Fast neutron-induced structural rearrangements at a soybean NAP1 locus result in gnarled trichomes.
Three adjacent and distinct sequence rearrangements were identified at a NAP1 locus in a soybean mutant. Genetic dissection and validation revealed the function of this gene in soybean trichome development. A soybean (Glycine max (L.) Merr.) gnarled trichome mutant, exhibiting stunted trichomes compared to wild-type, was identified in a fast neutron mutant population. Genetic mapping using whole genome sequencing-based bulked segregant analysis identified a 26.6 megabase interval on chromosome 20 that co-segregated with the phenotype. Comparative genomic hybridization analysis of the mutant indicated that the chromosome 20 interval included a small structural variant within the coding region of a soybean ortholog (Glyma.20G019300) of Arabidopsis Nck-Associated Protein 1 (NAP1), a regulator of actin nucleation during trichome morphogenesis. Sequence analysis of the candidate allele revealed multiple rearrangements within the coding region, including two deletions (approximately 1-2 kb each), a translocation, and an inversion. Further analyses revealed that the mutant allele perfectly co-segregated with the phenotype, and a wild-type soybean NAP1 transgene functionally complemented an Arabidopsis nap1 mutant. In addition, mapping and exon sequencing of NAP1 in a spontaneous soybean gnarled trichome mutant (T31) identified a frame shift mutation resulting in a truncation of the coding region. These data indicate that the soybean NAP1 gene is essential for proper trichome development and show the utility of the soybean fast neutron population for forward genetic approaches for identifying genes.
Department of Agronomy and Plant Genetics, University of Minnesota, Saint Paul, MN, 55108, USA.
Benjamin W
BW
Campbell
Department of Agronomy and Plant Genetics, University of Minnesota, Saint Paul, MN, 55108, USA.
Anna N
AN
Hofstad
Department of Agronomy and Plant Genetics, University of Minnesota, Saint Paul, MN, 55108, USA.
Suma
S
Sreekanta
Department of Agronomy and Plant Genetics, University of Minnesota, Saint Paul, MN, 55108, USA.
Fengli
F
Fu
Department of Agronomy and Plant Genetics, University of Minnesota, Saint Paul, MN, 55108, USA.
Thomas J Y
TJ
Kono
USDA-ARS, Corn Insects and Crop Genetics Research, Iowa State University, Ames, IA, 50011, USA.
Jamie A
JA
O'Rourke
Department of Agronomy and Plant Genetics, University of Minnesota, Saint Paul, MN, 55108, USA.
Carroll P
CP
Vance
Department of Agronomy and Plant Genetics, University of Minnesota, Saint Paul, MN, 55108, USA.|Department of Plant Biology, University of Minnesota, Saint Paul, MN, 55108, USA.
Gary J
GJ
Muehlbauer
Department of Agronomy and Plant Genetics, University of Minnesota, Saint Paul, MN, 55108, USA. stup0004@umn.edu.
Robert M
RM
Stupar
D000483:Alleles; D017360:Arabidopsis / Q000235:genetics; D002874:Chromosome Mapping; D055028:Comparative Genomic Hybridization; D005214:Fast Neutrons; D017343:Genes, Plant; D005838:Genotype; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics*; D030821:Plants, Genetically Modified / Q000235:genetics; D018749:RNA, Plant / Q000235:genetics; D017423:Sequence Analysis, RNA; D017384:Sequence Deletion; D013025:Glycine max / Q000235:genetics* / Q000254:growth & development; D064201:Trichomes / Q000254:growth & development*
D010940:Plant Proteins; D018749:RNA, Plant