The SHOOT MERISTEMLESS gene is required for maintenance of undifferentiated cells in Arabidopsis shoot and floral meristems and acts at a different regulatory level than the meristem genes WUSCHEL and ZWILLE
| Autor: | Thomas Laux, Joshua Z. Levin, Karin Endrizzi, Achim Haecker, Bernard Moussian |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Plant stem cell
Meristem Arabidopsis Plant Science Biology Genes Plant Models Biological Basal shoot Botany Morphogenesis Genetics Arabidopsis thaliana Primordium Alleles Plant Proteins Homeodomain Proteins Arabidopsis Proteins fungi food and beverages Cell Differentiation Epistasis Genetic Cell Biology Meristem maintenance biology.organism_classification Cell biology Plant Leaves Phenotype Mutation Seeds Shoot Plant Shoots |
| Zdroj: | The Plant Journal. 10:967-979 |
| ISSN: | 1365-313X 0960-7412 |
| DOI: | 10.1046/j.1365-313x.1996.10060967.x |
| Popis: | The function of the SHOOT MERISTEMLESS (STM) gene in shoot and floral meristems throughout Arabidopsis development has been analyzed. The results show that STM plays a major role in maintaining shoot and floral meristems. In an allelic series of stm mutants the shoot meristem was either reduced or completely absent in mature embryos and mutant seedling cotyledons showed partial fusion, indicating that the STM gene affects embryonic shoot meristem development and spacing of cotyledons. Postembryonically, stm mutants initiated adventitious shoot development at a position corresponding to the shoot meristem in wild-type. Repetitively initiated defective mutant shoot and floral meristems were consumed during primordia formation and typically terminated prematurely in fused ectopic primordia, indicating that STM is required for continuous shoot and floral meristem function. Analogous defects were observed in stm embryonic and postembryonic development suggesting that similar mechanisms are employed in embryonic and postembryonic organ primordia initiation. Allelic combination suggest different thresholds for STM requirement during plant development. STM requirement could not be bypassed by standard growth factor regimes or by shoot regeneration from calli. The results suggest that STM functions by preventing incorporation of cells in the meristem center into differentiating organ primordia and that this role can completely account for all defects observed in stm mutants. Mutations in the WUSCHEL (WUS) and ZWILLE (ZLL) genes result in defective organization and premature termination of shoot meristems. Genetic interactions between STM, WUS and ZLL were analyzed and the results indicate that STM acts upstream of WUS and ZLL. Therefore, while STM appears to function in keeping central meristem cells undifferentiated, WUS and ZLL seem to be subsequently required for proper function of these cells. |
| Databáze: | OpenAIRE |
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