, barley, foxtail millet, wheat, and banana, respectively. Of the four clades (A-D) initially reported in Arabidopsis thaliana, our data shows that monocot genomes have retained clade C, with reduction in clades A, B, and complete loss of clade D. Many instances of likely tandem duplication and chromosomal clustering were found. A prevalence of purifying selection was also seen, which has been shown in domesticated species. Characterization of the candidate R-genes involved in stem and leaf rust diseases is underway. Implications will include not limited to better understanding of evolutionary pressure of the gene families and application in crop improvement with durable resistance.

Related Links:
SDSU Nepal Lab

1 - South Dakota State University, Biology And Microbiology, Northern Plain Biostress Laboratory, Brookings, SD, 57007, USA
2 - South Dakota State University, Bio/Micro, SNP 249B, Box 2140D, Brookings, SD, 57007, USA
3 - South Dakota State University, Plant Science, Brookings, SD, 57007
4 - South Dakota State University , Biology and Microbiology , Edgar S. McFadden Biostress Laboratory , Brookings , SD, 57007

Keywords:
Disease Resistance Genes 
NBS-LRR
Purifying Selection
Durable Resistance 
Monocot Genomes .

Presentation Type: Poster
Session: P, Phylogenomics Posters
Location: Exhibit Hall/Savannah International Trade and Convention Center
Date: Monday, August 1st, 2016
Time: 5:30 PM This poster will be presented at 6:15 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PPY008
Abstract ID:551
Candidate for Awards:Genetics Section Poster Award