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Evidence that ethylene signalling is not involved in selective root placement by tobacco plants in response to nutrient‐rich soil patches
Author(s) -
Visser Eric J. W.,
Bögemann Gerard M.,
Smeets Maaike,
De Bruin Susanne,
De Kroon Hans,
Bouma Tjeerd J.
Publication year - 2008
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2007.02256.x
Subject(s) - tetr , ethylene , nicotiana tabacum , nutrient , phosphate , biology , botany , root system , nitrate , horticulture , chemistry , biochemistry , ecology , gene expression , repressor , catalysis , gene
Summary• Ethylene is a strong controller of root development, and it has been suggested that it is involved in the increase of lateral root development in nutrient‐rich soil patches (selective root placement). Here, this contention was tested by comparing selective root placement of an ethylene‐insensitive transgenic tobacco ( Nicotiana tabacum ) genotype (Tetr) with that of wild‐type (Wt) plants. • Wt and Tetr plants were grown in pots with locally increased nitrate or phosphate concentrations, after which the root growth patterns were compared with those of plants grown in pots with homogeneous nutrient distribution. • Tetr plants responded to nutrient patches in a similar way to Wt plants, by placing their roots preferentially at locations with higher nutrient content, and other aspects of plant morphology were also not greatly influenced by ethylene insensitivity. The response of both Wt and Tetr plants to high‐nitrate patches was considerably stronger than to locally high phosphate, suggesting that the two responses are not linked in any functional or regulatory way. • As the response to nutrient patches was similar in ethylene‐sensing and ethylene‐insensitive plants, it is concluded that selective root placement in response to nitrate or phosphate is, at least in tobacco, not mediated or modified by ethylene action.