Somatic embryogenesis receptor-like kinase 1 (SERK1) is a membrane receptor that might serve as common co-regulator of plant cell differentiation processes by forming heterodimers with specific receptor-like kinases. The Coffea canephora SERK1 homolog (CcSERK1) was cloned in this work, and its early function in the transcription of embryogenesis master genes and of genes encoding proteins involved in auxin metabolism was investigated by externally manipulating its expression in embryogenic leaf explants, before the appearance of embryogenic structures. Overexpression of CcSERK1 early during embryogenesis caused an increase in the number of somatic embryos when the 55-day process was completed. Suppression of CcSERK1 expression by RNA interference almost abolished somatic embryogenesis. Real time-PCR experiments revealed that the transcription of the CcAGL15, CcWUS, CcBBM, CcPKL, CcYUC1, CcPIN1 and CcPIN4 homologs was modified in direct proportion to the expression of CcSERK1 and that only CcLEC1 was inversely affected by the expression levels of CcSERK1. The expression of the CcYUC4 homolog was induced to more than 80-fold under CcSERK1 overexpression conditions, but it was also induced when CcSERK1 expression was silenced. The level of CcTIR1 was not affected by CcSERK1 overexpression but was almost abolished during CcSERK1 silencing. These results suggest that CcSERK1 co-regulates the induction of somatic embryogenesis in Coffea canephora by early activation of YUC-dependent auxin biosynthesis, auxin transport mediated by PIN1 and PIN4, and probably auxin perception by the TIR1 receptor, leading to the induction of early-stage homeotic genes (CcAGL15, CcWUS, CcPKL and CcBBM) and repression of late-stage homeotic genes (CcLec1).

Virus-induced gene silencing is based on the sequence-specific degradation of RNA. Here, a gene silencing vector derived from EuMV-YP, named pEuMV-YP:ΔAV1, was used to silence ChlI and NPR1 genes in Nicotiana benthamiana. The silencing of the ChlI transcripts was efficient in the stems, petioles and leaves as reflected in tissue bleaching and reduced transcript levels. The silencing was stable, reaching the flowers and fruits, and was observed throughout the life cycle of the plants. Additionally, the silencing of the NPR1 gene was efficient in both N. benthamiana and Capsicum annuum. After silencing, the plants' viral symptoms increased to levels similar to those seen in wild-type plants. These results suggest that NPR1 plays a role in the compatible interactions of EuMV-YP N. benthamiana and EuMV-C. annum var. anaheim.

The type-h thioredoxins (TRXs) play a fundamental role in oxidative stress tolerance and defense responses against pathogens. In pepper plants, type-h TRXs participate in the defense mechanism against Cucumber mosaic virus. The goal of this study was to analyze the role of the CaTRXh1-cicy gene in pepper plants during compatible interaction with a DNA virus, the Euphorbia mosaic virus-Yucatan Peninsula (EuMV-YP). The effects of a transient silencing of the CaTRXh1-cicy gene in pepper plants wëre evaluated by observing the accumulation of viral DNA and the visible symptoms of pepper plants under different treatments. The accumulation of salicylic acid (SA) and the relative expression of the defense genes NPR1 and PR10 were also evaluated. Results showed that viral DNA accumulation was higher in transiently CaTRXh1-cicy silenced plants that were also infected with EuMV-YP. Symptoms in these plants were more severe compared to the non-silenced plants infected with EuMV-YP. The SA levels in the EuMV-YP-infected plants were rapidly induced at 1 h post infection (hpi) in comparison to the non-silenced plants inoculated with EuMV-YP. Additionally, in pepper plants infected with EuMV-YP, the expression of NPR1 decreased by up to 41 and 58 % at 28 days post infection (dpi) compared to the non-silenced pepper plants infected with only EuMV-YP and healthy non-inoculated pepper plants, respectively. PR10 gene expression decreased by up to 70 % at 28 dpi. Overall, the results indicate that the CaTRXh1-cicy gene participates in defense mechanisms during the compatible interaction of pepper plants with the EuMV-YP DNA virus.

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Microalgae have been positioned as excellent models for producing new sources of energy (biofuels and biohydrogen). Some investigations in these biological models have been directed to know if the enzymes ferredoxin (FDX) and hydrogenase (HYD) are involved in the algae producing different concentrations of molecular hydrogen (H 2 ). To date, little is known about the concomitant transcriptional regulation of both enzymes during H 2 evolution in algae. In this research, we evaluated the relative expression of hdy and fdx genes during the evolution of H 2 in three microalgae (Chlorella vulgaris, Scenedesmus obliquus, and Chlamydomonas reinhardtii) in N-deprived anaerobic cultures in the presence of Fe, and 12:24 and 24:24 h dark:light cycles. We also detected structural differences in the enzymes. The 3D modeling indicated that the 3D structure of HYD and FDX are conserved in most algal genera, and the results of our grouping according to the aa characteristics of the proteins showed two grouping trends: One, according to the algae's phylogenetic classification, and another one according to the species-specific enzyme's characteristics, and the grouping could perhaps be more influenced by the algae's ability to produce H 2 . The three microalgae species reached maximum H 2 accumulation values in 24h:24 h dark:light conditions in Fe-supplemented media (4.2 AE 0.12 mL L À1 in C. vulgaris, 3.9 AE 0.10 mL L À1 in S. obliquus, and 4.5 AE 0.10 mL L À1 in C. reinhardtii), and the highest global relative expression of hyd and fdx genes was reached during the first hour of exposure to light, which suggests concomitant expression of both enzymes at the beginning of H 2 production. The behavior of the expression of the hyd and fdx genes in these algal species proved to be similar between species. A better understanding of the concomitant regulation of both enzymes could lay the groundwork for the future use of both enzymes to improve H 2 yields in microalgae.

The Mexican territory of the Yucatan Peninsula has a tropical climate and harbors a wide variety of domestic, synanthropic, and wild animals, as well as disease vectors. To determine the distribution of recorded zoonotic diseases in the Yucatan Peninsula, scientific publications referring to these diseases in animals and containing geographic coordinates of disease occurrence, were studied. The epidemiological bulletins of the national government were also consulted to obtain information on zoonotic diseases reported in humans in the territory. The territory harbors a wide variety of tropical zoonotic pathogens, including Trypanosoma cruzi, Leptospira interrogans, Toxoplasma gondii, Leishmania mexicana, Dirofilaria immitis, and Rickettsia felis. A variety of domestic, synanthropic, and wild animals act as hosts or reservoirs in the transmission cycle of the zoonotic diseases in the Yucatan Peninsula, and some spillover into human populations has also been recorded. There are still zoonotic diseases that have rarely or never been reported in humans, but it is not clear whether this is because these diseases in humans are not common, there is a lack of viable transmission cycle or there is a lack of appropriate diagnosis. It is necessary to continue monitoring vectors, animal hosts, and humans to identify risk factors for zoonotic diseases in the Yucatan Peninsula.

Plants have evolved defense mechanisms to suppress viral transcription and replication by transcriptional and post-transcriptional gene silencing mediated by virus-derived small interfering RNAs (vsiRNAs). Based on this response, virus-induced gene silencing (VIGS)-based technology has been developed to silence target genes on either host plants or insect pests. This mechanism could also be used for the silencing of genes of interest in the medical field. We used the VIGS vector pEuMV-YP:Krt18, which was obtained by inserting the Mus musculus (M. musculus) Krt18 sequence into pEuMV-YP:ΔAV1. The objective was to evaluate the capacity of pEuMV-YP:Krt18 to induce Nicotiana benthamiana (N. benthamiana) production of vsiRNAs of a specific sequence that belongs to neither the plant genome nor the wild virus genome, which were used to induce cross-kingdom gene silencing between plants and mammals. The percentage of vsiRNA for each viral gene was calculated from an sRNA library of N. benthamiana plants infected by pEuMV-YP: Krt18. When the vsiRNAs were characterized, it was found that they corresponded to all the genes of the pEuMV-YP:Krt18 vector. These vsiRNAs induced the silencing of the Krt18 gene in M. musculus macrophages, supporting the ability to use VIGS vectors in plants as biofactories for the production of sRNAs that induce gene silencing in mammals.

Fruits of species of the genus Bromelia contain compounds with health benefits and potential biotechnological applications. For example, Bromelia karatas fruits contain antioxidants and proteins with bactericidal activity, but studies regarding the activity of these metabolites and potential benefits are required. We evaluated the bactericidal activity of the methanolic extract (treated and not treated with activated charcoal) and its fractions (hexane, ethyl acetate, and methanol) from ripe B. karatas fruit (8 °Brix) against Escherichia coli, Enterococcus faecalis, Salmonella enteritidis, and Shigella flexneri. The methanolic extract (ME) minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined at eight concentrations. The methanolic extract MIC was 5 mg/mL for E. faecalis and 10 mg/mL for the other bacteria; the MBC was 20 mg/mL for E. coli and E. faecalis, and 40 mg/mL for S. enteritidis and S. flexneri. Through gas chromatography–mass spectrometry, 131 compounds were identified, some of which had previously been reported to have biological activities, such as bactericidal, fungicide, anticancer, anti-inflammatory, enzyme inhibiting, and anti-allergic properties. The most abundant compounds found in the ME of B. karatas fruits were maleic anhydride, 5-hydroxymethylfurfural, and itaconic anhydride. This study shows that B. karatas fruits contain metabolites that are potentially beneficial for health.