TY - JOUR
T1 - POLYGALACTURONASE INVOLVED IN EXPANSION3 functions in seedling development, rosette growth, and stomatal dynamics in Arabidopsis thaliana
AU - Rui, Yue
AU - Xiao, Chaowen
AU - Yi, Hojae
AU - Kandemir, Baris
AU - Wang, James Z.
AU - Puri, Virendra M.
AU - Anderson, Charles T.
N1 - Funding Information:
We thank Liza Wilson for assistance with pectin molecular weight determination, Juan Du for assistance with protein extraction, Jozef Mravec for providing the COS488probe, and members of the Anderson lab, especially Will Barnes, for helpful advice and discussions. Research supplies were purchased with support from a Huck Dissertation Research Award to Y.R. Pectin molecular mass and PG activity were measured with support from the Center for Lignocellulose Structure and Formation, an Energy Frontier Research Center funded by the U.S. Department of Energy, OfficeofScience,BasicEnergySciences(AwardDE-SC0001090).Allother research and manuscript preparation were supported by National Science Foundation Grant MCB-1616316 to C.T.A., V.M.P., and J.Z.W.
Publisher Copyright:
© 2017 ASPB.
PY - 2017/10
Y1 - 2017/10
N2 - Plant cell separation and expansion require pectin degradation by endogenous pectinases such as polygalacturonases, few of which have been functionally characterized. Stomata are a unique system to study both processes because stomatal maturation involves limited separation between sister guard cells and stomatal responses require reversible guard cell elongation and contraction. However, the molecular mechanisms for how stomatal pores form and how guard cell walls facilitate dynamic stomatal responses remain poorly understood. We characterized POLYGALACTURONASE INVOLVED IN EXPANSION3 (PGX3), which is expressed in expanding tissues and guard cells. PGX3-GFP localizes to the cell wall and is enriched at sites of stomatal pore initiation in cotyledons. In seedlings, ablating or overexpressing PGX3 affects both cotyledon shape and the spacing and pore dimensions of developing stomata. In adult plants, PGX3 affects rosette size. Although stomata in true leaves display normal density and morphology when PGX3 expression is altered, loss of PGX3 prevents smooth stomatal closure, and overexpression of PGX3 accelerates stomatal opening. These phenotypes correspond with changes in pectin molecular mass and abundance that can affect wall mechanics. Together, these results demonstrate that PGX3-mediated pectin degradation affects stomatal development in cotyledons, promotes rosette expansion, and modulates guard cell mechanics in adult plants.
AB - Plant cell separation and expansion require pectin degradation by endogenous pectinases such as polygalacturonases, few of which have been functionally characterized. Stomata are a unique system to study both processes because stomatal maturation involves limited separation between sister guard cells and stomatal responses require reversible guard cell elongation and contraction. However, the molecular mechanisms for how stomatal pores form and how guard cell walls facilitate dynamic stomatal responses remain poorly understood. We characterized POLYGALACTURONASE INVOLVED IN EXPANSION3 (PGX3), which is expressed in expanding tissues and guard cells. PGX3-GFP localizes to the cell wall and is enriched at sites of stomatal pore initiation in cotyledons. In seedlings, ablating or overexpressing PGX3 affects both cotyledon shape and the spacing and pore dimensions of developing stomata. In adult plants, PGX3 affects rosette size. Although stomata in true leaves display normal density and morphology when PGX3 expression is altered, loss of PGX3 prevents smooth stomatal closure, and overexpression of PGX3 accelerates stomatal opening. These phenotypes correspond with changes in pectin molecular mass and abundance that can affect wall mechanics. Together, these results demonstrate that PGX3-mediated pectin degradation affects stomatal development in cotyledons, promotes rosette expansion, and modulates guard cell mechanics in adult plants.
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U2 - 10.1105/tpc.17.00568
DO - 10.1105/tpc.17.00568
M3 - Article
C2 - 28974550
AN - SCOPUS:85033688723
SN - 1040-4651
VL - 29
SP - 2413
EP - 2432
JO - Plant Cell
JF - Plant Cell
IS - 10
ER -