Rab11 GTPase-Regulated Membrane Trafficking Is Crucial for Tip-Focused Pollen Tube Growth in Tobacco
| Autor: | Hen-Ming Wu, Alice Y. Cheung, Barend H. J. de Graaf, Tatyana Andreyeva, Kathryn Levasseur, Marcia J. Kieliszewski |
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| Rok vydání: | 2005 |
| Předmět: |
Recombinant Fusion Proteins
Nicotiana tabacum Molecular Sequence Data Flowers Plant Science GTPase medicine.disease_cause Cell Wall Pollen Tobacco otorhinolaryngologic diseases medicine Pollen tube tip Research Articles Plant Proteins biology Vesicle Cell Membrane Membrane Proteins food and beverages Biological Transport Cell Biology biology.organism_classification Sperm Actins Endocytosis Cell biology rab GTP-Binding Proteins Mutation Pollen tube Rab |
| Zdroj: | The Plant Cell. 17:2564-2579 |
| ISSN: | 1532-298X |
| Popis: | Pollen tube growth is a polarized growth process whereby the tip-growing tubes elongate within the female reproductive tissues to deliver sperm cells to the ovules for fertilization. Efficient and regulated membrane trafficking activity incorporates membrane and deposits cell wall molecules at the tube apex and is believed to underlie rapid and focused growth at the pollen tube tip. Rab GTPases, key regulators of membrane trafficking, are candidates for important roles in regulating pollen tube growth. We show that a green fluorescent protein–tagged Nicotiana tabacum pollen-expressed Rab11b is localized predominantly to an inverted cone-shaped region in the pollen tube tip that is almost exclusively occupied by transport vesicles. Altering Rab11 activity by expressing either a constitutive active or a dominant negative variant of Rab11b in pollen resulted in reduced tube growth rate, meandering pollen tubes, and reduced male fertility. These mutant GTPases also inhibited targeting of exocytic and recycled vesicles to the pollen tube inverted cone region and compromised the delivery of secretory and cell wall proteins to the extracellular matrix. Properly regulated Rab11 GTPase activity is therefore essential for tip-focused membrane trafficking and growth at the pollen tube apex and is pivotal to reproductive success. |
| Databáze: | OpenAIRE |
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