title: Increased leaf mesophyll porosity following transient retinoblastoma-related protein silencing is revealed by microcomputed tomography imaging and leads to a system-level physiological response to the altered cell division pattern.
abstract: The causal relationship between cell division and growth in plants is complex. Although altered expression of cell-cycle genes frequently leads to altered organ growth, there are many examples where manipulation of the division machinery leads to a limited outcome at the level of organ form, despite changes in constituent cell size. One possibility, which has been under-explored, is that altered division patterns resulting from manipulation of cell-cycle gene expression alter the physiology of the organ, and that this has an effect on growth. We performed a series of experiments on retinoblastoma-related protein (RBR), a well characterized regulator of the cell cycle, to investigate the outcome of altered cell division on leaf physiology. Our approach involved combination of high-resolution microCT imaging and physiological analysis with a transient gene induction system, providing a powerful approach for the study of developmental physiology. Our investigation identifies a new role for RBR in mesophyll differentiation that affects tissue porosity and the distribution of air space within the leaf. The data demonstrate the importance of RBR in early leaf development and the extent to which physiology adapts to modified cellular architecture resulting from altered cell-cycle gene expression.
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK.
authors.forename: Carmen
authors.initials: C
authors.lastname: Dorca-Fornell
authors.forename: Radoslaw
authors.initials: R
authors.lastname: Pajor
authors.forename: Christoph
authors.initials: C
authors.lastname: Lehmeier
authors.forename: Marísa
authors.initials: M
authors.lastname: Pérez-Bueno
authors.forename: Marion
authors.initials: M
authors.lastname: Bauch
authors.forename: Jen
authors.initials: J
authors.lastname: Sloan
authors.forename: Colin
authors.initials: C
authors.lastname: Osborne
authors.forename: Stephen
authors.initials: S
authors.lastname: Rolfe
authors.forename: Craig
authors.initials: C
authors.lastname: Sturrock
authors.forename: Sacha
authors.initials: S
authors.lastname: Mooney
authors.forename: Andrew
authors.initials: A
authors.lastname: Fleming
mesh_terms: D000872:Anthocyanins / Q000032:analysis / Q000378:metabolism; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002453:Cell Cycle; D002454:Cell Differentiation; D048429:Cell Size; D002734:Chlorophyll / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter; D058503:Mesophyll Cells / Q000166:cytology / Q000502:physiology; D010641:Phenotype; D045332:Photosystem II Protein Complex / Q000502:physiology; D019441:Plant Epidermis / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D018515:Plant Leaves / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D054046:Plant Stomata / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D018526:Plant Transpiration / Q000502:physiology; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics; D055114:X-Ray Microtomography / Q000379:methods*
chemical_list: D000872:Anthocyanins; D029681:Arabidopsis Proteins; D045332:Photosystem II Protein Complex; C487568:RBR1 protein, Arabidopsis; D012333:RNA, Messenger; D002734:Chlorophyll
keywords: Arabidopsis thaliana; cell cycle; development; imaging; leaf; physiology