Activation of plant immunity through conversion of a helper NLR homodimer into a resistosome.

Nucleotide-binding domain and leucine-rich repeat (NLR) proteins can engage in complex interactions to detect pathogens and execute a robust immune response via downstream helper NLRs. However, the biochemical mechanisms of helper NLR activation by upstream sensor NLRs remain poorly understood. Here, we show that the coiled-coil helper NLR NRC2 from Nicotiana benthamiana accumulates in vivo as a homodimer that converts into a higher-order oligomer upon activation by its upstream virus disease resistance protein Rx. The cryo-EM structure of NbNRC2 in its resting state revealed intermolecular interactions that mediate homodimer formation and contribute to immune receptor autoinhibition. These dimerization interfaces have diverged between paralogous NRC proteins to insulate critical network nodes and enable redundant immune pathways, possibly to minimise undesired cross-activation and evade pathogen suppression of immunity. Our results expand the molecular mechanisms of NLR activation pointing to transition from homodimers to higher-order oligomeric resistosomes.

Integrative analysis of the transcriptome and proteome reveals the molecular responses of tobacco to boron deficiency.

BACKGROUND: Boron (B) is an essential micronutrient for plants. Inappropriate B supply detrimentally affects the productivity of numerous crops. Understanding of the molecular responses of plants to different B supply levels would be of significance in crop improvement and cultivation practices to deal with the problem. RESULTS: We conducted a comprehensive analysis of the transcriptome and proteome of tobacco seedlings to investigate the expression changes of genes/proteins in response to different B supply levels, with a particular focus on B deficiency. The global gene and protein expression profiles revealed the potential mechanisms involved in the responses of tobacco to B deficiency, including up-regulation of the NIP5;1-BORs module, complex regulation of genes/proteins related to cell wall metabolism, and up-regulation of the antioxidant machinery. CONCLUSION: Our results demonstrated that B deficiency caused severe morphological and physiological disorders in tobacco seedlings, and revealed dynamic expression changes of tobacco genes/proteins in response to different B supply levels, especially to B deficiency, thus offering valuable insights into the molecular responses of tobacco to B deficiency.

Elevated pretreatment serum apolipoprotein E level associated with poor prognosis of patients with COVID-19 during the omicron BA.5 and BF.7 wave.

The SARS-CoV-2 virus is responsible for the human disease known as COVID-19. This virus is capable of generating a spectrum of infections ranging from moderate to severe. Serum apolipoprotein E (ApoE) inhibits inflammation by preserving immune regulatory function. Nonetheless, the relationship between serum ApoE and clinical prognosis in omicron remains elusive. A cohort of 231 patients was observed for 65 days, with death as the primary outcome. Based on their ApoE levels, the patients were categorized into patients with elevated ApoE levels and those with lower ApoE levels. To do statistical comparisons, the log-rank test was utilized, and the Kaplan-Meier method was utilized to estimate survival rates. Cox hazard models, both univariate and multivariate, were employed to examine the prognostic relevance. According to our research, omicron had significantly greater ApoE levels. In mild-to-moderate and severe cases, the study identified a statistically significant variation in ApoE levels. Additionally, there was a drop in overall survival that is statistically significant (OS, p < 0.0001) for patients with greater ApoE levels. Multiple Cox proportional hazards regression analysis indicates that an elevated ApoE level was determined to be an adverse and independent prognostic factor of OS in patients with omicron. Taken together, our study found that the level of serum ApoE at the time of initial diagnosis was substantially connected to the severity and prognosis of omicron. Consequently, we propose that ApoE might be a poor prognostic factor in individuals afflicted with the omicron variant.

Plant pathogens convergently evolved to counteract redundant nodes of an NLR immune receptor network.

In plants, nucleotide-binding domain and leucine-rich repeat (NLR)-containing proteins can form receptor networks to confer hypersensitive cell death and innate immunity. One class of NLRs, known as NLR required for cell death (NRCs), are central nodes in a complex network that protects against multiple pathogens and comprises up to half of the NLRome of solanaceous plants. Given the prevalence of this NLR network, we hypothesised that pathogens convergently evolved to secrete effectors that target NRC activities. To test this, we screened a library of 165 bacterial, oomycete, nematode, and aphid effectors for their capacity to suppress the cell death response triggered by the NRC-dependent disease resistance proteins Prf and Rpi-blb2. Among 5 of the identified suppressors, 1 cyst nematode protein and 1 oomycete protein suppress the activity of autoimmune mutants of NRC2 and NRC3, but not NRC4, indicating that they specifically counteract a subset of NRC proteins independently of their sensor NLR partners. Whereas the cyst nematode effector SPRYSEC15 binds the nucleotide-binding domain of NRC2 and NRC3, the oomycete effector AVRcap1b suppresses the response of these NRCs via the membrane trafficking-associated protein NbTOL9a (Target of Myb 1-like protein 9a). We conclude that plant pathogens have evolved to counteract central nodes of the NRC immune receptor network through different mechanisms. Coevolution with pathogen effectors may have driven NRC diversification into functionally redundant nodes in a massively expanded NLR network.

Elucidating the links between N2O dynamics and changes in microbial communities following saltwater intrusions.

Saltwater intrusion in estuarine ecosystems alters microbial communities as well as biogeochemical cycling processes and has become a worldwide problem. However, the impact of salinity intrusion on the dynamics of nitrous oxide (N2O) and associated microbial community are understudied. Here, we conducted field microcosms in a tidal estuary during different months (December, April and August) using dialysis bags, and microbes inside the bags encountered a change in salinity in natural setting. We then compared N2O dynamics in the microcosms with that in natural water. Regardless of incubation environment, saltwater intrusion altered the dissolved N2O depending on the initial saturation rates of N2O. While the impact of saltwater intrusion on N2O dynamics was consistent across months, the dissolved N2O was higher in summer than in winter. The N-related microbial communities following saltwater intrusion were dominated by denitrifers, with fewer nitrifiers and bacterial taxa involved in dissimilatory nitrate reduction to ammonium. While denitrification was a significant driver of N2O dynamics in the studied estuary, nitrifier-involved denitrification contributed to the additional production of N2O, evidenced by the strong associations with amoA genes and the abundance of Nitrospira. Higher N2O concentrations in the field microcosms than in natural water limited N2O consumption in the former, given the lack of an association with nosZ gene abundance. The differences in the N2O dynamics observed between the microcosms and natural water could be that the latter comprised not only indigenous microbes but also those accompanied with saltwater intrusion, and that immigrants might be functionally rich individuals and able to perform N transformation in multiple pathways. Our work provides the first quantitative assessment of in situ N2O concentrations in an estuary subjected to a saltwater intrusion. The results highlight the importance of ecosystem size and microbial connectivity in the source-sink dynamics of N2O in changing environments.

Spartina alterniflora invasion altered phosphorus retention and microbial phosphate solubilization of the Minjiang estuary wetland in southeastern China.

Spartina alterniflora invasion is considered a critical event affecting sediment phosphorus (P) availability and stock. However, P retention and microbial phosphate solubilization in the sediments invaded with or without S. alterniflora have not been fully investigated. In this study, a sequential fractionation method and high-throughput sequencing were used to analyze P transformation and the underlying microbial mechanisms in the sediments of no plant (NP) zone, transition (T) zone, and plant (P) zone. Results showed that except for organic phosphate (OP), total phosphate (TP), inorganic phosphate (IP), and available phosphate (AP) all followed a significant decrease trend from the NP site to the T site, and to the P site. The vertical decrease of TP, IP, and AP was also observed with an increase in soil depth. Among the six IP fractions, Fe-P, Oc-P, and Ca10-P were the predominant forms, while the presence of S. alterniflora resulted in an obvious P depletion except for Ca8-P and Al-P. Although S. alterniflora invasion did not significantly alter the alpha diversity of phosphate-solubilizing bacteria (PSB) harboring phoD gene, several PSB belonging to p_Proteobacteria, p_Planctomycetes, and p_Cyanobacteriota showed close correlations with P speciation and IP fractions. Further correlation analysis revealed that the reduced soil pH, soil TN and soil EC, and the increased soil TOC mediated by the invasion of S. alterniflora also significantly correlated to these PSB. Overall, this study elucidates the linkage between PSB and P speciation and provides new insights into understanding P retention and microbial P transformation in the coastal sediment invaded by S. alterniflora.

Lignin Degradation by Klebsiella aerogenes TL3 under Anaerobic Conditions.

Lignin, the largest non-carbohydrate component of lignocellulosic biomass, is also a recalcitrant component of the plant cell wall. While the aerobic degradation mechanism of lignin has been well-documented, the anaerobic degradation mechanism is still largely elusive. In this work, a versatile facultative anaerobic lignin-degrading bacterium, Klebsiella aerogenes TL3, was isolated from a termite gut, and was found to metabolize a variety of carbon sources and produce a single kind or multiple kinds of acids. The percent degradation of alkali lignin reached 14.8% under anaerobic conditions, and could reach 17.4% in the presence of glucose within 72 h. Based on the results of infrared spectroscopy and 2D nuclear magnetic resonance analysis, it can be inferred that the anaerobic degradation of lignin may undergo the cleavage of the C-O bond (ß-O-4), as well as the C-C bond (ß-5 and ß-ß), and involve the oxidation of the side chain, demethylation, and the destruction of the aromatic ring skeleton. Although the anaerobic degradation of lignin by TL3 was slightly weaker than that under aerobic conditions, it could be further enhanced by adding glucose as an electron donor. These results may shed new light on the mechanisms of anaerobic lignin degradation.

High-normal serum uric acid predicts macrovascular events in patients with type 2 diabetes mellitus without hyperuricemia based on a 10-year cohort.

BACKGROUND AND AIMS: The upper limits of normal serum uric acid (SUA) or the lower limits of hyperuricemia were frequently set at 420 or 360 µmol/L (7.0 or 6.0 mg/dL). We aimed to explore the association between high-normal SUA (360 ≤ SUA≤420 µmol/L) and incidence of macrovascular and renal events based on a 10-year cohort with type 2 diabetes mellitus (T2DM) to explore which cut-off was more appropriate. METHODS AND RESULTS: A total of 2988 patients with T2DM without hyperuricemia (SUA≤420 µmol/L) were included and followed up. Cox proportional hazards models and restricted cubic spline regression were used to evaluate the relationship between baseline SUA (as continuous and categorical variable) and macrovascular and renal events. Patients were grouped as low-normal (SUA<360 µmol/L) and high-normal groups based on baseline SUA, and the latter group had higher incidence of macrovascular events. Multivariate Cox regression analysis indicated that baseline levels of SUA were significantly associated with cardiovascular (HR = 1.385, 95%CI:1.190-1.613, P < 0.001) and peripheral vascular events (HR = 1.266, 95%CI:1.018-1.574, P = 0.034), and the linear association existed. Moreover, fully adjusted multivariable Cox analyses indicated high-normal SUA increased the risks of cardiovascular (HR = 1.835, 95%CI:1.319-2.554, P < 0.001) and peripheral vascular events (HR = 1.661, 95%CI:1.000-2.760, P = 0.050) compared to low-normal SUA. CONCLUSIONS: Baseline SUA levels were positively associated with cardiovascular and peripheral vascular events, and high-normal SUA increased the risks of these events in patients with T2DM even without hyperuricemia. A threshold value for SUA of 360 µmol/L should be more appropriate in terms of predicting macrovascular events risks compared to the value of 420 µmol/L.

Decolorization of reactive azo dye using novel halotolerant yeast consortium HYC and proposed degradation pathway.

The presence of high salinity levels in textile wastewater poses a significant obstacle to the process of decolorizing azo dyes. The present study involved the construction of a yeast consortium HYC, which is halotolerant and was recently isolated from wood-feeding termites. The consortium HYC was mainly comprised of Sterigmatomyces halophilus SSA-1575 and Meyerozyma guilliermondii SSA-1547. The developed consortium demonstrated a decolourization efficiency of 96.1% when exposed to a concentration of 50 mg/l of Reactive Black 5 (RB5). The HYC consortium significantly decolorized RB5 up to concentrations of 400 mg/l and in the presence of NaCl up to 50 g/l. The effects of physicochemical factors and the degradation pathway were systematically investigated. The optimal pH, salinity, temperature, and initial dye concentration were 7.0, 3%, 35 °C and 50 mg/l, respectively. The co-carbon source was found to be essential, and the addition of glucose resulted in a 93% decolorization of 50 mg/l RB5. The enzymatic activity of various oxido-reductases was assessed, revealing that NADH-DCIP reductase and azo reductase exhibited greater activity in comparison to other enzymes. UV-Visible (UV-vis) spectrophotometry, Fourier-transform infrared spectroscopy (FTIR), high-performance liquid chromatography (HPLC), and gas chromatography-mass spectrometry (GC-MS) were utilized to identify the metabolites generated during the degradation of RB5. Subsequently, a metabolic pathway was proposed. The confirmation of degradation was established through alterations in the functional groups and modifications in molecular weight. The findings indicate that this halotolerant yeast consortium exhibits promising potential of degrading dye compounds. The results of this study offer significant theoretical basis and crucial perspectives for the implementation of halotolerant yeast consortia in the bioremediation of textile and hypersaline wastewater. This approach is particularly noteworthy as it does not produce aromatic amines.

[Clinical characteristics and genetic analysis of four patients with central hypothyroidism due to IGSF1 gene variants].

OBJECTIVE: To explore the clinical manifestations and genetic characteristics of patients with congenital central hypothyroidism due to variants of IGSF1 gene. METHODS: Clinical data, results of genetic testing, and follow-up of four patients admitted to Children's Hospital of Soochow University during 2017 to 2021 were retrospectively analyzed. RESULTS: All of the four patients were males. Patient 1 had presented neonatal jaundice, patients 2 and 3 were admitted for growth retardation during childhood, and thyroid function test indicated slightly low free thyroxine (FT4), patient 4 was found to have reduced FT4 in the neonatal period. Genetic testing revealed that all of the four patients have harbored pathogenic variants of the IGSF1 gene, which were all inherited from their mothers. The thyroid functions in all patients were well controlled with oral levothyroxine and regular follow-up. CONCLUSION: Pathogenic variants of the IGSF1 gene probably underlay the congenital central hypothyroidism with a variety of clinical manifestations, and genetic testing can facilitate the diagnosis at an early stage.

The ZmMYB84-ZmPKSB regulatory module controls male fertility through modulating anther cuticle-pollen exine trade-off in maize anthers.

Anther cuticle and pollen exine are two crucial lipid layers that ensure normal pollen development and pollen-stigma interaction for successful fertilization and seed production in plants. Their formation processes share certain common pathways of lipid biosynthesis and transport across four anther wall layers. However, molecular mechanism underlying a trade-off of lipid-metabolic products to promote the proper formation of the two lipid layers remains elusive. Here, we identified and characterized a maize male-sterility mutant pksb, which displayed denser anther cuticle but thinner pollen exine as well as delayed tapetal degeneration compared with its wild type. Based on map-based cloning and CRISPR/Cas9 mutagenesis, we found that the causal gene (ZmPKSB) of pksb mutant encoded an endoplasmic reticulum (ER)-localized polyketide synthase (PKS) with catalytic activities to malonyl-CoA and midchain-fatty acyl-CoA to generate triketide and tetraketide α-pyrone. A conserved catalytic triad (C171, H320 and N353) was essential for its enzymatic activity. ZmPKSB was specifically expressed in maize anthers from stages S8b to S9-10 with its peak at S9 and was directly activated by a transcription factor ZmMYB84. Moreover, loss function of ZmMYB84 resulted in denser anther cuticle but thinner pollen exine similar to the pksb mutant. The ZmMYB84-ZmPKSB regulatory module controlled a trade-off between anther cuticle and pollen exine formation by altering expression of a series of genes related to biosynthesis and transport of sporopollenin, cutin and wax. These findings provide new insights into the fine-tuning regulation of lipid-metabolic balance to precisely promote anther cuticle and pollen exine formation in plants.

Decarbonylative/decarboxylative [4 + 2] annulation of phthalic anhydrides and cyclic iodoniums towards triphenylenes.

A palladium-catalyzed decarbonylative/decarboxylative [4 + 2] annulation of phthalic anhydrides with cyclic diaryliodonium salts to synthesize triphenylenes has been developed. The reaction shows broad substrate scope with a high yield of up to 99%, and it provides an efficient and fast way to access functionalized triphenylenes in only one hour.

High excellent hydrogen evolution characteristics and novel mechanism of two-dimensional tetra-phase OsN2 and ReN2.

It is essential to find a kind of electrocatalyst for hydrogen evolution reduction (HER) comparable with a noble metal that has good conductivity and abundant active sites. Based on systematic searches by first-principles calculations, we discovered two-dimensional transition-metal nitrides, tetra-phase OsN2 and ReN2 monolayers, as potential HER electrocatalysts with superior thermodynamic and kinetic stability. They exhibited excellent catalytic activity due to the presence of multiple active sites with a density of 8 × 1015 site per cm2 and an overpotential close to 0. In addition, we also found that the synergistic effect of strain and coverage makes them have a good hydrogen evolution activity. The ΔGH of the OsN2 monolayer at 1% tensile strain under 3/4 hydrogen coverage is 0.02 eV, and that of ReN2 at 1/2 hydrogen coverage could decrease to 0.001 eV. Different from other common transition metal nitrides, we found that the active sites of OsN2 and ReN2 monolayers are both at nitrogen atoms, which could be further understood by the crystal orbital Hamiltonian population analysis between N and metal atoms. All these interesting findings not only provide new excellent candidates but also provide new insights into the mechanism of hydrogen evolution of nitrides.

Arabinan hydrolysis by GH43 enzymes of Hungateiclostridium clariflavum and the potential synergistic mechanisms.

Glycoside hydrolase family 43 (GH43) represents a major source of arabinan- and arabinoxylan-active enzymes. Interestingly, some microbes remarkably enriched GH genes of this family, with the reason unknown. Hungateiclostridium clariflavum DSM 19,732 is an efficient lignocellulose degrader, which harbors up to 7 GH43 genes in its genome. We cloned three of the seven GH43 genes, and found that Abn43A is a unique endoarabinanase, which unprecedently showed approximately two times larger activity on sugar beet arabinan (116.8 U/mg) than that on linear arabinan, and it is efficient in arabinooligosaccharide production. Abn43B is an exoarabinanase which directly releases arabinose from linear arabinan. Abn43C is an α-L-arabinofuranosidase which is capable of splitting the arabinose side-chains from arabinooligosaccharides, arabinoxylooligosaccharides, and arabinoxylan. Most importantly, the three GH43 enzymes synergized in hydrolyzing arabinan. Compared to Abn43B alone, a supplement of Abn43A increased the arabinose production from linear arabinan by 150%, reaching 0.44 g/g arabinan. Moreover, an addition of Abn43C to Abn43A and Abn43B boosted the arabinose production from sugar beet arabinan by 15 times, reaching 0.262 g/g arabinan. Our work suggested the intensified functions of multiple GH43 enzymes toward arabinan degradation in H. clariflavum, and a potential synergetic mechanism among the three GH43 enzymes is suggested. KEY POINTS: • Endoarabinanase GH43A prefers branched substrate to linear one • Exoarabinanase GH43B can directly release arabinose from linear arabinan • The three GH43 enzymes synergized in arabinan hydrolysis.

Whole-exome sequencing in diagnosing 2 cases of Gitelman syndrome. / å ¨å¤–æ˜¾å­ç»„æµ‹åºè¯Šæ–­2例Gitelman综合征.

Two patients with Gitelman syndrome were admitted to the Department of Endocrinology, Third Xiangya Hospital of Central South University. The genomic DNA from the patients' peripheral blood was extracted and the whole-exome sequencing was performed to detect the possible mutations. The function of the mutation sites was analyzed by bioinformatics software. Through whole-exome sequencing and Sanger sequencing, we have found that 2 patients with Gitelman syndrome carried compound heterozygous mutations of SLC12A3 gene, which were c.486_490delTACGGinsA, p.R943W, p.D486N, and p.R928C. Among them, c.486_490delTACGGinsA insertion deletion mutation causes frame shift and protein truncation. The p.R943W, p.D486N, and p.R928C of SLC12A3 gene were predicted to be pathogenic mutations by SIFT, PolyPhen2, and Mutation Taster. These 4 mutations were all reported, but p.R943W was first reported in Chinese population. Gitelman syndrome is rare in clinic and the rate of missed diagnosis is high. Early genetic analysis in patients with Gitelman syndrome is helpful to determine the etiology and guide the treatment.

KCNH6 protects pancreatic ß-cells from endoplasmic reticulum stress and apoptosis.

Adult patients with dysfunction in human ether-a-go-go 2 (hERG2) protein, encoded by KCNH6, present with hypoinsulinemia and hyperglycemia. However, the mechanism of KCNH6 action in glucose disorders has not been clearly defined. Previous studies identified that sustained endoplasmic reticulum (ER) stress-mediated apoptosis of pancreatic ß-cells and directly contributed to diabetes. In the present study, we showed that Kcnh6 knockout (KO) mice had impaired glucose tolerance mediated by high ER stress levels, and showed increased apoptosis and elevated intracellular calcium levels in pancreatic ß-cells. In contrast, KCNH6 overexpression in islets isolated from C57BL/6J mice attenuated ER stress induced by thapsigargin or palmitic acid. This effect contributed to better preservation of ß-cells, as reflected in increased ß cell survival and enhanced glucose-stimulated insulin secretion. These results were further corroborated by studies evaluating KCNH6 overexpression in KO islets. Similarly, induction of Kcnh6 in KO mice by lentivirus injection improved glucose tolerance by reducing pancreatic ER stress and apoptosis. Our data provide new insights into how Kcnh6 deficiency causes ER calcium depletion and ß cell dysfunction.

Heterozygous PAX6 mutations may lead to hyper-proinsulinaemia and glucose intolerance: A case-control study in families with congenital aniridia.

AIM: PAX6 is a transcription factor involved in embryonic development of many organs, including the eyes and the pancreas. Mutations of PAX6 gene is the main cause of a rare disease, congenital aniridia (CA). This case-control study aims to investigate the effects of PAX6 mutations on glucose metabolism and insulin secretion in families with CA. METHODS: In all, 21 families with CA were screened by Sanger sequencing. Patients with PAX6 mutations and CA (cases) and age-matched healthy family members (controls) were enrolled. Oral glucose tolerance test (OGTT) was performed to detect diabetes or impaired glucose tolerance (IGT). Insulin and proinsulin secretion were evaluated. RESULTS: Among 21 CA families, heterozygous PAX6 mutations were detected in five families. Among cases (n = 10) from the five families, two were diagnosed with newly identified diabetes and another two were diagnosed with IGT. Among controls (n = 12), two had IGT. The levels of haemoglobin A1c were 36 ± 4 mmol/mol (5.57 ± 0.46%) and 32 ± 5 mmol/L (5.21 ± 0.54%) in the cases and the controls, respectively (p = 0.049). More importantly, levels of proinsulin in the cases were significantly higher than that of the controls, despite similar levels of total insulin. The areas under the curve of proinsulin in the cases (6425 ± 4390) were significantly higher than that of the controls (3709 ± 1769) (p = 0.032). CONCLUSION: PAX6 may participate in the production of proinsulin to insulin and heterozygous PAX6 mutations may be associated with glucose metabolism in CA patients.

Two-dimensional Weyl semi-half-metallic NiCS3 with a band structure controllable by the direction of magnetization.

Two-dimensional (2D) Weyl semi-half-metals (WSHMs) have attracted tremendous interest for their fascinating properties combining half-metallic ferromagnetism and Weyl fermions. In this work, we present a NiCS3 monolayer as a new 2D WSHM material using systematic first-principles calculations. It has 12 fully spin-polarized Weyl nodal points in one spin channel with a Fermi velocity of 3.18 × 105 m s-1 and a fully gapped band structure in the other spin channel. It exhibits good mechanical and thermodynamic stabilities and the Curie temperature is estimated to be 403 K. The Weyl points are protected by vertical mirror plane symmetry along Γ-K, and each of them remains gapless even under spin-orbit coupling when the direction of spin is perpendicular to the Γ-K line including the Weyl point, which makes it possible to control the opening and closing of Weyl points by applying and rotating external magnetic fields. Our work not only provides a promising 2D WSHM material to explore the fundamental physics of symmetry protected ferromagnetic Weyl fermions, but also reveals a potential mechanism of band engineering of 2D WSHM materials in spintronics.

ZmFAR1 and ZmABCG26 Regulated by microRNA Are Essential for Lipid Metabolism in Maize Anther.

The function and regulation of lipid metabolic genes are essential for plant male reproduction. However, expression regulation of lipid metabolic genic male sterility (GMS) genes by noncoding RNAs is largely unclear. Here, we systematically predicted the microRNA regulators of 34 maize white brown complex members in ATP-binding cassette transporter G subfamily (WBC/ABCG) genes using transcriptome analysis. Results indicate that the ZmABCG26 transcript was predicted to be targeted by zma-miR164h-5p, and their expression levels were negatively correlated in maize B73 and Oh43 genetic backgrounds based on both transcriptome data and qRT-PCR experiments. CRISPR/Cas9-induced gene mutagenesis was performed on ZmABCG26 and another lipid metabolic gene, ZmFAR1. DNA sequencing, phenotypic, and cytological observations demonstrated that both ZmABCG26 and ZmFAR1 are GMS genes in maize. Notably, ZmABCG26 proteins are localized in the endoplasmic reticulum (ER), chloroplast/plastid, and plasma membrane. Furthermore, ZmFAR1 shows catalytic activities to three CoA substrates in vitro with the activity order of C12:0-CoA > C16:0-CoA > C18:0-CoA, and its four key amino acid sites were critical to its catalytic activities. Lipidomics analysis revealed decreased cutin amounts and increased wax contents in anthers of both zmabcg26 and zmfar1 GMS mutants. A more detailed analysis exhibited differential changes in 54 monomer contents between wild type and mutants, as well as between zmabcg26 and zmfar1. These findings will promote a deeper understanding of miRNA-regulated lipid metabolic genes and the functional diversity of lipid metabolic genes, contributing to lipid biosynthesis in maize anthers. Additionally, cosegregating molecular markers for ZmABCG26 and ZmFAR1 were developed to facilitate the breeding of male sterile lines.

[Clinical and genetic analysis of five Chinese pedigrees affected with short stature due to variants of ACAN gene].

OBJECTIVE: To analyze the clinical and genetic characteristics of five Chinese pedigrees affected with short stature. METHODS: A retrospective analysis was carried out for the clinical data and results of genetic testing for the probands. A literature search was also conducted. RESULTS: The five probands have all featured short stature with a family history. Genetic testing has revealed that they have harbored variants of the ACAN gene, including p.Val2042Argfs*6, p.Val1597del, c.630-1G>A, c.23delT and c.2026+1G>A(previously reported). CONCLUSION: Except for short stature, children harboring heterozygous variants of the ACAN gene may have no involvement of other systems. Some of these children may response to short-term growth hormone treatment.