Beatriz Xoconostle-Cázares

• Center for Research and Advanced Studies of the National Polytechnic Institute

Plant breeding plays a pivotal role in the development of improved tomato cultivars, addressing various challenges faced by this crop worldwide. Tomato crop yield is affected by biotic and abiotic stress, including diverse pathogens and pests, extreme temperatures, drought, and soil salinity, thus affecting fruit quality, and overall crop productiv...

Huanglongbing, also known as citrus greening, is currently the most devastating citrus disease with limited success in prevention and mitigation. A promising strategy for Huanglongbing control is the use of antimicrobials fused to a carrier protein (phloem protein of 16 kDa or PP16) that targets vascular tissues. This study investigated the effects...

Tree roots are associated with a high diversity of microorganisms that play key roles in soil fertility and plant nutrition and health. Here we examine the composition and diversity of bacterial community in ectomycorrhizal root (ECR) and their ectomycorrhizosphere (EMR) of the Neotropical tree Pinus montezumae inoculated with Laccaria laccata and...

Modern crop production relies on the application of chemical pesticides and fertilizers causing environmental and economic challenges. In response, less environmentally impactful alternatives have emerged such as the use of beneficial microorganisms. These microorganisms, particularly plant growth-promoting bacteria (PGPB), have demonstrated their...

Crop genetic improvement in Latin America is necessary to address the region’s agricultural challenges and to enhance food security. The use of advanced biotechnological techniques, such as genetic engineering and molecular breeding, should enable the development of crops with improved traits tailored to the unique agroecological conditions prevale...

Members of the phloem protein 16 (PP16) gene family are induced by elicitors in rice and the corresponding proteins from cucurbits, which display RNA binding and intercellular transport activities, are accumulated in phloem sap. These proteins facilitate the movement of protein complexes through the phloem translocation flow and may be involved in...

Simple Summary Insects are rapidly adapting to novel niches, such as crops. This is the case of the sugarcane aphid, a pest from Africa that is currently spreading worldwide. In the absence of males, aphids asexually generate many females, causing important economic losses for farmers. The microbiota in the insect was characterized and the presence...

Pancreatic ductal adenocarcinoma (PDAC) has the worst prognosis among all human cancers as it is highly resistant to che-motherapy. K-Ras mutations usually trigger the development and progression of PDAC. We hypothesized that compounds stabilizing the KRas4B/PDE6δ complex could serve as PDAC treatments. Using in silico approaches, we identified the...

Ouabain, an organic compound with the ability to strengthen the contraction of the heart muscle, was originally derived from plants. It has been observed that certain mammalian species, including humans, naturally produce ouabain, leading to its classification as a new type of hormone. When ouabain binds to Na+/K+-ATPase, it elicits various physiol...

During a study of fungal species with biocultural importance in the Sierra Mixe in the state of Oaxaca, Mexico, specimens belonging to the genus Calostoma were collected in 2015. Morphological characteristics, electron micrographs and phylogenetic analyses of the collected specimens were used to identify the fungi at the species level. Herein we de...

Long-distance signaling molecules in plants, including different RNA species, play a crucial role in the development and environmental responses. Among these mobile signals, the Translationally Controlled Tumor Protein (TCTP) mRNA is one of the most abundant. TCTP regulates cell-cycle progression and programmed cell death and is involved in respons...

The Translationally Controlled Tumor Protein (TCTP) is a multifunctional protein found in most eukaryotic taxa. In plants, TCTP regulates cell-cycle progression as well as programmed cell death and is involved in plant regeneration and responses to abiotic and biotic stress, among other functions. Additionally, there is evidence that the transcript...

The pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has affected millions of people worldwide. Public health strategies to reduce viral transmission are based on widespread diagnostic testing to detect and isolate contagious patients. Several reverse transcription (RT)-PCR tests, along with other SARS-CoV-2 diagn...

Although real‐time quantitative reverse transcription polymerase chain reaction (RT‐qPCR) is the gold standard for detecting the virus severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) and other pathogens, the coronavirus disease 2019 (COVID‐19) pandemic has highlighted the scarcity of instruments, devices, and reagents for polymerase ch...

Drought is by far one of the main agricultural problems affecting crop production worldwide, generating even more economic losses than all biotic factors combined. Humankind has pursued the improvement of crops to enhance plant productivity under water-limiting conditions since the dawn of agriculture, initially through conventional breeding and mo...

Nucleotide-binding leucine-rich repeat (NLR) plant immune receptors mediate the recognition and activation of defense signaling pathways in response to intra- and extracellular pathogens. Several NLR such as Tm-2 and Tm-2² have been introgressed into commercial solanaceous varieties to confer protection against different tobamoviruses. Particularly...

The β1-subunit of the Na⁺/K⁺-ATPase is a cell membrane protein, beyond its classic functions, it is also a cell adhesion molecule. β1-subunits on the lateral membrane of dog kidney epithelial cells trans-interact with β1-subunits from another neighboring cells. The β-β interaction is essential for the formation and stabilization of intercellular ju...

Reverse transcriptases (RTs) are RNA-dependent DNA polymerases able of synthesizing DNA (complementary DNA or cDNA) from an RNA template. RTs are especially useful in RNA-based nucleic acid detection techniques. Due to its high catalytic activity and fidelity, one of the most widely used RTs in diagnostics and molecular biology is the RT from the M...

Bst is a type I DNA polymerase with strong strand displacement activity isolated from Geobacillus stearothermophyllus (previously Bacillus steathermophylus). Bst enzyme is a gold standard in isothermal nucleic acid amplification diagnostic techniques, especially in Loop-mediated isothermal amplification (LAMP). LAMP is a low-cost technique, provide...

CmNACP1 mRNA has been shown to move long distance through the phloem in Cucurbita maxima (pumpkin) and through a graft junction. Whereas the phloem transport of several different mRNAs has been documented in other systems as well, its function remains, for most of these RNAs, largely unknown. To gain insight into the possible role of these RNAs, we...

Citrus tristeza virus (CTV) is an important threat to the global citrus industry, causing severe economic losses worldwide. The disease management strategies are focused on vector control, tree culling, and the use of resistant varieties and rootstocks. Sweet orange (Citrus sinensis) trees showing either severe or mild CTV symptoms have been observ...

The plant vasculature is a central organ for long-distance transport of nutrients and signaling molecules that coordinate vegetative and reproductive processes, and adaptation response mechanisms to biotic and abiotic stress. In angiosperms, the sieve elements are devoid of nuclei, thus depending on the companion cells for the synthesis of RNA and...

In the present study, a droplet digital PCR assay was developed for detection of Tomato brown rugose fruit virus, a new Tobamovirus of tomato and other solanaceous plants, which expands the diagnostic strategies for this pathogen. Candidate reference DNA material was also obtained to be employed as positive control in tomato and pepper samples. Rec...

Background The rapid mutation of the H1N1 strain of the Influenza virus makes it quite difficult to treat once the infection has spread. The development of new treatments based on the destabilization of the genetic material, regardless of the sequence, is necessary. Objective The study aims to evaluate the antiviral properties of Pt/TiO2-SiO2 bion...

Citrus are among the most prevailing fruit crops produced worldwide. The implementation of effective and reliable breeding programs is essential for coping with the increasing demands of satisfactory yield and quality of the fruit as well as to deal with the negative impact of fast-spreading diseases. Conventional methods are time-consuming and of...

Solanum lycopersicum L. is affected among other pests and diseases, by the actinomycete Clavibacter michiganensis subsp. michiganensis (Cmm), causing important economic losses worldwide. Antimicrobial peptides (AMPs) are amphipathic cationic oligopeptides with which the development of pathogenic microorganisms has been inhibited. Therefore, in this...

The Receptor-Binding Domain (RBD) of the Spike (S) protein from Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has glycosylation sites which can limit the production of reliable antigens expressed in prokaryotic platforms, due to glycan-mediated evasion of the host immune response. However, protein regions without glycosylated residue...

Tomato brown rugose fruit virus (ToBRFV) is a novel tobamovirus initially reported in Jordan and Israel, and, more recently, in Europe, China, the USA and México, which causes severe symptoms in tomato and pepper, as well as in other members of Solanaceae. ToBRFV can cause important losses so early detection is crucial to help thwart its dispersal,...

The AVRPPHB SUSCEPTIBLE1 (PBS1) and RESISTANCE TO PSEUDOMONAS SYRINGAE 5 (RPS5) proteins are involved in signal transduction to evoke innate plant immune response. In Arabidopsis, PBS1 is cleaved by the AvrPphB (Pseudomonas phaseolicola Avirulence protein B) protease, activating RPS5 and turning in a hypersensitive response (HR). We searched for PB...

Xylella fastidiosa is a xylem-inhabiting phytopathogenic bacterium that affects diverse agriculturally relevant crops. In Mexico, X. fastidiosa has been reported in the states of Baja California, Coahuila, and Querétaro. In order to determine the genetic diversity of this bacterium in Mexico, 408 grapevine samples were collected from the main produ...

Drought is one of the main abiotic factors that affect agricultural productivity, jeopardizing food security. Modern biotechnology is a useful tool for the generation of stress-tolerant crops, but its release and field-testing involves complex regulatory frameworks. However, gene editing technology mediated by the CRISPR/Cas9 system is a suitable s...

Introduction and aim Occult hepatitis B virus infection (OBI) is characterized by the presence of replication-competent hepatitis B virus (HBV) DNA in the liver and/or serum of patients with undetectable levels of the HBV surface antigen (HBsAg). Due to the shared infection routes HIV positive patients are at higher risk of developing OBI, thus, th...

Infectivity of an alfalfa mosaic virus (AMV) isolate from Leonotis nepetaefolia in different tomato cultivars was analyzed. Symptoms typical of AMV infection were observed in indicator plants, but not in Flora Dade and Rio Grande tomato cultivars; however, mild symptoms were observed in cv. Rutgers. Furthermore, at least 1 kb of the 3´ segment of R...

Coffee is an important crop worldwide, grown on about 10 million hectares in tropical regions including Latin America, Africa, and Asia. The genus Coffea includes more than 100 species; most are diploid, except for C. arabica, which is allotetraploid and autogamous. The genetic diversity of commercial coffee is low, likely due to it being self-poll...

Post-translational modifications of histone H3 N-terminal tails are key epigenetic regulators of virulence gene expression and sexual commitment in the human malaria parasite Plasmodium falciparum. Here, we identify proteolytic clipping of the N-terminal tail of nucleosome-associated histone H3 at amino acid position 21 as a new chromatin modificat...

Citrus huanglongbing (HLB) is a devastating disease associated with Candidatus Liberibacter asiaticus spp. (CLas), a bacterium restricted to the sieve tube system of the phloem that is transmitted by the psyllid vector, Diaphorina citri. In this study, the human antimicrobial peptides, lysozyme and β-defensin 2, were targeted to the vascular tissue...

We analyzed the infection of the model plant Arabidopsis thaliana by the basidiomycete phytopathogen of cereals Sporisorium reilianum in order to use it as an experimental pathosystem model. Sterile plantlets of A. thaliana were grown on MS solid medium, and inoculated with haploid strains or mixtures of sexually compatible S. reilianum strains. In...

p> Background. All of the Pinaceae require the ectomycorrhizal interaction to survive under field conditions. However, their use has not traditionally been considered in the production of forest plants in Neotropical areas. Hypothesis. There will be an increase in plant quality in greenhouse and in survival in the field of Pinus pringlei inoculate...

Maize is a staple crop in many developing countries and its cultivation is challenged by both biotic and abiotic stresses. Trehalose is frequently used as a carbon source in many organisms but, its function is equally important as an osmoprotectant and signaling molecule. In this work, we explored the effect of the expression of a trehalase antisen...

The translationally controlled tumor protein (TCTP) is a small, multifunctional protein found in most, if not all, eukaryotic lineages, involved in a myriad of key regulatory processes. Among these, the control of proliferation and inhibition of cell death, as well as differentiation, are the most important, and it is probable that other responses...

Background Dried blood and serum samples are useful resources for detecting antiviral antibodies. The conditions for elution of the sample need to be optimized for each disease. Dengue is a widespread disease in Mexico which requires continuous surveillance. In this study, we standardized and validated a protocol for the specific detection of dengu...

An ectomycorrhiza is a mutualistic symbiosis of paramount importance in forestry and tree production. One of the selection criteria of ectomycorrhizal fungi that has currently gained importance is their edibility due to the economic, ecological and cultural relevance of edible ectomycorrhizal mushrooms as a non-timber forest product. The effect of...

Background: The bacterial disease citrus huanglongbing (HLB), associated with "Candidatus Liberibacter asiaticus" (C.Las) has severely impacted the citrus industry, causing a significant reduction in production and fruit quality. In the present study, it was monitored the C.Las population dynamics in symptomatic, HLB-positive Mexican lime trees (C...

Chavarin-Palacio, Jesus Moya-Hinojosa, Francisco Javier Trujillo-Arriaga, Rosalia Lira Carmona and Beatriz Xoconostle-Cazares Abstract: Background: The bacterial disease citrus huanglongbing (HLB), associated with "Candidatus Liberibacter asiaticus" (C.Las) has severely impacted the citrus industry, causing a significant reduction in production an...

OBJETIVO: determinar, mediante reacción en cadena de la polimerasa (PCR), si C. albicans y C. glabrata son causantes de las recurrencias de candidiasis vulvovaginal y si suelen colonizar la vagina de mujeres mexicanas asintomáticas en edad reproductiva. MATERIALES Y MÉTODOS: estudio analítico, transversal, prospectivo, experimental, de casos y con...

BACKGROUND: 75% of women are affected with vulvovaginal candidiasis and 10% of them will have at least 4 episodes during one year. The most common etiological agents are C. albicans and C. glabrata, which is usually the responsible of the recurrent cases when the patients have received inadequate treatment. Up to 55% of asymptomatic women can have...

Trehalose and Trehalose-6-phosphate (T6P) have been described as signaling molecules involved in plant growth, development, carbon partitioning, flowering and response to biotic and abiotic stress. In order to investigate the role of T6P in vascular tissue signaling, Arabidopsis, plants expressing the TPS1 gene under the control of the actin depoly...

The vascular tissue has been essential for the evolutionary radiation of land plants, and has allowed them to colonise a wide range of habitats. The phloem is involved in the distribution of fixed carbon throughout the whole plant. The concept of this tissue as a central distributor of signals that regulate plant development and responses to enviro...

Background Mexico is an important global reservoir of biological and cultural richness and traditional knowledge of wild mushrooms. However, there is a high risk of loss of this knowledge due to the erosion of traditional human cultures which is related with the rapid acculturation linked to high migration of rural populations to cities and the U.S...

Plants, as most eukaryotic organisms, harbor several genes encoding a reverse transcriptase domain. The majority of them are part of transposable elements (TEs) and/or retroviral genomes that have been inserted into their genomes. However, there are some examples of RT domain-containing genes that have been endogenized during plant evolution; these...

In this dataset we integrated figures comparing leaf number and rosette diameter in three Arabidopsis FT overexpressor lines (AtFTOE) driven by KNAT1 promoter, “A member of the KNOTTED class of homeodomain proteins encoded by the STM gene of Arabidopsis” [5], vs Wild Type (WT) Arabidopsis plats. Also, presented in the tables are some transcriptomic...

Here we analyzed in leaves the effect of FT overexpression driven by meristem-specific KNAT1 gene homolog of Arabidopsis thaliana (Lincoln et al., 1994; Long et al., 1996) on the transcriptomic response during plant development. Our results demonstrated that meristematic FT overexpression generates a phenotype with an early flowering independent of...

In this research, we evaluated the toxic effect of metal ions on mycelial growth and phosphate-solubilising activity of soil-borne micromycetes isolated from the Phragmites australis rhizosphere using Pikovskaya-agar plates supplemented with four metal concentrations. The diameter growth rate (DGR) decreased as the metal concentration rise for all...

The Translationally Controlled Tumor Proteins, or TCTP, is a superfamily of exclusively eukaryotic proteins essential in the regulation of proliferation and general growth. However, it is clear that these are multifunctional proteins given (1) the pleiotropic effects of its mutations, and (2), the multiple processes in which this protein is involve...

The Translationally Controlled Tumor Protein (TCTP) is a central regulator of cell proliferation and differentiation in animals, and probably also in plants. Arabidopsis harbors two TCTP genes, AtTCTP1 (At3g16640), which is an important mitotic regulator, and AtTCTP2 (At3g05540), which is considered a pseudogene. Nevertheless, we have obtained evid...

This study analyzed the accumulation of arsenic and its influence on the content of P, Mn, Fe, Cu, Zn, S, Ca, Cl, and K in fronds of Azolla filiculoides via X-ray fluorescence (XRF). Azolla was exposed to increased concentrations of sodium arsenate (0, 5, 10, 20, and 30 μg ml − 1) in Yoshida's nutrient solution. After 96 h, fronds were collected an...

En condiciones naturales, los árboles de cítricos son dependientes de los hongos micorrízicos arbusculares (HMA) para su crecimiento, desarrollo y nutrición, sin embargo, el efecto de éstos en plantas de cítricos transgénicos se desconoce. De igual manera no se ha analizado como el ambiente rizosférico de estas plantas transgénicas se afecta y su r...

RESUMEN En condiciones naturales, los árboles de cítricos son dependientes de los hongos micorrízicos arbusculares (HMA) para su crecimiento, desarrollo y nutrición, sin embargo, el efecto de éstos en plantas de cítricos transgénicos se desco-noce. De igual manera no se ha analizado como el ambiente rizosférico de estas plantas transgénicas se afec...

Currently there are no efficient stable transformation methods for pumpkin. In this work we report an efficient genetic transient transformation method of whole pumpkin (Cucurbita maxima cv. Big Max, a dicot) plants in the cotyledonary stage via direct inoculation of Agrobacterium tumefaciens and A. rhizogenes. A vector harboring a uidA-GFP transla...

Translationally Controlled Tumor Protein (TCTP) is an almost ubiquitous protein found in eukaryotes, fundamental for the regulation of development and general growth. The multiple functions of TCTP have been inferred from its involvement in several cell pathways, but the specific function of TCTP is still not known in detail. On the other hand, TCT...

The concentrations of hydrocarbons and organochlorine pesticides (OCPs), nutrients and tolerant microorganisms in an agricultural soil from a locality in Tepeaca, Puebla, Mexico, were determined to define its feasibility for bioremediation. The OCPs detected were heptachlor, aldrin, trans-chlordane, endosulfán I, endosulfán II, 1,1,1-bis-(4-chlorop...

Uno de los componentes de mayor relevancia en la estructura y funcionamiento de la biota del suelo de los ecosistemas terrestres, son los hongos. Esto debido a su importancia en el reciclaje nutrimental y en el establecimiento de simbiosis mutualistas con el componente vegetal a través de la simbiosis micorrízícas. Adicionalmente, existen países co...

Uno de los componentes de mayor relevancia en la estructura y funcionamiento de la biota del suelo de los ecosistemas terrestres, son los hongos. Esto debido a su importancia en el reciclaje nutrimental y en el establecimiento de simbiosis mutualistas con el componente vegetal a través de la simbiosis micorrízícas. Adicionalmente, existen países co...

Abstract The phloem plays an important role in the delivery of nutrients and signals between photosynthetic to heterotrophic tissues. Proteins and RNAs in the phloem translocation stream may have an important role in maintaining the integrity of the sieve tube system, as well as in long-distance signaling. CmPP16 is a pumpkin phloem protein, which...

The Translationally Controlled Tumor Protein (TCTP) is a highly conserved protein at the level of sequence, considered to play an essential role in the regulation of growth and development in eukaryotes. However, this function has been inferred from studies in a few model systems, such as mice and mammalian cell lines, Drosophila and Arabidopsis. T...

The causal agents of Citrus leprosis are viruses; however, extant diagnostic methods to identify them have failed to detect known viruses in orange, mandarin, lime and bitter orange trees with severe leprosis symptoms in Mexico, an important citrus producer. Using high throughput sequencing, a virus associated with citrus leprosis was identified, b...

Ectomycorrhizal symbiosis results in profound morphological and physiological modifications in both plant and fungus. This in turn is the product of differential gene expression in both co-symbionts, giving rise to specialized cell types capable of performing novel functions. During the precolonization stage, chemical signals from root exudates are...

Plasmodium falciparum secretes a homologue of the translationally controlled tumor protein (TCTP) into serum of infected individuals, although its role in pathogenesis or virulence is unknown. To determine the effect of P. falciparum TCTP on B cells as compared to human TCTP, fluorescently labeled proteins were incubated on primary cultures of mous...

Key message: Identified SSR markers ( Xcfd49 and Xbarc183 ) linked with stem rust resistance for efficient use in marker-assisted selection and stacking of resistance genes in wheat breeding programs. More than 80 % of the worldwide wheat (Triticum aestivum L.) area is currently sown with varieties susceptible to the Ug99 race group of stem rust f...

In higher plants, the phloem plays a central role in the delivery of nutrients and signals from source to sink tissues. These signals likely coordinate different aspects of plant development, as well as its response to environmental cues. Although some phloem-transported proteins and RNAs may function as signaling molecules in plants, their mode of...

The phloem is the conduit through which photoassimilates are distributed from autotrophic to heterotrophic tissues and is involved in the distribution of signaling molecules that coordinate plant growth and responses to the environment. Phloem function depends on the coordinate expression of a large array of genes. We have previously identified con...

Phylogenetic analysis of the APL gene. Arabidopsis APL protein sequence was retrieved form TAIR (http://www.arabidopsis.org) and used as query. Protein homologs were identified by BLAST search against the phytozome database (http://phytozome.net). Full length protein sequences were aligned with ClustalX2. The alignment parameters used were: Pairwis...

Phylogenetic analysis of FT gene in plant species. Arabidopsis FT protein sequence was retrieved form TAIR (http://www.arabidopsis.org) and used as query. Protein homologs were identified by BLAST search against the phytozome database (http://phytozome.net). Full length protein sequences were aligned with ClustalX2. The alignment parameters used we...

Phylogenetic analysis of CmPP16 homologs. CmPP16 protein sequence was retrieved form TAIR (http://www.arabidopsis.org) and used as query. Protein homologs were identified by BLAST search against the phytozome database (http://phytozome.net). Full-length protein sequences were aligned with ClustalX2. The alignment parameters used were: Pairwise alig...

Phylogenetic analysis of OCTOPUS gene in plant species. Arabidopsis OCTOPUS protein sequence was retrieved form TAIR (http://www.arabidopsis.org) and used as query. Protein homologs were identified by BLAST search against the phytozome database (http://phytozome.net). Full length protein sequences were aligned with ClustalX2. The alignment paramete...