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The removal of the tetra-azo dye Direct Black 22 (DB22) using the microalga Chlorella vulgaris was evaluated in the present study, aiming to understand the contribution of different processes (biodegradation, photodegradation, and adsorption) in the removal of this contaminant. The growth and morphological characteristics of C. vulgaris were not affected by the presence of the dye in the reaction medium. The efficiency of dye removal was 62.6 ± 1.46%, 47.7 ± 7.2% of which was attributed to photodegradation, while 13.2 ± 6.5% were associated with the contribution of the microalga by an enzymatic route and 1.7 ± 9.6% with an adsorption process. Additionally, tests with the organism Allium cepa as a bioindicator revealed that DB22 and its byproducts did not induce toxicity, but cytotoxicity and genotoxicity were induced. We observed that genotoxicity was reduced after the remediation process. Our results establish photodegradation as the primary mechanism and biodegradation as the secondary mechanism driving the removal of DB22 within a Chlorella culture. Researchers must carefully consider all aspects involved in the removal process, including photodegradation, biodegradation, and adsorption processes.

The genus Vigna (Leguminosae) comprises about 150 species grouped into five subgenera. The present study aimed to improve the understanding of karyotype diversity and evolution in Vigna, using new and previously published data through different cytogenetic and DNA content approaches. In the Vigna subgenera, we observed a random distribution of rDNA patterns. The 35S rDNA varied in position, from terminal to proximal, and in number, ranging from one (V. aconitifolia, V. subg. Ceratotropis) to seven pairs (V. unguiculata subsp. unguiculata, V. subg. Vigna). On the other hand, the number of 5S rDNA was conserved (one or two pairs), except for V. radiata (V. subg. Ceratotropis), which had three pairs. Genome size was relatively conserved within the genus, ranging from 1C = 0.43 to 0.70 pg in V. oblongifolia and V. unguiculata subsp. unguiculata, respectively, both belonging to V. subg. Vigna. However, we observed a positive correlation between DNA content and the number of 35S rDNA sites. In addition, data from chromosome-specific BAC-FISH suggest that the ancestral 35S rDNA locus is conserved on chromosome 6 within Vigna. Considering the rapid diversification in the number and position of rDNA sites, such conservation is surprising and suggests that additional sites may have spread out from this ancestral locus., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Groundwater and soil contamination by aromatic amines (AAs), used in the production of polymers, plastics, and pesticides, often results from improper waste disposal and accidental leaks. These compounds are resistant to anaerobic degradation; however, micro-aeration can enhance this process by promoting microbial interactions. In batch assays, anaerobic degradation of aniline (0.14 mM), a model AA, was tested under three micro-aeration conditions: T30, T15, and T10 (30, 15, and 10 min of micro-aeration every 2 h, respectively). Aniline degradation occurred in all conditions, producing both aerobic (catechol) and anaerobic (benzoic acid) byproducts. The main genera involved in T30 and T15 were Comamonas , Clostridium , Longilinea , Petrimonas , Phenylobacterium , Pseudoxanthomonas , and Thiobacillus . In contrast, in T10 were Pseudomonas , Delftia , Leucobacter , and Thermomonas . While T30 and T15 promoted microbial cooperation for anaerobic degradation and facultative respiration, T10 resulted in a competitive environment due to dominance and oxygen scarcity. Despite aniline degradation in 9.4 h under T10, this condition was toxic to Allium cepa seeds and exhibited cytogenotoxic effects. Therefore, T15 emerged as the optimal condition, effectively promoting anaerobic degradation without accumulating toxic byproducts. Intermittent micro-aeration emerges as a promising strategy for enhancing the anaerobic degradation of AA-contaminated effluents., Competing Interests: The authors declare there is no conflict., (© 2024 The Authors This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (CC BY-NC-ND 4.0), which permits copying and redistribution for non-commercial purposes with no derivatives, provided the original work is properly cited (http://creativecommons.org/licenses/by-nc-nd/4.0/).)

Satellite DNAs (satDNAs) are highly repetitive sequences that occur in virtually all eukaryotic genomes and can undergo rapid copy number and nucleotide sequence variation among relatives. After chromosomal mapping of the satDNA JcSAT1, it was found a large accumulation at subtelomeres of Jatropha curcas (subgenus Curcas), but an absence of these monomers in J. integerrima (subgenus Jatropha). This fact suggests a dynamic scenario for this satellite repeat in Jatropha genomes. Here, we used a multitasking approach (sequence analysis, DNA blotting and chromosomal mapping) to investigate the molecular organization and chromosomal abundance and distribution of JcSAT1 in a broader group of species from the subgenus Jatropha (J. gossypiifolia, J. mollissima, J. podagrica, and J. multifida) in addition to J. curcas, with the aiming of understanding the evolution of this satDNA. Based on the analysis of BAC clone sequences of J. curcas, a large array (~ 30 kb) of 80 homogeneous monomers of JcSAT1 was identified in BAC 23J11. The monomer size was conserved (~ 358 bp) and contained a telomeric motif at the 5' end. PCR amplification coupled with a Southern blot revealed the presence of JcSAT1-like sequences in all species examined. However, a large set of genome copies was identified only in J. curcas, where a ladder-like pattern with multimers of different sizes was observed. In situ hybridization of BAC 23J11 confirmed the subtelomeric pattern for J. curcas, but showed no signals on chromosomes of species from the subgenus Jatropha. Our data indicate that JcSAT1 is a highly homogeneous satDNA that originated from a region near the telomeres and spread throughout the chromosomal subtermini, possibly due to frequent ectopic recombination between these regions. The abundance of JcSAT1 in the genome of J. curcas suggests that an amplification event occurred either at the base of the subgenus Curcas or at least in this species, although the repeat is shared by all species of the genus studied so far., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Key Message: Inversions and translocations are the major chromosomal rearrangements involved in Vigna subgenera evolution, being Vigna vexillata the most divergent species. Centromeric repositioning seems to be frequent within the genus. Oligonucleotide-based fluorescence in situ hybridization (Oligo-FISH) provides a powerful chromosome identification system for inferring plant chromosomal evolution. Aiming to understand macrosynteny, chromosomal diversity, and the evolution of bean species from five Vigna subgenera, we constructed cytogenetic maps for eight taxa using oligo-FISH-based chromosome identification. We used oligopainting probes from chromosomes 2 and 3 of Phaseolus vulgaris L. and two barcode probes designed from V. unguiculata (L.) Walp. genome. Additionally, we analyzed genomic blocks among the Ancestral Phaseoleae Karyotype (APK), two V. unguiculata subspecies (V. subg. Vigna), and V. angularis (Willd.) Ohwi & Ohashi (V. subg. Ceratotropis). We observed macrosynteny for chromosomes 2, 3, 4, 6, 7, 8, 9, and 10 in all investigated taxa except for V. vexillata (L.) A. Rich (V. subg. Plectrotropis), in which only chromosomes 4, 7, and 9 were unambiguously identified. Collinearity breaks involved with chromosomes 2 and 3 were revealed. We identified minor differences in the painting pattern among the subgenera, in addition to multiple intra- and interblock inversions and intrachromosomal translocations. Other rearrangements included a pericentric inversion in chromosome 4 (V. subg. Vigna), a reciprocal translocation between chromosomes 1 and 5 (V. subg. Ceratotropis), a potential deletion in chromosome 11 of V. radiata (L.) Wilczek, as well as multiple intrablock inversions and centromere repositioning via genomic blocks. Our study allowed the visualization of karyotypic patterns in each subgenus, revealing important information for understanding intrageneric karyotypic evolution, and suggesting V. vexillata as the most karyotypically divergent species., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Stylosanthes scabra is a scientifically orphaned legume found in the Brazilian Caatinga biome (a semi-arid environment). This work utilized omics approaches to investigate some ecophysiological aspects of stress tolerance/resistance in S. scabra , study its genomic landscape, and predict potential metabolic pathways. Considering its high-confidence conceptual proteome, 1694 (~2.6%) proteins were associated with resistance proteins, some of which were found in soybean QTL regions that confer resistance to Asian soybean rust. S. scabra was also found to be a potential source of terpenes, as biosynthetic gene clusters associated with terpene biosynthesis were identified in its genome. The analysis revealed that mobile elements comprised approximately 59% of the sequenced genome. In the remaining 41% of the sections, some of the 22,681 protein-coding gene families were categorized into two informational groups: those that were specific to S. scabra and those that expanded significantly compared to their immediate ancestor. Biological process enrichment analyses indicated that these gene families play fundamental roles in the adaptation of S. scabra to extreme environments. Additionally, phylogenomic analysis indicated a close evolutionary relationship between the genera Stylosanthes and Arachis . Finally, this study found a high number (57) of aquaporin-encoding loci in the S. scabra genome. RNA-Seq and qPCR data suggested that the PIP subfamily may play a key role in the species' adaptation to water deficit conditions. Overall, these results provide valuable insights into S. scabra biology and a wealth of gene/transcript information for future legume omics studies.

Amburana cearensis leaves have been used in folk medicine to treat respiratory diseases and inflammations. This study aimed to evaluate the biological potential of A. cearensis leaves by antioxidant and in vitro cytogenotoxic analyses of ethanolic crude extract (EE) and its fractions in healthy human cells. The EE was obtained by percolation, followed by fractionation using dichloromethane, cyclohexane, ethyl acetate (EtOAc), and methanol (MeOH) as organic solvents. Extract and all fractions were evaluated for their antioxidant potential by DPPH and reducing power tests. In vitro cytotoxic activity was determined in human peripheral blood mononuclear cells by MTT assay for the extract, EtOAc and MeOH fractions. In turn, the genotoxic activity was determined in human lymphocytes by the Cytokinesis Block Micronucleus assay only for the EtOAc fraction. Only EtOAc fraction was analyzed via gas chromatography coupled to mass spectrometry due to its higher biological activity. Considering the antioxidant potential, the EtOAc fraction was most effective in DPPH (EC 50 43.37 µg/mL) and reducing power (EC 50 89.80 µg/mL) assays. GC-MS analysis of the EtOAc fraction led to the identification of guaiacol, 2,3-dihydro-benzofuran, 2-methoxy-4-vinylphenol, isovanillic acid methyl ester, 4-hydroxybenzaldehyde, and 4-(ethoxymethyl)-phenol. The EE (400-1000 µg/mL), EtOAc (≤150 µg/mL) and MeOH (50 and 150-600 µg/mL) fractions were not cytotoxic by MTT test. Additionally, the EtOAc fraction (100-400 µg/mL) did not induce significant genotoxic damage. Concentrations of the EtOAc fraction with antioxidant activity showed no cytotoxicity, nor genotoxicity potential, indicating them as a nontoxic natural antioxidant source.

The tribe Phaseoleae includes several legume crops with assembled genomes. Comparative genomic studies have evidenced the preservation of large genomic blocks among legumes, although chromosome dynamics during Phaseoleae evolution has not been investigated. We conducted a comparative genomic analysis to define an informative genomic block (GB) system and to reconstruct the ancestral Phaseoleae karyotype (APK). We identified GBs based on the orthologous genes between Phaseolus vulgaris and Vigna unguiculata and searched for GBs in different genomes of the Phaseolinae (P. lunatus) and Glycininae (Amphicarpaea edgeworthii) subtribes and Spatholobus suberectus (sister to Phaseolinae and Glycininae), using Medicago truncatula as the outgroup. We also used oligo-FISH probes of two P. vulgaris chromosomes to paint the orthologous chromosomes of two non-sequenced Phaseolinae species. We inferred the APK as having n = 11 and 19 GBs (A to S), hypothesizing five chromosome fusions that reduced the ancestral legume karyotype to n = 11. We identified the rearrangements among the APK and the subtribes and species, with extensive centromere repositioning in Phaseolus. We also reconstructed the chromosome number reduction in S. suberectus. The development of the GB system and the proposed APK provide useful approaches for future comparative genomic analyses of legume species., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

Cowpea [Vigna unguiculata (L.) Walp.] is one of the most tolerant legume crops to drought and salt stresses. WRKY transcription factor (TF) family members stand out among plant transcriptional regulators related to abiotic stress tolerance. However, little information is currently available on the expression of the cowpea WRKY gene family (VuWRKY) in response to water deficit. Thus, we analyzed genomic and transcriptomic data from cowpea to identify VuWRKY members and characterize their structure and transcriptional response under root dehydration stress. Ninety-two complete VuWRKY genes were found in the cowpea genome based on their domain characteristics. They were clustered into three groups: I (15 members), II (58), and III (16), while three genes were unclassified. Domain analysis of the encoded proteins identified four major variants of the conserved heptapeptide motif WRKYGQK. In silico analysis of VuWRKY gene promoters identified eight candidate binding motifs of cis-regulatory elements, regulated mainly by six TF families associated with abiotic stress responses. Ninety-seven VuWRKY modulated splicing variants associated with 55 VuWRKY genes were identified via RNA-Seq analysis available at the Cowpea Genomics Consortium (CpGC) database. qPCR analyses showed that 22 genes are induced under root dehydration, with VuWRKY18, 21, and 75 exhibiting the most significant induction levels. Given their central role in activating signal transduction cascades in abiotic stress response, the data provide a foundation for the targeted modification of specific VuWRKY family members to improve drought tolerance in this important climate-resilient legume in the developing world and beyond., (Copyright © 2022 Elsevier B.V. All rights reserved.)