Biologist Posgrado en Ciencias Biológicas, Instituto de Biología, Universidad Nacional Autónoma de México Coyoacan, Distrito Federal, Mexico
Body of Abstract: PLETHORA (PLT) genes are a part of the AP2/ERP family. The six PLT genes that have been described in Arabidopsis thaliana code for transcription factors which play a key role in root development regulating processes like rhizotaxis and the maintenance of the root apical meristem. Although various hypotheses have been proposed regarding what the effects of changes in the number of homologues, copies, and structure of these genes may be, studies have centered in A. thaliana. We worked with the molecular isolation of the putative homologues of the PLT genes in Mammillaria san-angelensis (the San Angel pincushion cactus), to set the foundations towards the comprehensive study of the role of PLT homologues in this non-model organism. The genome of M. san-angelensis was sequenced, then a bioinformatic pipeline was stablished trough which we were able to isolate 19 candidate sequences. We took those sequences, as well as the putative homologues to the A. thaliana PLTs that could be found in S. undatus (Cactaceae), Pachycereus pringlei (Cactaceae) and Beta vulgaris (Amaranthaceae), and used them to build gene trees. After discarding repeated sequences, we were able to identify the M. san angelensis homologues to PLT1, PLT2, PLT3, PLT5, and PLT7. Using primers designed for these sequences we were able to amplify by PCR 4 of these genes from M. san-angelensis gDNA and a total of 11 genes from cDNA belonging to different species of the Mammillaria genus. We hypothesize that the absence of a PLT4 homologue in M. san-angelensis could be affecting root development. Our study not only provides experimental evidence for the existence of these homologues, but it also provides the basic framework for the study of the PLT genes in M. san-angelensis