Expression of fungal pectin methylesterase in transgenic tobacco leads to alteration in cell wall metabolism and a dwarf phenotype

• Published in: Journal of biotechnology 2004-08, Vol.111 (3), p.241-251
• Main Authors: Hasunuma, Tomohisa, Fukusaki, Ei-ichiro, Kobayashi, Akio
• Format: Article
• Language: English
• Subjects: Aspergillus; Aspergillus niger; Aspergillus niger - enzymology; Aspergillus niger - genetics; Biological and medical sciences; Biotechnology; Carboxylic Ester Hydrolases - genetics; Carboxylic Ester Hydrolases - metabolism; Cell Division - physiology; Cell Membrane - metabolism; Cell wall metabolism; Cells, Cultured; Dwarf; dwarfing; Fundamental and applied biological sciences. Psychology; gene expression; Gene Expression Regulation, Enzymologic - physiology; Gene Expression Regulation, Plant - physiology; Gene Transfer Techniques; Monosaccharides; Nicotiana - physiology; Nicotiana tabacum; Pectin; Pectin methylesterase; pectinesterase; Pectins - metabolism; Phenotype; plant development; Plants, Genetically Modified - physiology; Recombinant Proteins - metabolism; transgenic plants; Transgenic tobacco plant
• ISSN: 0168-1656; 1873-4863
• DOI: 10.1016/j.jbiotec.2004.04.015

A transgenic tobacco plant ( Nicotiana tabacum L.) expressing a fungal pectin methylesterase (PME; EC 3.1.1.11) gene derived from a black filamentous fungus, Aspergillus niger was created. Fungal PME should have a wider range of adaptability to substrate pectin compared with plant PME. As expected, the proportion of methyl esters in pectin was reduced in the transgenic tobacco. Consequently, the transgenic plant showed short internodes, small leaves and a dwarf phenotype. At a cellular level, the longitudinal lengths of stem epidermal cells were shorter than those of control plants. This is the first report that fungal PME promotes dwarfism in plants. It is worth noting that in the PME-expressing dwarf plant, the expression levels of cell wall metabolism related genes that included endo-1,4-β-glucanase, cellulose synthase, endo-xyloglucan transferase and expansin gene were decreased. These results suggest that the expression of fungal PME in plants affects the cell wall metabolism.