Mutation of WRKY transcription factors initiates pith secondary wall formation and increases stem biomass in dicotyledonous plants.

ABSTRACT: Stems of dicotyledonous plants consist of an outer epidermis, a cortex, a ring of secondarily thickened vascular bundles and interfascicular cells, and inner pith parenchyma cells with thin primary walls. It is unclear how the different cell layers attain and retain their identities. Here, we show that WRKY transcription factors are in part responsible for the parenchymatous nature of the pith cells in dicotyledonous plants. We isolated mutants of Medicago truncatula and Arabidopsis thaliana with secondary cell wall thickening in pith cells associated with ectopic deposition of lignin, xylan, and cellulose, leading to an ∼50% increase in biomass density in stem tissue of the Arabidopsis mutants. The mutations are caused by disruption of stem-expressed WRKY transcription factor (TF) genes,

SUBMITTER: Wang H 

PROVIDER: S-EPMC3009815 | biostudies-literature | 2010 Dec

REPOSITORIES: biostudies-literature