Transcriptome analysis of bolting in A. tequilana reveals roles for florigen, MADS, fructans and gibberellins

Reliable indicators for the onset of flowering are not available for most perennial monocarpicspecies, representing a drawback for crops such as bamboo, agaveand banana. The ability to predict and control the transition to the reproductive stage in A. tequilana would represent an advantage for field management of agavesfor tequila production and for the development of a laboratory model for agavespecies. Consistent morphological features could not be determined for the vegetative to reproductive transition in A. tequilana. However, changes in carbohydrate metabolismwhere sucrose decreased and fructansof higher degreeof polymerizationincreased in leaves before and after the vegetative to reproductive transition were observed. At the molecular level, transcriptome analysis from leaf and shoot apical meristem tissue of A. tequilana plants from different developmental stages identified OASES as the most effective assembly program and revealed evidence for incomplete transcript processing in the highly redundant assembly obtained. Gene ontology analysis uncovered enrichment for terms associated with carbohydrate and hormone metabolism and detailed analysis of expression patterns for individual genes revealed roles for specific Flowering locus T ( florigen), MADS boxproteins, gibberellinsand fructansin the transition to flowering. Based on the data obtained, a preliminary model was developed to describe the regulatory mechanisms underlying the initiation of flowering in A. tequilana. Identification of specific promoter and repressor Flowering Locus T and MADS boxgenes facilitates functional analysis and the development of strategies to modulate the vegetative to reproductive transition in A. tequilana.