First global transcriptome analysis of brown algae Macrocystis integrifolia (Phaeophyceae) under marine intertidal conditions

Abstract

To understand the physiological responses of the brown macroalga during the marine tidal cycle, two RNA libraries were prepared from algal frond samples collected in the intertidal zone (0 m depth) and subtidal zone (10 m depth). Samples collected from intertidal zone during low tide was considered as abiotic stressed (MI0), while samples collected from subtidal zone was considered as control (MI10). Both RNA libraries were sequenced on Illumina NextSeq 500 which generated approx. 46.9 million and 47.7 million raw paired-end reads for MI0 and MI10, respectively. Among the representative transcripts (RTs), a total of 16,398 RTs (39.20%) from MI0 and 21,646 RTs (39.24%) from MI10 were successfully annotated. A total of 535 unigenes (271 upregulated and 264 downregulated) showed significantly altered expression between MI0 and MI10. In abiotic-stressed condition (MI0), the relative expression levels of genes associated with antioxidant defenses (vanadium-dependent bromoperoxidase, glutathione S-transferase, lipoxygenase, serine/threonine-protein kinase, aspartate Aminotransferase, HSPs), water transport (aquaporin), photosynthesis (light-harvesting complex) protein were significantly upregulated, while in control condition (MI10) most of the genes predominantly involved in energy metabolism (NADH-ubiquinone oxidoreductase/NADH dehydrogenase, NAD(P)H-Nitrate reductase, long-chain acyl-CoA synthetase, udp-n-acetylglucosamine pyrophosphorylase) were overexpressed.

Rapid turnover of life-cycle-related genes in the brown algae

“…Analyses of generation-biased gene expression used published RNA-seq datasets (at least two replicate samples) for gametophytes and sporophytes of the model brown alga Ectocarpus sp. [27, 31], S. japonica [25, 32] and M. pyrifera [27, 33]. For S. lomentaria , a published dataset was available for the gametophyte generation [31] and we generated RNA-seq data for duplicate samples of sporophytes (Additional file 1: Table S3 and “Methods” section for details).…”

“…All data generated or analysed during this study are included in this published article and its supplementary information files. The datasets generated and analysed in this article are available in the SRA repository under accession numbers: SRR6742570-71; SRR4446494-95, SRR5026349-55, SRR5026357, SRR5026360-63, SRR5026366, SRR5026588, SRR5026590-94 [27]; SRR1166427-30, SRR1166441, SRR1166452, SRR1660829-30, SRR5026364-65, SRR5026634-35 [31]; SRR5860560-68 [32]; SRR3544557, SRR3615022 [33]. Details of SRA references for sequence data are also included in Additional file 1: Table S3.…”

Exploring Core Response Mechanisms to Multiple Environmental Stressors Via A Genome‐Wide Study in the Brown Alga Saccharina japonica (Laminariales, Phaeophyceae)

“…2012, Salavarría et al. 2018). Altogether, our results conform to previous studies which demonstrated that antioxidant defense might be an important acclimation of brown macroalgae to environmental stress conditions.…”

Different Early Responses of Laminariales to an Endophytic Infection Provide Insights About Kelp Host Specificity

“…The other gene regulations occurring after 48 h could be related to the accumulation and perception of cell wall degradation products, such as oligoalginates (Figure 4B). Indeed, some stress-response related genes were upregulated in S. latissima such as vanadium dependent bromoperoxidases (vBPO) and vanadium dependent iodoperoxidases (vIPO) involved in halide metabolism of brown algae and upregulated during abiotic and biotic oxidative responses (Cosse et al, 2009;Strittmatter et al, 2016;Salavarría et al, 2018). Other upregulated genes were putatively involved in calcium and oxylipin signaling pathways, two key pathways activated upon biotic and abiotic stress (Knight, 1999;Eckardt, 2008;Zhang et al, 2014).…”