RT Journal Article
SR Electronic
T1 Comparative analysis highlights variable genome content of wheat rusts and divergence of the mating loci
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 060665
DO 10.1101/060665
A1 Christina A. Cuomo
A1 Guus Bakkeren
A1 Hala Badr Khalil
A1 Vinay Panwar
A1 David Joly
A1 Rob Linning
A1 Sharadha Sakthikumar
A1 Xiao Song
A1 Xian Adiconis
A1 Lin Fan
A1 Jonathan M. Goldberg
A1 Joshua Z. Levin
A1 Sarah Young
A1 Qiandong Zeng
A1 Yehoshua Anikster
A1 Myron Bruce
A1 Meinan Wang
A1 Chuntao Yin
A1 Brent McCallum
A1 Les J. Szabo
A1 Scot Hulbert
A1 Xianming Chen
A1 John P. Fellers
YR 2016
UL http://biorxiv.org/content/early/2016/06/24/060665.abstract
AB Three members of the Puccini genus, P. triticina (Pt), P. striiformis f.sp. tritici(Pst), and P. graminis f.sp. tritici (Pgt), cause the most common and often most significant foliar diseases of wheat. While similar in biology and life cycle, each species is uniquely adapted and specialized. The genomes of Pt and Pst were sequenced and compared to that of Pgt to identify common and distinguishing gene content, to determine gene variation among wheat rust pathogens, other rust fungi and basidiomycetes, and to identify genes of significance for infection. Pt had the largest genome of the three, estimated at 135 Mb with expansion due to mobile elements and repeats encompassing 50.9% of contig bases; by comparison repeats occupy 31.5% for Pst and 36.5% for Pgt. We find all three genomes are highly heterozygous, with Pst (5.97 SNPs/kb) nearly twice the level detected in Pt (2.57 SNPs/kb) and that previously reported for Pgt. Of 1,358 predicted effectors in Pt, 784 were found expressed across diverse life cycle stages including the sexual stage. Comparison to related fungi highlighted the expansion of gene families involved in transcriptional regulation and nucleotide binding, protein modification, and carbohydrate enzyme degradation. Two allelic homeodomain, HD1 and HD2, pairs and three pheromone receptor (STE3) mating-type genes were identified in each dikaryotic Puccinia species. The HD proteins were active in a heterologous Ustilago maydis mating assay and host induced gene silencing of the HD and STE3 alleles reduced wheat host infection.