Cluster roots of Embothrium coccineum modify their metabolism and show differential gene expression in response to phosphorus supply
| Autor: | Rodrigo Hasbún, Carlos Henríquez-Castillo, Mabel Delgado, Patricia Hanna, Ariana Bertin-Benavides, Alejandra Zúñiga-Feest, Marjorie Reyes-Díaz, Francisco Sepúlveda V |
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| Rok vydání: | 2020 |
| Předmět: |
0106 biological sciences
0301 basic medicine Physiology chemistry.chemical_element Gene Expression Plant Science 01 natural sciences Plant Roots Proteaceae 03 medical and health sciences chemistry.chemical_compound Soil Nutrient Biosynthesis Gene expression Botany Genetics Carboxylate biology Phosphorus Embothrium coccineum Metabolism biology.organism_classification 030104 developmental biology chemistry Phosphoenolpyruvate carboxylase 010606 plant biology & botany |
| Zdroj: | Plant physiology and biochemistry : PPB. 161 |
| ISSN: | 1873-2690 |
| Popis: | Embothrium coccineum produces cluster roots (CR) to acquire sparingly soluble phosphorus (P) from the soil through the exudation of organic compounds. However, the physiological mechanisms involved in carbon drainage through its roots, as well as the gene expression involved in the biosynthesis of carboxylates and P uptake, have not been explored. In this work, we evaluated the relationship between carboxylate exudation rate and phosphoenolpyruvate carboxylase (PEPC) activity in roots of E. coccineum seedlings grown in a nutrient-poor volcanic substrate. Second, we evaluated CR formation and the expression of genes involved in the production of carboxylates (PEPC) and P uptake (PHT1) in E. coccineum seedlings grown under three different P supplies in hydroponic conditions. Our results showed that the carboxylate exudation rate was higher in CR than in non-CR, which was consistent with the higher PEPC activity in CR. We found higher CR formation in seedlings grown at 5 μM of P supply, concomitant with a higher expression of EcPEPC and EcPHT1 in CR than in non-CR. Overall, mature CR of E. coccineum seedlings growing on volcanic substrates poor in nutrients modify their metabolism compared to non-CR, enhancing carboxylate biosynthesis and subsequent carboxylate exudation. Additionally, transcriptional responses of EcPEPC and EcPHT1 were induced simultaneously when E. coccineum seedlings were grown in P-limited conditions that favored CR formation. Our results showed, for the first time, changes at the molecular level in CR of a species of the Proteaceae family, demonstrating that these root structures are highly specialized in P mobilization and uptake. |
| Databáze: | OpenAIRE |
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