New distribution record of a true coral species, Psammocora contigua (Esper, 1794) from Gulf of Kachchh Marine National Park & Sanctuary, India

Reef-building corals are generally confined to tropical waters across the world oceans. But some coral species are able to tolerate even inhospitable environments and suboptimal extremes, and form lower diversity reefs habitats such as the Gulf of Kachchh, located along the northwestern coast of India. Among the reported hard coral species so far from the Gulf of Kachchh, genus Psammocora is represented by only one species, P. digitata. The present study confirmed a new distribution record of Psammocora contigua from Narara Island. Due to the changing hydro-geographic conditions in the Kachchh region, ramose and branching coral species have been believed to be extinct completely, leaving no sign of live colonies. P. contigua, recorded during the present study is the only living species with ramose growth form recorded so far from the Kachchh waters. The present study also holds out hope to record more new coral species records from the region.

Proteogenomics analysis of CUG codon translation in the human pathogen Candida albicans

Background Yeasts of the CTG-clade lineage, which includes the human-infecting Candida albicans, Candida parapsilosis and Candida tropicalis species, are characterized by an altered genetic code. Instead of translating CUG codons as leucine, as happens in most eukaryotes, these yeasts, whose ancestors are thought to have lost the relevant leucine-tRNA gene, translate CUG codons as serine using a serine-tRNA with a mutated anticodon, $$ {\mathrm{tRNA}}_{\mathrm{CAG}}^{\mathrm{Ser}} $$ tRNA CAG Ser . Previously reported experiments have suggested that 3–5% of the CTG-clade CUG codons are mistranslated as leucine due to mischarging of the $$ {\mathrm{tRNA}}_{\mathrm{CAG}}^{\mathrm{Ser}} $$ tRNA CAG Ser . The mistranslation was suggested to result in variable surface proteins explaining fast host adaptation and pathogenicity. Results In this study, we reassess this potential mistranslation by high-resolution mass spectrometry-based proteogenomics of multiple CTG-clade yeasts, including various C. albicans strains, isolated from colonized and from infected human body sites, and C. albicans grown in yeast and hyphal forms. Our data do not support a bias towards CUG codon mistranslation as leucine. Instead, our data suggest that (i) CUG codons are mistranslated at a frequency corresponding to the normal extent of ribosomal mistranslation with no preference for specific amino acids, (ii) CUG codons are as unambiguous (or ambiguous) as the related CUU leucine and UCC serine codons, (iii) tRNA anticodon loop variation across the CTG-clade yeasts does not result in any difference of the mistranslation level, and (iv) CUG codon unambiguity is independent of C. albicans’ strain pathogenicity or growth form. Conclusions Our findings imply that C. albicans does not decode CUG ambiguously. This suggests that the proposed misleucylation of the $$ {\mathrm{tRNA}}_{\mathrm{CAG}}^{\mathrm{Ser}} $$ tRNA CAG Ser might be as prevalent as every other misacylation or mistranslation event and, if at all, be just one of many reasons causing phenotypic diversity.

Recent spruce (Picea abies) treeline ecotonal progression since the late1980s in the Swedish Scandes-a repeat photographic narration and analysis

This study reports a case of climate-mediated transformation and physiognomic progression of the Norway spruce (Picea abies) treeline ecotone since the mid-1990s in the Swedish Scandes. The methods include repeat photography and foliation estimates of old-established clonal spruces. An air and soil temperature nadir by the 1980s had caused extensive needle and shoot mortality, evident at the landscape-scale. Subsequent winter and summer temperature rises induced a striking canopy recovery, including densification and vertical growth. Release from low soil temperature stress appears as instrumental for canopy progression and shift from stunted growth to erect tree forms. Seed-based regeneration of new individuals has been virtually nil and the ecotone appears to be spatially stable. Ongoing ecotonal shifts has the character of growth form transformations in accordance with climatic conjunctures.

Updated Checklist of Vascular Plants Endemic to Mongolia

The aim of the present study is to update the checklist of vascular plants endemic to Mongolia using previous checklists, publications, herbarium collections, and field observations. The revised checklist includes 102 endemic taxa (95 species, five subspecies, and two nothospecies) from 43 genera and 19 families. The majority of endemic taxa were distributed in western and central Mongolia, and high endemic species richness was identified in four phytogeographical regions, namely Mongolian Altai, Khangai, Dzungarian Gobi, and Gobi Altai, which harbor 49, 27, 20, and 16 endemic taxa, respectively. For each endemic taxon, we compiled information about growth form, conservation status (if already assessed), phytogeographical distribution, and voucher specimens. Data on each taxon’s type specimen were also collected, and the majority of the type specimens were accessioned at the LE (58 taxa), MW (20 taxa), and UBA (7 taxa) herbaria.

Moss phyllid morphology varies systematically with substrate slope

Background and aims – Tracheophyte leaf morphology is well studied but it is unclear if the findings generalize to poikilohydric plants. We tested combinations of hypotheses to determine if microhabitat characteristics, including light exposure, moisture availability, and substrate slope, controlled for morphological differences between upright and prostrate growth forms, affect phyllid surface area and costa length of mosses.Material and methods – We quantified mean phyllid surface-area and costa lengths for four replicates of 38 moss species from Alabama. Phylogenetic comparative methods that model adaptation were used to evaluate the relative evidence for each hypothesis using information criteria. To further explore mechanistic explanations involving substrate slope, we tested whether mosses on vertical substrates differed from those on horizontal substrates in the average amount of water-retaining, nutrient-rich litter they accumulated.Key results – Substrate slope and growth form combined were the best predictors of phyllid surface area. Mosses growing on vertical substrates exhibited smaller phyllid surface area for both growth forms. Although growth form and phyllid length best explained costa length variation, a more complex model including substrate slope performed nearly as well. Within the prostrate growth forms, species growing on vertical substrates exhibit longer relative costa than those on horizontal substrates. We also estimated rapid rates of adaptation for both traits.Conclusion – The smaller phyllid surface area of both upright and prostrate growth forms is possibly an adaptive response to reduced habitat moisture-retention or nutrient quality that vertical substrates offer. The longer costa lengths of prostrate mosses growing on vertical surfaces relative to prostrate mosses on horizontal surfaces, possibly make up for the decreased ability of smaller phyllids to rapidly reabsorb water when it is available. Further work is required to determine if it is truly substrate slope itself that matters or other variables associated with the differences in slope, and to determine how general this phenomenon is.

Macroevolutionary Changes of Plants on Islands

<p>Insularity is known to produce predictable evolutionary changes in plants. For example, herbaceous plants often evolve woodiness and seeds tend to have reduced dispersal capabilities on islands. However, our understanding of how other plant traits may evolve on islands is lacking. Furthermore, plants are modular organisms and by investigating evolutionary changes in specific plant traits we may better understand macroevolutionary processes on islands. In this thesis, I investigate evolutionary changes in a range of plant traits on islands. First, I tested for evolutionary changes in seed size on islands (Chapter 2). Island plants consistently produced larger seeds than mainland relatives. Furthermore, this result was consistent regardless of differences in dispersal mode, growth form and evolutionary history. Selection may favour increased seed size to reduce dispersal distances. Additionally, selection may favour larger seeds due to the competitive advantage conferred to developing seedlings. Many animal taxa exhibit increased sexual size dimorphism (SSD) on islands, as predicted by the niche variation hypothesis. However, patterns of SSD among dioecious plants on islands are unknown. In Chapter 3 I tested for differences in SSD of dioecious plants that colonized four island groups from New Zealand (mainland). The degree of SSD did not vary predictable between island and mainland plants, contrary to predictions of the niche variation hypothesis. However, SSD was consistently female biased on the mainland and results suggest selection is acting to increase the size of both sexes on islands. Evolutionary changes in island plants may be a response to herbivory by unique large browsers. For example, the divaricate growth form is common in the New Zealand flora and may have deterred browsing moa. In Chapter 4 I tested for differences in traits associated with the divaricate growth form between plants from mainland New Zealand and Chatham Island. Results suggest that an absence of moa on Chatham Island has relaxed selection for traits associated with the divaricate growth form. An emerging body of research suggests aposematism (warning signals to herbivores) may be common in plants. However, previous investigations have not appreciated the fact that the perspective of terrestrial herbivores changes as plants grown vertically. Furthermore, ontogenetic changes in the capacity of plants to defend themselves may influence the reliability of warning signals. In Chapter 5 I tested for ontogenetic changes in two potentially aposematic signals produced by Pseudopanax crassifolius. Aposematism on upper leaf surfaces peaked early in ontogeny, providing a dishonest signal of defense. Conversely, signaling on the underside of leaves peaked later in ontogeny and scaled positively with structural defenses. The results of this thesis suggest selection is acting on specific plant traits on islands. Evolutionary pathways, such as the evolution of woodiness, may be better explained by considering selection acting on other plant traits. For example, selection acting on seed size may facilitate evolutionary size changes evident at later life-history stages. A lack of consensus exists regarding the role of insular herbivores in the evolution of island plants. The results of Chapters 4 and 5 suggest herbivory has played an important role in the evolution of novel morphology of island plants. Considering trait specific changes of plants on islands may further our understanding of prominent evolutionary pathways by pinpointing the action of selection.</p>

Lactobacillus Biofilms Influence Anti-Candida Activity

Lactobacilli are the dominant members of the healthy human vaginal microbiota and represent the first defense line from pathogen infection, including vulvovaginal candidiasis. Biofilm is the predominant microbial growth form in nature, and the formation of biofilms inside the human body has important implications in health and disease. In particular, the formation of biofilm by members of the human resident microbiota is desirable, as it can improve microbial persistence and influence functionality. In the present study, we investigated the capability of 16 vaginal Lactobacillus strains (belonging to Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus vaginalis, and Lactobacillus plantarum species) to form biofilms, and we correlated their mode of growth to anti-Candida activity. L. plantarum strains were the best biofilm producers, and high variability was registered in the level of biofilm formation among L. crispatus and L. gasseri strains. Culture supernatants derived from Lactobacillus biofilm and planktonic growth were tested toward a panel of Candida clinical isolates (Candida albicans, Candida glabrata, Candida lusitaniae, Candida tropicalis, Candida krusei, and Candida parapsilosis) and their metabolome assessed by 1H-NMR. L. crispatus and L. plantarum strains exhibited the best fungistatic profile, and biofilms enhanced their anti-Candida activity; on the contrary, L. gasseri strains were more effective when grown in a planktonic mode. Biofilm/planktonic mode of growth also affects Lactobacillus metabolism, mainly influencing nitrogen and amino acid pathways, and anti-Candida activity is instead strictly related to carbohydrate metabolism. The present study underlined the strict interdependence between microbial mode of growth, metabolism, and functional properties. Biofilm formation by members of the healthy human microbiota represents a crucial issue in the field of microbial physiology and host–microbiota interactions, beyond supporting the development of new antimycotic strategies based on probiotics grown in adherence.

Microclimatic Warming Leads to a Decrease in Species and Growth Form Diversity: Insights From a Tropical Alpine Grassland

Due to warming, changes in microclimatic temperatures have shifted plant community structure and dynamics in tundra and alpine regions. The directionality and magnitude of these changes are less known for tropical alpine ecosystems. To understand the likely trajectory of these shifts in the Andes, we conducted a warming experiment in the northern Andes—using open-top chambers (OTC). In this study, we ask (1) how do OTCs affect air and soil temperatures in microclimates of tropical alpine regions, year-round and during the dry season? (2) What are the effects of 7 years of warming on (a) the aboveground biomass (AGB) and (b) the plant taxonomic and growth form diversity? We installed five monitoring blocks in 2012 at ca. 4,200 m asl with 20 OTCs and 50 control plots randomly distributed within each block. We measured AGB, plant community diversity, and growth form diversity between 2014 and 2019. After 7 years of warming, we found significant increases in mean monthly (+0.24°C), daily (+0.16°C), and night air temperatures (+0.33°C) inside the OTCs, and the OTCs intensified microclimatic conditions during the dry season. Additionally, OTCs attenuated extreme temperatures—particularly in the soil—and the number of freezing events. AGB significantly increased in OTCs, and by 2019, it was 27% higher in OTCs than in control. These changes were driven mainly by a progressive increment of tussock grasses such as Calamagrostis intermedia, typical of lower elevations. The increase of tussocks led to a significant decrease in species diversity and evenness inside OTCs, but not in species richness after accounting by sampling time. Furthermore, cushions and herbs decreased inside OTCs. Our results show that experimental warming using OTCs in equatorial regions leads to decreased daily thermal amplitude and night temperatures rather than the level of increase in mean temperatures observed in temperate regions. The increase of tussocks and decrease in diversity of species and growth forms due to prolonged modifications in microclimatic temperature might be a step toward shrub-dominated ecosystems. Further research on this topic would help understand shifts in growth form dominance and the direction and rate of change of the system.