Highly expressed cell wall genes contribute to robustness of sepal size

Abstract

Reproducibility in organ size and shape is a fascinating trait of living organisms. The mechanisms underlying such robustness remain, however, to be elucidated. Taking the sepal of Arabidopsis as a model, we investigated whether variability of gene expression plays a role in variation of organ morphology. Previous work from our team identified cell-wall related genes as being enriched among the genes whose expression is highly variable. We then hypothesized that the variation of measured morphological parameters in cell-wall related single knockout mutants could be correlated with the variation in gene expression of the corresponding gene (the knocked-out gene) in wild-type plants. We analyzed sepal morphology from 16 cell-wall mutants and found that, unexpectedly, the higher a gene is expressed in wild type, the more variable the size of the corresponding mutant. These findings support a contribution of cell-wall related genes to the robustness of sepal size.