Acquisition and Diversification of Cladodes: Leaf-Like Organs in the Genus Asparagus
| Autor: | Hokuto Nakayama, Takahiro Yamaguchi, Hirokazu Tsukaya |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
biology
Molecular Sequence Data fungi Gene Expression Regulation Developmental food and beverages Cell Biology Plant Science Shoot morphology biology.organism_classification Plant Leaves Asparagus asparagoides Gene Expression Regulation Plant RNA Plant Officinalis Botany Axillary shoots Cladodes Primordium Asparagus Asparagus Plant Leaf development Research Articles Phylogeny Plant Shoots Cell Proliferation |
| Zdroj: | The Plant Cell. 24:929-940 |
| ISSN: | 1532-298X 1040-4651 |
| DOI: | 10.1105/tpc.111.092924 |
| Popis: | The genus Asparagus is unusual in producing axillary, determinate organs called cladodes, which may take on either a flattened or cylindrical form. Here, we investigated the evolution of cladodes to elucidate the mechanisms at play in the diversification of shoot morphology. Our observations of Asparagus asparagoides , which has leaf-like cladodes, showed that its cladodes are anatomically and developmentally similar to leaves but differ in the adaxial/abaxial polarity of the vasculature. In addition to the expression of an ortholog of KNAT1 , orthologous genes that are normally expressed in leaves, ASYMMETRIC LEAVES1 and HD-ZIPIII , were found to be expressed in cladode primordia in a leaf-like manner. The cylindrical cladodes of Asparagus officinalis showed largely similar expression patterns but showed evidence of being genetically abaxialized. These results provide evidence that cladodes are modified axillary shoots, suggest that the co-option of preexisting gene networks involved in leaf development transferred the leaf-like form to axillary shoots, and imply that altered expression of leaf polarity genes led to the evolution of cylindrical cladodes in the A. officinalis clade. |
| Databáze: | OpenAIRE |
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