RopGEF1 Plays a Critical Role in Polar Auxin Transport in Early Development
| Autor: | Alice Y. Cheung, Xiaowei Wu, Li-zhen Tao, Hen-Ming Wu, Qingkun Dong, Yuting Liu, Jia-bao Huang, Daniel Kita, Guolan Liu, Xiaoyue Zhu |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Auxin influx food.ingredient Physiology Meristem Arabidopsis Plant Science Plant Roots 03 medical and health sciences food Auxin Genetics Arabidopsis thaliana Guanine Nucleotide Exchange Factors heterocyclic compounds chemistry.chemical_classification biology Indoleacetic Acids Arabidopsis Proteins fungi food and beverages Articles Apical membrane biology.organism_classification Actins Cell biology 030104 developmental biology chemistry Biochemistry Seedlings Seeds Guanine nucleotide exchange factor Polar auxin transport Cotyledon |
| Zdroj: | Plant physiology. 175(1) |
| ISSN: | 1532-2548 |
| Popis: | Polar auxin transport, facilitated by the combined activities of auxin influx and efflux carriers to maintain asymmetric auxin distribution, is essential for plant growth and development. Here, we show that Arabidopsis (Arabidopsis thaliana) RopGEF1, a guanine nucleotide exchange factor and activator of Rho GTPases of plants (ROPs), is critically involved in polar distribution of auxin influx carrier AUX1 and differential accumulation of efflux carriers PIN7 and PIN2 and is important for embryo and early seedling development when RopGEF1 is prevalently expressed. Knockdown or knockout of RopGEF1 induces embryo defects, cotyledon vein breaks, and delayed root gravity responses. Altered expression from the auxin response reporter DR5rev:GFP in the root pole of RopGEF1-deficient embryos and loss of asymmetric distribution of DR5rev:GFP in their gravistimulated root tips suggest that auxin distribution is affected in ropgef1 mutants. This is reflected by the polarity of AUX1 being altered in ropgef1 embryos and roots, shifting from the normal apical membrane location to a basal location in embryo central vascular and root protophloem cells and also reduced PIN7 accumulation at embryos and altered PIN2 distribution in gravistimulated roots of mutant seedlings. In establishing that RopGEF1 is critical for AUX1 localization and PIN differential accumulation, our results reveal a role for RopGEF1 in cell polarity and polar auxin transport whereby it imapcts auxin-mediated plant growth and development. |
| Databáze: | OpenAIRE |
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