Journal Article

Reactive oxygen species mediate conical cell shaping in Arabidopsis thaliana petals

Lin, Deshu, Chen, Binqinq, Dang, Xie, Zhang, Yu, Li, Yajun, Yu, Peihang, Yang, Yanqiu, Ren, Huibo

2018

Overview

Plants have evolved diverse cell types with distinct sizes, shapes, and functions. For example, most flowering plants contain specialized petal conical epidermal cells that are thought to attract pollinators and influence light capture and reflectance, but the molecular mechanisms controlling conical cell shaping remain unclear. Here, through a genetic screen in Arabidopsis thaliana, we demonstrated that loss-of-function mutations in ANGUSTIFOLIA (AN), which encodes for a homolog of mammalian CtBP/BARs, displayed conical cells phenotype with wider tip angles, correlating with increased accumulation of reactive oxygen species (ROS). We further showed that exogenously supplied ROS generated similar conical cell phenotypes as the an mutants. Moreover, reduced endogenous ROS levels resulted in deceased tip sharpening of conical cells. Furthermore, through enhancer screening, we demonstrated that mutations in katanin (KTN1) enhanced conical cell phenotypes of the an-t1 mutants. Genetic analyses showed that AN acted in parallel with KTN1 to control conical cell shaping. Both increased or decreased ROS levels and mutations in AN suppressed microtubule organization into well-ordered circumferential arrays. We demonstrated that the AN-ROS pathway jointly functioned with KTN1 to modulate microtubule ordering, correlating with the tip sharpening of conical cells. Collectively, our findings revealed a mechanistic insight into ROS homeostasis regulation of microtubule organization and conical cell shaping.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Arabidopsis - cytology / Arabidopsis - physiology / Arabidopsis Proteins - genetics / Arabidopsis thaliana / Biology / Biology and Life Sciences / Cell Shape - physiology / Cellulose / Epidermal Cells - metabolism / Epidermis - metabolism / Flowering / Flowers - genetics / Flowers - metabolism / Gene expression / Genetic analysis / Genetic aspects / Genetic screening / Health aspects / Homeostasis / Katanin - genetics / Kinases / Laboratories / Life sciences / Microtubules - genetics / Molecular modelling / Morphogenesis / Mutation / Phenotypes / Pollinators / Proteins / Proteomics / Reactive oxygen species / Reactive Oxygen Species - metabolism / Repressor Proteins - genetics / Research and Analysis Methods