Repositorio Nacional

Resilience of growing in arid and semiarid regions and a high capacity of accumulating sugar-rich biomass with low lignin percentages have placed Agave species as an emerging bioen-ergy crop. Although transcriptome sequencing of fiber-producing agave species has been explored, molecular bases that control wall cell biogenesis and metabolism in agave species are still poorly understood. Here, through RNAseq data mining, we reconstructed the cellulose biosynthesis pathway and the phenylpropanoid route producing lignin monomers in A. tequilana, and evaluated their expression patterns in silico and experimentally. Most of the orthologs retrieved showed differential expression levels when they were analyzed in different tissues with contrasting cellulose and lignin accumulation. Phylogenetic and structural motif analyses of putative CESA and CAD proteins allowed to identify those potentially involved with secondary cell wall formation. RT-qPCR assays revealed enhanced expression levels of AtqCAD5 and AtqCESA7 in parenchyma cells associated with extraxylary fibers, suggesting a mechanism of formation of sclerenchyma fibers in Agave similar to that reported for xylem cells in model eudicots. Overall, our results provide a framework for un-derstanding molecular bases underlying cell wall biogenesis in Agave species studying mechanisms involving in leaf fiber development in monocots. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.

AGAVE CELL WALLS LIGNOCELLULOSE CAD PROTEIN CESA PROTEIN SCLERENCHYMA BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA GENÉTICA GENÉTICA MOLECULAR DE PLANTAS GENÉTICA MOLECULAR DE PLANTAS

The banana MaWRKY18, MaWRKY45, MaWRKY60 and MaWRKY70 genes encode functional transcription factors and display differential expression in response to defense phytohormones

SERGIO GARCIA LAYNES VIRGINIA AURORA HERRERA VALENCIA Lilia Guadalupe Tamayo Torres VERONICA LIMONES BRIONES FELIPE ALONSO BARREDO POOL FRAY MARTIN BAAS ESPINOLA Angel Alpuche-Solis CARLOS ALBERTO PUCH HAU SANTY PERAZA ECHEVERRIA (2022, [Artículo])

WRKY transcription factors (TFs) play key roles in plant defense responses through phytohormone signaling pathways. However, their functions in tropical fruit crops, especially in banana, remain largely unknown. Several WRKY genes from the model plants rice (OsWRKY45) and Arabidopsis (AtWRKY18, AtWRKY60, AtWRKY70) have shown to be attractive TFs for engineering disease resistance. In this study, we isolated four banana cDNAs (MaWRKY18, MaWRKY45, MaWRKY60, and MaWRKY70) with homology to these rice and Arabidopsis WRKY genes. The MaWRKY cDNAs were isolated from the wild banana Musa acuminata ssp. malaccensis, which is resistant to several diseases of this crop and is a progenitor of most banana cultivars. The deduced amino acid sequences of the four MaWRKY cDNAs revealed the presence of the conserved WRKY domain of ~60 amino acids and a zinc-finger motif at the N-terminus. Based on the number of WRKY repeats and the structure of the zinc-finger motif, MaWRKY18 and MaWRKY60 belong to group II of WRKY TFs, while MaWRKY45 and MaWRKY70 are members of group III. Their corresponding proteins were located in the nuclei of onion epidermal cells and were shown to be functional TFs in yeast cells. Moreover, expression analyses revealed that the majority of these MaWRKY genes were upregulated by salicylic acid (SA) or methyl jasmonate (MeJA) phytohormones, although the expression levels were relatively higher with MeJA treatment. The fact that most of these banana WRKY genes were upregulated by SA or MeJA, which are involved in systemic acquired resistance (SAR) or induced systemic resistance (ISR), respectively, make them interesting candidates for bioengineering broad-spectrum resistance in this crop. © 2022 by the authors.

BANANA TRANSCRIPTION FACTOR WRKY DEFENSE PHYTOHORMONES SALICYLIC ACID METHYL JASMONATE SAR ISR BROAD-SPECTRUM RESISTANCE BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA GENÉTICA GENÉTICA MOLECULAR DE PLANTAS GENÉTICA MOLECULAR DE PLANTAS

Retención larvaria en abulón azul Haliotis fulgens mediante análisis de parentesco en B.C.S., México

ADRIANA MAX AGUILAR (2014, [Tesis de maestría])

El abulón azul (Haliotis fulgens) es un molusco gasterópodo de importancia comercial en México. Es un recurso de alto valor comercial (70 M en 2011) debido a su gran demanda a nivel internacional; su pesquería constituye una de las actividades más importantes que se desarrollan en la costa occidental de la península de Baja California. Esta pesquería ha sufrido de manera histórica una disminución significativa, por lo que es necesario reforzar y continuar los programas de investigación y manejo actual para garantizar la recuperación de los bancos abuloneros. Un aspecto crucial en el manejo y administración de las pesquerías, es el claro entendimiento del concepto de unidad de stock, el cual requiere un mejor conocimiento del reclutamiento en función de la dinámica larvaria y la conectividad entre bancos (dados por los niveles de retención y dispersión), lo que ampliaría la precisión de las estrategias de manejo actuales. En el caso del abulón se han propuesto dos modelos de conectividad: (1) Las larvas son transportadas a grandes distancias de sus padres y llegan a sustentar otros bancos; y (2) el intercambio larvario entre bancos es limitado y cada banco es un pequeño stock que es autosustentable. En cualquier caso, es necesario determinar si en un banco lo que ocurre preponderantemente es el auto-reclutamiento, o si por el contrario, las larvas provienen principalmente de otros sitios. El objetivo del presente trabajo fue estimar el índice de retención larvaria del abulón azul Haliotis fulgens en dos sitios de la costa occidental de Baja California Sur, mediante el uso de marcadores genéticos tipo microsatélite en análisis de parentesco. Se estandarizaron y caracterizaron nuevos loci microsatélites específicos para H. fulgens con los cuales se determinó el índice de retención larvaria a través de la asignación genética de juveniles a progenitores que se encontraran en el mismo sitio de muestreo mediante análisis de paternidad con el programa CERVUS 3.0. Se obtuvieron 24 loci microsatélites potenciales para utilizarlos en análisis genéticos, de los cuales se caracterizaron 12 loci polimórficos. Se determinó que 11 de ellos son factibles de utilizar en análisis de parentesco por su alto polimorfismo (Número de alelos: de 5-17; HE de 0.69-0.92; PIC de 0.64-0.90) y presentar Equilibrio de Hardy-Weinberg [...]

The green abalone (Haliotis fulgens) is a marine gastropod mollusk in Mexico with a high commercial value (70 M in 2011) because of its high demand in the international market. Its fishery is an important commercial activity in the west coast of Baja California Sur, and has historically suffered a significant decline in its captures. Thus it is necessary to continue research and current management programs to ensure the recovery of abalone in reef systems. A crucial consideration in management and administration of this fishery is a clear understanding of the concept of a stock unit, which requires a better understanding of recruitment on defined spatial scales, depending on the larval dynamics and connectivity among reefs (given by the levels of retention and dispersal). This knowledge will extend the accuracy of current management strategies. Two different models on connectivity have been proposed for abalone: (1) the larvae can be transported for long distances from their parent’s reef and supply other distant reefs; and (2) larval exchange between reefs is limited, and each one is a small self-replenishing bank. In any case, it is necessary to determine whether a reef is mainly maintained by self-recruitment, or if larvae come mainly from other sites. The objective of this work was estimate the proportion of green abalone Haliotis fulgens larval retention in two sites on the western coast of Baja California Sur, using microsatellite markers in paternity analysis. New microsatellite markers in H. fulgens were standardized and characterized. The larval retention was estimated by the proportion of juveniles genetically assigned to the possible parents in the same site by paternity analysis using CERVUS 3.0. Twenty-four microsatellite loci potentially useful in genetic analysis were obtained, from which 12 polymorphic loci were characterized. From these, 11 were useful in paternity analysis due to their high polymorphism (number of alleles: 5-17; HE: 0.69-0.92; PIC: 0.64-0.90) and because they were in Hardy-Weinberg equilibrium [...]

Retención larvaria; microsatélites; auto-reclutamiento BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA GENÉTICA GENÉTICA DE POBLACIONES GENÉTICA DE POBLACIONES