Longitudinal zonation pattern in Arabidopsis root tip defined by a multiple structural change algorithm.
Ann Bot
; 118(4): 763-776, 2016 Oct 01.
Article
in En
| MEDLINE
| ID: mdl-27358290
ABSTRACT
Background and Aims The Arabidopsis thaliana root is a key experimental system in developmental biology. Despite its importance, we are still lacking an objective and broadly applicable approach for identification of number and position of developmental domains or zones along the longitudinal axis of the root apex or boundaries between them, which is essential for understanding the mechanisms underlying cell proliferation, elongation and differentiation dynamics during root development. Methods We used a statistics approach, the multiple structural change algorithm (MSC), for estimating the number and position of developmental transitions in the growing portion of the root apex. Once the positions of the transitions between domains and zones were determined, linear models were used to estimate the critical size of dividing cells (LcritD) and other parameters. Key Results The MSC approach enabled identification of three discrete regions in the growing parts of the root that correspond to the proliferation domain (PD), the transition domain (TD) and the elongation zone (EZ). Simultaneous application of the MSC approach and G2-to-M transition (CycB1;1DBGFP) and endoreduplication (pCCS52A1GUS) molecular markers confirmed the presence and position of the TD. We also found that the MADS-box gene XAANTAL1 (XAL1) is required for the wild-type (wt) PD increase in length during the first 2 weeks of growth. Contrary to wt, in the xal1 loss-of-function mutant the increase and acceleration of root growth were not detected. We also found alterations in LcritD in xal1 compared with wt, which was associated with longer cell cycle duration in the mutant. Conclusions The MSC approach is a useful, objective and versatile tool for identification of the PD, TD and EZ and boundaries between them in the root apices and can be used for the phenotyping of different genetic backgrounds, experimental treatments or developmental changes within a genotype. The tool is publicly available at www.ibiologia.com.mx/MSC_analysis.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Type of study:
Prognostic_studies
/
Risk_factors_studies
Language:
En
Journal:
Ann Bot
Year:
2016
Document type:
Article
Affiliation country: