A transferred regulator that contributes to Xanthomonas oryzae pv.oryzicola oxidative stress adaptation and virulence by regulating the expression of cytochrome bd oxidase genes

Horizontal gene transfer(HGT)has been well documented as a driving force in the evolution of bacteria.It has been shown that a horizontally acquired gene,xoc_2868,involved in the global response against oxidative stress and pathogenicity of Xanthomonas oryzae pv.oryzicola strain BLS256.However,as a transcriptional factor(TF),the regulatory mechanism of XOC_2868 has not yet been revealed.Here,evolutionary analysis suggested XOC_2868 might be co-transferred with its physically proximate downstream genes from a Burkholderiaceae ancestor.Interestingly,RNA-seq data of wild-type(BLS256)andΔxoc_2868 strains under oxidative stress showed that XOC_2868 did not regulate the expression of its adjacent genes,but remarkably influenced the expression of several genes involved in the extracellular polysaccharide(EPS)production and xanthan biosynthesis.Chromatin immunoprecipitation-sequence(ChIP-seq)combined with transcriptome analysis revealed that XOC_2868 directly regulates a cydAB operon,encoding two subunits of cytochrome bd oxidase and involved in redox balance.Consistent withΔxoc_2868 strain,cydA-and cydAB-knockout mutants also showed a higher sensitivity to H_(2)O_(2)along with a reduced bacterial virulence compared with the wild-type strain.Overall,our findings raise the possibility of regulatory circuit evolution shaped by HGT and driven by selection and reveal a novel regulatory pathway that regulates the expression of cytochrome bd oxidase and thus contributes to the virulence of BLS256.

Sulfated peptides and their receptors:Key regulators of plant development and stress adaptation

Four distinct types of sulfated peptides have been identified in Arabidopsis thaliana.These peptides play crucial roles in regulating plant development and stress adaptation.Recent studies have revealed that Xan-thomonas and Meloidogyne can secrete plant-like sulfated peptides,exploiting the plant sulfated peptide signaling pathway to suppress plant immunity.Over the past three decades,receptors for these four types of sulfated peptides have been identified,all of which belong to the leucine-rich repeat receptor-like protein kinase subfamily.A number of regulatory proteins have been demonstrated to play important roles in their corresponding signal transduction pathways.In this review,we comprehensively summarize the discov-eries of sulfated peptides and their receptors,mainly in Arabidopsis thaliana.We also discuss their known biological functions in plant development and stress adaptation.Finally,we put forward a number of ques-tions for reference in future studies.

Emotions and Stressing Situations Adaptation of Nursing Students in the New Normality

Background: New normality is uncertain in every sense, specifically in education and for many health disciplines. Being immersed in COVID-19 pandemics brought serious consequences for mental health, and is very important to handle emotions and stress coping strategies to obtain positive outcomes. Objective: To identify the most frequent emotions, as well as the adaptation strategies to the new normality faced by the students of nursing. Methods: Qualitative and phenomenological research, with the participation of 20 students from both genders in the middle term of nursing career at Faculty of Higher Studies Iztacala, National Autonomous University of Mexico, from August to November 2021. Information was collected from a focal group for ten sessions;analysis was according to De Souza Minayo, and there was a signed informed consent letter from participants. Results: Four categories emerged with sub-categories. Category I Maximized emotions. Sub-categories: 1) Frustration, anger, disappointment;2) Personal disappointment, hopelessness, uncertainty;3) Depression. Category II Support elements close to the new normality. Sub-categories: 1) Family communication;2) Education for mental and physical health. Category III Stressing situations that exceeded the student. Sub-category: Disease in lovely ones. Category IV Stress coping strategies. Sub-categories: 1) Friends and relatives that help to get better;2) Family values. Informers pointed out to have maximized emotion, and having no self-control on its negative outcomes occurred;in addition, the situation was not favorable at home with several losses of loved ones, as well as a poor economy that threatened students to give up studies. Conclusion: Emotions facing this new normality are very important and should be attended to, their proper handling will result in a new learning of socio-emotional abilities, stress coping strategies development, better adaptation and informed decisions taken.

ABOUT TWO TYPES OF MICROSTRUCTURES ADAPTED TO HEAT EVACUATION AND ELASTIC STRESS:SNOW FLAKES AND QUASI-CRYSTALS

I first met Constantine Dafermos in August 1974, at a meeting at Brown University, where I was invited because my former advisor （Jacques-Louis LIONS） could not come, and he had proposed my name. I was happily surprised that Constantine greeted me as if he knew me well, and since for many years now I have considered him as if he was an older brother, I wonder when this feeling started.

A first order system model of fracture healing

A first order system model is proposed for simulating the influence of stress stimulation on fracture strength during fracture healing. To validate the model, the diaphyses of bilateral tibiae in 70 New Zealand rabbits were osteotomized and fixed with rigid plates and stress-relaxation plates, respectively. Stress shielding rate and ultimate bending strength of the healing bone were measured at 2 to 48 weeks postoperatively. Ratios of stress stimulation and fracture strength of the healing bone to those of intact bone were taken as the system input and output. The assumed first order system model can approximate the experimental data on fracture strength from the input of stress stimulation over time, both for the rigid plate group and the stress-relaxation plate group, with different system parameters of time constant and gain. The fitting curve indicates that the effect of mechanical stimulus occurs mainly in late stages of healing. First order system can model the stress adaptation process of fracture healing. This approach presents a simple bio-mathematical model of the relationship between stress stimulation and fracture strength, and has the potential to optimize planning of functional exercises and conduct parametric studies.

Transcriptome assembly of Modiolus modiolus and comparative analysis with Bathymodiolus platifrons

The genetic basis for bivalves＇ adaptation and evolution is not well understood. Even few studies have focused on the mechanism of molluscan molecular evolution between the coastal intertidal zone and deep-sea environment.In our studies, we first conducted the transcritpome assembly of Modiolus modiolus mussels living in coastal intertidal zones. Also, we conducted transcriptome comparison analyses between M. modiolus and Bathymodiolus platifrons living in hydrothermal vents and cold methane/sulfide-hydrocarbon seeps. De novo assemblies of the clean reads yielded a total of 182 476 and 156 261 transcripts with N50 values of 1 769 and 1 545 in M. modiolus and B. platifrons. A total of 27 868 and 23 588 unigenes were identified, which also displayed the similar GO representation patterns. Among the 10 245 pairs of putative orthologs, we identified 26 protein-coding genes under strong positive selection（Ka/Ks〉1） and 12 genes showing moderate positive selection（0.5

ORF355 confers enhanced salinity stress adaptability to S-type cytoplasmic male sterility maize by modulating the mitochondrial metabolic homeostasis

Moderate stimuli in mitochondria improve wideranging stress adaptability in animals, but whether mitochondria play similar roles in plants is largely unknown. Here, we report the enhanced stress adaptability of S-type cytoplasmic male sterility(CMS-S) maize and its association with mild expression of sterilizing gene ORF355. A CMS-S maize line exhibited superior growth potential and higher yield than those of the near-isogenic N-type line in saline fields. Moderate expression of ORF355 induced the accumulation of reactive oxygen species and activated the cellular antioxidative defense system. This adaptive response was mediated by elevation of the nicotinamide adenine dinucleotide concentration and associated metabolic homeostasis. Metabolome analysis revealed broad metabolic changes in CMS-S lines, even in the absence of salinity stress. Metabolic products associated with amino acid metabolism and galactose metabolism were substantially changed, which underpinned the alteration of the antioxidative defense system in CMS-S plants. The results reveal the ORF355-mediated superior stress adaptability in CMS-S maize and might provide an important route to developing salt-tolerant maize varieties.

The transcription factor HSFA7b controls thermomemory at the shoot apical meristem by regulating ethylene biosynthesis and signaling in Arabidopsis

The shoot apical meristem(SAM)is responsible for overall shoot growth by generating all aboveground structures.Recent research has revealed that the SAM displays an autonomous heat stress(HS)memory of a previous non-lethal HS event.Considering the importance of the SAM for plant growth,it is essential to determine how its thermomemory is mechanistically controlled.Here,we report that HEAT SHOCK TRAN-SCRIPTION FACTOR A7b(HSFA7b)plays a crucial role in this process in Arabidopsis,as the absence of functional HSFA7b results in the temporal suppression of SAM activity after thermopriming.We found that HSFA7b directly regulates ethylene response at the SAM by binding to the promoter of the key ethylene signaling gene ETHYLENE-INSENSITIVE 3 to establish thermotolerance.Moreover,we demonstrated that HSFA7b regulates the expression of ETHYLENE OVERPRODUCER 1(ETO1)and ETO1-LIKE 1,both of which encode ethylene biosynthesis repressors,thereby ensuring ethylene homeostasis at the SAM.Taken together,these results reveal a crucial and tissue-specic role for HSFA7b in thermomemory at the Arabidopsis SAM.

OsPRMT6a-mediated arginine methylation of OsJAZ1 regulates jasmonate signaling and spikelet development in rice

Although both protein arginine methylation(PRMT)and jasmonate(JA)signaling are crucial for regulating plant development,the relationship between these processes in the control of spikelet development remains unclear.In this study,we used the CRISPR/Cas9 technology to generate two OsPRMT6a loss-of-function mutants that exhibit various abnormal spikelet structures.Interestingly,we found that OsPRMT6a can methylate arginine residues in JA signal repressors OsJAZ1 and OsJAZ7.We showed that arginine methylation of OsJAZ1 enhances the binding affinity of OsJAZ1 with the JA receptors OsCOI1a and OsCOI1b in the presence of JAs,thereby promoting the ubiquitination of OsJAZ1 by the SCF^(OsCOI1a/OsCOI1b) complex and degradation via the 26S proteasome.This process ultimately releases OsMYC2,a core transcriptional regulator in the JA signaling pathway,to activate or repress JA-responsive genes,thereby maintaining normal plant(spikelet)development.However,in the osprmt6a-1 mutant,reduced arginine methylation of OsJAZ1 impaires the interaction between OsJAZ1 and OsCOI1a/OsCOI1b in the presence of JAs.As a result,OsJAZ1 proteins become more stable,repressing JA responses,thus causing the formation of abnormal spikelet structures.Moreover,we discovered that JA signaling reduces the OsPRMT6a mRNA level in an OsMYC2-dependent manner,thereby establishing a negative feedback loop to balance JA signaling.We further found that OsPRMT6a-mediated arginine methylation of OsJAZ1 likely serves as a switch to tune JA signaling to maintain normal spikelet development under harsh environmental conditions such as high temperatures.Collectively,our study establishes a direct molecular link between arginine methylation and JA signaling in rice.

Non-CG DNA methylation-deficiency mutations enhance mutagenesis rates during salt adaptation in cultured Arabidopsis cells

Much has been learned about how plants acclimate to stressful environments,but the molecular basis of stress adaptation and the potential involvement of epigenetic regulation remain poorly understood.Here,we examined if salt stress induces mutagenesis in suspension cultured plant cells and if DNA methylation affects the mutagenesis using whole genome resequencing analysis.We generated suspension cell cultures from two Arabidopsis DNA methylation-deficient mutants and wild-type plants,and subjected the cultured cells to stepwise increases in salt stress intensity over 40 culture cycles.We show that ddc(drm1 drm2 cmt3)mutant cells can adapt to grow in 175 mM NaCl-containing growth medium and exhibit higher adaptability compared to wild type Col-0 and nrpe1 cells,which can adapt to grow in only 125mM NaCl-containing growth medium.Salt treated nrpe1 and ddc cells but not wild type cells accumulate more mutations compared with their respective untreated cells.There is no enrichment of stress responsive genes in the list of mutated genes in salt treated cells compared to the list of mutated genes in untreated cells.Our results suggest that DNA methylation prevents the induction of mutagenesis by salt stress in plant cells during stress adaptation.

Expression Profiling and Structural Characterization of Micro RNAs in Adipose Tissues of Hibernating Ground Squirrels

Micro RNAs（mi RNAs） are small non-coding RNAs that are important in regulating metabolic stress. In this study, we determined the expression and structural characteristics of 20 mi RNAs in brown（BAT） and white adipose tissue（WAT） during torpor in thirteen-lined ground squirrels. Using a modified stem-loop technique, we found that during torpor, expression of six mi RNAs including let-7a, let-7b, mi R-107, mi R-150, mi R-222 and mi R-31 was significantly downregulated in WAT（P 〈 0.05）, which was 16%–54% of euthermic non-torpid control squirrels,whereas expression of three mi RNAs including mi R-143, mi R-200 a and mi R-519 d was found to be upregulated by 1.32–2.34-fold. Similarly, expression of more mi RNAs was downregulated in BAT during torpor. We detected reduced expression of 6 mi RNAs including mi R-103 a, mi R-107, mi R-125 b, mi R-21, mi R-221 and mi R-31（48%–70% of control）, while only expression of mi R-138 was significantly upregulated（2.91 ± 0.8-fold of the control, P 〈 0.05）. Interestingly,mi RNAs found to be downregulated in WAT during torpor were similar to those dysregulated in obese humans for increased adipogenesis, whereas mi RNAs with altered expression in BAT during torpor were linked to mitochondrial b-oxidation. mi RPath target prediction analysis showed that mi RNAs downregulated in both WAT and BAT were associated with the regulation of mitogen-activated protein kinase（MAPK） signaling, while the mi RNAs upregulated in WAT were linked to transforming growth factor b（TGFb） signaling. Compared to mouse sequences, no unique nucleotide substitutions within the stem-loop region were discovered for the associated pre-mi RNAs for the mi RNAs used in this study, suggesting no structure-influenced changes in pre-mi RNA processing efficiency in the squirrel. As well, the expression of mi RNA processingenzyme Dicer remained unchanged in both tissues during torpor. Overall, our findings suggest that changes of mi RNA expression in adipose tissues may be linked to distinct biological roles in WAT and BAT during hibernation and may involve the regulation of signaling cascades.

Belgica antarctica(Diptera: Chironomidae): A natural modelorganism for extreme environments

Belgica antarctica(Diptera:Chironomidae),a brachypterous midge endemicto the maritime Antarctic,was first described in 1900.Over more than a century of study,a vast amount of information has been compiled on the species(3750000 Google searchresults as of January 10,2021),encompassing its ecology and biology,life cycle and re-production,polytene chromosomes,physiology,biochemistry and,increasingly,omics.In2014,B.antarctica’s genome was sequenced,further boosting research.Certain develop-mental stages can be cultured successfully in the laboratory.Taken together,this wealthof information allows the species to be viewed as a natural model organism for studies ofadaptation and function in extreme environments.

Biomechanical Effect of Chinese Immobilization Using Little Splint

Immobilization using little splint is an original innovation of Chinese people for the fracture fixation, which is simple to use and clinically effective. It was found that Chinese immobilization using little splint can make the non-invasive,uncovering, and trouble free healing of bone fracture via harmonious unity of the structure stability and the force balance, of the motion stability and the stress adaptability, of the constant and discontinuous physiological stress. The biomechanical effect of Chinese immobilization using little splint, including entirety, dynamic, and functional fixity, is the root cause of its inheritance and the use up to now, and also is a direction of today's fracture fixation towards personalization, individuality and entirety.