The plasticity of NBS resistance genes in sorghum is driven by multiple evolutionary processes

BMC Plant Biology

Research Article

Shuaishuai Tai¹  Wushu Hu¹  Jun Wang²  Bradley Campbell³  David Innes³  Emma Mace⁴  Alan Cruickshank⁴  David Jordan⁵  Peter Prentis⁶  Ian Godwin⁷  Edward Gilding⁸ 

[1] BGI-Shenzhen, Shenzhen, China;BGI-Shenzhen, Shenzhen, China;Department of Biology, University of Copenhagen, DK-2200, Copenhagen, Denmark;The Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, DK-2200, Copenhagen, Denmark;Cooper’s Plains, DAFFQ, Brisbane, QLD, Australia;Department of Agriculture, Fisheries & Forestry (DAFF), Warwick, QLD, Australia;Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Warwick, QLD, Australia;Queensland University of Technology, Brisbane, QLD, Australia;School of Agriculture and Food Sciences, The University of Queensland, Brisbane, QLD, Australia;The Institute of Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia;

关键词: Cereals;    Disease resistance;    Domestication;    Maize;    NBS-LRR genes;    QTL;    Rice;    Selection;    Sorghum;   

DOI  :  10.1186/s12870-014-0253-z

 received in 2014-04-23, accepted in 2014-09-20,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundIncreased disease resistance is a key target of cereal breeding programs, with disease outbreaks continuing to threaten global food production, particularly in Africa. Of the disease resistance gene families, the nucleotide-binding site plus leucine-rich repeat (NBS-LRR) family is the most prevalent and ancient and is also one of the largest gene families known in plants. The sequence diversity in NBS-encoding genes was explored in sorghum, a critical food staple in Africa, with comparisons to rice and maize and with comparisons to fungal pathogen resistance QTL.ResultsIn sorghum, NBS-encoding genes had significantly higher diversity in comparison to non NBS-encoding genes and were significantly enriched in regions of the genome under purifying and balancing selection, both through domestication and improvement. Ancestral genes, pre-dating species divergence, were more abundant in regions with signatures of selection than in regions not under selection. Sorghum NBS-encoding genes were also significantly enriched in the regions of the genome containing fungal pathogen disease resistance QTL; with the diversity of the NBS-encoding genes influenced by the type of co-locating biotic stress resistance QTL.ConclusionsNBS-encoding genes are under strong selection pressure in sorghum, through the contrasting evolutionary processes of purifying and balancing selection. Such contrasting evolutionary processes have impacted ancestral genes more than species-specific genes. Fungal disease resistance hot-spots in the genome, with resistance against multiple pathogens, provides further insight into the mechanisms that cereals use in the “arms race” with rapidly evolving pathogens in addition to providing plant breeders with selection targets for fast-tracking the development of high performing varieties with more durable pathogen resistance.

【 授权许可】

CC BY   
© Mace et al.; licensee BioMed Central Ltd. 2014