Screening of endophytic fungi from Antarctic mosses: Potential production for L-asparaginase free of glutaminase and urease activity.

Studies involving endophytic fungi aim to identify organisms inhabiting extreme and relatively unexplored environments, as these fungi possess unique characteristics and uncommon biochemical pathways that enable them to produce compounds with biotechnological potential. Among various enzymes, L-Asparaginase is employed in the treatment of Acute Lymphoblastic Leukemia. In this study, we identified endophytic fungi from Sanionia uncinata and Polytrichastrum alpinum collected on King George Island in Antarctica. The fungi were categorized into morphological groups based on their characteristics, molecularly identified, and assessed for L-Asparaginase (L-ASNase) enzyme production. Subsequently, production optimization was conducted. A total of 161 endophytes were isolated from 504 moss gametophytes, with 107 originating from P. alpinum and 54 from S. uncinata. These isolates were categorized into 31 morphotypes. Fungi exhibiting high enzyme production were identified molecularly. Among them, nine identified isolates belonged to the genera Aspergillus, Collariella, Diaporthe, Epicoccum, Peroneutypa, Xylaria, and Trametes. Three of these isolates were identified at the species level through multigene phylogeny, namely Epicoccum nigrum, Collariella virescens, and Peroneutypa scoparia. All 31 fungi were subjected to solid media testing for L-ASNase enzyme production, with 22 isolates demonstrating production capability, and 13 of them produced L-ASNase free from Urease and Glutaminase. The isolates displaying solid media production underwent further testing in liquid media, all of which exhibited enzyme production ranging from 0.75 to 1.29 U g-1. Notably, the three fungi identified at the species level were the highest producers of the enzyme (1.29, 1.17, and 1.13 U g-1). The production of these fungi was optimized using the Taguchi method, resulting in production values ranging from 0.687 to 2.461 U g-1. In conclusion, our findings indicate that Antarctic moss endophytic fungi exhibit significant potential for the production of the anti-leukemic enzyme L-ASNase.

Variability and genetic structure in fragments of Eugenia involucrata De Candolle established through microsatellite markers / Variabilidade e estruturação genética em fragmentos de Eugenia involucrata de Candolle utilizando marcadores microssatélites

ABSCTRACT: Eugenia involucrata DC. is a forest species with high environmental and economic potential. The objective of this study was to quantify the genetic variability and analyzed the genetic structure of three natural fragments located in the central region of the Rio Grande do Sul state, Brazil. We used four microsatellite loci developed for the congener species Eugenia uniflora and using GenAlEx 6.5 software, parameters of genetic variability and its partition among and within fragments were estimated for each locus. We observed high levels of genetic variability (3.67 alleles per locus; HO = 0.815; HE = 0.625; FIS = −0.294), most of which (93%) were distributed within the fragments, suggesting that these individuals came from a single original population. Gene flow between fragments was high (2.35 to 4.56 migrants per generation), resulting in low genetic differentiation indexes (FST values ranging from 0.052 to 0.096). The fragments showed high genetic variability, distributed within the remnants themselves, and low genetic differentiation. Our results have repercussions for planning locally adapted germplasm collections for forest restoration programs, thereby avoiding the implantation of populations with an exogamous depression.

RESUMO: Eugenia involucrata DC. é uma espécie florestal com elevado potencial ambiental e econômico. O presente trabalho teve por objetivo quantificar a variabilidade e analisar a estruturação genética em três fragmentos naturais localizados na região central do estado do Rio Grande do Sul, Brasil. Com o emprego de quatro locos microssatélites desenvolvidos para a espécie congênere Eugenia uniflora e usando-se o software GenAlEx 6.5, foram estimados parâmetros de variabilidade genética, para cada loco, e sua partição entre e dentro dos fragmentos. Foram observados altos índices de variabilidade genética (3,67 alelos por loco; HO = 0,815; HE = 0,625; FIS = -0,294), com a maior proporção (93%) distribuída dentro dos fragmentos, sugerindo que os indivíduos estudados são provenientes de uma única população original. O fluxo gênico foi elevado entre os fragmentos, variando de 2,35 a 4,56 migrantes por geração, resultando em baixo índice de diferenciação genética (FST), entre 0,052 a 0,096. Os fragmentos estudados apresentam elevada variabilidade genética, a maior parte distribuída dentro dos próprios remanescentes, e baixa diferenciação genética. Os resultados observados têm repercussões no planejamento de coleta de germoplasma com adaptação local para programas de restauração florestal, assim evitando a implantação de populações com depressão exogâmica.

Whole Plastome Sequences of Two Drug-Type Cannabis: Insights Into the Use of Plastid in Forensic Analyses.

DNA is one of the fastest growing tools in forensic sciences, increasing reliability in forensic reports and judgments. The use of DNA has increased in different areas of the forensic sciences, such as investigation of plant species, where plastid DNA has been used to elucidate and generate evidence in cases of traceability of genetically modified and controlled plants. Even with several advances and the practice of using DNA in forensic investigations, there are just few studies related to the identification of genetic tools for the characterization of drug and nondrug-types of Cannabis. Herein, the whole plastomes of two drug-type Cannabis are presented and have their structures compared with other Cannabis plastomes deposited in the GenBank, focusing in the forensic use of plastome sequences. The plastomes of Cannabis sativa "Brazuka" and of the hybrid Cannabis AK Royal Automatic presented general structure that does not differs from the reported for other C. sativa cultivars. A phylogenomic analyses grouped C. sativa "Brazuka" with the nondrug C. sativa cultivars, while the hybrid Cannabis AK Royal Automatic placed isolated, basal to this group. This suggests that the analysis of plastomes is useful toward genetic identification of hybrids in relation to C. sativa.

Phylogeography of plastid DNA sequences suggests post-glacial southward demographic expansion and the existence of several glacial refugia for Araucaria angustifolia.

Despite the high diversity of the Southern South American environments, the patterns and processes driving both their species diversity and demographic history are still poorly known and are a challenging task. In this study, we evaluate plastid DNA sequences of the conifer species Araucaria angustifolia aiming to (i) assess the species genetic structure within its main range of occurrence, (ii) infer its population demographic history, looking for evidence of southward expansion, (iii) search for evidence of glacial refugia within the species distribution area and (iv) discuss some conservation and management strategies for this species. Twenty haplotypes were identified, revealing the presence of three distinct genetic groups across the geographic range of the species and structuring the populations into Northern, Central and Southern groups. Our results suggest the occurrence of post-glacial expansion of A. angustifolia towards the south, as well as the existence of at least three refugia within the species occurrence area. Testing the occurrence of historical demographic expansion, we suggest that genetic groups experienced fluctuations in effective size, associated to a structured distribution of populations. The identification of three genetic groups in this study corroborates the proposition of using the geographic distribution of A. angustifolia for selecting in situ conservation areas, for planning seed collection for ex situ conservation, as well as for the delineation of seed zones.

Characterization of Plastidial and Nuclear SSR Markers for Understanding Invasion Histories and Genetic Diversity of Schinus molle L.

Invasive plant species are expected to display high dispersal capacity but low levels of genetic diversity due to the founder effect occurring at each invasion episode. Understanding the history of invasions and the levels of genetic diversity of such species is an important task for planning management and monitoring strategy for these events. Peruvian Peppertree (Schinus molle L.) is a pioneer tree species native from South America which was introduced in North America, Europe and Africa, becoming a threat to these non-native habitats. In this study, we report the discovery and characterization of 17 plastidial (ptSSR) and seven nuclear (nSSR) markers for S. molle based on low-coverage whole-genome sequencing data acquired through next-generation sequencing. The markers were tested in 56 individuals from two natural populations sampled in the Brazilian Caatinga and Pampa biomes. All loci are moderately to highly polymorphic and revealed to be suitable for genetic monitoring of new invasions, for understanding the history of old invasions, as well as for genetic studies of native populations in their natural occurrence range and of orchards established with commercial purposes.