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Drought stress provokes the down‐regulation of methionine and ethylene biosynthesis pathways in M edicago truncatula roots and nodules
Author(s) -
LARRAINZAR ESTÍBALIZ,
MOLENAAR JOHANNA A.,
WIENKOOP STEFANIE,
GILQUINTANA ERENA,
ALIBERT BÉNÉDICTE,
LIMAMI ANIS M.,
ARRESEIGOR CESAR,
GONZÁLEZ ESTHER M.
Publication year - 2014
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.12285
Subject(s) - medicago truncatula , biosynthesis , nitrogen fixation , root nodule , methionine , ethylene , legume , biology , botany , biochemistry , chemistry , symbiosis , enzyme , nitrogen , amino acid , genetics , organic chemistry , bacteria , catalysis
Symbiotic nitrogen fixation is one of the first physiological processes inhibited in legume plants under water‐deficit conditions. Despite the progress made in the last decades, the molecular mechanisms behind this regulation are not fully understood yet. Recent proteomic work carried out in the model legume M edicago truncatula provided the first indications of a possible involvement of nodule methionine ( M et) biosynthesis and related pathways in response to water‐deficit conditions. To better understand this involvement, the drought‐induced changes in expression and content of enzymes involved in the biosynthesis of M et, S ‐adenosyl‐ L ‐methionine ( SAM ) and ethylene in M . truncatula root and nodules were analyzed using targeted approaches. Nitrogen‐fixing plants were subjected to a progressive water deficit and a subsequent recovery period. Besides the physiological characterization of the plants, the content of total sulphur, sulphate and main S ‐containing metabolites was measured. Results presented here show that S availability is not a limiting factor in the drought‐induced decline of nitrogen fixation rates in M . truncatula plants and provide evidences for a down‐regulation of the M et and ethylene biosynthesis pathways in roots and nodules in response to water‐deficit conditions.