Functional characterisation of genes involved in cell wall metabolism from the flowering plant Arabidopsis thaliana

• Main Author: Chairam, Issariya
• Other Authors: Hamann, Thorsten
• Published: Imperial College London 2014
• Subjects: 583
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.695494

The plant cell wall is a complex and dynamic structure, involved in interaction with the environment, cell-cell interactions as well as plant growth and development. Although structure and architecture of the walls have been studied extensively, knowledge regarding the mechanisms required to generate the complexity and control dynamic changes of the walls is limited. In order to improve our understanding, this study employs a combination of genetic, molecular and biochemical methods to characterize the functions of three candidate genes, At1g65610, At3g44990 and At1g07260. They encode a putative membrane-bound endo-1,4-β-glucanase (KORRIGAN2), a putative xyloglucan endo-transferase/hydrolase (XTH31) and a putative UDP-glycosyltransferase (UGT71C3) from Arabidopsis thaliana. The expression of the candidate genes changes in response to treatment with the cellulose biosynthesis inhibitor isoxaben. Plants with loss of gene activity of the target genes show only subtle growth phenotypes under standard growth conditions. However, cell wall analysis of stems from mature plants found distinct differences between the mutant plants and their wild type controls. In addition, my research showed that during early stage phenotypes, germination, root growth and isoxaben hypersensitivity phenotypes were observed in korrigan2 and xth31 seedlings. Interestingly, ugt71c3 seedlings exhibited early germination phenotypes but no effects on root growth. In parallel, it was found that all mutant seedlings tested produce more ectopic lignin upon isoxaben treatment than wild type controls. These results show that the genes characterized are involved in cell wall metabolism and are required for the growth as well as the response to cell wall damage simulated by isoxaben treatment.