Transcript Stomata Development

Stomata – Development
Philipp Gerke
PCDU-Seminar
16.12.2015
Stomata Development – Cell State Transition
MYB transcription factors:
Part of the cell cycle
machinery
bHLHs
=
• basic helix-loop-helix
Transcription factors
• SPCH, MUTE, FAMA
Are key switches
partial expressed
• SCREAMs/ICEs
Maintenance for development
Consecutive expressed
MYB88
Four lips (FLP)
SLGC
Counterpart of FAMA
Stomata Patterning – One Cell Spacing Rule
1. SLGC are dividing away from existing stomata
SLGC
SLGC
2. Two misplaced meristemoids next to each other divides away from each other
One cell spacing rule
cell-cell communication via short distance signals
Leucin Rich Repeat Receptor Like Kinases (LRR-RLK)
• Over 200 members in Plants
• Single pass trans membrane proteins
• Forms functional homo- and heterodimers
Ligand
binding
domain
Members involved in stomatal development:
• ERECTA
expressed in protodermal cells
• ERL1
expressed in meristemoids GMCs and young GCs
• ERL2
• TMM
expressed across the stomatal lineage
lacking the kinase domain
Kinase
domain
Epidermal Patterning Factor Like (EPFL) Family
• 11 members in this family
• Secreted cysteine-rich peptides
• ~50-90 amino acid
• Characteristic intramolecular disulfid bonds
Members involved in stomatal development:
• EPF1
secreted by late meristemoids and GMCs
• EPF2
secreted by MMCs and early meristemoids
• EPFL9 (Stomagen)
secreted by mesophyll tissue obove the epidermis
Receptor Ligand Interaction
Treatment with
Arrested
meristemoids
Only
pavement cells
EPF2/ERECTA prevents surrounding protodermal cells to perform a entry division
EPF1/ERL1 promotes a the correct spacing and repress meristemoids differentiation
Receptor Ligand Interaction
Mesophyll tissue
Stomagen has a positive influence on stomata development
Signal transduction from the cell membrane to the
Surrounding
nucleus
epidermis cells
Phytohormones
Photosynthetic tissue
MAPK Cascade:
• Also present in yeast and animals
• Activation by sequential phosphorylation
of 3 kinase modules
• Deactivation of SPCH via phosphorylation
MAPK Cascade is an integration point of other developing signals
HIC proteins
CO2
Temperature
Asymmetric cell division and division polarity
Problems … no recognizable homologs of animal or fungal polarity genes !
… the mechanical restrictions of the cell wall
Plant specific polarity genes were identified BASL and POLAR
Conclusion
• Stomata are produced through a characteristic series of divisions controlled via the coordinated
activities of transcription factors that can directly regulate core cell-cycle genes.
• Correct stomatal patterning and initiation requires intercellular communication through the activity
of secreted peptide ligands, receptor kinases, and MAPK signaling modules.
• Environmental conditions impact the production of stomata in developing leaves via a longdistance signal initiated in mature leaves. MAPK modules may provide a common integration
point among multiple environmental inputs.
• Polarity localized proteins (BASL and POLAR) provide the first examples polarity factors in plants.
References
• Facette, Michelle R.; Smith, Laurie G. (2012): Division polarity in developing stomata. In: Current
Opinion in Plant Biology 15 (6), S. 585–592. DOI: 10.1016/j.pbi.2012.09.013.
• Lau, On Sun; Bergmann, Dominique C. (2012): Stomatal development: a plant's perspective on cell
polarity, cell fate transitions and intercellular communication. In: Development (Cambridge, England)
139 (20), S. 3683–3692. DOI: 10.1242/dev.080523.
• Pillitteri, Lynn Jo; Torii, Keiko U. (2012): Mechanisms of stomatal development. In: Annual Review of
Plant Biology 63, S. 591–614. DOI: 10.1146/annurev-arplant-042811-105451.
• Simmons, Abigail R.; Bergmann, Dominique C. (2015): Transcriptional control of cell fate in the
stomatal lineage. In: Current Opinion in Plant Biology 29, S. 1–8. DOI: 10.1016/j.pbi.2015.09.008.
• Torii, Keiko U. (2012): Mix-and-match: ligand-receptor pairs in stomatal development and beyond. In:
Trends in Plant Science 17 (12), S. 711–719. DOI: 10.1016/j.tplants.2012.06.013.