Size ofAT(n)Insertions in Promoter Region ModulatesGmhsp17.6-LmRNA Transcript Levels

Abstract

During earlier experiments, an SSR molecular marker (176 Soy HSP) showing high correlation (70%) with resistance/susceptibility to javanese root-knot nematodeMeloidogyne javanicawas identified in soybean. After being sequenced, results indicated that the SSR 176 Soy HSP marker was inserted in the promoter region ofGmhsp17.6-Lgene. It was also detected in this region that resistant genotypes presented insertions betweenAT(31)andAT(33)in size and susceptible genotypes,AT(9).Gmhsp17.6-Lgene coding region presented a perfect match in amino acid sequence in all soybean genotypes. A ribonuclease protection assay showed thatGmhsp17.6-Lgene mRNA transcripts were present in all genotypes. A real-time relative quantification (qPCR) indicated in the resistant individuals higher mRNA transcripts levels, which presented in the sequencing moreAT(n)insertions. These results suggest that the number ofAT(n)insertions inside this promoter region could modulate up or down gene levels. Those findings can lead to the possibility of manipulating, between some limits, the mRNA transcripts levels using different sizes ofAT(n)insertions.