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Antarctica is one of the most inhospitable continents on the planet, with lichens and mosses being the most common terrestrial organisms in ice-free areas. Antarctica is represented by only two species of Angiosperms, Deschampsia antarctica Desv. (Poaceae) and Colobanthus quitensis (Kunth) Bartl. (Caryophyllaceae). In this study, we characterized fungi isolated from the fresh leaves of this grass species. The fungi were isolated from four individual plants from Half Moon Island (246 leaf fragments investigated), and seven from King George Island-Keller Peninsula (with 111 leaf fragments investigated) Antarctica. Neoascochyta paspali, Septoriella elongata, Pyrenophora cf. chaetomioides and Alternaria sp. were associated with the plant and identified through analysis of the sequences of the internal transcribed spacer region (ITS) of the rDNA and nuclear ribosomal large subunit rRNA gene (LSU) as well as through macro and micro-morphological characteristics. The isolates showed higher growth rate ranging from 10 to 20 °C. An interesting result was that the aforementioned fungi are already recognized as both plant pathogens and endophytic fungi. The results demonstrate that D. antarctica is an interesting fungal source. Those species might provide important information about the relationship on the endemic Antarctic biota.

Cooking quality is an important attribute in Common/Asian rice (Oryzasativa L.) varieties, being highly dependent on grain starch composition. This composition is known to be highly dependent on a cultivar’s genetics, but the way in which their genes express different phenotypes is not well understood. Further analysis of variation of grain quality genes using new information obtained from the wild relatives of rice should provide important insights into the evolution and potential use of these genetic resources. All analyses were conducted using bioinformatics approaches. The analysis of the protein sequences of grain quality genes across the Oryza suggest that the deletion/mutation of amino acids in active sites result in variations that can negatively affect specific steps of starch biosynthesis in the endosperm. On the other hand, the complete deletion of some genes in the wild species may not affect the amylose content. Here we present new insights for Starch Synthesis-Related Genes (SSRGs) evolution from starch-specific rice phenotypes.

Endophyte biology is a branch of science that contributes to the understanding of the diversity and ecology of microorganisms that live inside plants, fungi, and lichen. Considering that the diversity of endolichenic fungi is little explored, and its phylogenetic relationship with other lifestyles (endophytism and saprotrophism) is still to be explored in detail, this paper presents data on axenic cultures and phylogenetic relationships of three endolichenic fungi, isolated in laboratory. Cladonia curta Ahti & Marcelli, a species of lichen described in Brazil, is distributed at three sites in the Southeast of the country, in mesophilous forests and the Cerrado. Initial hyphal growth of Xylaria spp. on C. curta podetia started four days after inoculation and continued for the next 13 days until the hyphae completely covered the podetia. Stromata formation and differentiation was observed, occurring approximately after one year of isolation and consecutive subculture of lineages. Phylogenetic analyses indicate lineages of endolichenic fungi in the genus Xylaria, even as the morphological characteristics of the colonies and anamorphous stromata confirm this classification. Our preliminary results provide evidence that these endolichenic fungi are closely related to endophytic fungi, suggesting that the associations are not purely incidental. Further studies, especially phylogenetic analyses using robust multi-locus datasets, are needed to accept or reject the hypothesis that endolichenic fungi isolated from Xylaria spp. and X. berteri are conspecific.

Prasiola crispa is a macroscopic green algae found in abundance in Antarctica ice free areas. Prasiola crispan-hexaneextract (HPC) induced insecticidal activity in Nauphoeta cinerea cockroaches after 24 h of exposure. The chemical analysis of HPC revealed the presence of the followingphytosterols: β-sitosterol, campesterol and stigmasterol. The incubation of cockroach semi-isolated heart preparations with HPC caused a significant negative chronotropic activity in the heartbeats. HPC affected the insect neuromuscular function by inducing a complete inhibition of the cockroach leg-muscle twitch tension. When the isolated phytosterols were injected at in vivo cockroach neuromuscular preparations, there was a progressive inhibition of muscle twitches on the following order of potency: β-sitosterol > campesterol > stigmasterol. HPC also provoked significant behavioral alterations, characterized by the increase or decrease of cockroach grooming activity, depending on the dose assayed. Altogether, the results presented here corroborate the insecticide potential of Prasiola crispa Antarctic algae. They also revealed the presence of phytosterols and the involvement of these steroidal compounds in the entomotoxic activity of the algae, potentially by modulating octopaminergic-cholinergic pathways. Further phytochemical-combined bioguided analysis of the HPC will unveil novel bioactive compounds that might be an accessory to the insecticide activity of the algae.

In the current study, we present the molecular characterization of an endophyte fungus associated with the leaves of Deschampsia antarctica Desv. (Poaceae), a monocot species native to Antarctica. The isolate was obtained from 90 leaf fragments from two distinct collection sites, both located on Half Moon Island, South Shetland Islands and Maritime Antarctica. The internal transcribed spacer region (ITS) was sequenced and the endophytic fungus was identified as belonging to the genus Juncaceicola Tennakoon, Camporesi, Phook and K.D. Hyde (99% nucleotide sequence identity). When compared to all fungi of the genus Juncaceicola deposited in data base, our isolate showed greater proximity with Juncaceicola typharum, however, because it presents a low bootstrap value to be considered a new species, we treat it as Juncaceicola cf. typharum. Moreover, the identification of our isolate as belonging to the genus Juncaceicola makes this the first occurrence of a species of this genus to be associated with the leaves of Antarctic plants. This work is considered as a starting point for other studies with fungi of this genus associated with leaves of Deschampsia antarctica, as it presents results from two collection points on a single Antarctic island, suggesting that new sites and new Antarctic islands should be explored.