Marker-Assisted Recurrent Selection for Pyramiding Leaf Rust and Coffee Berry Disease Resistance Alleles in Coffea arabica L.

In this study, marker-assisted recurrent selection was evaluated for pyramiding resistance gene alleles against coffee leaf rust (CLR) and coffee berry diseases (CBD) in Coffea arabica. A total of 144 genotypes corresponding to 12 hybrid populations from crosses between eight parent plants with desired morphological and agronomic traits were evaluated. Molecular data were used for cross-certification, diversity study and resistance allele marker-assisted selection (MAS) against the causal agent of coffee leaf rust (Hemileia vastatrix) and coffee berry disease (Colletotrichum kahawae). In addition, nine morphological and agronomic traits were evaluated to determine the components of variance, select superior hybrids, and estimate genetic gain. From the genotypes evaluated, 134 were confirmed as hybrids. The genetic diversity between and within populations was 75.5% and 24.5%, respectively, and the cluster analysis revealed three primary groups. Pyramiding of CLR and CBD resistance genes was conducted in 11 genotypes using MAS. A selection intensity of 30% resulted in a gain of over 50% compared to the original population. Selected hybrids with increased gain also showed greater genetic divergence in addition to the pyramided resistance alleles. The strategies used were, therefore, efficient to select superior coffee hybrids for recurrent selection programs and could be used as a source of resistance in various crosses.

Autophagy modulates growth and development in the moss Physcomitrium patens.

Physcomitrium patens apical growing protonemal cells have the singularity that they continue to undergo cell divisions as the plant develops. This feature provides a valuable tool to study autophagy in the context of a multicellular apical growing tissue coupled to development. Herein, we showed that the core autophagy machinery is present in the moss P. patens, and characterized the 2D and 3D growth and development of atg5 and atg7 loss-of-function mutants under optimal and nutrient-deprived conditions. Our results showed that 2D growth of the different morphological and functional protonemata apical growing cells, chloronema and caulonema, is differentially modulated by this process. These differences depend on the protonema cell type and position along the protonemal filament, and growth condition. As a global plant response, the absence of autophagy favors the spread of the colony through protonemata growth at the expense of a reduction of the 3D growth, such as the buds and gametophore development, and thus the adult gametophytic and reproductive phases. Altogether this study provides valuable information suggesting that autophagy has roles during apical growth with differential responses within the cell types of the same tissue and contributes to life cycle progression and thus the growth and development of the 2D and 3D tissues of P. patens.

A non-conformational QSAR study for plant-derived larvicides against Zika Aedes aegypti L. vector.

A set of 263 plant-derived compounds with larvicidal activity against Aedes aegypti L. (Diptera: Culicidae) vector is collected from the literature, and is studied by means of a non-conformational quantitative structure-activity relationships (QSAR) approach. The balanced subsets method (BSM) is employed to split the complete dataset into training, validation and test sets. From 26,775 freely available molecular descriptors, the most relevant structural features of compounds affecting the bioactivity are taken. The molecular descriptors are calculated through four different freewares, such as PaDEL, Mold2, EPI Suite and QuBiLs-MAS. The replacement method (RM) variable subset selection technique leads to the best linear regression models. A successful QSAR equation involves 7-conformation-independent molecular descriptors, fulfiling the evaluated internal (loo, l30%o, VIF and Y-randomization) and external (test set with Ntest = 65 compounds) validation criteria. The practical application of this QSAR model reveals promising predicted values for some natural compounds with unknown experimental larvicidal activity. Therefore, the present model constitutes the first one based on a large molecular set, being a useful computational tool for identifying and guiding the synthesis of new active molecules inspired by natural products.

Phosphatidylinositol 3-kinase function at very early symbiont perception: a local nodulation control under stress conditions?

Root hair curling is an early and essential morphological change required for the success of the symbiotic interaction between legumes and rhizobia. At this stage rhizobia grow as an infection thread within root hairs and are internalized into the plant cells by endocytosis, where the PI3K enzyme plays important roles. Previous observations show that stress conditions affect early stages of the symbiotic interaction, from 2 to 30 min post-inoculation, which we term as very early host responses, and affect symbiosis establishment. Herein, we demonstrated the relevance of the very early host responses for the symbiotic interaction. PI3K and the NADPH oxidase complex are found to have key roles in the microsymbiont recognition response, modulating the apoplastic and intracellular/endosomal ROS induction in root hairs. Interestingly, compared with soybean mutant plants that do not perceive the symbiont, we demonstrated that the very early symbiont perception under sublethal saline stress conditions induced root hair death. Together, these results highlight not only the importance of the very early host-responses on later stages of the symbiont interaction, but also suggest that they act as a mechanism for local control of nodulation capacity, prior to the abortion of the infection thread, preventing the allocation of resources/energy for nodule formation under unfavorable environmental conditions.

Quantitative structure-activity relationship (QSAR) analysis of plant-derived compounds with larvicidal activity against Zika Aedes aegypti (Diptera: Culicidae) vector using freely available descriptors.

BACKGROUND: We have developed a quantitative structure-activity relationship (QSAR) model for predicting the larvicidal activity of 60 plant-derived molecules against Aedes aegypti L. (Diptera: Culicidae), a vector of several diseases such as dengue, yellow fever, chikungunya and Zika. The balanced subsets method (BSM) based on k-means cluster analysis (k-MCA) was employed to split the data set. The replacement method (RM) variable subset selection technique coupled with multivariable linear regression (MLR) proved to be successful for exploring 18 326 molecular descriptors and fingerprints calculated with PaDEL, Mold2 and EPI Suite open-source softwares. RESULTS: A robust QSAR model (Rtrain2=0.84, Strain = 0.20 and Rtest2=0.92, Stest = 0.23) involving five non-conformational descriptors was established. The model was validated and tested through the use of an external test set of compounds, the leave-one-out (LOO) and leave-more-out (LMO) cross-validation methods, Y-randomization and applicability domain (AD) analysis. CONCLUSION: The QSAR model surpasses previously published models based on geometrical descriptors, thereby representing a suitable tool for predicting larvicidal activity against the vector A. aegypti using a conformation-independent approach. © 2018 Society of Chemical Industry.

Concordancia entre la percepción materna y el estado nutricional de sus hijos antes y después de una intervención educativa / Concordance between maternal perception and child's nutritional status before and after an educational intervention

RESUMEN La malnutrición por exceso es un problema de salud y su rápida pesquisa mediante percepción materna (PM), permite intervenciones tempranas enfocadas a disminuir sus consecuencias y costos asociados. El objetivo fue determinar la concordancia entre PM y estado nutricional (EN) de sus hijos, antes y después de una intervención educativa. Participaron 116 diadas madre-hijo de 2 a 5 años, de 4 jardines de Viña del Mar, donde se determinó EN y PM mediante imágenes corporales de los niños. Posteriormente, 57 madres con PM erradas respecto a estado nutricional de su hijo participaron de una intervención educativa de 40 minutos cada 15 días por 3 meses. La concordancia entre el PM y estado nutricional fue evaluada con el test de Kappa. El EN de los niños fue: 3,4% bajo peso; 49,1% normal; 28,4% sobrepeso y 19,0% obesidad. Para la PM el 99,1% subestimó el EN de su hijo (Kappa= 0,022 y p= 0,610). Posterior a la intervención, mejoró la PM en 59,6% y un 40,3% continuó subestimando el EN (kappa= 0,362 y p= 0,000). En este estudio, la PM tiende a subestimar el EN de sus hijos y una intervención educativa mejoró la PM y la concordancia entre PM y el EN de ellos.

ABSTRACT Overnutrition is a health problem and its rapid diagnosis through maternal perception (MP), allows for early intervention focused on reducing consequences and associated costs. The objective of this study was to determine the concordance between MP and child's nutritional status, before and after an educational intervention. Participants were 116 mother-child (2 to 5 years old) dyads from, from 4 daycare centers in Viña del Mar, Chile. Nutritional status was determined and MP was performed using children's body images. Subsequently 57 mothers with MP discordant with child's nutritional status participated in a 40-minute educational intervention every 15 days for 3 months. Concordance between MP and child's nutritional status was evaluated with Kappa. Nutritional status of the 116 children was: 3.4% underweight; 49.1% normal; 28.4% overweight, 19.0% obesity. MP indicated that 99.1% underestimated their child's nutritional status (Kappa = 0.022 and p= 0.610). After intervention, MP improved to 59.6% and 40.3% continued to underestimating child's nutritional status (kappa= 0.362 and p= 0.000). In this study, mothers tended to underestimate the nutritional status of their children. An educational intervention improved MP and the agreement between MP and child's nutritional status.

Quantitative Structure-Antifungal Activity Relationships for cinnamate derivatives.

Quantitative Structure-Activity Relationships (QSAR) are established with the aim of analyzing the fungicidal activities of a set of 27 active cinnamate derivatives. The exploration of more than a thousand of constitutional, topological, geometrical and electronic molecular descriptors, which are calculated with Dragon software, leads to predictions of the growth inhibition on Pythium sp and Corticium rolfsii fungi species, in close agreement to the experimental values extracted from the literature. A set containing 21 new structurally related cinnamate compounds is prepared. The developed QSAR models are applied to predict the unknown fungicidal activity of this set, showing that cinnamates like 38, 28 and 42 are expected to be highly active for Pythium sp, while this is also predicted for 28 and 34 in C. rolfsii.

Clinical research in pediatric organ transplantation.

Solid organ transplantation has greatly improved survival in children with end-stage disease, becoming one of the main treatment options in this population. Nonetheless, there are significant challenges associated with validating and optimizing the effects of these interventions in clinical trials. Therefore, we reviewed the main issues related to conducting clinical transplantation research in children. We divided these challenges into three different categories: (i) challenges related to surgical techniques and anesthetic procedures, (ii) challenges related to post-transplant care and (iii) challenges specific to a particular population group and disease type. Some of the observed burdens for clinical research in this field are related to the limitations of conducting studies with a placebo or sham procedure, determining the standard of care for a control group, low prevalence of cases, ethical concerns related to use of a placebo control group and lack of generalizability from animal studies and clinical trials conducted in adult populations. To overcome some of these barriers, it is necessary to utilize alternative clinical trial designs, such as observational studies or non-inferiority trials, and to develop multicenter collaborations to increase the recruitment rate. In conclusion, the lack of robust data related to pediatric transplantation remains problematic, and further clinical trials are needed to develop more efficacious and safer treatments.

Clinical research in pediatric organ transplantation

Solid organ transplantation has greatly improved survival in children with end-stage disease, becoming one of the main treatment options in this population. Nonetheless, there are significant challenges associated with validating and optimizing the effects of these interventions in clinical trials. Therefore, we reviewed the main issues related to conducting clinical transplantation research in children. We divided these challenges into three different categories: (i) challenges related to surgical techniques and anesthetic procedures, (ii) challenges related to post-transplant care and (iii) challenges specific to a particular population group and disease type. Some of the observed burdens for clinical research in this field are related to the limitations of conducting studies with a placebo or sham procedure, determining the standard of care for a control group, low prevalence of cases, ethical concerns related to use of a placebo control group and lack of generalizability from animal studies and clinical trials conducted in adult populations. To overcome some of these barriers, it is necessary to utilize alternative clinical trial designs, such as observational studies or non-inferiority trials, and to develop multicenter collaborations to increase the recruitment rate. In conclusion, the lack of robust data related to pediatric transplantation remains problematic, and further clinical trials are needed to develop more efficacious and safer treatments.

A dehydrin gene in Physcomitrella patens is required for salt and osmotic stress tolerance.

We isolated a dehydrin-like (DHN-like) gene fragment, PpDHNA, from the moss Physcomitrella patens by PCR amplification using degenerate primers directed against conserved amino acid segments of DHNs of higher plants. The full-length cDNA was found to encode a 59.2-kDa glycine-rich protein, DHNA, with typical characteristics of DHNs, including the presence of several Y repeats and one conserved K segment. DHNA had a high sequence similarity with a protein from Tortula ruralis, Tr288, which is thought to be involved in cellular dehydration tolerance/repair in this moss. Northern and Western analysis showed that PpDHNA is upregulated upon treatment of plants with abscisic acid, NaCl or mannitol, indicating a similar expression pattern to DHNs from higher plants. To analyze the contribution of DHNA to osmotic stress tolerance, we generated a knockout mutant (dhnA) by disruption of the gene using homologous recombination. Growth and stress response studies of the mutant showed that dhnA was severely impaired in its capacity to resume growth after salt and osmotic-stress treatments. We provide direct genetic evidence in any plant species for a DHN exerting a protective role during cellular dehydration allowing recovery when returned to optimal growth conditions.