High level transcription of a member of a repeated gene family confers dehydration tolerance to callus tissue of Craterostigma plantagineum

Furini, Antonella

doi:10.1093/emboj/16.12.3599

Cited by 132 publications

(111 citation statements)

References 70 publications

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“…The expression of transgenes encoding stress-induced transcriptional factors or other components of stress-related signal transduction pathways (Table 2) might enable the coordinated upregulation of entire metabolic and/or signal transduction pathways affecting osmolyte levels in a developmentally, temporally and spatially controlled manner. The viability of this approach was recently shown by Furini et al (1997).…”

Section: Signal Transduction Mechanisms Regulating Osmolyte Accumulationmentioning

confidence: 96%

Dissecting the roles of osmolyte accumulation during stress

Hare

Cress

Staden

1998

Plant Cell & Environment

1,197

744

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Many plants accumulate organic osmolytes in response to the imposition of environmental stresses that cause cellular dehydration. Although an adaptive role for these compounds in mediating osmotic adjustment and protecting subcellular structure has become a central dogma in stress physiology, the evidence in favour of this hypothesis is largely correlative. Transgenic plants engineered to accumulate proline, mannitol, fructans, trehalose, glycine betaine or ononitol exhibit marginal improvements in salt and/or drought tolerance. While these studies do not dismiss causative relationships between osmolyte levels and stress tolerance, the absolute osmolyte concentrations in these plants are unlikely to mediate osmotic adjustment. Metabolic benefits of osmolyte accumulation may augment the classically accepted roles of these compounds. In re-assessing the functional significance of compatible solute accumulation, it is suggested that proline and glycine betaine synthesis may buffer cellular redox potential. Disturbances in hexose sensing in transgenic plants engineered to produce trehalose, fructans or mannitol may be an important contributory factor to the stress-tolerant phenotypes observed. Associated effects on photoassimilate allocation between root and shoot tissues may also be involved. Whether or not osmolyte transport between subcellular compartments or different organs represents a bottleneck that limits stress tolerance at the whole-plant level is presently unclear. None the less, if osmolyte metabolism impinges on hexose or redox signalling, then it may be important in long-range signal transmission throughout the plant.Key-words: betaine; cold stress; drought; fructans; mannitol; osmolytes; proline; salinity; sugar signalling; trehalose. Abbreviations INTRODUCTIONEnvironmental stress is the major factor limiting plant productivity . Abiotic stresses which cause depletion of cellular water (drought, high soil salinity and temperature extremes) are responsible for the greatest agricultural losses. Upon exposure to these prevalent stresses, many plants accumulate organic osmolytes, most commonly polyhydroxylic compounds (saccharides and polyhydric alcohols) and zwitterionic alkylamines (amino acids and quaternary ammonium compounds).Several recent reviews discuss osmolyte accumulation in plants (Ingram & Bartels 1996;Serrano 1996). It is generally accepted that the increase in cellular osmolarity which results from the accumulation of non-toxic (thus 'compatible') osmotically active solutes is accompanied by the influx of water into, or at least a reduced efflux from, cells, thus providing the turgor necessary for cell expansion. None the less, a conclusive demonstration that osmotic adjustment contributes to fitness in stressful environments has yet to be achieved (Munns 1993). Since all subcellular structures must exist in an aqueous environment, tolerance to dehydration also depends on the ability of cells to maintain membrane integrity and prevent protein denaturation. Hypotheses that attribut...

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Section: Signal Transduction Mechanisms Regulating Osmolyte Accumulationmentioning

confidence: 96%

Dissecting the roles of osmolyte accumulation during stress

Hare

Cress

Staden

1998

Plant Cell & Environment

1,197

744

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“…Analysis of RNA transcripts showed that genes were constitutively expressed in the mutant callus, which in non-transformed calli can only be induced by ABA treatment. The gene targeted by the T-DNA, which led to the constitutive activation of desiccation-related genes, was isolated and named CDT-1 (Furini et al, 1997). CDT-1 is present in multiple copies in the genome of C. plantagineum and its expression can be induced by ABA in nontransformed callus and plants.…”

Section: The Novel Cdt-1 Genementioning

confidence: 99%

Desiccation Tolerance in the Resurrection Plant Craterostigma plantagineum. A Contribution to the Study of Drought Tolerance at the Molecular Level

2001

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“…This difference implies the existence of additional, unique protective mechanisms in the resurrection plants, a notion corroborated by the identification of the unusual eight-carbon sugar octulose, the CDT1 gene in Craterostigma plantagineum, and the phenolic antioxidant 3,4,5-tri-O-galloylquinic acid in Myrothamnus flabellifolia [12][13][14][15]. Furthermore, there is increasing evidence that some of the drought-protective mechanisms inducible in most plants by mild drought are constitutively active in resurrection plants [16,17].…”

Section: Introductionmentioning

confidence: 98%