Mechanisms Of Environmental Adaptation Research Articles

Functional versatility of Zur in metal homeostasis, motility, biofilm formation, and stress resistance in Yersinia pseudotuberculosis.

Bacteria encounter diverse stresses in the environment and possess essential regulators to modulate the expression of genes in responding to the stresses for better fitness and survival. Zur (zinc uptake regulator) plays a vital role in zinc homeostasis. Studies of Zur from multiple species reviewed that it influences cell development, stress resistance, and virulence of bacteria. Y. pseudotuberculosis is an enteric pathogen that serves a model organism in the study of pathogenicity, virulence factors, and mechanism of environmental adaptation. In this study, transcriptomics analysis of Zur's regulons was conducted in Y. pseudotuberculosis. The functions of Zur as a global regulator in metal homeostasis, motility, nutrient acquisition, glycan metabolism, and nucleotide metabolism, in turn, increasing the biofilm formation, stress resistance, and virulence were reviewed. The importance of Zur in environmental adaptation and pathogenicity of Y. pseudotuberculosis was emphasized.

The re-establishment of desiccation tolerance in germinated tomato (Solanum lycopersicum) seeds

Abstract Desiccation tolerance (DT) of seeds, one of the plant's environmental adaptation mechanisms, allows them to survive as seeds in a quiescent state under extremely water-deficient conditions during the plant's life cycle, followed by seed germination and seedling establishment under favourable water conditions. The seed-DT is lost after radicle emergence; however, there is a developmental period called the ‘DT window’ during which the germinating seeds can re-induce DT following a cue from their ambient low water potential (i.e. mild osmotic stress). The DT re-inducibility within the DT window has been used as a model biosystem for understanding molecular mechanisms that activate/supress DT in a number of plant species. However, the characteristics of the DT window for species particularly important to the agroindustry are still largely fragmented. Here, physiological analyses were performed, aiming to elucidate the properties of the DT window in tomato, a model species for Solanaceae, holding a key strategic position for the seed industry and commercial use around the world. We revealed that (i) the DT window of tomato seeds is closed when the developing radicle reaches about 4 mm after germination, (ii) the most effective ambient water potential to re-induce DT into seeds is about −1.5 MPa and (iii) there is organ specificity of DT re-induction with hypocotyls, showing a longer DT window than cotyledons and roots in post-germination seeds.

Identification of Selection Signatures and Candidate Genes Related to Environmental Adaptation and Economic Traits in Tibetan Pigs.

Tibetan pigs are indigenous to the Qinghai-Tibet Plateau and have been the subject of extensive genomic research primarily focused on their adaptation to high altitudes. However, genetic modifications associated with their response to low-altitude acclimation have not been thoroughly explored. To investigate the genetic basis underlying the low-altitude acclimation of Tibetan pigs, we generated and analyzed genotyping data of Tibetan pigs that inhabit high-altitude regions (average altitude 4000 m) and Tibetan pigs that have inhabited nearby low-altitude regions (average altitude 500 m) for approximately 20 generations. We found that the highland and lowland Tibetan pigs have distinguishable genotype and phenotype variations. We identified 46 and 126 potentially selected SNPs associated with 29 and 56 candidate genes in highland and lowland Tibetan pigs, respectively. Candidate genes in the highland Tibetan pigs were involved in immune response (NFYC and STAT1) and radiation (NABP1), whereas candidate genes in the lowland Tibetan pigs were related to reproduction (ESR2, DMRTA1, and ZNF366), growth and development (NTRK3, FGF18, and MAP1B), and blood pressure regulation (CARTPT). These findings will help to understand the mechanisms of environmental adaptation in Tibetan pigs and offer valuable information into the genetic improvement of Tibetan pigs pertaining to low-altitude acclimation and economic traits.

High-quality genome assembly and genetic transformation system of Lasiodiplodia theobromae strain LTTK16-3, a fungal pathogen of Chinese hickory.

Lasiodiplodia theobromae, as one of the causative agents associated with Chinese hickory trunk cankers, has caused huge economic losses to the Chinese hickory industry. Although the biological characteristics of this pathogen and the occurrence pattern of this disease have been well studied, few studies have addressed the related mechanisms due to the poor molecular and genetic study basis of this fungus. In this study, we sequenced and assembled L. theobromae strain LTTK16-3, isolated from a Chinese hickory tree (cultivar of Linan) in Linan, Zhejiang province, China. Phylogenetic analysis and comparative genomics analysis presented crucial cues in the prediction of LTTK16-3, which shared similar regulatory mechanisms of transcription, DNA replication, and DNA damage response with the other four Chinese hickory trunk canker-associated Botryosphaeria strains including, Botryosphaeria dothidea, Botryosphaeria fabicerciana, Botryosphaeria qingyuanensis, and Botryosphaeria corticis. Moreover, it contained 18 strain-specific protein clusters (not conserved in the other L. theobromae strains, AM2As and CITRA15), with potential roles in specific host-pathogen interactions during the Chinese hickory infection. Additionally, an efficient system for L. theobromae protoplast preparation and polyethylene glycol (PEG) -mediated genetic transformation was firstly established as the foundation for its future mechanisms study. Collectively, the high-quality genome data and the efficient transformation system of L. theobromae here set up the possibility of targeted molecular improvements for Chinese hickory canker control.IMPORTANCEFungi with disparate genomic features are physiologically diverse, possessing species-specific survival strategies and environmental adaptation mechanisms. The high-quality genome data and related molecular genetic studies are the basis for revealing the mechanisms behind the physiological traits that are responsible for their environmental fitness. In this study, we sequenced and assembled the LTTK16-3 strain, the genome of Lasiodiplodia theobromae first obtained from a diseased Chinese hickory tree (cultivar of Linan) in Linan, Zhejiang province, China. Further phylogenetic analysis and comparative genomics analysis provide crucial cues in the prediction of the proteins with potential roles in specific host-pathogen interactions during the Chinese hickory infection. An efficient PEG-mediated genetic transformation system of L. theobromae was established as the foundation for the future mechanisms exploration. The above genetic information and tools set up valuable clues to study L. theobromae pathogenesis and assist in Chinese hickory canker control.

Population structure and adaptability analysis of Schizothorax o’connori based on whole-genome resequencing

BackgroundSchizothorax o’connori is an endemic fish distributed in the upper and lower reaches of the Yarlung Zangbo River in China. It has experienced a fourth round of whole gene replication events and is a good model for exploring the genetic differentiation and environmental adaptability of fish in the Qinghai-Tibet Plateau. The uplift of the Qinghai-Tibet Plateau has led to changes in the river system, thereby affecting gene exchange and population differentiation between fish populations. With the release of fish whole genome data, whole genome resequencing has been widely used in genetic evolutionary analysis and screening of selected genes in fish, which can better elucidate the genetic basis and molecular environmental adaptation mechanisms of fish. Therefore, our purpose of this study was to understand the population structure and adaptive characteristics of S. o’connori using the whole-genome resequencing method.ResultsThe results showed that 23,602,746 SNPs were identified from seven populations, mostly distributed on chromosomes 2 and 23. There was no significant genetic differentiation between the populations, and the genetic diversity was relatively low. However, the Zangga population could be separated from the Bomi, Linzhi, and Milin populations in the cluster analysis. Based on historical dynamics analysis of the population, the size of the ancestral population of S. o’connori was affected by the late accelerated uplift of the Qinghai Tibet Plateau and the Fourth Glacial Age. The selected sites were mostly enriched in pathways related to DNA repair and energy metabolism.ConclusionOverall, the whole-genome resequencing analysis provides valuable insights into the population structure and adaptive characteristics of S. o’connori. There was no obvious genetic differentiation at the genome level between the S. o’connori populations upstream and downstream of the Yarlung Zangbo River. The current distribution pattern and genetic diversity are influenced by the late accelerated uplift of the Qinghai Tibet Plateau and the Fourth Ice Age. The selected sites of S. o’connori are enriched in the energy metabolism and DNA repair pathways to adapt to the low temperature and strong ultraviolet radiation environment at high altitude.

Characterization and analysis of multi-organ full-length transcriptomes in Sphaeropteris brunoniana and Alsophila latebrosa highlight secondary metabolism and chloroplast RNA editing pattern of tree ferns

BackgroundSphaeropteris brunoniana and Alsophila latebrosa are both old relict and rare tree ferns, which have experienced the constant changes of climate and environment. However, little is known about their high-quality genetic information and related research on environmental adaptation mechanisms of them. In this study, combined with PacBio and Illumina platforms, transcriptomic analysis was conducted on the roots, rachis, and pinna of S. brunoniana and A. latebrosa to identify genes and pathways involved in environmental adaptation. Additionally, based on the transcriptomic data of tree ferns, chloroplast genes were mined to analyze their gene expression levels and RNA editing events.ResultsIn the study, we obtained 11,625, 14,391 and 10,099 unigenes of S. brunoniana root, rachis, and pinna, respectively. Similarly, a total of 13,028, 11,431 and 12,144 unigenes were obtained of A. latebrosa root, rachis, and pinna, respectively. According to the enrichment results of differentially expressed genes, a large number of differentially expressed genes were enriched in photosynthesis and secondary metabolic pathways of S. brunoniana and A. latebrosa. Based on gene annotation results and phenylpropanoid synthesis pathways, two lignin synthesis pathways (H-lignin and G-lignin) were characterized of S. brunoniana. Among secondary metabolic pathways of A. latebrosa, three types of WRKY transcription factors were identified. Additionally, based on transcriptome data obtained in this study, reported transcriptome data, and laboratory available transcriptome data, positive selection sites were identified from 18 chloroplast protein-coding genes of four tree ferns. Among them, RNA editing was found in positive selection sites of four tree ferns. RNA editing affected the protein secondary structure of the rbcL gene. Furthermore, the expression level of chloroplast genes indicated high expression of genes related to the chloroplast photosynthetic system in all four species.ConclusionsOverall, this work provides a comprehensive transcriptome resource of S. brunoniana and A. latebrosa, laying the foundation for future tree fern research.

Insights into group-specific pattern of secondary metabolite gene cluster in Burkholderia genus.

Burkholderia is a versatile strain that has expanded into several genera. It has been steadily reported that the genome features of Burkholderia exhibit activities ranging from plant growth promotion to pathogenicity across various isolation areas. The objective of this study was to investigate the secondary metabolite patterns of 366 Burkholderia species through comparative genomics. Samples were selected based on assembly quality assessment and similarity below 80% in average nucleotide identity. Duplicate samples were excluded. Samples were divided into two groups using FastANI analysis. Group A included B. pseudomallei complex. Group B included B. cepacia complex. The limitations of MLST were proposed. The detection of genes was performed, including environmental and virulence-related genes. In the pan-genome analysis, each complex possessed a similar pattern of cluster for orthologous groups. Group A (n = 185) had 14,066 cloud genes, 2,465 shell genes, 682 soft-core genes, and 2,553 strict-core genes. Group B (n = 181) had 39,867 cloud genes, 4,986 shell genes, 324 soft-core genes, 222 core genes, and 2,949 strict-core genes. AntiSMASH was employed to analyze the biosynthetic gene cluster (BGC). The results were then utilized for network analysis using BiG-SCAPE and CORASON. Principal component analysis was conducted and a table was constructed using the results obtained from antiSMASH. The results were divided into Group A and Group B. We expected the various species to show similar patterns of secondary metabolite gene clusters. For in-depth analysis, a network analysis of secondary metabolite gene clusters was conducted, exemplified by BiG-SCAPE analysis. Depending on the species and complex, Burkholderia possessed several kinds of siderophore. Among them, ornibactin was possessed in most Burkholderia and was clustered into 4,062 clans. There was a similar pattern of gene clusters depending on the species. NRPS_04014 belonged to siderophore BGCs including ornibactin and indigoidine. However, it was observed that each family included a similar species. This suggests that, besides siderophores being species-specific, the ornibactin gene cluster itself might also be species-specific. The results suggest that siderophores are associated with environmental adaptation, possessing a similar pattern of siderophore gene clusters among species, which could provide another perspective on species-specific environmental adaptation mechanisms.

Surrogate-model-based dynamic-sensing optimization method for high-speed elevator car horizontal vibration reduction

The horizontal vibration of high-speed elevators has a significant impact on ride comfort and safety stability. Plenty of intelligent methods have been implemented in horizontal vibration reduction. The conventional optimization process for vibration reduction design involves conducting numerous complex dynamics simulations to establish the correlation between design parameters and vibration response. However, this method is inefficient and costly due to the demanding computational power requirements and time-consuming nature of the simulations. This study proposes a surrogate-model-based dynamic-sensing optimization method. A Kriging model is developed based on dynamics simulations, providing an efficient approach for obtaining the vibration response with specified design parameters. The DSPSO algorithm was proposed by incorporating perceptual particles and environmental adaptation mechanisms into the PSO algorithm. The DSPSO algorithm can be nested and interact with the Kriging model to optimize design parameters. During evolution, feasible and uncertain solutions are extracted into the sample space to enhance the accuracy of the Kriging model. The effectiveness of the proposed method is validated using both the ZDT series test functions and elevators from Canny Elevator Co., Ltd.

Characterization of heterozygosity-rich regions in Italian and worldwide goat breeds

Heterozygosity-rich regions (HRR) are genomic regions of high heterozygosity, which may harbor loci related to key functional traits such as immune response, survival rate, fertility, and other fitness traits. This study considered 30 Italian and 19 worldwide goat breeds genotyped with the Illumina GoatSNP50k BeadChip. The aim of the work was to study inter-breed relationships and HRR patterns using Sliding Window (SW) and Consecutive Runs (CR) detection methods. Genetic relationships highlighted a clear separation between non-European and European breeds, as well as the north–south geographic cline within the latter. The Pearson correlation coefficients between the descriptive HRR parameters obtained with the SW and CR methods were higher than 0.9. A total of 166 HRR islands were detected. CHI1, CHI11, CHI12 and CHI18 were the chromosomes harboring the highest number of HRR islands. The genes annotated in the islands were linked to various factors such as productive, reproductive, immune, and environmental adaptation mechanisms. Notably, the Montecristo feral goat showed the highest number of HRR islands despite the high level of inbreeding, underlining potential balancing selection events characterizing its evolutionary history. Identifying a species-specific HRR pattern could provide a clearer view of the mechanisms regulating the genome modelling following anthropogenic selection combined with environmental interaction.

Characterization of a DsbA family protein reveals its crucial role in oxidative stress tolerance of Listeria monocytogenes.

Listeria monocytogenes is a facultative, intracellular foodborne pathogen widely distributed in nature and is responsible for severe invasive infection in humans and animals with a mortality rate as high as 30%. L. monocytogenes can adapt to various oxidative stresses since it has evolved oxidative modification and regulation mechanisms. The disulfide bond formation protein (Dsb) is required to catalyze the formation of disulfide bonds to promote oxidative folding or modification of proteins involved in bacterial virulence and survival. However, the functions of Lmo1059, a DsbA family protein of L. monocytogenes, remain unknown. In this study, we found that Lmo1059 could efficiently catalyze oxidized glutathione (GSSG) reduction, with the residues Cys36 and Cys39 as the key amino acids for its catalytic activity. Moreover, Lmo1059 plays a critical role in oxidative stress tolerance for L. monocytogenes, and Cys36 is the crucial amino acid to participate in this process. When Lmo1059 was deleted, the adhesion and invasion of L. monocytogenes were reduced while the cell-to-cell spread was increased, suggesting an intricate role of Lmo1059 during bacterial infection. Altogether, these data indicate that the DsbA family protein Lmo1059 is an important participant in the antioxidant stress system and works in concert with other proteins to help protect L. monocytogenes from oxidative stress and establish intracellular infection. IMPORTANCE The adaption and tolerance to various environmental stresses are the fundamental factors for the widespread existence of Listeria monocytogenes. Anti-oxidative stress is the critical mechanism for the survival and pathogenesis of L. monocytogenes. The thioredoxin (Trx) and glutaredoxin (Grx) systems are known to contribute to the anti-oxidative stress of L. monocytogenes, but whether the Dsb system has similar roles remains unknown. This study demonstrated that the DsbA family protein Lmo1059 of L. monocytogenes participates in bacterial oxidative stress tolerance, with Cys36 as the key amino acid of its catalytic activity and anti-oxidative stress ability. It is worth noting that Lmo1059 was involved in the invading and cell-to-cell spread of L. monocytogenes. This study lays a foundation for further understanding the specific mechanisms of oxidative cysteine repair and antioxidant stress regulation of L. monocytogenes, which contributes to an in-depth understanding of the environmental adaptation mechanisms for foodborne bacterial pathogens.

Trichocoleus desertorum isolated from Negev desert petroglyphs: Characterization, adaptation and bioerosion potential

The Negev petroglyphs are considered valuable cultural heritage sites, but unfortunately, they are exposed to deterioration processes caused by anthropogenic and natural forces. Despite the many studies that have already pointed to the role of cyanobacteria in biogenic rock weathering, the knowledge involved in the process is still lacking. In this study, a cyanobacterial strain was isolated from the Negev Desert petroglyphs aiming to reveal its involvement in geochemical cycles and in the weathering processes of the rock substrate. The strain was characterized using morphological, molecular, and microscopic studies. The morphological research revealed a green-bluish, bundle-forming filamentous strain characterized by trichomes embedded in a common sheath. A combination of Nanopore and Illumina sequencing technologies facilitated the assembly of a near-complete genome containing 5,458,034 base pairs. A total of 5027 coding sequences were revealed by implementing PROKKA software. Annotation of five replicas of the 16S ribosomal RNA genes revealed that the Negev cyanobacteria isolate is closely (99.73 %) related to Trichocoleus desertorum LSB90_MW403957 isolated from the Sahara Desert, Algeria. The local strain was thus named Trichocoleus desertorum NBK24 CP116619. Several gene sequences that code for possible environmental adaptation mechanisms were found. Our study also identified genes for membrane transporters involved in the exchange of chemical elements, suggesting a possible interaction with rock minerals. Microscopic observations of T. desertorum NBK24 CP116619 infected onto calcareous stone slabs under laboratory conditions demonstrated the effect of the isolated cyanobacteria on stone surface degradation. In conclusion, the findings of this study further our understanding of terrestrial cyanobacterial genomes and functions and highlight the role of T. desertorum NBK24 CP116619 in stone weathering processes. This information may contribute to the creation of efficient restoration strategies for stone monuments affected by cyanobacteria.

Listeria monocytogenes GshF contributes to oxidative stress tolerance via regulation of the phosphoenolpyruvate-carbohydrate phosphotransferase system.

Glutathione (GSH) is an essential component of the glutaredoxin (Grx) system, and it is synthesized by the enzyme glutathione synthase GshF in Listeria monocytogenes. GSH plays a crucial role in regulating Listeria virulence by modifying the virulence factors LLO and PrfA. In this study, we investigated the involvement of L. monocytogenes GshF in oxidative tolerance and intracellular infection. Our findings revealed that the deletion of gshF resulted in a significant reduction in bacterial growth in vitro when exposed to diamide and copper ions stress. More importantly, this deletion also impaired the efficiency of invasion and proliferation in macrophages and mice organs. Furthermore, GshF influenced global transcriptional profiles, including carbohydrate and amino acid metabolism, particularly those related to the phosphoenolpyruvate-carbohydrate phosphotransferase system (PTS) genes lmo1997-lmo2004, under oxidative stress conditions. In the wild-type strain, the transcription of lmo1997-lmo2004 was notably downregulated in response to copper ions and diamide stress compared to normal conditions. However, in the absence of gshF, the transcripts of lmo1997-lmo2004 were upregulated in response to these stress conditions. Notably, the deletion of iiBman (lmo2002) enhanced oxidative stress tolerance to copper ions, whereas overexpression of iiBman reduced this resistance. In conclusion, our study provides the first evidence that L. monocytogenes GshF plays a crucial role in bacterial antioxidation through the regulation of iiBman.IMPORTANCEListeria monocytogenes has developed various mechanisms to withstand oxidative stress, including the thioredoxin and glutaredoxin systems. However, the specific role of the glutathione synthase GshF, responsible for synthesizing GSH in L. monocytogenes, in oxidative tolerance remains unclear. This study aimed to elucidate the relationship between GshF and oxidative tolerance in L. monocytogenes by examining the efficiency of invasion and proliferation in macrophages and mice organs, as well as analyzing global transcriptional profiles under oxidative stress conditions. The results revealed that GshF plays a significant role in L. monocytogenes' response to oxidative stress. Notably, GshF acts to suppress the transcription of phosphoenolpyruvate-carbohydrate phosphotransferase system genes lmo1997-lmo2004, among which iiBman (lmo2002) was identified as the most critical gene for resisting oxidative stress. These findings enhance our understanding of how L. monocytogenes adapts to its environment and provide valuable insights for investigating the environmental adaptation mechanisms of other pathogenic bacteria.

Extreme environmental adaptation mechanisms of Antarctic bryophytes are mainly the activation of antioxidants, secondary metabolites and photosynthetic pathways

The environment in Antarctica is characterized by low temperature, intense UVB and few vegetation types. The Pohlia nutans M211 are bryophytes, which are the primary plants in Antarctica and can thrive well in the Antarctic harsh environment. The transcriptional profiling of Pohlia nutans M211 under low temperature and high UVB conditions was analyzed to explore their polar adaptation mechanism in the extreme Antarctic environment by third-generation sequencing and second-generation sequencing. In comparison to earlier second-generation sequencing techniques, a total of 43,101 non-redundant transcripts and 10,532 lncRNA transcripts were obtained, which were longer and more accurate. The analysis results of GO, KEGG, AS (alternative splicing), and WGCNA (weighted gene co-expression network analysis) of DEGs (differentially expressed genes), combined with the biochemical kits revealed that antioxidant, secondary metabolites pathways and photosynthesis were the key adaptive pathways for Pohlia nutans M211 to the Antarctic extreme environment. Furthermore, the low temperature and strong UVB are closely linked for the first time by the gene HY5 (hlongated hypocotyl 5) to form a protein interaction network through the PPI (protein–protein interaction networks) analysis method. The UVR8 module, photosynthetic module, secondary metabolites synthesis module, and temperature response module were the key components of the PPI network. In conclusion, this study will help to further explore the polar adaptation mechanism of Antarctic plants represented by bryophytes and to enrich the polar gene resources.

Viruses in deep-sea cold seep sediments harbor diverse survival mechanisms and remain genetically conserved within species

Deep sea cold seep sediments have been discovered to harbor novel, abundant, and diverse bacterial and archaeal viruses. However, little is known about viral genetic features and evolutionary patterns in these environments. Here, we examined the evolutionary ecology of viruses across active and extinct seep stages in the area of Haima cold seeps in the South China Sea. A total of 338 viral operational taxonomic units are identified and linked to 36 bacterial and archaeal phyla. The dynamics of host-virus interactions are informed by diverse antiviral defense systems across 43 families found in 487 microbial genomes. Cold seep viruses are predicted to harbor diverse adaptive strategies to persist in this environment, including counter-defense systems, auxiliary metabolic genes, reverse transcriptases, and alternative genetic code assignments. Extremely low nucleotide diversity is observed in cold seep viral populations, being influenced by factors including microbial host, sediment depth, and cold seep stage. Most cold seep viral genes are under strong purifying selection with trajectories that differ depending on whether cold seeps are active or extinct. This work sheds light on the understanding of environmental adaptation mechanisms and evolutionary patterns of viruses in the sub-seafloor biosphere.

The suitability of isotopic methods in identifying water sources of a shallow-rooted herbaceous plant in a desert steppe

Isotopic methodologies have gained prominence in investigating the composition of plant water sources; however, concerns regarding their suitability and reliability in diverse environments have emerged in recent years. This study presents a comparative analysis of root, soil, and liquid water (precipitation, dew, and groundwater) samples obtained from a desert steppe using isotope ratio infrared spectrometry (IRIS) and isotope ratio mass spectrometry (IRMS). The objective was to evaluate the applicability of these techniques in discerning the water sources of Stipa breviflora, a shallow-rooted herbaceous plant species. Additionally, we explored the root water uptake characteristics and water use strategy of S. breviflora. Our findings indicate that the IRIS method had more enriched values of D compared to the IRMS method across all samples, while no discernible pattern was observed for 18O. Notably, the differences observed among all samples exceeded the instruments' accuracies. Moreover, an unexpected occurrence was noted, whereby both D and 18O values in the root water were more enriched than in any of the considered water sources, rendering identification of the plant water sources unattainable. By conducting a re-analysis of more refined soil layer samples, we discovered that S. breviflora exhibits the ability to absorb and utilize water sources in close proximity to the soil surface. It further suggested that the shallow-rooted herbaceous plants in desert steppes can exploit small rainfalls, frequently overlooked in their ecological importance. Considering the distinctive soil and plant characteristics of desert steppes, we recommend adopting IRMS methods in conjunction with refined surface soil sampling for isotopic analysis aiming to identify water sources of shallow-rooted herbaceous plants. This study provides novel insights into assessing the suitability of isotopic techniques for analyzing plant water sources, while enhancing our understanding of water use strategies and environmental adaptation mechanisms employed by shallow-rooted herbaceous plants within xerophytic grassland ecosystems.

Coat Color in Local Goats: Influence on Environmental Adaptation and Productivity, and Use as a Selection Criterion.

This paper aims to review, systematically synthesize, and analyze fragmented information about the importance of coat color in local goats and its relationship with productivity and other important traits. Topics on current research on color expression are addressed, the relationship that has as a mechanism of environmental adaptation, its relationship with the production of meat, milk, and derivates, and the economic value of this characteristic. The use of this attribute as a tool to establish selection criteria in breeding programs based on results reported in the scientific literature is significant, particularly for low-income production systems, where the implementation of classic genetic improvement schemes is limited due to the lack of productive information, which is distinctive of extensive marginal or low scaled production systems around the world.

Chromosome-level genome assembly and annotation of the prickly nightshade Solanum rostratum Dunal

The prickly nightshade Solanum rostratum, an annual malignant weed, is native to North America and has globally invaded 34 countries, causing serious threats to ecosystems, agriculture, animal husbandry, and human health. In this study, we constructed a chromosome-level genome assembly and annotation of S. rostratum. The contig-level genome was initially assembled in 898.42 Mb with a contig N50 of 62.00 Mb from PacBio high-fidelity reads. With Hi-C sequencing data scaffolding, 96.80% of the initially assembled sequences were anchored and orientated onto 12 pseudo-chromosomes, generating a genome of 869.69 Mb with a contig N50 of 72.15 Mb. We identified 649.92 Mb (72.26%) of repetitive sequences and 3,588 non-coding RNAs in the genome. A total of 29,694 protein-coding genes were predicted, with 28,154 (94.81%) functionally annotated genes. We found 99.5% and 91.3% complete embryophyta_odb10 genes in the pseudo-chromosomes genome and predicted gene datasets by BUSCO assessment. The present genomic resource provides essential information for subsequent research on the mechanisms of environmental adaptation of S. rostratum and host shift in Colorado potato beetles.

Comprehensive analysis of the complete mitochondrial genomes of three Coptis species (C. chinensis, C. deltoidea and C. omeiensis): the important medicinal plants in China.

Coptis plants (Ranunculaceae) contain high levels of isoquinoline alkaloids and have a long history of medicinal use. Coptis species are of great value in pharmaceutical industries and scientific research. Mitochondria are considered as one of the central units for receiving stress signals and arranging immediate responses. Comprehensive characterizations of plant mitogenomes are imperative for revealing the relationship between mitochondria, elucidating biological functions of mitochondria and understanding the environmental adaptation mechanisms of plants. Here, the mitochondrial genomes of C. chinensis, C. deltoidea and C. omeiensis were assembled through the Nanopore and Illumina sequencing platform for the first time. The genome organization, gene number, RNA editing sites, repeat sequences, gene migration from chloroplast to mitochondria were compared. The mitogenomes of C. chinensis, C. deltoidea and C. omeiensis have six, two, two circular-mapping molecules with the total length of 1,425,403 bp, 1,520,338 bp and 1,152,812 bp, respectively. The complete mitogenomes harbors 68-86 predicted functional genes including 39-51 PCGs, 26-35 tRNAs and 2-5 rRNAs. C. deltoidea mitogenome host the most abundant repeat sequences, while C. chinensis mitogenome has the largest number of transferred fragments from its chloroplasts. The large repeat sequences and foreign sequences in the mitochondrial genomes of Coptis species were related to substantial rearrangements, changes in relative position of genes and multiple copy genes. Further comparative analysis illustrated that the PCGs under selected pressure in mitochondrial genomes of the three Coptis species mainly belong to the mitochondrial complex I (NADH dehydrogenase). Heat stress adversely affected the mitochondrial complex I and V, antioxidant enzyme system, ROS accumulation and ATP production of the three Coptis species. The activation of antioxidant enzymes, increase of T-AOC and maintenance of low ROS accumulation in C. chinensis under heat stress were suggested as the factors for its thermal acclimation and normal growth at lower altitudes. This study provides comprehensive information on the Coptis mitogenomes and is of great importance to elucidate the mitochondrial functions, understand the different thermal acclimation mechanisms of Coptis plants, and breed heat-tolerant varieties.

Thiomicrorhabdus marina sp.nov., an obligate chemolithoautotroph isolated from tidal zone sediment, and genome insight into the genus Thiomicrorhabdus

The contribution of microbes to the marine sulfur cycle has received considerable attention in recent years. In this study, a new Gram-stain-negative, aerobic sulfur-oxidizing bacterium, designated strain 6S2-11T, was isolated from tidal zone sediment of the coast of Weihai, China. Strain 6S2-11T was an obligate chemolithoautotroph utilizing thiosulfate as the energy source. Physiological and biochemical experiments, phylogenetic analysis, and comparative genomic analysis were done with strain 6S2-11T. According to genomic analysis, strain 6S2-11T owned a complete thiosulfate oxidation pathway and an untypical nitrogen metabolism pathway. Its relatively small genome also has multiple environmental adaptation mechanisms. The DNA G+C content of strain 6S2-11T was 44.1%. Strain 6S2-11T was observed to grow at 20-37°C (optimum, 35°C), pH 6.0-9.5 (optimum, pH 7.5), and 0.5-5% (w/v) NaCl (optimum, 2.5%). The major cellular fatty acids (>10%) of strain 6S2-11T were Summed Feature 8 (C18:1ω7c/C18:1ω6c), C16:0 and Summed Feature 3 (C16:1ω7c/C16:1ω6c). The comparison of 16S rRNA gene sequences indicated that strain 6S2-11T was most closely to Thiomicrorhabdus xiamenensis G2T (96.8%). Based on the results of phylogenetic analysis, the strain 6S2-11T is a novel specie of the genus Thiomicrorhabdus, for which name Thiomicrorhabdus marina sp.nov. is proposed with the type strain 6S2-11T (=MCCC 1H00523T=KCTC 82994T).

Functional analysis of two mitogen-activated protein kinases involved in thermal resistance of the predatory mite Neoseiulus californicus (Acari: Phytoseiidae).

Predatory mites are important biological control agents used against phytophagous mites and small insects. They face various environmental pressures, especially fluctuating climate factors. Neoseiulus californicus, a commercially available phytoseiid mite, is adapted to a wide range of temperature conditions. We investigated the regulatory mechanisms governing the plastic response of N. californicus for coping with environmental temperature variations. The mitogen-activated protein kinase (MAPK) signaling pathway is a highly conserved pathway of cell signal transduction that responds to environmental stress. We isolated two MAPKK genes (NcMAPKK4 and NcMAPKK6) from N. californicus and studied their functions. Developmental stage-specific expression level analysis showed that in adults, particularly females, NcMAPKK4 and NcMAPKK6 levels were higher than in other developmental stages. The expression level analysis at extremely high and low temperature conditions demonstrated that NcMAPKK4 could be induced significantly by adverse thermal stresses, whereas NcMAPKK6 distinctly responded to heat shock, indicating their different roles in thermal stress responses. After silencing of NcMAPKK4, both heat and cold resistance decreased significantly, whereas NcMAPKK6 knockdown had a greater influence on heat resistance. Knockdown of NcMAPKKs also reduced the activities of antioxidant enzymes, suggesting the regulation of NcMAPKKs was closely related to the antioxidant process in oxidative stress caused by external stimuli. These results indicate an important role of NcMAPKKs in the response to thermal stress and provide insight into the MAPK cascade pathway in the environmental adaptation mechanisms of phytoseiid mites.