Journal article
Hypersensitivity of an Arabidopsis Sugar Signaling Mutant toward Exogenous Proline Application
Plant physiology (Bethesda), Vol.122(2), pp.357-368
02/01/2000
Handle:
https://hdl.handle.net/2376/103980
PMID: 10677429
Abstract
In transgenic Arabidopsis a patatin class I promoter from potato is regulated by sugars and proline (Pro), thus integrating signals derived from carbon and nitrogen metabolism. In both cases a signaling cascade involving protein phosphatases is involved in induction. Other endogenous genes are also regulated by both Pro and carbohydrates. Chalcone synthase (CHS) gene expression is induced by both, whereas the Pro biosynthetic Δ1-pyrroline-5-carboxylate synthetase (P5CS) is induced by high Suc concentrations but repressed by Pro, and Pro dehydrogenase (ProDH) is inversely regulated. The mutantrsr1-1, impaired in sugar dependent induction of the patatin promoter, is hypersensitive to low levels of external Pro and develops autofluorescence and necroses. Toxicity of Pro can be ameliorated by salt stress and exogenously supplied metabolizable carbohydrates. The rsr1-1 mutant shows a reduced response regarding sugar induction of CHS andP5CS expression. ProDH expression is de-repressed in the mutant but still down-regulated by sugar. Pro toxicity seems to be mediated by the degradation intermediate Δ1-pyrroline-5-carboxylate. Induction of the patatin promoter by carbohydrates and Pro, together with the Pro hypersensitivity of the mutant rsr1-1, demonstrate a new link between carbon/nitrogen and stress responses.
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Details
- Title
- Hypersensitivity of an Arabidopsis Sugar Signaling Mutant toward Exogenous Proline Application
- Creators
- Hanjo HellmannDietmar FunckDoris RentschWolf B Frommer
- Publication Details
- Plant physiology (Bethesda), Vol.122(2), pp.357-368
- Academic Unit
- Biological Sciences, School of
- Identifiers
- 99900547000801842
- Language
- English
- Resource Type
- Journal article