Developmental Genetics of Corolla Tube Formation: Role of the tasiRNA-ARF Pathway and a Conceptual Model
| Autor: | Baoqing Ding, Vandana Gurung, Qiaoshan Lin, Lauren E. Stanley, Janelle M. Sagawa, Pamela K. Diggle, Yao-Wu Yuan, Rui Xia, Matthew Strobel, Blake C. Meyers |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
0106 biological sciences
0301 basic medicine Mutant Plant Science 01 natural sciences Plant reproduction 03 medical and health sciences Auxin Nectar Primordium Mimulus 030304 developmental biology chemistry.chemical_classification Tube formation 0303 health sciences biology fungi Wild type food and beverages Cell Biology biology.organism_classification Cell biology 030104 developmental biology chemistry Petal Polar auxin transport 010606 plant biology & botany |
| Zdroj: | The Plant Cell. 32:3452-3468 |
| ISSN: | 1532-298X 1040-4651 |
| DOI: | 10.1105/tpc.18.00471 |
| Popis: | More than 80,000 angiosperm species produce flowers with petals fused into a corolla tube. As an important element of the tremendous diversity of flower morphology, the corolla tube plays a critical role in many specialized interactions between plants and animal pollinators (e.g., beeflies, hawkmoths, hummingbirds, nectar bats), which in turn drives rapid plant speciation. Despite its clear significance in plant reproduction and evolution, the corolla tube remains one of the least understood plant structures from a developmental genetics perspective. Through mutant analyses and transgenic experiments, here we show that the tasiRNA-ARF pathway is required for corolla tube formation in the monkeyflower speciesMimulus lewisii. Loss-of-function mutations in theM. lewisiiorthologs ofARGONAUTE7andSUPPRESSOR OF GENE SILENCING 3cause a dramatic decrease in abundance ofTAS3-derived small RNAs and a moderate up-regulation ofAUXIN RESPONSE FACTOR 3(ARF3) andARF4, which lead to inhibition of lateral expansion of the bases of petal primordia and complete arrest of the upward growth of the inter-primordial regions, resulting in unfused corollas. By using an auxin reporter construct, we discovered that auxin distribution is continuous along the petal primordium base and the inter-primordial region during the critical stage of corolla tube formation in the wild-type, and that this auxin distribution is much weaker and more restricted in the mutant. Together, these results suggest a new conceptual model highlighting the central role of auxin directed synchronized growth of the petal primordium base and the inter-primordial region in corolla tube formation. |
| Databáze: | OpenAIRE |
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