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Synergistic Pectin Degradation and Guard Cell Pressurization Underlie Stomatal Pore Formation
- Source :
- Plant Physiology. 180:66-77
- Publication Year :
- 2019
- Publisher :
- Oxford University Press (OUP), 2019.
-
Abstract
- Stomatal pores are vital for the diffusion of gasses into and out of land plants and are, therefore, gatekeepers for photosynthesis and transpiration. Although much published literature has described the intercellular signaling and transcriptional regulators involved in early stomatal development, little is known about the cellular details of the local separation between sister guard cells that give rise to the stomatal pore or how formation of this pore is achieved. Using three-dimensional (3D) time-lapse imaging, we found that stomatal pore formation in Arabidopsis (Arabidopsis thaliana) is a highly dynamic process involving pore initiation and enlargement and traverses a set of morphological milestones in 3D. Confocal imaging data revealed an enrichment of exocytic machinery, de-methyl-esterified pectic homogalacturonan (HG), and an HG-degrading enzyme at future pore sites, suggesting that both localized HG deposition and degradation might function in pore formation. By manipulating HG modification via enzymatic, chemical, and genetic perturbations in seedling cotyledons, we found that augmenting HG modification promotes pore formation, whereas preventing HG de-methyl-esterification delays pore initiation and inhibits pore enlargement. Through mechanical modeling and experimentation, we tested whether pore formation is an outcome of sister guard cells being pulled away from each other upon turgor increase. Osmotic treatment to reduce turgor pressure did not prevent pore initiation but did lessen pore enlargement. Together, these data provide evidence that HG delivery and modification, and guard cell pressurization, make functional contributions to stomatal pore initiation and enlargement.
- Subjects :
- Research Report
0106 biological sciences
biology
Physiology
Chemistry
Turgor pressure
Arabidopsis
Plant physiology
Plant Science
biology.organism_classification
Osmosis
Models, Biological
Time-Lapse Imaging
01 natural sciences
Osmotic Pressure
Guard cell
Plant Stomata
Genetics
Biophysics
Pectins
Arabidopsis thaliana
Intracellular
010606 plant biology & botany
Transpiration
Subjects
Details
- ISSN :
- 15322548 and 00320889
- Volume :
- 180
- Database :
- OpenAIRE
- Journal :
- Plant Physiology
- Accession number :
- edsair.doi.dedup.....d790f653cdc395a816cdaee22ce23df8