Biology subjects

Miura, N.

Publications and source records attributed to Miura, N..

3 recordsLinked to original sources

bioRxiv2024

Quantifying Forest Biomass and Genetic Contribution using Light Detection and Ranging

The growing focus on the role of forests in carbon sequestration highlights the importance of accurately and efficiently measuring biophysical traits, such as diameter at breast height (DBH) and tree height. Understanding genetic contributions to trait variation is crucial for enhancing carbon storage through genetic improvement of forest trees. Light detection and ranging (LiDAR) has been used to estimate DBH and tree height; however, few studies have explored the heritability of these traits or assessed the accuracy of biomass increment selections based on these traits. Therefore, this study aimed to leverage LiDAR to measure DBH and tree height, estimate tree heritability, and evaluate the accuracy of timber volume selections based on these traits using 60-year-old larch as the study material. Unmanned aerial vehicle (UAV) and backpack LiDAR were compared against hand-measured values. The accuracy of DBH estimations using backpack LiDAR resulted in a root mean square error (RMSE) of 2.7 cm and a coefficient of determination of 0.67. Conversely, the accuracy achieved with UAV LiDAR was 4.0 cm in RMSE and a 0.24 coefficient of determination. The heritability of DBH was found to be higher for backpack LiDAR than for UAV LiDAR and even exceeded that of hand measurements. Comparisons of the accuracy of timber volume selections based on the measured traits demonstrated comparable performances between the backpack and UAV LiDAR. Overall, these findings underscore the potential of using LiDAR remote sensing to quantitatively measure forest tree biomass and facilitate their genetic improvement of carbon-sequestration ability based on these measurements.

genetics↗

bioRxiv2023

Characterization of carotenoid-producing Muricauda sp. strains isolated from the reef-building coral Galaxea fascicularis and subtropical seawater

Bacterial symbionts in corals and coral-associated zooxanthellae are attracting increasing attention as potential probiotics. Some members of the family Flavobacteriaceae are zooxanthellae-associated bacteria, which are known to protect zooxanthellae from stresses such as heat and light by producing carotenoids that reduce reactive oxygen species production. This study characterized two Flavobacteriaceae bacteria, Muricauda sp. strains ORYM1 (NBRC115792) and ORYM2 (NBRC115793), isolated from the reef-building coral Galaxea fascicularis and its surrounding seawater in Okinawa, Japan, respectively. The Muricauda sp. strain ORYM2 was isolated from subtropical seawater, and carotenoid production was assessed using ORYM2 as well as ORYM1, which was previously isolated from G. fascicularis. De novo genome sequencing revealed that both strains contain complete sets of zeaxanthin biosynthesis genes, similar to those found in other Muricauda spp. Thin-layer chromatography and high-performance liquid chromatography analyses demonstrated that ORYM1 and ORYM2 produce several carotenoids. The bacterial strains and carotenoids identified in this study provide insights into the biological roles of zooxanthellae-associated bacteria in protecting zooxanthellae and reef-building corals from environmental stresses. Statements and declarationsCompeting interests: The authors declare no competing interests.

microbiology↗

bioRxiv2023

Deciphering mechanisms of UV filter- and temperature-induced bleaching in the coral Acropora tenuis, using ecotoxicogenomics

Coral reefs are at risk of bleaching due to various environmental and anthropogenic stressors such as global warming and chemical pollutants. However, there is little understanding of stressor-specific mechanisms that cause coral bleaching. Therefore, conducting accurate ecotoxicological risk assessments and deciphering modes of action of potentially deleterious ultraviolet (UV) filters (sunscreen compounds) are crucial issues. In this study, we evaluated the toxicity and bleaching effect of benzophenone-3 (BP-3), which is widely used in sunscreen products, on the reef-building coral Acropora tenuis. Furthermore, to understand differences in UV filter- and temperature-induced bleaching, a comparative ecotoxicogenomic approach using RNA-seq was integrated into a toxicity test to clarify differences in gene expression changes induced by BP-3 and heat stress (31{degrees}C). The lethal concentration 50% (LC50) was calculated as 3.9 mg/L, indicating that emission level of BP-3 was properly controlled based on the risk assessment. Differentially expressed genes related to oxidative stress and extracellular matrix organization were involved in coral responses to both BP-3 and heat stress, but their patterns differed. Whereas immune and heat-shock responses were activated in response to heat stress, activation of a drug metabolism pathway and several signal transduction pathways were identified in BP-3 treatment groups. Our study enhances understanding of stress responses in corals induced by UV filters and thermal stress. Using potential gene markers identified in this study for eco-epidemiological surveys of stressed corals, we urgently need to develop effective countermeasures.

ecology↗