Pablo del Cerro

Pablo del Cerro
John Innes Centre · Department of Cell and Developmental Biology

PhD

About

18
Publications
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Introduction
Pablo Del Cerro Sanchez currently works at the Cell and Developmental Biology department of the John innes Centre. Pablo does research in Microbiology, Molecular Biology, Plant Science, Agronomy and Biotechnology.

Publications

Publications (18)
Article
Full-text available
Nodulation and symbiotic nitrogen fixation are mediated by several genes, both of the host legume and of the bacterium. The rhizobial regulatory nodD gene plays a critical role, orchestrating the transcription of the other nodulation genes. Rhizobium tropici strain CIAT 899 is an effective symbiont of several legumes-with an emphasis on common bean...
Article
Full-text available
In the symbiotic associations between rhizobia and legumes, NodD promotes the expression of the nodulation genes in the presence of appropriate flavonoids. This set of genes is implied in the synthesis of Nodulation factors, which are responsible for launching the nodulation process. Rhizobium tropici CIAT 899 is the most successful symbiont of Pha...
Article
Full-text available
Nuclear movement is involved in cellular and developmental processes across eukaryotic life, often driven by Linker of Nucleoskeleton and Cytoskeleton (LINC) complexes, which bridge the nuclear envelope (NE) via the interaction of Klarsicht/ANC-1/Syne-1 Homology (KASH) and Sad1/UNC-84 (SUN) proteins. Arabidopsis (Arabidopsis thaliana) LINC complexe...
Article
Full-text available
Rhizobium tropici CIAT 899 is a broad host-range rhizobial strain that establishes symbiotic interactions with legumes and tolerates different environmental stresses such as heat, acidity or salinity. This rhizobial strain produces a wide variety of symbiotically active nodulation factors (NF) induced by the presence of plant-released flavonoids, b...
Article
Full-text available
Significance Oscillations in intracellular calcium concentration play an essential role in the regulation of multiple cellular processes. In plants capable of root endosymbiosis with nitrogen-fixing bacteria and/or arbuscular mycorrhizal fungi, nuclear localized calcium oscillations are essential to transduce the microbial signal. Although the ion...
Article
In the symbiotic associations between rhizobia and legumes, the NodD regulators orchestrate the transcription of the specific nodulation genes. This set of genes is involved in the synthesis of nodulation factors, which are responsible for initiating the nodulation process. Rhizobium tropici CIAT 899 is the most successful symbiont of Phaseolus vul...
Article
Full-text available
Aims The symbiosis between rhizobia and their host legumes is initiated by a complex molecular dialogue in which the activation of bacterial NodD proteins by appropriate plant flavonoids triggers the expression of the bacterial nodulation (nod) genes. These genes are involved in the synthesis and export of the Nodulation factors (NF), which are sig...
Article
Rhizobium tropici strain CIAT 899 possesses outstanding agronomic properties as it displays tolerance to environmental stresses, a broad host range and high effectiveness in fixing nitrogen with the common bean (Phaseolus vulgaris L.); in addition, it carries intriguing features such as five copies of the regulatory nodD gene, and the capacity to s...
Article
Full-text available
The symbiosis between rhizobia and legumes is characterized by a complex molecular dialogue in which the bacterial NodD protein plays a major role due to its capacity to activate the expression of the nodulation genes in the presence of appropiate flavonoids. These genes are involved in the synthesis of molecules, the nodulation factors (NF), respo...
Article
Full-text available
Quorum‐sensing (QS) mechanisms are important in intra‐ and inter‐specific communication among bacteria. We investigated QS mechanisms in Bradyrhizobium japonicum strain CPAC 15 and Azospirillum brasilense strains Ab‐V5 and Ab‐V6, used in commercial co‐inoculants for the soybean crop in Brazil. A transconjugant of CPAC 15‐QS with partial inactivatio...
Article
Full-text available
Azospirillum brasilense is an important plant-growth promoting bacterium (PGPB) that requires several critical steps for root colonization, including biofilm and exopolysaccharide (EPS) synthesis and cell motility. In several bacteria these mechanisms are mediated by quorum sensing (QS) systems that regulate the expression of specific genes mediate...
Article
Full-text available
Simultaneous quantification of transcripts of the whole bacterial genome allows the analysis of the global transcriptional response under changing conditions. RNA-seq and microarrays are the most used techniques to measure these transcriptomic changes, and both complement each other in transcriptome profiling. In this review, we exhaustively compil...
Article
Full-text available
Background Common bean (Phaseolus vulgaris L.) is the most important legume cropped worldwide for food production and its agronomic performance can be greatly improved if the benefits from symbiotic nitrogen fixation are maximized. The legume is known for its high promiscuity in nodulating with several Rhizobium species, but those belonging to the...
Article
Full-text available
The establishment of nitrogen-fixing rhizobium-legume symbioses requires a highly complex cascade of events. In this molecular dialogue the bacterial NodD transcriptional regulators in conjunction with plant inducers, mostly flavonoids, are responsible for the biosynthesis and secretion of Nod factors which are key molecules for successful nodulati...
Article
Full-text available
Rhizobium tropici strain CIAT 899 establishes effective symbioses with several legume species, including Phaseolus vulgaris and Leucaena leucocephala. This bacterium synthesizes a large variety of nodulation factors in response to nod-gene inducing flavonoids and, surprisingly, also under salt stress conditions. The aim of this study was to identif...
Article
Full-text available
Background Transcription of nodulation genes in rhizobial species is orchestrated by the regulatory nodD gene. Rhizobium tropici strain CIAT 899 is an intriguing species in possessing features such as broad host range, high tolerance of abiotic stresses and, especially, by carrying the highest known number of nodD genes—five—and the greatest divers...
Article
Full-text available
Bacterial surface components, especially exopolysaccharides, in combination with bacterial Quorum Sensing signals are crucial for the formation of biofilms in most species studied so far. Biofilm formation allows soil bacteria to colonize their surrounding habitat and survive common environmental stresses such as desiccation and nutrient limitation...
Article
Full-text available
Plant growth-promoting rhizobacteria (PGPR) are free-living bacteria which actively colonize plant roots, exerting beneficial effects on plant development. The PGPR may (i) promote the plant growth either by using their own metabolism (solubilizing phosphates, producing hormones or fixing nitrogen) or directly affecting the plant metabolism (increa...

Projects

Projects (2)
Project
Sinorhizobium fredii HH103 is a broad host-range rhizobial strain able to nodulate dozens of legume Genera. It is probably the best characterized S. fredii strain, together with strain NGR234. Among the factors essential for this bacterium to nodulate such a huge number of legume species is the type III secretion system (T3SS). This secretion system is involved in host-range determination, symbiotic efficiency and suppression of host-defense responses. Now that most of the effectors have been identified in this strain, it is necessary to identify their plant targets to determine their function in symbiosis as well as the plant pathways they interfere. We are specially interested in the Rhizobium-specific effectors NopC, NopI, NopL, and NopP since no other homologues have been found in other plant or animal pathogens (in some cases even in bacteria other than those belonging to the Genus Sinorhizobium). We are also interested in the biotechnological use of this secretion system in agriculture.
Project
Rhizobium tropici CIAT 899 is peculiar because it synthesizes nodulation factors (LCOs) in the absence of flavonoids and in the presence of salt. This new regulatory circuit seems to be mediated by the nodD2 and araC genes while nodD1 is directly involved in the activation of nodulation genes in the presence of flavonoids. One of the proposed objectives of this project is to carry out a transcriptome analysis of mutants in these nodD genes and araC to find differentially expressed mRNAs in control conditions, in the presence of the flavonoid apigenin (3.7 uM) and in the presence of salt stress (300 mM NaCl) and determine which genes are under the influence of these transcriptional regulators. The interesting genes will be mutated and its symbiotic phenotype and other interesting features, such as the production of EPS, motility or the production of AHLs, which may be important in colonization. CIAT 899 harbours three copies of the nodA gene in its symbiotic plasmid, and so far it is not known whether they are functional copies. Therefore, a nonpolar deletion of the nodA1 gene, located in the operon nodA1BCSUIJHPQ, will be carried out. We will determine if this mutant is still able to nodulate bean and leucena. In the case that the nodA1 mutant nodulates these plants, we will determine whether the gene responsible for this phenotype is nodA2 and / or nodA3. A triple nodA mutant will also be constructed. One by one the wild type copies of the three nodA genes will be untroduced in the triple mutant in order to determine the function of each nodA gene in symbiosis. The LCOs profiles of these strains also will be analysed. Moreover, it is known that LCOs applied as commercial inoculants in roots and leaves affects the crops productivity. However, it is unknown the molecular mechanisms triggered in plants. In this context, besides the determination by MALDI-imaging if LCOs, applied in root and leaf is able to penetrate into the plant tissues. It will also be studied if the LCOs application triggers responses as the presence of reactive oxygen species (ROS) and if it modified parameters such as chlorophyll content or total plant nitrogen content. In these studies a legume (bean) and a cereal (corn) will be used. Finally, since the CIAT 899/bean symbiosis has a low productivity in comparison to other symbiotic associations, studies of inoculation of bean plants with CIAT 899 inoculants with high bacterial density and stability will be carried out. In addition, pre-activated rhizobia, grown under saline stress, for biosynthesis of LCOs, will be assayed. In other cases, also coinoculation studies using plant growth promoting bacteria, such as Azospirillum strains and other plant growth promoting rhizobacteria will be analysed. The same studies will be undertaken, also in corn plants. In addition to these inoculants, an inoculant with LCOs molecules will also be assayed in order to determine their effectiveness in promoting plant growth. These LCOs will be applied in root and leaf. We now know that certain CIAT 899 mutants produce a greater diversity of LCOs than the parental strain. Therefore, the effect of these LCOs will be analysed in bean and corn and compared with the results obtained with the LCOs produced by the wild-type strain. A special attention to the development of these innovative inoculants will be paid.