Regulatory motifs found in the small heat shock protein (sHSP) gene family in tomato

ARCE, DEBORA; SPETALE, FLAVIO; KRSTICEVIC, FLAVIA; CACCHIARELLI, PAOLO; DE LAS RIVAS, JAVIER; PONCE, SERGIO; PRATTA, GUILLERMO; TAPIA, ELIZABETH

BMC GENOMICS

BIOMED CENTRAL LTD

Lugar: Londres; Año: 2018 vol. 19

1471-2164

Background:Inliving organisms, small heat shock proteins (sHSPs) are triggered inresponse to stress situations. This family of proteins is large inplants and, in the case of tomato (Solanum lycopersicum), 33 geneshave been identified, most of them related to heat stress responseand to the ripening process. Transcriptomic and proteomic studieshave revealedcomplex patterns of expression for these genes. In this work, weinvestigate the coregulation of these genes by performing acomputational analysis of their promoter architecture to findregulatory motifs known as heat shock elements (HSEs). We leveragethe presence of sHSP members that originated from tandem duplicationevents and analyze the promoter architecture diversity of the wholesHSP family, focusing on the identification of HSEs.Results:Weperformed a search for conserved genomic sequences in the promoterregions of the sHSPs of tomato, plus several other proteins (mainlyHSPs) that are functionally related to heat stress situations or toripening. Several computational analyses were performed to buildmultiple sequence motifs and identify transcription factor binding sites(TFBS) homologous to HSF1AE and HSF21 in Arabidopsis. We alsoinvestigated the expression and interaction of these proteins undertwo heat stress situations in whole tomato plants and in protoplastcells, both in the presence and in the absence of heat shocktranscription factor A2 (HsfA2). The results of these analysesindicate that different sHSPs are up-regulated depending on theactivation or repression of HsfA2, a key regulator of HSPs. Further,the analysisof protein-protein interaction between the sHSP protein family andother heat shock response proteins (Hsp70, Hsp90 and MBF1c) suggeststhat several sHSPs are mediating alternative stress response througha regulatory subnetwork that is not dependent on HsfA2.Conclusions:Overall,this study identifies two regulatory motifs (HSF1AE and HSF21)associated with the sHSP family in tomato which are consideredgenomic HSEs. The study also suggests that, despite the apparentredundancy of these proteins, which has been linked to geneduplication, tomato sHSPs showed different up-regulation and differentinteraction patterns when analyzed under different stress situationsp { margin-bottom: 0.21cm; }p.western { }p.cjk { font-family: "Times New Roman", serif; }p.ctl { font-family: "Times New Roman", serif; }a:link { color: rgb(0, 0, 255); }