RESUMO
Lupinus albescens is a resistant cover plant that establishes symbiotic relationships with bacteria belonging to the Bradyrhizobium genus. This symbiosis helps the development of these plants in adverse environmental conditions, such as the ones found in arenized areas of Southern Brazil. This work studied three Bradyrhizobium sp. (AS23, NAS80 and NAS96) isolated from L. albescens plants that grow in extremely poor soils (arenized areas and adjacent grasslands). The genomes of these three strains were sequenced in the Ion Torrent platform using the IonXpress library preparation kit, and presented a total number of bases of 1,230,460,823 for AS23, 1,320,104,022 for NAS80, and 1,236,105,093 for NAS96. The genome comparison with closest strains Bradyrhizobium japonicum USDA6 and Bradyrhizobium diazoefficiens USDA110 showed important variable regions (with less than 80% of similarity). Genes encoding for factors for resistance/tolerance to heavy metal, flagellar motility, response to osmotic and oxidative stresses, heat shock proteins (present only in the three sequenced genomes) could be responsible for the ability of these microorganisms to survive in inhospitable environments. Knowledge about these genomes will provide a foundation for future development of an inoculant bioproduct that should optimize the recovery of degraded soils using cover crops.
RESUMO
Given their distribution, importance, and richness, Myrtaceae species comprise a model system for studying the evolution of tropical plant diversity. In addition, chloroplast (cp) genome sequencing is an efficient tool for phylogenetic relationship studies. Feijoa [Acca sellowiana (O. Berg) Burret; CN: pineapple-guava] is a Myrtaceae species that occurs naturally in southern Brazil and northern Uruguay. Feijoa is known for its exquisite perfume and flavorful fruits, pharmacological properties, ornamental value and increasing economic relevance. In the present work, we reported the complete cp genome of feijoa. The feijoa cp genome is a circular molecule of 159,370 bp with a quadripartite structure containing two single copy regions, a Large Single Copy region (LSC 88,028 bp) and a Small Single Copy region (SSC 18,598 bp) separated by Inverted Repeat regions (IRs 26,372 bp). The genome structure, gene order, GC content and codon usage are similar to those of typical angiosperm cp genomes. When compared to other cp genome sequences of Myrtaceae, feijoa showed closest relationship with pitanga (Eugenia uniflora L.). Furthermore, a comparison of pitanga synonymous (Ks) and nonsynonymous (Ka) substitution rates revealed extremely low values. Maximum Likelihood and Bayesian Inference analyses produced phylogenomic trees identical in topology. These trees supported monophyly of three Myrtoideae clades.