Microbe-induced gene silencing explores interspecies RNAi and opens up possibilities of crop protection

In most eukaryotes, small RNA(sRNA)-mediated RNA silencing(or RNA interference, RNAi) is an evolutionarily conserved mechanism that regulates gene expression in a sequence-specific manner.Generally, s RNAs are produced by the RNase III enzymes Dicers and then incorporated into Argonaute(AGO) proteins to regulate gene expression by mRNA degradation.

Profile of Prof.Ke-Qin Zhang

Dr.Ke-Qin Zhang is a microbiologist who has spent more than 40 years on harnessing the natural existing nematophagous microorganisms to combat against plant-parasitic nematodes.Dr.Zhang received his Ph.D.degree from China Agricultural University in 1998 and then joined as the director of the Key Laboratory of Industrial Microbiology and Fermentation Technology of Yunnan in Yunnan University.

Plasma non-transferrin-bound iron uptake by the small intestine leads to intestinal injury and intestinal flora dysbiosis in an iron overload mouse model and Caco-2 cells

Iron overload often occurs during blood transfusion and iron supplementation, resulting in the presence of non-transferrin-bound iron(NTBI) in host plasma and damage to multiple organs, but effects on the intestine have rarely been reported. In this study, an iron overload mouse model with plasma NTBI was established by intraperitoneal injection of iron dextran. We found that plasma NTBI damaged intestinal morphology, caused intestinal oxidative stress injury and reactive oxygen species(ROS) accumulation,and induced intestinal epithelial cell apoptosis. In addition, plasma NTBI increased the relative abundance of Ileibacterium and Desulfovibrio in the cecum, while the relative abundance of Faecalibaculum and Romboutsia was reduced. Ileibacterium may be a potential microbial biomarker of plasma NTBI. Based on the function prediction analysis, plasma NTBI led to the weakening of intestinal microbiota function, significantly reducing the function of the extracellular structure. Further investigation into the mechanism of injury showed that iron absorption in the small intestine significantly increased in the iron group. Caco-2 cell monolayers were used as a model of the intestinal epithelium to study the mechanism of iron transport. By adding ferric ammonium citrate(FAC, plasma NTBI in physiological form) to the basolateral side, the apparent permeability coefficient(Papp) values from the basolateral to the apical side were greater than 3×10^(-6)cm s^(-1). Intracellular ferritin level and apical iron concentration significantly increased, and SLC39A8(ZIP8) and SLC39A14(ZIP14) were highly expressed in the FAC group.Short hairpin RNA(sh RNA) was used to knock down ZIP8 and ZIP14 in Caco-2 cells. Transfection with ZIP14-specific sh RNA decreased intracellular ferritin level and inhibited iron uptake. These results revealed that plasma NTBI may cause intestinal injury and intestinal flora dysbiosis due to the uptake of plasma NTBI from the basolateral side into the small intestine, which is probably mediated by ZIP14.

A noncoding secret to stay young—protecting T_(reg)cells to keep the balance in the liver

The liver plays a crucial role in maintaining whole-body metabolic homeostasis and harbors a distinct immune environment(Robinson et al.,2016).However,during the aging process,the liver undergoes structural and functional changes that can disrupt the delicate balance between the immune system and liver function.These age-related alterations can lead to increased susceptibility to metabolic diseases,including non-alcoholic fatty liver disease(NAFLD),and impairments in immune cell regulation and tissue repair(Albillos et al.,2022;Anstee et al.,2019).

Nodule-specific energy sensors determine symbiotic nitrogen fixation by regulating phosphoenolpyruvate allocation

Legume roots can fix atmospheric nitrogen(N2)via symbiotic bacteria of the Rhizobium genus in root nodules.The symbiotic nitrogen fixation(SNF)by rhizobia can fix up to80%of biologically fixed nitrogen in agricultural fields.This ability of legumes makes them environment-friendly crops by reducing the usage of nitrogen fertilizer(Gong et al.,2020).The SNF in legume nodules is a highly energy-demanding process,fueled by plants that supply photoassimilates mainly in the form of sucrose(Udvardi and Poole,2013).

Enabling technology and core theory of synthetic biology

Synthetic biology provides a new paradigm for life science research(“build to learn”)and opens the future journey of biotechnology(“build to use”).Here,we discuss advances of various principles and technologies in the mainstream of the enabling technology of synthetic biology,including synthesis and assembly of a genome,DNA storage,gene editing,molecular evolution and de novo design of function proteins,cell and gene circuit engineering,cell-free synthetic biology,artificial intelligence(AI)-aided synthetic biology,as well as biofoundries.We also introduce the concept of quantitative synthetic biology,which is guiding synthetic biology towards increased accuracy and predictability or the real rational design.We conclude that synthetic biology will establish its disciplinary system with the iterative development of enabling technologies and the maturity of the core theory.

Nematode-induced trap formation regulated by the histone H3K4 methyltransferase AoSET1 in the nematode-trapping fungus Arthrobotrys oligospora

The methylation of lysine 4 of histone H3(H3K4),catalyzed by the histone methyltransferase KMT2/SET1,has been functionally identified in many pathogenic fungi but remains unexplored in nematode-trapping fungi(NTFs).Here,we report a regulatory mechanism of an H3K4-specific SET1 orthologue,AoSET1,in the typical nematode-trapping fungus Arthrobotrys oligospora.When the fungus is induced by the nematode,the expression of AoSET1 is up-regulated.Disruption of AoSet1 led to the abolishment of H3K4me.Consequently,the yield of traps and conidia ofΔAoSet1 was significantly lower than that of the WT strain,and the growth rate and pathogenicity were also compromised.Moreover,H3K4 trimethylation was enriched mainly in the promoter of two bZip transcription factor genes(AobZip129 and AobZip350)and ultimately up-regulated the expression level of these two transcription factor genes.In theΔAoSet1 and AoH3K4A strains,the H3^(K4)me modification level was significantly decreased at the promoter of transcription factor genes AobZip129 and AobZip350.These results suggest that AoSET1-mediated H3KEme serves as an epigenetic marker of the promoter region of the targeted transcription factor genes.Furthermore,we found that AobZip129 negatively regulates the formation of adhesive networks and the pathogenicity of downstream AoPABP1 and AoCPR1.Our findings confirm that the epigenetic regulatory mechanism plays a pivotal role in regulating trap formation and pathogenesis in NTFs,and provide novel insights into the mechanisms of interaction between NTFs and nematodes.

Genomic insights into versatile lifestyle of three new bacterial candidate phyla

Metagenomic explorations of the Earth's biosphere enable the discovery of previously unknown bacterial lineages of phylogenetic and ecological significance.Here,we retrieved 11 metagenomic-assembled genomes(MAGs)affiliated to three new monophyletic bacterial lineages from the seawater of the Yap Trench.Phylogenomic analysis revealed that each lineage is a new bacterial candidate phylum,subsequently named Candidatus Qinglongiota,Candidatus Heilongiota,and Candidatus Canglongiota.Metabolic reconstruction of genomes from the three phyla suggested that they adopt a versatile lifestyle,with the potential to utilize various types of sugars,proteins,and/or short-chain fatty acids through anaerobic pathways.This was further confirmed by a global distribution map of the three phyla,indicating a preference for oxygen-limited or particle-attached niches,such as anoxic sedimentary environments.Of note,Candidatus Canglongiota genomes harbor genes for the complete WoodLjungdahl pathway and sulfate reduction that are similar to those identified in some sulfate-reducing bacteria.Evolutionary analysis indicated that gene gain and loss events,and horizontal gene transfer(HGT)play important roles in shaping the genomic and metabolic features of the three new phyla.This study presents the genomic insight into the ecology,metabolism,and evolution of three new phyla,which broadens the phylum-level diversity within the domain Bacteria.

The relative and combined effects of herbivore assemblage and soil nitrogen on plant diversity

Plant diversity can be affected by both herbivore grazing and soil resources. However, it is unclear if the joint effects of herbivores and soil resources might vary with components of plant diversity. Here, we evaluated the relative and combined effects of herbivore assemblage and soil nitrogen(N) quantity and heterogeneity on the α and β components of plant diversity in a grassland that was subjected to four years of grazing under differing herbivore assemblages(no grazing, cattle grazing, sheep grazing, and mixed grazing). We found that herbivore assemblage combined with soil N quantity explained 41% of the variation in plant α-diversity, while herbivore assemblage combined with soil N heterogeneity explained 15% of the variation in plant β-diversity. The independent effects of herbivore assemblage explained more than those of soil N for both α-and β-diversity(α-diversity: 12% vs. 4%;β-diversity: 18% vs. 16%). We concluded that the effects of herbivores are stronger than those of soil N,and that grazing-induced changes in soil resources are important drivers of plant diversity change, especially α-diversity.Therefore, we suggest that managing herbivore species by accounting for the effects that their grazing can have on soil resources may be significant for plant diversity maintenance.

Susceptibility of patients with chronic obstructive pulmonary disease to heart rate difference associated with the short-term exposure to metals in ambient fine particles:A panel study in Beijing,China

Susceptibility of patients with chronic obstructive pulmonary disease(COPD)to cardiovascular autonomic dysfunction asso-ciated with exposure to metals in ambient fine particles(PM2.5,particulate matter with aerodynamic diameter≤2.5µm)remains poorly evidenced.Based on the COPDB(COPD in Beijing)panel study,we aimed to compare the associations of heart rate(HR,an indicator of cardiovascular autonomic function)and exposure to metals in PM2.5 between 53 patients with COPD and 82 healthy controls by using linear mixed-effects models.In all participants,the HR levels were significantly associated with interquartile range increases in the average concentrations of Cr,Zn,and Pb,but the strength of the associations differed by exposure time(from 1.4%for an average 9 days(d)Cr exposure to 3.5%for an average 9 d Zn exposure).HR was positively associated with the average concentrations of PM2.5 and certain metals only in patients with COPD.Associations between HR and exposure to PM2.5,K,Cr,Mn,Ni,Cu,Zn,As,and Se in patients with COPD significantly differed from those in health controls.Furthermore,association between HR and Cr exposure was robust in COPD patients.In conclusion,our findings indicate that COPD could exacerbate difference in HR following exposure to metals in PM2.5.

Magnetoresponsive nanozyme:magnetic stimulation on the nanozyme activity of iron oxide nanoparticles

The iron oxide nanoparticles(IONPs)that combine the nanozyme activity and magnetothermal properties have attracted significant interest for various biomedical applications.However,the effect of magnetic stimulation in fine-tuning the nanozyme activities remains unclear.Here,we have constructed a series of IONPs with different magneto-thermal conversion abilities,and systematically study the effect of magnetic field stimulation on the peroxidase(POD)activity of IONPs.The results show that POD activity is effectively amplified via an in situ alternating magnetic field(AMF)stimulation with no solution temperature rise,and the degree of activity enhancement is closely related to the magnetic heating ability of the IONPs,confirming the origin of activity enhancement arises from the local magnetothermal effect.As the first report to prove magnetothermal regulation on nanozyme activity and to shed lights on the underlying correlation between activity enhancement and the intrinsic specific absorption rate(SAR),this work is expected to provide important support for future design of new magnetoresponsive nanozymes in various practical applications.

Cancer challenges worldwide and in China:preparing for the inevitable

As socioeconomic development is closely associated with changes in various risk factors for cancer,a timely and worldwide depiction of temporal and geographic cancer burden can provide insights on the effective prevention and treatment of this disease.Recently,the International Agency for Research on Cancer issued an update regarding the status of the global cancer burden for 36 forms of cancer in 185 countries(Sung et al.,2021).The report revealed that the worldwide cancer burden had increased rapidly between 2018 and 2020.Notably,female-specific breast cancer has replaced lung cancer as the most commonly diagnosed form,and its incidence rate is increasing rapidly,especially in Asia.Against this background,the study will review and compare global cancer statistics between 2018 and 2020(Sung et al.,2021;Bray et al.,2018),Cancer Country Profiles China 2020(World Health Organization(WHO),2020)。

Introduction of a multicenter online database for non-metastatic breast cancer in China

Dear Editor,Breast cancer is now the most frequently diagnosed cancer and is the fifth leading cause of cancer-related death in Chinese women. Therefore, the burden of breast cancer in China is gradually increasing. According to figures released by the Chinese Cancer Center in 2018, the number of newly diagnostic breast cancer is about 278,900 cases, accounting for 16.51%of all women who were diagnosed with the first primary malignant tumors;and 66,000 cases of breast cancer died in 2014 (Chen et al., 2016).

Neural mechanisms of feature binding

An object is usually composed of different features(e.g.,color,orientation,and motion),which are processed by segregated visual pathways and represented by functionally specialized brain areas.However,we perceive an object as a coherent whole,rather than its isolated features.How we integrate those isolated features and achieve a precise perception of objects is a fundamental challenge for the visual system,which is referred to as the binding problem.

A brief introduction to biophotonic techniques and methods

Biophotonics is not a standard word listed in a classical dictionary. The meaning of "biophotonics" is essentially the use of photonic technologies to detect and perhaps to control a biological phenomenon or event, at different levels ranging from molecules, cells, tissue, organisms, to intact animals and even human bodies(Yeh and Krishnan, 2018). The field of biophotonics is not well defined because it is a multidisciplinary research field at the intersection of physics,biology, chemistry, medicine and engineering(Tsia, 2016;Vo-Dinh, 2014;Wang and Tuchin, 2016). As alternatives to biophotonics, the term "biomedical photonics" and "biomedical optics" have also been popularly used, with no exact distinction among them(Vo-Dinh, 2014).

Dissociated deficits in attentional networks in social anxiety and depression

A critical cognitive symptom that is commonly involved in social anxiety and depression is attentional deficit. However, the functional relationship between attentional deficit and these two disorders remains poorly understood. Here, we behaviorally disentangled the three key attentional components(alerting, orienting, and executive control) using the established attentional network task(ANT) to investigate how social anxiety and depression are related to deficits in these attention components. We identified a double dissociation between the symptoms of social anxiety and depression and the attentional component deficits when processing non-emotional stimuli. While individuals vulnerable to social anxiety exhibited deficits in the orienting component, individuals vulnerable to depression were impaired in the executive control component. Our findings showed that social anxiety and depression were associated with deficits in different attentional components, which are not specific to emotional information.

Strengthening the functional research on the interaction between host genes and microbiota

In recent years,many studies have focused on the interaction between host genes and microbiota and their mutual influence(Bonder et al.,2016;Goodrich et al.,2014;Rothschild et al.,2018;Wang et al.,2016;Zhang et al.,2019).Host genetic variation influences the composition of the microbial community,for instance in inflammatory bowel disease,host genetic susceptibilities induce pathological shifts in microbiome composition.

A UV-B-responsive glycosyltransferase,OsUGT706C2,modulates flavonoid metabolism in rice

Although natural variations in rice flavonoids exist, and biochemical characterization of a few flavonoid glycosyltransferases has been reported, few studies focused on natural variations in tricin-lignan-glycosides and their underlying genetic basis. In this study, we carried out metabolic profiling of tricin-lignan-glycosides and identified a major quantitative gene annotated as a UDPdependent glycosyltransferase OsUGT706C2 by metabolite-based genome-wide association analysis. The putative flavonoid glycosyltransferase OsUGT706C2 was characterized as a flavonoid 7-O-glycosyltransferas in vitro and in vivo. Although the in vitro enzyme activity of OsUGT706C2 was similar to that of OsUGT706D1, the expression pattern and induced expression profile of OsUGT706C2 were very different from those of OsUGT706D1. Besides, OsUGT706C2 was specifically induced by UV-B. Constitutive expression of OsUGT706C2 in rice may modulate phenylpropanoid metabolism at both the transcript and metabolite levels. Furthermore, overexpressing OsUGT706C2 can enhance UV-B tolerance by promoting ROS scavenging in rice. Our findings might make it possible to use the glycosyltransferase OsUGT706C2 for crop improvement with respect to UVB adaptation and/or flavonoid accumulation, which may contribute to stable yield.

Pathogenic mutations in two Chinese patients exhibiting severe early-onset obesity

Dear Editor.During the past decades,the rising prevalence of obesity,especially in children,has become one of the major public health challenges in modern China and worldwide.This increase in prevalence of obesity can partly be attributed to high-calorie food intake and lack of exercise.Conversely,previous research has demonstrated the importance of genetic factors in the etiology of obesity.

Genome-editing technologies: the gap between application and policy

Genome editing is a new technology for manipulating genomic DNA sequences at specific sites,and researchers worldwide are rapidly developing new variants of genomeediting applications that target mRNAs,viruses,chromatin structure,and other cellular processes.