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

Abstract

Recently 18 Bangiales seaweed species were reported for the Chilean coast, including Pyropia orbicularis and Pyropia variabilis (large [LM] and green [GM] morphotypes). Porphyra/Pyropia spp. occur mainly in the upper intertidal where desiccation stress is triggered by tidal fluctuations. However, the influence of environmental and ecophysiological variables and seasonal differences on Porphyra/Pyropia (microhabitats) intertidal distributions is unknown. Accordingly, we determined (i) the effect of environmental variables (temperature [T], relative humidity [RH], and photosynthetically active radiation [PAR]) and season on distribution, and (ii) physiological (cellular activity and lipid peroxidation [LPX]) and molecular responses (antioxidant enzymes expression at biochemical and transcript level) to desiccation stress in both Pyropia species and morphotypes (common garden experiment, on flat rocky platforms). Multivariate analyses of coverage and abundance in relation to environmental variables revealed a significant effect of temperature on P. variabilis GM distribution, GM dominating almost exclusively on rocky walls (where lowest PAR and T values but maximum RH were registered). Conversely, Pyropia orbicularis and Pyropia variabilis LM were found in high abundance on flat rocky platforms in summer, LM and GM also dominating flat rocky platforms in winter and spring. LPX and catalase activity did not differed among species in summer, while in winter activity and transcription of cat were higher in P. orbicularis than P. variabilis. Results suggest that tolerance to environmental stresses such as temperature could regulate the occurrence of P. variabilis GM on rocky walls; conversely, abundances of P. variabilis and P. orbicularis on flat rocky platforms would be also regulated by other abiotic and/or biotic factors.

Enhancement of Xanthophyll Synthesis in Porphyra/Pyropia Species (Rhodophyta, Bangiales) by Controlled Abiotic Factors: A Systematic Review and Meta-Analysis

“…Species of the Porphyra and Pyropia genera inhabit highly dynamic environments (the intertidal zone), where abiotic factors play a key role in modulating their ecological distribution (e.g., the temperature, irradiance, and salinity) [58]. Consequently, these species have developed effective mechanisms to counteract the oxidative stress damage that these factors can trigger [59].…”

More than What Meets the Eye: Differential Spatiotemporal Distribution of Cryptic Intertidal Bangiales

“…This idea is supported by the slightly distinct gene expression and ecophysiological responses of Pyropia orbicularis and Py. variabilis to desiccation [ 32 ]. Similarly, variations in ecophysiological responses have been used to explain differences in species distribution among cryptic red algae of the genus Bostrychia [ 33 ].…”

First approach of characterization of bioactive compound in Pyropia orbicularis during the daily tidal cycle

“…The abiotic and biotic gradients factors along the rocky intertidal zone, such as temperature, light intensity, desiccation, competition and predation among others, make it a highly heterogeneous environment (Stephenson & Stephenson, 1949;Davison & Pearson, 1996). The organisms inhabiting the intertidal present diverse mechanisms of stress tolerance depending of the distribution zone (high, middle, low or rocky walls) __________________ Corresponding editor: Sergio Palma or small scale microenvironments (Davison & Pearson, 1996;Flores-Molina et al, 2014;Meynard et al, 2019;Zapata et al, 2019). Organisms, under constant environmental pressures, generate an overproduction of reactive oxygen species (ROS), such as superoxide ion (O 2-), hydrogen peroxide (H2O2) or hydroperoxides (ROOH) among others (Ray et al, 2012), which in turn can cause oxidative damage to important biomolecules (membrane lipids, nucleic acids and proteins) (Mittler, 2002).…”