Effects of externally supplied protein on root morphology and biomass allocation in Arabidopsis.
Growth, morphogenesis and function of roots are influenced by the concentration and form of nutrients present in soils, including low molecular mass inorganic N (IN, ammonium, nitrate) and organic N (ON, e.g. amino acids). Proteins, ON of high molecular mass, are prevalent in soils but their possible effects on roots have received little attention. Here, we investigated how externally supplied protein of a size typical of soluble soil proteins influences root development of axenically grown Arabidopsis. Addition of low to intermediate concentrations of protein (bovine serum albumen, BSA) to IN-replete growth medium increased root dry weight, root length and thickness, and root hair length. Supply of higher BSA concentrations inhibited root development. These effects were independent of total N concentrations in the growth medium. The possible involvement of phytohormones was investigated using Arabidopsis with defective auxin (tir1-1 and axr2-1) and ethylene (ein2-1) responses. That no phenotype was observed suggests a signalling pathway is operating independent of auxin and ethylene responses. This study expands the knowledge on N form-explicit responses to demonstrate that ON of high molecular mass elicits specific responses.
School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD, 4072, Australia.
Thierry G A
TG
Lonhienne
School of Agriculture and Food Sciences, The University of Queensland, St. Lucia, QLD, 4072, Australia.
Yuri
Y
Trusov
Plant Pathology Herbarium, Queensland Primary Industries and Fisheries, QLD, 4068, Australia.
Anthony
A
Young
Institute of Plant Sciences, University of Bern, 3013 Bern, Switzerland.
Doris
D
Rentsch
Department of Forest Ecology and Management, and Department of Forest Genetics and Plant Physiology, SLU, SE-901 83 Umeå, Sweden.
Torgny
T
Näsholm
School of Agriculture and Food Sciences, The University of Queensland, St. Lucia, QLD, 4072, Australia.
Susanne
S
Schmidt
School of Agriculture and Food Sciences, The University of Queensland, St. Lucia, QLD, 4072, Australia.
Chanyarat
C
Paungfoo-Lonhienne
D000818:Animals; D017360:Arabidopsis / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000378:metabolism*; D018533:Biomass; D002417:Cattle; D005030:Ethylenes / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000494:pharmacology; D009566:Nitrates / Q000494:pharmacology; D010641:Phenotype; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D012710:Serum Albumin, Bovine / Q000378:metabolism*; D015398:Signal Transduction
C100794:AUX1 protein, Arabidopsis; D029681:Arabidopsis Proteins; C119963:EIN2 protein, Arabidopsis; D005030:Ethylenes; D007210:Indoleacetic Acids; D009566:Nitrates; D011956:Receptors, Cell Surface; D012710:Serum Albumin, Bovine; C036216:ethylene; C006568:ammonium nitrate