Judith Felten: "Ethylene signaling via Ethylene Response Factors (ERFs) modifies wood development in hybrid aspen"(Plant Sciences Freiburg Kolloquium)
von 17:15 bis 18:00
|Wo||Schänzlestr. 1 (Institut für Biologie II/II), Raum 0043|
|Name||Prof. K. Palme|
Open to University employees
Umeå Plant Science Center, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
Ethylene signaling via Ethylene Response Factors (ERFs) modifies wood development in hybrid aspen
The phytohormone ethylene (ET) has the potential to regulate secondary growth of plants. We demonstrated previously that application of exogenous ET or its in planta precursor 1-aminocyclopropane-1-carboxylic acid (ACC) as well as endogenous ET accumulation during leaning stimulate xylem growth in stems of hybrid aspen (Populus tremula x Populus tremuloides) and requires functional ethylene signaling1. Ethylene Response Factors (ERFs) act downstream of ET perception and activate transcription of ET-responsive target genes. We analyze here whether ERFs are regulators of wood development in hybrid aspen.
We identified 169 ERF genes in Populus and studied their responsiveness to ethylene, ACC and tension wood formation in hybrid aspen stems using qPCR. Twenty-six ERFs were expressed in stem tissues and inducible by at least two of the three treatments. Twenty of these ERFs were overexpressed in cambium/xylem in transgenic hybrid aspen but caused only mild alterations of height and radial growth in a greenhouse trial, except for one ERF candidate. A Fourier-Transformed Infra Red spectroscopy and Pyrolysis GC-MS based screening of the ERF-overexpressors revealed changes in xylem cell wall composition (lignin abundance and structure (S:G ratio), glycosidic linkages, cellulose abundance) in xylem tissue. This suggests that ERFs have the ability to modify cell wall composition in wood forming tissues.
1Love J, Björklund S, Vahala J, Hertzberg M, Kangasjärvi J and Sundberg B, PNAS, 2009, 106, 5984-5989.