Xyloglucans and Microtubules Synergistically Maintain Meristem Geometry and Phyllotaxis  . Issue 3 (19th September 2019)

• Record Type: Journal Article
• Authors: Zhao, Feng; Chen, Wenqian; Sechet, Julien; Martin, Marjolaine; Bovio, Simone; Lionnet, Claire; Long, Yuchen; Battu, Virginie; Mouille, Grégory; Monéger, Françoise; Traas, Jan
• Is Part Of: Plant physiology. Volume 181:Issue 3(2019)
• Page Start: 1191
• Page End: 1206
• Publication Date: 2019-09-19
• Subjects: Plant physiology -- Periodicals; Botany -- Periodicals; Periodicals; Electronic journals; 571.2
• DOI: 10.1104/pp.19.00608
• Languages: English
• ISSNs: 0032-0889

Abstract

Abstract : Xyloglucans and microtubule dynamics synergistically maintain meristem geometry and robustness of phyllotaxis in Arabidopsis. Abstract: The shoot apical meristem (SAM) gives rise to all aerial plant organs. Cell walls are thought to play a central role in this process, translating molecular regulation into dynamic changes in growth rate and direction, although their precise role in morphogenesis during organ formation is poorly understood. Here, we investigated the role of xyloglucans (XyGs), a major, yet functionally poorly characterized, wall component in the SAM of Arabidopsis ( Arabidopsis thaliana ). Using immunolabeling, biochemical analysis, genetic approaches, microindentation, laser ablation, and live imaging, we showed that XyGs are important for meristem shape and phyllotaxis. No difference in the Young's modulus (i.e. an indicator of wall stiffness) of the cell walls was observed when XyGs were perturbed. Mutations in enzymes required for XyG synthesis also affect other cell wall components such as cellulose content and pectin methylation status. Interestingly, control of cortical microtubule dynamics by the severing enzyme KATANIN became vital when XyGs were perturbed or absent. This suggests that the cytoskeleton plays an active role in compensating for altered cell wall composition.