Segmental and Tandem Duplications Driving the Recent NBS-LRR Gene Expansion in the Asparagus Genome

Garden asparagus is an important horticultural plant worldwide. It is, however, susceptible to a variety of diseases, which can affect the potential yield, spear quality, and lifespan of production fields. Screening studies have identified resistant germplasm. The genetic resistance is usually complex, and the genes underlying that resistance are still unknown. Most often, disease resistance is determined by resistance genes (R). The most predominant R-genes contain nucleotide binding site and leucine-rich repeat (NBS-LRR) domains. Using bioinformatics and data mining approaches, we identified and characterized 68 NBS predicted proteins encoded by 49 different loci in the asparagus genome. The NBS-encoding genes were grouped into seven distinct classes based on their domain architecture. The NBS genes are unevenly distributed through the genome and nearly 50% of the genes are present in clusters. Chromosome 6 is significantly NBS-enriched and one single cluster hosts 10% of the genes. Phylogenetic analysis points to their diversification into three families during their evolution. Recent duplications are likely to have dominated the NBS expansion with both tandem genes and duplication events across multiple chromosomes. Transcriptome sequencing data provided evidence for their transcription and tissue-specific expression. The total number of cis-regulatory elements as well as their relative positions within the NBS promoters suggests a complex transcriptional network regulating defense responses. Our study provides a strong groundwork for the isolation of candidate R-genes in garden asparagus

QTL Analysis of Morpho-Agronomic Traits in Garden Asparagus (Asparagus officinalis L.)

In order to understand the genetic control of quantitative agronomic traits in garden asparagus, we performed a quantitative trait loci (QTL) analysis. A population (n = 167) derived from a cross between a female and male plants was evaluated for morpho-agronomic traits over three years. Interval mapping (IM) and restricted multiple QTL mapping (rMQM) analysis was applied, and 18 QTLs were detected. QTLs were located in two linkage groups (LG): 5 in LG5 and 13 in LG6. The physical position of markers of both groups was mapped onto the reference genome through BLAST analysis. LG5 and LG6 match with chromosome 1 (sex-determining chromosome) and chromosome 5, respectively. Haplotypes of both chromosomes of the heterozygous parent and their progeny were obtained, and a bin map was developed. Bins were used to map the QTLs on the reference genome and to perform the association analysis with the morpho-agronomic traits. Two major and stable QTLs over the years (R2 > 10%) for number of stalk and earliness were mapped in the end of chromosome 1 into a bin that spans 3.25 Mb and includes the sex-determination locus. In chromosome 5, some QTLs were located in the center of chromosome for the year 2016. Branching is tightly regulated by both internal factors (such as plant hormones) and external factors (such as light conditions). QTLs for branching height and earliness were detected in a bin that spans 4.96 Mb. Functional annotation of genes within the two bins revealed candidate genes with potential roles in SA and light signaling and photomorphogenesis pathways that may be involved in branching and/or tillering. This is the first study providing the identification of genomic regions associated with yield-related morpho-agronomic traits in asparagus

Characterization and Analysis of Anthocyanin-Related Genes in Wild-Type Blueberry and the Pink-Fruited Mutant Cultivar ‘Pink Lemonade’: New Insights into Anthocyanin Biosynthesis

Blueberries are one of the richest sources of antioxidants, such as anthocyanins, among fruits and vegetables. Anthocyanin mutants, like the pink-fruited cultivar ‘Pink Lemonade’, are valuable resources for investigating anthocyanin biosynthesis in blueberries. In this study, we examined expression of flavonoid pathway genes during fruit development in wild-type, blue-fruited blueberries using quantitative real-time PCR. Expression was also compared between wild-type and the pink-fruited ‘Pink Lemonade’. This revealed significantly lower expression in ‘Pink Lemonade’ than in wild-type of nearly all the structural genes examined suggesting that a transcriptional regulator of the pathway was affected. Hence, we compared expression of three known regulatory genes and found that the gene encoding the transcription factor MYB1 was expressed at a significantly lower level in ‘Pink Lemonade’ than in the wild-type. To validate the capacity of this MYB1 to regulate the transcription of anthocyanin genes in blueberries, a transient expression assay was conducted. Results indicated MYB1 overexpression enhanced anthocyanin production. Comparative sequence analysis between wild-type and mutant MYB1 variants found differences in highly conserved features suggesting a mechanistic explanation for the mutant phenotype. Collectively, the results presented here contribute to a better understanding of mechanisms regulating anthocyanin biosynthesis in Vaccinium

RNA-seq combined with a bulked-segregant analysis identifies candidate genes for the waxy coating on blueberry fruit

The most significant difference between blueberries with a light blue fruit color and black fruit color is the visible layer of an epicuticular waxy coating. This layer functions in disease defense and prevention of water loss. In this study, we constructed a northern-adapted rabbiteye hybrid breeding population, ‘Nocturne’ x T 300, which segregated for fruit color (light blue versus black). We screened this population and selected plants of each extreme phenotype, waxy- coated plants with light blue colored fruit versus non-waxy plants with black colored fruit, then isolated RNA from fruit tissue of each bulk, respectively. We sequenced the transcriptome of each bulk using RNA-seq, which resulted in a total of 167,093,354 reads for both libraries combined. We de novo assembled this data set into 171,678 contigs and used the assembled transcriptome as a reference for differential expression analysis using EdgeR. A total of 515 differentially expressed genes were identified with at least a four-fold difference in expression, and efforts were made to functionally annotate them using publicly available databases. From these, one excellent candidate ‘waxy’ gene has emerged, which we are investigating further

Aldehyde Dehydrogenase 3 Is an Expanded Gene Family with Potential Adaptive Roles in Chickpea

Legumes play an important role in ensuring food security, improving nutrition and enhancing ecosystem resilience. Chickpea is a globally important grain legume adapted to semi-arid regions under rain-fed conditions. A growing body of research shows that aldehyde dehydrogenases (ALDHs) represent a gene class with promising potential for plant adaptation improvement. Aldehyde dehydrogenases constitute a superfamily of proteins with important functions as ‘aldehyde scavengers’ by detoxifying aldehydes molecules, and thus play important roles in stress responses. We performed a comprehensive study of the ALDH superfamily in the chickpea genome and identified 27 unique ALDH loci. Most chickpea ALDHs originated from duplication events and the ALDH3 gene family was noticeably expanded. Based on the physical locations of genes and sequence similarities, our results suggest that segmental duplication is a major driving force in the expansion of the ALDH family. Supported by expression data, the findings of this study offer new potential target genes for improving stress tolerance in chickpea that will be useful for breeding programs

Evaluación del trabajo colaborativo en Iniciación a la Investigación en Biología

Tras el trabajo previo de diseño de la asignatura Iniciación a la Investigación en Biología, el equipo multidisciplinar de profesores y profesoras de la Red Docente INVES ha desarrollado una metodología propia de trabajo en equipo, no sólo entre el diferente profesorado que la compone, sino también con el profesorado de la asignatura Estadística, con la que se comparten objetivos de aprendizaje comunes. Se ha optimizado el sistema de evaluación del trabajo colaborativo del alumnado, mediante el uso de rubricas y auto-evaluación. Dicho trabajo consiste en el diseño y desarrollo de un proyecto de investigación bibliométrico de temática biológica realizado por los estudiantes, propiciando la adquisición de competencias transversales mediante una dinámica de trabajo en grupo que culmina en la edición de unas Jornadas Científicas. Por otra parte, se han consensuado criterios comunes de evaluación continua, mejorando en la eficiencia de la evaluación, y determinado un incremento de la capacidad de aprendizaje del alumnado a lo largo de los cursos 2010-11 al 2013-14. La oferta formativa se completa mediante la formación de un grupo de Alto Rendimiento Académico con docencia en lengua inglesa. Esto permite al alumnado implementar el objetivo general de compresión de lengua extranjera inglés en lo relativo al ámbito científico

Avances en el trabajo colaborativo en Iniciación a la Investigación en Biología

Un equipo multidisciplinar de profesores y profesoras que componen la Red Docente INVES e imparten docencia en la asignatura Iniciación a la Investigación en Biología, ha desarrollado una metodología propia de trabajo en equipo, en coordinación con el profesorado de la asignatura Estadística, con la que se comparten objetivos de aprendizaje comunes. El sistema de evaluación del trabajo colaborativo del alumnado se ha optimizado mediante el uso de rúbricas y auto-evaluación. Se ha propiciado la adquisición de competencias transversales mediante una dinámica de trabajo en grupo. El diseño y desarrollo de un proyecto de investigación bibliométrico, de temática biológica, es realizado por los y las estudiantes, y culmina con la edición de unas Jornadas Científicas. Con el fin de mejorar la eficiencia de la evaluación, se han consensuado criterios comunes de evaluación continua entre el profesorado. Ello ha determinado un incremento de la capacidad de aprendizaje del alumnado a lo largo de los cursos 2010-11 al 2013-14. La lectura y compresión de textos científicos en inglés junto a la formación de un grupo de Alto Rendimiento Académico con docencia en lengua inglesa completa la oferta formativa, permitiendo al alumnado implementar el objetivo general de compresión de lengua extranjera inglés en lo relativo al ámbito científico

Four haplotype blocks linked to Ascochyta blight disease resistance in chickpea under Mediterranean conditions

Ascochyta blight, caused by the fungal pathogen Ascochyta blight, caused by the fungal pathogen Ascochyta rabiei, is a devastating biotic stress that poses a significant threat to chickpea cultivation worldwide. To combat this disease, breeding programs have focused on developing cultivars with resistance to Ascochyta blight. However, a comprehensive understanding of the underlying plant defense mechanism is still lacking. To identify genomic regions associated with resistance, a recombinant inbred line (RIL) population was created by crossing ILC3279 (kabuli, resistant) and WR315 (desi, susceptible), which was then phenotyped and sequenced using a tuneable genotyping-by-sequencing (tGBS) protocol to obtain single nucleotide polymorphisms (SNPs). We further validated the association of genomic regions with Ascochyta blight resistance in a second recombinant inbred line\population derived from the cross between JG62 (desi, susceptible) and ILC72 (kabuli, resistant). Our analysis identified four genomic regions associated with Ascochyta blight resistance in chromosomes 2 and 4, among which a region spanning from 3.52 to 8.20 Mb in chromosome 4 was the most robust candidate for resistance, being associated with resistance in both years and populations. A total of 30 genes from the identified regions were selected as robust candidates, and LOC101507066, which encodes a leucine-rich repeat receptor-like protein kinase, was the most robust candidate gene, as it plays critical roles in plant stress responses and immunity. Our findings have potential to accelerate marker-assisted genetic improvement and facilitate the development of integrated strategies for crop protection

Hackathon in teaching: Machine Learning applied to Life Sciences

La programación ha sido tradicionalmente una competencia perteneciente a las ingenierías, que recientemente está adquiriendo una importancia significativa en áreas como Ciencias de la Vida, donde resulta fundamental para la resolución de problemas de análisis de datos. Este trabajo es un caso de estudio enmarcado en la necesidad de mejorar las habilidades, sobre análisis de datos en el alumnado de Ciencias de la Vida y de la base temática en los estudiantes de ingeniería. Mediante la herramienta del hackathon y el trabajo en equipo, se combinó al alumnado de ambas disciplinas y se le enfrentó a una serie de problemas de análisis de datos. Se establecieron equipos de trabajo que recibieron una formación previa al comienzo de la competición. De cada equipo, se valoró la metodología empleada para la obtención de los datos, su análisis, interpretación de resultados, y exposición de las diversas tareas. Se hizo un análisis descriptivo de los resultados del Proyecto mediante encuestas al alumnado, así como su percepción sobre las actividades realizadas. El Proyecto ha conseguido que el alumnado resuelva los problemas planteados, difícilmente abordables con equipos unidisciplinares, generando un aprendizaje común y una experiencia multidisciplinar altamente satisfactoria tanto para el alumnado como para el profesorado.Programming has traditionally been an engineering competence, but recently it is acquiring significant importance in several areas, such as Life Sciences, which is considered essential for problem-solving based on data analysis. This work is a case study framed within the need to improve not only the data analysis skills of life science students, but also the biological background concerning the given issue of engineering students. Using hackathon and teamwork-based tools, students from both disciplines have been made and challenged with a series of problems in the area of Life Sciences. To solve these problems, we established work teams trained before the competition's beginning. Their results were assessed concerning the approach to obtain the data, perform the analysis, and finally interpret and present the results to solve the challenges. The project outcomes were assessed using structured surveys for students and their overall perception. The project succeeded, meaning students solved the proposed problems and achieved the activity's goals. These goals would have been difficult to address with teams composed of students from the same field of study. The hackathon succeeded in generating a shared learning and a multidisciplinary experience for their professional training, being highly rewarding for both students and faculty members