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Relationship between gibberellin, ethylene and nodulation in Pisum sativum
Author(s) -
Ferguson Brett J.,
Foo Eloise,
Ross John J.,
Reid James B.
Publication year - 2011
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.1469-8137.2010.03542.x
Subject(s) - pisum , sativum , gibberellin , mutant , biology , ethylene , nodule (geology) , meristem , botany , shoot , wild type , biochemistry , horticulture , gene , paleontology , catalysis
Summary• Gibberellin (GA) deficiency resulting from the na mutation in pea ( Pisum sativum ) causes a reduction in nodulation. Nodules that do form are aberrant, having poorly developed meristems and a lack of enlarged cells. Studies using additional GA‐biosynthesis double mutants indicate that this results from severe GA deficiency of the roots rather than simply dwarf shoot stature. • Double mutants isolated from crosses between na and three supernodulating pea mutants exhibit a supernodulation phenotype, but the nodule structures are aberrant. This suggests that severely reduced GA concentrations are not entirely inhibitory to nodule initiation, but that higher GA concentrations are required for proper nodule development. • na mutants evolve more than double the amount of ethylene produced by wild‐type plants, indicating that low GA concentrations can promote ethylene production. The excess ethylene may contribute to the reduced nodulation of na plants, as application of an ethylene biosynthesis inhibitor increased na nodule numbers. However, these nodules were still aberrant in structure. • Constitutive GA signalling mutants also form significantly fewer nodules than wild‐type plants. This suggests that there is an optimum degree of GA signalling required for nodule formation and that the GA signal, and not the concentration of bioactive GA per se , is important for nodulation.