Figure 4

Volcano plot depicting DEGs obtained using P. fastigiatum full-lengths ESTs as a reference for tag mapping (P0). 1,239 and 1,039 genes were determined as differentially expressed in P. enysii (circles) and P. fastigiatum (triangles), respectively. Log fold ratios >28 and < −28 indicate genes with zero tags in either of both species whereas log fold ratios between −10 and 10 indicates genes with tags present in both species but differing in abundance. Five glucosinolate metabolism loci show similar up-regulation as in a previous microarray analysis [12] in P. enysii (AT1G54040, AT2G43100, AT5G23010, AT5G14200, AT5G57220; filled circles) as well as two loci in P. fastigiatum (AT3G14210, AT1G54030; filled triangles). Thus conclusions drawn from microarray analyses regarding glucosinolate phenotypes (AT1G54040 - ESP up-regulation indicates that P. enysii produces nitriles; AT3G14210 - ESM1 up-regulation indicates that P. fastigiatum produces isothiocyanates; AT5G23010, AT2G43100, AT5G14200 - up-regulation of methylthioalkylmalate synthase 1, methylthioalkylmalate isomerase, methylthioalkylmalate dehydrogenase indicates that P. enysii produces C4 glucosinolates) can be equally drawn from this tag profiling study. Eight additional loci involved in glucosinolate metabolism could be identified for P. enysii (AT5G26000, AT3G19710, AT2G20610, AT1G62560, AT5G48180, AT1G18590, AT5G07690, AT5G61210; empty circles) and five for P. fastigiatum (AT3G14220, AT1G62540, AT5G23020, AT4G13770, AT5G60890; empty triangles).