Abstract
Plant cell walls participate in all plant-environment interactions. Maintaining cell wall integrity (CWI) during these interactions is essential. This realization led to increased interest in CWI and resulted in knowledge regarding early perception and signalling mechanisms active during CWI maintenance. By contrast, knowledge regarding processes mediating changes in cell wall metabolism upon CWI impairment is very limited. To identify genes involved and to investigate their contributions to the processes we selected 23 genes with altered expression in response to CWI impairment and characterized the impact of T-DNA insertions in these genes on cell wall composition using Fourier-Transform Infrared Spectroscopy (FTIR) in Arabidopsis thaliana seedlings. Insertions in 14 genes led to cell wall phenotypes detectable by FTIR. A detailed analysis of four genes found that their altered expression upon CWI impairment is dependent on THE1 activity, a key component of CWI maintenance. Phenotypic characterizations of insertion lines suggest that the four genes are required for particular aspects of CWI maintenance, cell wall composition or resistance to Plectosphaerella cucumerina infection in adult plants. Taken together, the results implicate the genes in responses to CWI impairment, cell wall metabolism and/or pathogen defence, thus identifying new molecular components and processes relevant for CWI maintenance.
Footnotes
Funding
This work was supported through Gatsby AdHoc funds and a grant from the Peder Sather Center for Advanced Study to T.H. and Chris Somerville. L.K. was supported by a Ph.D. Fellowship from the Porter Institute at Imperial College and I.C. by a PhD fellowship provided by the Royal Thai government. L.D. and A.W were supported through postdoctoral fellowships provided by the Porter Institute at Imperial College. T.E. was supported through a EU Marie Curie Fellowship “SUGAROSMO-SIGNALLING” and a DFG postdoctoral fellowship (EN 1071/1-1). N.G. was supported through the EEA project grant CYTOWALL. Research by A.M. was supported by Spanish Ministry of Economy and Competitiveness (MINECO) grant BIO2015-64077-R.