Preferential Expression of a Bromoperoxidase in Sporophytes of a Red Alga, Pyropia yezoensis

Abstract

A 2,158 bp cDNA (PyBPO1) encoding a bromoperoxidase (BPO) of 625 amino acids was isolated from Pyropia yezoensis. Phylogenetic analysis using amino acid sequences of BPOs suggested that P. yezoensis and cyanobacteria were grouped in the same clade and separated from brown algae. Genomic Southern blot analysis suggested that PyBPO1 existed as a single copy per haploid genome. RT-PCR revealed that PyBPO1 was actively expressed in filamentous sporophytes but repressed in leafy gametophytes under normal growth conditions. High expression levels of PyBPO1 in sporophytes were observed when sporophytes were grown under gametophyte conditions, suggesting that preferential expression of PyBPO1 occurs during the sporophyte phase. BPO activity of cell-free extracts from sporophytes and gametophytes was examined by activity staining on native PAGE gel using o-dianisidine. One activity band was detected in sporophyte sample, but not in gametophyte sample. In addition, we found that bromide and iodide were effective substrate, but chloride was not. BPO activity was observed-likely in chloroplasts-when sporophyte cells were incubated with o-dianisidine and hydrogen peroxide. Cellular BPO staining showed the same halogen preference identified by in-gel BPO staining. Based on GS-MS analysis, bromoform was detected in medium containing sporophytes. Bromoform was not detected under dark culture conditions but was detected in the culture exposed to low light intensity (5 μmol m(-2) s(-1)) and increased under a moderate light intensity (30 μmol m(-2) s(-1)).

A unique life cycle transition in the red seaweed Pyropia yezoensis depends on apospory

“…Therefore, we first evaluated the expression of thallus- and conchocelis-specific genes in the conchosporangium by quantitative reverse-transcriptase PCR (qRT-PCR). Previous reports have shown that genes encoding the alginate lyase (PyAly) 25 , sodium pump (PyKPA2) 26 , and ammonium transporter (PyAMT1) 27 are thallus specific, whereas genes encoding the sodium pump (PyKPA1) 28 , bromoperoxidase (PyBPO) 29 , and urea transporter (PyDUR3.3) 30 are conchocelis specific. Thus, we compared the expression levels of these genes in the thallus, conchosporangium, and conchocelis by qRT-PCR with gene-specific primers (Supplementary Table 1).…”

Antibacterial Activities and Life Cycle Stages of Asparagopsis armata: Implications of the Metabolome and Microbiome

“…A differential expression of haloperoxidases, which could then lead to the differential production of halogenated molecules, could explain the observed differences in the abundance of not only compound 4 but also other halogenated compounds. The preferential expression of a gene encoding for bromoperoxidase was already reported in the sporophyte stage of the red algae Pyropia yezoensis [ 33 ]. The authors showed that it was actively expressed in filamentous sporophytes, leading to bromoform production, but repressed in leafy gametophytes under normal growth conditions, which is in accordance with our hypothesis.…”

Genetic toolkits of the red alga Pyropia tenera against the three most common diseases in Pyropia farms

“…Our results showed that a homologue of haloperoxidase was significantly up-regulated in all infection experiments. Quantitative PCR analysis on a boromoperoxidase isolated from Pyropia yezoensis showed that it is actively expressed in filamentous sporophytes but repressed in leafy gametophytes under normal growth conditions (Matsuda et al 2015). Further studies on isolated halogenated compounds are necessary to understand their role in Pyropia defense against pathogens.…”