Identificación de genes involucrados en la arquitectura del almendro influenciados por el portainjerto mediante análisis transcriptómico

Publishe

Characterization of almond scion/rootstock communication in cultivar and rootstock tissues through a RNA-Seq approach

Background: Rootstock genotype determines multiple aspects of the scion development, including the scion three-dimensional structure, or tree architecture. Thus, rootstock choice is an important factor in the establishment of new almond (Prunus amygdalus (L.) Batsch, syn P. dulcis (Mill.)) planting systems, which demand cultivars whose vigor and shape adapt to these new requirements. However, if the rootstock genotype is able to alter scion development, it is likely that the scion genotype affects the rootstock performance. Results: We carried out a transcriptomic analysis of the scion/rootstock interaction in young trees, focusing on the scion effect in the rootstock molecular response. Two commercial almond cultivars were grafted onto two hybrid rootstocks, resulting in four combinations, whose gene expression in both scion and rootstock tissue was analyzed via RNA-Seq. We observed that, in fact, the scion genotype has an impact on the rootstock expression profile, affecting the expression of genes associated with hormonal regulation, root development and light signaling. Conclusions: Scion/rootstock communication has a pivotal role in the development of both scion and rootstock, accentuating the importance of a correct choice when establishing new almond orchards.Publishe

Proleptic and Sylleptic Shoot Formation Is Affected by Rootstock Genotype in Two-Year-Old Branches of Almond Trees

The implementation of new planting systems in almond (Prunus amygdalus (L.) Batsch, syn P. dulcis (Mill.)) orchards for more sustainable practices has made tree architecture increasingly relevant as an important selection trait in plant breeding. Multiple features define the three-dimensional structure of the tree, with shoot production being the most important. Shoots can develop after a period of rest (proleptic shoots) or immediately (sylleptic shoots), at the same time as the extension of the parent shoot. Scion/rootstock interactions may change the proportion of proleptic and sylleptic shoots and thus alter tree architecture. To study this effect, we analyzed shoot formation on three almond scion cultivars grafted onto five interspecific hybrid rootstocks. The type of shoot (proleptic or sylleptic) and internode number per shoot were collected for two-year-old branches on three-year-old unpruned trees. We found that rootstock genotypes can alter the pattern of shoot production, especially the number of sylleptic shoots formed. More information on the molecular response is needed to comprehend the biological processes behind these differential phenotypes, which appear to be modulated by both apical dominance and apical control.Publishe

Caracterización del efecto de la interacción injerto-portainjerto en rasgos de la arquitectura del almendro

Este trabajo ha sido financiado por la Agencia Estatal de Investigación (AEI), el proyecto RTI2018-094210-R-100 y el Grupo de Investigación A12 del Gobierno de AragónPublishe

Phenotyping Almond Orchards for Architectural Traits Influenced by Rootstock Choice

The cropping potential of almond (Prunus amygdalus (L.) Batsch, syn P. dulcis (Mill.)) cultivars is determined by their adaptation to edaphoclimatic and environmental conditions. The effects of scion–rootstock interactions on vigor have a decisive impact on this cropping success. Intensively planted orchards with smaller less vigorous trees present several potential benefits for increasing orchard profitability. While several studies have examined rootstock effects on tree vigor, it is less clear how rootstocks influence more specific aspects of tree architecture. The objective of this current study was to identify which architectural traits of commercially important scion cultivars are influenced by rootstock and which of these traits can be useful as descriptors of rootstock performance in breeding evaluations. To do this, 6 almond cultivars of commercial significance were grafted onto 5 hybrid rootstocks, resulting in 30 combinations that were measured after their second year of growth. We observed that rootstock choice mainly influenced branch production, but the effects were not consistent across the different scion–rootstock combinations evaluated. This lack of consistency in response highlights the importance of the unique interaction between each rootstock and its respective scion genotype.Publishe

Polymorphisms and gene expression in the almond IGT family are not correlated to variability in growth habit in major commercial almond cultivars

Almond breeding programs aimed at selecting cultivars adapted to intensive orchards have recently focused on the optimization of tree architecture. This multifactorial trait is defined by numerous components controlled by processes such as hormonal responses, gravitropism and light perception. Gravitropism sensing is crucial to control the branch angle and therefore, the tree habit. A gene family, denominated IGT family after a share conserved domain, has been described as involved in the regulation of branch angle in several species, including rice and Arabidopsis, and even in fruit trees like peach. Here we identified six members of this family in almond: LAZY1, LAZY2, TAC1, DRO1, DRO2, IGT-like. After analyzing their protein sequences in forty-one almond cultivars and wild species, little variability was found, pointing a high degree of conservation in this family. Gene expression was analyzed in fourteen cultivars of agronomical interest comprising diverse tree habit phenotypes. Only LAZY1, LAZY2 and TAC1 were expressed in almond shoot tips during the growing season. No relation was established between the expression profile of these genes and the tree habit. However, some insight has been gained in how LAZY1 and LAZY2 are regulated, identifying the IPA1 almond homologues and other transcription factors involved in hormonal responses as regulators of their expression. Besides, we have found various polymorphisms that could not be discarded as involved in a potential polygenic origin of regulation of architectural phenotypes. Therefore, we have established that unlike many species, IGT family genes do not play a critical role in the control of tree habit in currently commercialized almond cultivars, with other gene families contributing to the variability of these traits.Unpublishe

Análisis genómico de los mecanismos moleculares asociados a la arquitectura del almendro (póster)

Este trabajo ha sido financiado por la Agencia Estatal de Investigación (AEI), el proyecto RTI2018-094210-R-100 y el Grupo de Investigación A12 del Gobierno de AragónPublishe

Evaluación agronómica de siete portainjertos de Prunus en dos condiciones edafológicas diferentes (póster)

Este trabajo fue financiado por la Agencia Estatal de Investigación (AEI) Proyecto núm. RTI2018-094210-R100 y el Grupo de Investigación A12 del Gobierno de AragónPublishe

Diversidad y evolución molecular de genes de respuesta a sequía en almendro y otras plantas leñosas

El aumento de estrés por sequía, acentuado por el cambio climático, es uno de los principales problemas para la agricultura a corto plazo, haciendo necesaria la selección de portainjertos tolerantes a estas condiciones ambientales. Sin embargo, el conocimiento actual a nivel molecular sobre la respuesta a sequía en plantas leñosas es muy limitado. En un análisis transcriptómico previo en tejido radicular del portainjerto híbrido almendro x melocotonero ‘Garnem’, se identificaron varias familias de genes involucrados en la respuesta a sequía: Homeodomain Superfamily, Heat Shock Proteins (HSPs), Late Embryogenesis Abundant (LEA) y Dehydration-Responsive Element-Binding (DREB). El objetivo de este estudio fue comprender la evolución de estas familias de genes en varias especies leñosas. Los genes estudiados se identificaron en los genomas de nueve especies (Prunus dulcis, P. persica, Malus domestica, Festuca vesca, Citrus sinensis, Arabadopsis thaliana, Quercus rubra, Pinus taeda and P. lambertiana), representando así una elevada diversidad vegetal. Con las secuencias de dichos genes, se realizó un análisis filogenético mediante estimación de máxima verosimilitud, donde se observaron diferentes patrones evolutivos.Publishe