Transmitting tissue architecture in basal-relictual angiosperms: Implications for transmitting tissue origins
| Autor: | Greta Chiu, Peter H. Weston, Peter Bernhardt, Katerina Hristova-Sarkovski, Joelle Lyew, Vincenza Pontieri, Shaheen Bagha, Tammy L. Sage, Veronica Koehl |
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| Rok vydání: | 2009 |
| Předmět: |
0106 biological sciences
Most recent common ancestor Gametophyte 0303 health sciences Tissue architecture Gynoecium Plant Science Biology medicine.disease_cause 010603 evolutionary biology 01 natural sciences Cell biology Stigma (anatomy) Extracellular matrix 03 medical and health sciences Pollen Botany Genetics medicine Pollen tube Ecology Evolution Behavior and Systematics 030304 developmental biology |
| Zdroj: | American Journal of Botany. 96:183-206 |
| ISSN: | 0002-9122 |
| DOI: | 10.3732/ajb.0800254 |
| Popis: | Carpel transmitting tissue is a major floral innovation that is essential for angiosperm success. It facilitates the rapid adhesion, hydration, and growth of the male gametophyte to the female gametophyte. As well, it functions as a molecular screen to promote male gametophytic competition and species-specific recognition and compatibility. Here, we characterize the transmitting tissue extracellular matrix (ECM) and pollen tube growth in basal-relictual angiosperms and test the hypothesis that a freely flowing ECM (wet stigma) was ancestral to a cuticle-bound ECM (dry stigma). We demonstrate that the most recent common ancestor of extant angiosperms produced an ECM that was structurally and functionally equivalent to a dry stigma. Dry stigmas are composed of a cuticle and primary wall that contains compounds that facilitate the adhesion and growth of the male gametophyte. These compounds include methyl-esterified homogalacturonans, arabinogalactan-proteins, and lipids. We propose that transmitting tissue evolved in concert with an increase in cuticle permeability that resulted from modifications in the biosynthesis and secretion of fatty acids needed for cuticle construction. Increased cuticle permeability exposed the male gametophyte to pre-existing molecules that enabled rapid male gametophyte adhesion, hydration, and growth as well as species-specific recognition and compatibility. |
| Databáze: | OpenAIRE |
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