A CPD photolyase gene PnPHR1 from Antarctic moss Pohlia nutans is involved in the resistance to UV-B radiation and salinity stress

Microbial-derived salt-tolerant proteases and their applications in high-salt traditional soybean fermented foods: a review

Different microorganisms can produce different proteases, which can adapt to different industrial requirements such as pH, temperature, and pressure. Salt-tolerant proteases (STPs) from microorganisms exhibit higher salt tolerance, wider adaptability, and more efficient catalytic ability under extreme conditions compared to conventional proteases. These unique enzymes hold great promise for applications in various industries including food, medicine, environmental protection, agriculture, detergents, dyes, and others. Scientific studies on microbial-derived STPs have been widely reported, but there has been little systematic review of microbial-derived STPs and their application in high-salt conventional soybean fermentable foods. This review presents the STP-producing microbial species and their selection methods, and summarizes and analyzes the salt tolerance mechanisms of the microorganisms. It also outlines various techniques for the isolation and purification of STPs from microorganisms and discusses the salt tolerance mechanisms of STPs. Furthermore, this review demonstrates the contribution of modern biotechnology in the screening of novel microbial-derived STPs and their improvement in salt tolerance. It highlights the potential applications and commercial value of salt-tolerant microorganisms and STPs in high-salt traditional soy fermented foods. The review ends with concluding remarks on the challenges and future directions for microbial-derived STPs. This review provides valuable insights into the separation, purification, performance enhancement, and application of microbial-derived STPs in traditional fermented foods.

Basking in the sun: how mosses photosynthesise and survive in Antarctica

The Antarctic environment is extremely cold, windy and dry. Ozone depletion has resulted in increasing ultraviolet-B radiation, and increasing greenhouse gases and decreasing stratospheric ozone have altered Antarctica's climate. How do mosses thrive photosynthetically in this harsh environment? Antarctic mosses take advantage of microclimates where the combination of protection from wind, sufficient melt water, nutrients from seabirds and optimal sunlight provides both photosynthetic energy and sufficient warmth for efficient metabolism. The amount of sunlight presents a challenge: more light creates warmer canopies which are optimal for photosynthetic enzymes but can contain excess light energy that could damage the photochemical apparatus. Antarctic mosses thus exhibit strong photoprotective potential in the form of xanthophyll cycle pigments. Conversion to zeaxanthin is high when conditions are most extreme, especially when water content is low. Antarctic mosses also produce UV screening compounds which are maintained in cell walls in some species and appear to protect from DNA damage under elevated UV-B radiation. These plants thus survive in one of the harshest places on Earth by taking advantage of the best real estate to optimise their metabolism. But survival is precarious and it remains to be seen if these strategies will still work as the Antarctic climate changes.

High Resilience and Fast Acclimation Processes Allow the Antarctic Moss Bryum argenteum to Increase Its Carbon Gain in Warmer Growing Conditions

Climate warming in Antarctica involves major shifts in plant distribution and productivity. This study aims to unravel the plasticity and acclimation potential of Bryum argenteum var. muticum, a cosmopolitan moss species found in Antarctica. By comparing short-term, closed-top chamber warming experiments which mimic heatwaves, with in situ seasonal physiological rates from Cape Hallett, Northern Victoria Land, we provide insights into the general inherent resilience of this important Antarctic moss and into its adaptability to longer-term threats and stressors associated with climate change. Our findings show that B. argenteum can thermally acclimate to mitigate the effects of increased temperature under both seasonal changes and short-term pulse warming events. Following pulse warming, this species dramatically increased its carbon uptake, measured as net photosynthesis, while reductions in carbon losses, measured as dark respiration, were not observed. Rapid growth of new shoots may have confounded the effects on respiration. These results demonstrate the high physiological plasticity of this species, with acclimation occurring within only 7 days. We show that this Antarctic moss species appears to have a high level of resilience and that fast acclimation processes allow it to potentially benefit from both short-term and long-term climatic changes.

Recombinant Photolyase-Thymine Alleviated UVB-Induced Photodamage in Mice by Repairing CPD Photoproducts and Ameliorating Oxidative Stress

Cyclobutane pyrimidine dimers (CPDs) are the main mutagenic DNA photoproducts caused by ultraviolet B (UVB) radiation and represent the major cause of photoaging and skin carcinogenesis. CPD photolyase can efficiently and rapidly repair CPD products. Therefore, they are candidates for the prevention of photodamage. However, these photolyases are not present in placental mammals. In this study, we produced a recombinant photolyase-thymine (rPHO) from Thermus thermophilus (T. thermophilus). The rPHO displayed CPD photorepair activity. It prevented UVB-induced DNA damage by repairing CPD photoproducts to pyrimidine monomers. Furthermore, it inhibited UVB-induced ROS production, lipid peroxidation, inflammatory responses, and apoptosis. UVB-induced wrinkle formation, epidermal hyperplasia, and collagen degradation in mice skin was significantly inhibited when the photolyase was applied topically to the skin. These results demonstrated that rPHO has promising protective effects against UVB-induced photodamage and may contribute to the development of anti-UVB skin photodamage drugs and cosmetic products.

Bryophyte ultraviolet-omics: from genes to the environment

Ultraviolet (UV) radiation has contributed to the evolution of organisms since the origins of life. Bryophytes also have evolutionary importance as the first clearly identified lineage of land plants (embryophytes) colonizing the terrestrial environment, thus facing high UV and water scarcity, among other new challenges. Here we review bryophyte UV-omics, the discipline relating bryophytes and UV, with an integrative perspective from genes to the environment. We consider species and habitats investigated, methodology, response variables, protection mechanisms, environmental interactions, UV biomonitoring, molecular and evolutionary aspects, and applications. Bryophyte UV-omics shows convergences and divergences with the UV-omics of other photosynthetic organisms, from algae to tracheophytes. All these organisms converge in that UV damage may be limited under realistic UV levels, due to structural protection and/or physiological acclimation capacity. Nevertheless, bryophytes diverge because they have a unique combination of vegetative and reproductive characteristics to cope with high UV and other concomitant adverse processes, such as desiccation. This interaction has both evolutionary and ecological implications. In addition, UV effects on bryophytes depend on the species and the evolutionary lineage considered, with mosses more UV-tolerant than liverworts. Thus, bryophytes do not constitute a homogeneous functional type with respect to their UV tolerance.

Mechanism on the microbial salt tolerance enhancement by electrical stimulation

The application of biological methods in industrial saline wastewater treatment is limited, since the activities of microorganisms are strongly inhibited by the highly concentrated salts. Acclimatized halotolerant and halophilic microorganisms are of high importance since they can resist the environmental stresses of high salinity. The acclimation to salinity can be passive or active based on whether external simulation is used. However, there is a need for development of economic, efficient and reliable active biological stimulation technologies to accelerate salinity acclimation. Recent studies have shown that electrical stimulation can effectively enhance microbial salt tolerance and pollutant removal ability. However, there have been no comprehensive reviews of the mechanisms involved. Therefore, this mini-review described the mechanisms of electrical stimulation that can significantly improve microbial bioactivity and biodiversity. These mechanisms include regulation of Na⁺ and K⁺ transporters by changing membranepotential and promoting ATP production, as well as regulation of extracellular polymer substances through enhanced release of low molecular weight EPS and quorum sensing molecules. The information provided herein will facilitate the application of biological high-salinity wastewater treatment.

Diversity, phylogeny, and adaptation of bryophytes: insights from genomic and transcriptomic data

Bryophytes including mosses, liverworts, and hornworts are among the earliest land plants, and occupy a crucial phylogenetic position to aid in the understanding of plant terrestrialization. Despite their small size and simple structure, bryophytes are the second largest group of extant land plants. They live ubiquitously in various habitats and are highly diversified, with adaptive strategies to modern ecosystems on Earth. More and more genomes and transcriptomes have been assembled to address fundamental questions in plant biology. Here, we review recent advances in bryophytes associated with diversity, phylogeny, and ecological adaptation. Phylogenomic studies have provided increasing supports for the monophyly of bryophytes, with hornworts sister to the Setaphyta clade including liverworts and mosses. Further comparative genomic analyses revealed that multiple whole-genome duplications might have contributed to the species richness and morphological diversity in mosses. We highlight that the biological changes through gene gain or neofunctionalization that primarily evolved in bryophytes have facilitated the adaptation to early land environments; among the strategies to adapt to modern ecosystems in bryophytes, desiccation tolerance is the most remarkable. More genomic information for bryophytes would shed light on key mechanisms for the ecological success of these 'dwarfs' in the plant kingdom.

The Antarctic Moss Pohlia nutans Genome Provides Insights Into the Evolution of Bryophytes and the Adaptation to Extreme Terrestrial Habitats

The Antarctic continent has extreme natural environment and fragile ecosystem. Mosses are one of the dominant floras in the Antarctic continent. However, their genomic features and adaptation processes to extreme environments remain poorly understood. Here, we assembled the high-quality genome sequence of the Antarctic moss (Pohlia nutans) with 698.20 Mb and 22 chromosomes. We found that the high proportion of repeat sequences and a recent whole-genome duplication (WGD) contribute to the large size genome of P. nutans when compared to other bryophytes. The genome of P. nutans harbors the signatures of massive segmental gene duplications and large expansions of gene families, likely facilitating neofunctionalization. Genomic characteristics that may support the Antarctic lifestyle of this moss comprise expanded gene families involved in phenylpropanoid biosynthesis, unsaturated fatty acid biosynthesis, and plant hormone signal transduction. Additional contributions include the significant expansion and upregulation of several genes encoding DNA photolyase, antioxidant enzymes, flavonoid biosynthesis enzymes, possibly reflecting diverse adaptive strategies. Notably, integrated multi-omic analyses elucidate flavonoid biosynthesis may function as the reactive oxygen species detoxification under UV-B radiation. Our studies provide insight into the unique features of the Antarctic moss genome and their molecular responses to extreme terrestrial environments.