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Author (up) Orellana, D.; Machuca, D.; Ibeas, M.A.; Estevez, J.M.; Poupin, M.J.
Title Plant-growth promotion by proteobacterial strains depends on the availability of phosphorus and iron in Arabidopsis thaliana plants Type
Year 2022 Publication Frontiers In Microbiology Abbreviated Journal Front. Microbiol.
Volume 13 Issue Pages 1083270
Keywords plant-growth promoting bacteria; phosphateiron; PSR; beneficial bacteria; plant nutrition; plant microbiome; nutrient deficiency
Abstract Phosphorus (as phosphate, Pi) and iron (Fe) are critical nutrients in plants that are often poorly available in the soil and can be microbially affected. This work aimed to evaluate how plant-rhizobacteria interaction changes due to different Pi or Fe nutritional scenarios and to study the underlying molecular mechanisms of the microbial modulation of these nutrients in plants. Thus, three proteobacteria (Paraburkholderia phytofirmans PsJN, Azospirillum brasilense Sp7, and Pseudomonas putida KT2440) were used to inoculate Arabidopsis seeds. Additionally, the seeds were exposed to a nutritional factor with the following levels for each nutrient: sufficient (control) or low concentrations of a highly soluble source or sufficient concentrations of a low solubility source. Then, the effects of the combinatorial factors were assessed in plant growth, nutrition, and genetic regulation. Interestingly, some bacterial effects in plants depended on the nutrient source (e.g., increased aerial zones induced by the strains), and others (e.g., decreased primary roots induced by Sp7 or KT2440) occurred regardless of the nutritional treatment. In the short-term, PsJN had detrimental effects on plant growth in the presence of the low-solubility Fe compound, but this was not observed in later stages of plant development. A thorough regulation of the phosphorus content was detected in plants independent of the nutritional treatment. Nevertheless, inoculation with KT2440 increased P content by 29% Pi-deficiency exposed plants. Conversely, the inoculation tended to decrease the Fe content in plants, suggesting a competition for this nutrient in the rhizosphere. The P-source also affected the effects of the PsJN strain in a double mutant of the phosphate starvation response (PSR). Furthermore, depending on the nutrient source, PsJN and Sp7 strains differentially regulated PSR and IAA- associated genes, indicating a role of these pathways in the observed differential phenotypical responses. In the case of iron, PsJN and SP7 regulated iron uptake-related genes regardless of the iron source, which may explain the lower Fe content in inoculated plants. Overall, the plant responses to these proteobacteria were not only influenced by the nutrient concentrations but also by their availabilities, the elapsed time of the interaction, and the specific identities of the beneficial bacteria.
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1664-302X ISBN Medium
Area Expedition Conference
Notes WOS:000904176100001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1702
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Author (up) Romero-Romero, J.L.; Inostroza-Blancheteau, C.; Orellana, D.; Aquea, F.; Reyes-Diaz, M.; Gil, P.M.; Matte, J.P.; Arce-Johnson, P.
Title Stomata regulation by tissue-specific expression of the Citrus sinensis MYB61 transcription factor improves water-use efficiency in Arabidopsis Type
Year 2018 Publication Plant Physiology And Biochemistry Abbreviated Journal Plant Physiol. Biochem.
Volume 130 Issue Pages 54-60
Keywords Drought tolerance; Abiotic stress; Water use efficiency; Arabidopsis; Cisgenic; MYB61 transcription factor; Citrus
Abstract Water-use efficiency (WUE) is a quantitative measurement of biomass produced per volume of water transpired by a plant. WUE is an important physiological trait for drought response to mitigate the water deficiency. In this work, a cisgenic construction from Citrus sinensis was developed and its function in the improvement of WUE was evaluated in Arabidopsis. Sequences of the CsMYB61 coding region, a transcription factor implicated in the closure of stomata, together with a putative stomata-specific promoter from CsMYB.1.5, were identified and cloned. The protein encoded in the CsMYB61 locus harbors domains and motifs characteristic of MYB61 proteins. In addition, a 1.2 kb promoter region of the gene CsMYB15 (pCsMYB15) containing regulatory elements for expression in guard cells and in response to Abscisic Acid (ABA) and light was isolated. In Arabidopsis, pCsMYB15 directs the expression of the reporter gene GUS in stomata in the presence of light. In addition, transgenic lines expressing the CsMYB61 coding region under transcriptional control of pCsMYB15 have a normal phenotype under in vitro and greenhouse conditions. These transgenic lines exhibited a smaller opening of the stomata pore, lower stomatal conductance and respiration rate, enhanced sensitivity to exogenous ABA, and high drought stress tolerance. Our results indicate that stomata-specific expression of CsMYB61 enhances water use efficiency under drought conditions in Arabidospis.
Address [Romero-Romero, Jesus L.; Orellana, Daniela; Pablo Matte, Juan; Arce-Johnson, Patricio] Pontificia Univ Catolica Chile, Fac Ciencias Biol, Dept Genet Mol & Microbiol, Santiago, Chile, Email: parce@bio.puc.cl
Corporate Author Thesis
Publisher Elsevier France-Editions Scientifiques Medicales Elsevier Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0981-9428 ISBN Medium
Area Expedition Conference
Notes WOS:000444789200006 Approved
Call Number UAI @ eduardo.moreno @ Serial 915
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