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Fungal histidine kinases (HKs) have been implicated in different processes, such as the osmostress response, hyphal development, sensitivity to fungicides and virulence. Members of HK class III are known to signal through the HOG mitogen‐activated protein kinase (MAPK), but possible interactions with other MAPKs have not been explored. In this study, we have characterized fhk1, encoding a putative class III HK from the soil‐borne vascular wilt pathogen Fusarium oxysporum. Inactivation of fhk1 resulted in resistance to phenylpyrrole and dicarboximide fungicides, as well as increased sensitivity to hyperosmotic stress and menadione‐induced oxidative stress. The osmosensitivity of Δfhk1 mutants was associated with a striking and previously unreported change in colony morphology. The Δfhk1 strains showed a significant decrease in virulence on tomato plants. Epistatic analysis between Fhk1 and the Fmk1 MAPK cascade indicated that Fhk1 does not function upstream of Fmk1, but that the two pathways may interact to control the response to menadione‐induced oxidative stress. 相似文献
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DI MARCO G.; GREGO S.; PIETROSANTI T.; TRICOLI D. 《Journal of experimental botany》1976,27(4):725-734
Nitrate reductase, RuDP1 carboxylase, PEP carboxylase, and water-solubleproteins have been studied during the vegetative cycles of onesoft and one hard wheat cultivar. Nitrate reductase was similarin amount and in pattern of variation in both varieties, thevariations being related to the phenological state of the plant,because the seasonal trend was not in phase in the two varieties.The pattern of change in water-soluble proteins was significantlydifferent in the two cultivars, namely in the consistent declineshown by the upper leaves of soft wheat. RuDP carboxylase was almost identical in amount and absolutelyin phase between the two varieties, showing a dependence onseasonal factors, possibly through a photoperiodic effect. Thechanges in PEP carboxylase were similar in the two wheats andgenerally synchronous. The fluctuation in the RuDP carboxylase/PEPcarboxylase ratio was due primarily to the increase in RuDPcarboxvlase activity. 相似文献
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The present work describes the genetic modification of a hybridoma cell line with the aim to change its metabolic behaviour,
particularly reducing the amounts of ammonia and lactate produced by the cells. The cellular excretion of ammonia was eliminated
by transfection of a cloned glutamine synthetase gene. The metabolic characterisation of the transformed cell line includes
the analysis of the changes introduced in its intracellular metabolic fluxes by means of a stoichiometric model. Furthermore,
the reduction of lactate accumulation was attempted through an antisense mRNA approach, aiming to generate a rate limiting
step in the glycolytic pathway, thus lowering the glucose consumption rate. The physiological results obtained with the transformed
cells are discussed. A maximum reduction of about 47% in the glucose consumption rate was obtained for one of the transformations.
However a main drawback was the lack of stability of the transformed cells
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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