Differential gene expression in Pyropia columbina (Bangiales, Rhodophyta) under natural hydration and desiccation conditions

Abstract

ABSTRACT. In rocky shores, desiccation is triggered by daily tide changes, and experimental evidence suggests that local distribution of algal species across the intertidal rocky zone is related to their capacity to tolerate desiccation. In this context, the permanence of Pyropia columbina in the high intertidal rocky zone is explained by its exceptional physiological tolerance to desiccation. This study explored the metabolic pathways involved in tolerance to desiccation in the Chilean P. columbina, by characterizing its transcriptome under contrasting conditions of hydration. We obtained 1,410 ESTs from two subtracted cDNA libraries in naturally hydrated and desiccated fronds. Results indicate that transcriptome from both libraries contain transcripts from diverse metabolic pathways related to tolerance. Among the transcripts differentially expressed, 15% appears involved in protein synthesis, processing and degradation, 14.4% are related to photosynthesis and chloroplast, 13.1% to respiration and mitochondrial function (NADH dehydrogenase and cytochrome c oxidase proteins), 10.6% to cell wall metabolism, and 7.5% are involved in antioxidant activity, chaperone and defense factors (catalase, thioredoxin, heat shock proteins, cytochrome P450). Both libraries highlight the presence of genes/proteins never described before in algae. This information provides the first molecular work regarding desiccation tolerance in P. columbina, and helps, to some extent, explaining the classical patterns of ecological distribution described for algae across the intertidal zone. Keywords: Pyropia, desiccation stress, ESTs, seaweeds, transcriptomics, proteins. Expresión diferencial de genes en Pyropia columbina (Bangiales, Rhodophyta)bajo hidratación y desecación natural RESUMEN. En zonas rocosas costeras, la desecación es gatillada por cambios diarios en los niveles de marea, y la evidencia experimental indica que la distribución de las algas en la zona intermareal está relacionada con su capacidad para tolerar la desecación. En este contexto, la presencia de Pyropia columbina en la zona alta del intermareal se explica por su excepcional tolerancia fisiológica a la desecación. Este estudio explora las vías metabólicas involucradas en la tolerancia a la desecación en P. columbina, a través de la caracterización de su transcriptoma bajo condiciones de hidratación contrastantes. Se obtuvo 1,410 ESTs provenientes de dos librerías de substracción de cDNA de frondas naturalmente hidratadas y desecadas. Los transcriptomas de ambas librerías contienen transcritos de diversas rutas metabólicas relacionadas a la tolerancia. Entre los transcritos expresados 15% están involucrados en la síntesis de proteínas, su procesamiento y degradación, 14,4% asociados a fotosíntesis y cloroplasto, 13,1% a respiración y función mitocondrial, 10,6% al metabolismo de la pared celular y 7,5% a la actividad antioxidante, proteínas chaperonas y factores de defensa (catalasa, tiorredoxina, proteínas de shock térmico, citocromo P450). En ambas librerías se de...

Non‐Random Distribution and Ecophysiological Differentiation of Pyropia Species (Bangiales, Rhodophyta) Through Environmental Gradients

“…qPCR data were analyzed using C t values and the reference gene sen (Contreras‐Porcia et al. ; HE859069).…”

“…Total RNA extraction. It was isolated from 1 g of fresh tissue according to Contreras-Porcia et al (2013). RNA yield and quality were assessed with the NanoDrop TM 1,000 Spectrophotometer (Thermo Fisher Scientific, Wilmington, DE, USA) and denaturing 1.2% formaldehyde agarose gel electrophoresis, respectively.…”

Health Functionality and Quality Control of Laver (Porphyra, Pyropia): Current Issues and Future Perspectives as an Edible Seaweed

“…With respect to the life cycle, previous studies focused on characterization of the evolutionary aspects of the distinct stages [158,159], development of applied technologies including the designation of biomarkers [160], and treatments affecting the regulation of gene expression linked to reproductive processes [161]. A major focus for genomic research has been the interpretation and/or comparative analysis of transcriptomic data relating to the responses of laver species to abiotic stress [162,163], principally environmental conditions such as high temperature [164][165][166], repeated desiccation-rehydration [167,168], and hypersalinity [169].…”

Salinity and Desiccation Induced Oxidative Stress Acclimation in Seaweeds

“…Transcriptome and microarray database of U. linza and C. crispus (Collen et al, 2007) has also evidenced the regulation of early light-induced proteins with higher expression under hyposaliny, high light and thermal stress; reduced expression in severe desiccation and unchanged under hypersalinity stress. In context to ROS attenuation by the antioxidant system during the hydration-desiccation cycle, several antioxidant enzymes and others including a peroxiredoxin, arachidonate 5-lipoxygenase, GSTs and several cytochrome P450 and HSPs (in hydrated thalli), whereas thioredoxin, CAT and low variants of HSPs70 and 90 (in desiccated thalli) were found upregulated in P. columbina analysed by suppression subtractive hybridisation and ESTs (Contreras-Porcia et al, 2013). Overexpression of many ribosomal protein genes and two ubiquitin ribosomal protein fusion genes in EST analysis of desiccation tolerant (Fucus vesiculosus) and susceptible (Fucus serratus) suggested that ribosome function and/or biogenesis are important during cycles of rapid desiccation and rehydration in the intertidal zone (Pearson et al, 2010).…”

“…Overexpression of many ribosomal protein genes and two ubiquitin ribosomal protein fusion genes in EST analysis of desiccation tolerant (Fucus vesiculosus) and susceptible (Fucus serratus) suggested that ribosome function and/or biogenesis are important during cycles of rapid desiccation and rehydration in the intertidal zone (Pearson et al, 2010). Furthermore, accumulation of abscisic acid (ABA) in P. columbina during desiccation suggested its involvement in transcription of regulatory networks of desiccation stress signals and gene expression involving sugars, proline and PAs (Contreras-Porcia et al, 2013). In context to ROS attenuation by the antioxidant system during the hydration-desiccation cycle, several antioxidant enzymes and others including a peroxiredoxin, arachidonate 5-lipoxygenase, GSTs and several cytochrome P450 and HSPs (in hydrated thalli), whereas thioredoxin, CAT and low variants of HSPs70 and 90 (in desiccated thalli) were found upregulated in P. columbina analysed by suppression subtractive hybridisation and ESTs (Contreras-Porcia et al, 2013).…”