Physical mapping of resistant and susceptible soybean genomes near the soybean cyst nematode resistance gene Rhg₄

Abstract

The soybean cyst nematode (SCN), Heterodera glycines Ichinohe, is the foremost pest of soybean (Glycine max L. Merr.). The rhg1 allele on linkage group (LG) G and the Rhg4 allele on LG A2 are important in conditioning resistance. Markers closely linked to the Rhg4 locus were used previously to screen a library of bacterial artificial chromosome (BAC) clones from susceptible 'Williams 82' and identified a single 150-kb BAC, Gm_ISb001_056_G02 (56G2). End-sequenced subclones positioned onto a restriction map provided landmarks for identifying the corresponding region from a BAC library from accession PI 437654 with broad resistance to SCN. Seventy-three PI 437654 BACs were assigned to contigs based upon HindIII restriction fragment profiles. Four contigs represented the PI 437654 counterpart of the 'Williams 82' BAC, with PCR assays connecting these contigs. Some of the markers on the PI 437654 contigs are separated by a greater physical distance than in the 'Williams 82' BAC and some primers amplify bands from BACs in the mid-portion of the connected PI 437654 BAC contigs that are not amplified from the 'Williams 82' BAC. These observations suggest that there is an insertion in the PI 437654 genome relative to the 'Williams 82' genome in the Rhg4 region.

The TMK Subfamily of Receptor-Like Kinases in Arabidopsis Display an Essential Role in Growth and a Reduced Sensitivity to Auxin

“…1A). Several orthologous sequences are present in rice ( Os ) [26], tobacco ( Nt ) [27] and soybean RHG4 [28], indicating potential roles for the TMK subfamily in both dicot and monocot species (Fig. 1A).…”

Engineered resistance and hypersusceptibility through functional metabolic studies of 100 genes in soybean to its major pathogen, the soybean cyst nematode

“…Rao-Arelli et al (1992) demonstrated that Peking and PI 90763, resistant to SCN race 3, had three genes in common, one of which was Rhg4 . The Rhg4 gene was mapped to linkage group A2 using molecular markers (Weisemann et al 1992; Matthews et al 1998; Cregan et al 1999; Qui et al 2003); then it was physically mapped using BAC libraries by Lewers et al 2001; 2002). TILLING experiments demonstrated that resistance is not conferred by the gene encoding an LRR-RLK that resides in the region (Liu et al 2011).…”

Achievement, Challenge and Future Perspective of BAC Library Technology with a Focus on its Application to Soybean Genomics Researches

“…In 1999 Tomkins et al, made a soybean BAC library using the plant introduction (PI) 437654 with 9 haploid genome equivalents for studying soybean cyst nematode (SCN) resistance genes [12]. In 2001 Lewerset et al, built a physical mapping of resistant and susceptible soybean genomes near the soybean cyst nematode resistance gene Rhg 4 , which has contribute the successful cloning of this gene [33,34]. Xia et al, constructed 53,760 clones with an average insert size of 116 kb for a Japanese cultivar, Misuzudaizu.…”