Abstract Detail

Development and Structure

Rodríguez-Alonso, Gustavo [1], Morales-Castillo, Sandra [1], Esteban-Hernández, Sofía [1], Lara-Vargas, Alejandra [1], Napsucialy-Mendivil, Selene [1], Ramírez-Yarza, Marcela [1], Matvienko, Marta [2], Dubrovsky, Joseph [1], Shishkova, Svetlana [1].

Development of the Cactaceae primary root and the genetic regulation of root apical meristem exhaustion.

In Cactaceae, the primary root undergoes root apical meristem (RAM) exhaustion shortly after germination, leading to a determinate growth. This developmental program is genetically stable and does not depend on environmental signals. Here we present a wide assessment of the incidence of the determinate growth of the primary root across Cactoideae, the Cactaceae subfamily that includes more than 80% of the described Cactaceae species. To address the genetic regulation of this growth pattern, we sequenced, de novo assembled, and annotated the root apex transcriptome of the Pachycereus pringlei primary root at three developmental stages, with active or exhausted RAM. The transcriptome was used to evaluate differential gene expression, and to infer a transcriptional regulatory network of the primary root apex. Our results in these two parts of the work show that the determinate growth of the primary root is widespread among Cactaceae, and that the transcriptional state of the P. pringlei root apex as the RAM becomes exhausted recapitulates the developmental trajectory of cells from the meristematic, elongation, and differentiation zones of Arabidopsis roots along the root axis. We identified putative orthologues of Arabidopsis regulators of RAM maintenance, as well as putative lineage-specific transcripts that might be involved in RAM exhaustion. Together, our results provide a primer to advance the understanding of determinate root growth in cacti species.

1 - Universidad Nacional Autónoma de México, Instituto de Biotecnología, Av Universidad 2001, Col Chamilpa, Cuernavaca, 62170, Mexico
2 - Frinj Coffee, Davis, CA, USA

Determinate root growth
Gene Regulatory Netvwork
Root Apical Meristem

Presentation Type: Oral Paper
Number: DS6003
Abstract ID:815
Candidate for Awards:None

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