Advances in Catalysts for Urea Electrosynthesis Utilizing CO2 and Nitrogenous Materials: A Mechanistic Perspective.

Electrocatalytic urea synthesis from CO2 and nitrogenous substances represents an essential advance for the chemical industry, enabling the efficient utilization of resources and promoting sustainable development. However, the development of electrocatalytic urea synthesis has been severely limited by weak chemisorption, poor activation and difficulties in C-N coupling reactions. In this review, catalysts and corresponding reaction mechanisms in the emerging fields of bimetallic catalysts, MXenes, frustrated Lewis acid-base pairs and heterostructures are summarized in terms of the two central mechanisms of molecule-catalyst interactions as well as chemical bond cleavage and directional coupling, which provide new perspectives for improving the efficiency of electrocatalytic synthesis of urea. This review provides valuable insights to elucidate potential electrocatalytic mechanisms.

Transcriptional and translational landscape fine-tune genome annotation and explores translation control in cotton.

INTRODUCTION: The unavailability of intergenic region annotation in whole genome sequencing and pan-genomics hinders efforts to enhance crop improvement. OBJECTIVES: Despite advances in research, the impact of post-transcriptional regulation on fiber development and translatome profiling at different stages of fiber growth in cotton (G. hirsutum) remains unexplored. METHODS: We utilized a combination of reference-guided de novo transcriptome assembly and ribosome profiling techniques to uncover the hidden mechanisms of translational control in eight distinct tissues of upland cotton. RESULTS: Our study identified P-site distribution at three-nucleotide periodicity and dominant ribosome footprint at 27 nucleotides. Specifically, we have detected 1,589 small open reading frames (sORFs), including 1,376 upstream ORFs (uORFs) and 213 downstream ORFs (dORFs), as well as 552 long non-coding RNAs (lncRNAs) with potential coding functions, which fine-tune the annotation of the cotton genome. Further, we have identified novel genes and lncRNAs with strong translation efficiency (TE), while sORFs were found to affect mRNA transcription levels during fiber elongation. The reliability of these findings was confirmed by the high consistency in correlation and synergetic fold change between RNA-sequencing (RNA-seq) and Ribosome-sequencing (Ribo-seq) analyses. Additionally, integrated omics analysis of the normal fiber ZM24 and short fiber pag1 cotton mutant revealed several differentially expressed genes (DEGs), and fiber-specific expressed (high/low) genes associated with sORFs (uORFs and dORFs). These findings were further supported by the overexpression and knockdown of GhKCS6, a gene associated with sORFs in cotton, and demonstrated the potential regulation of the mechanism governing fiber elongation on both the transcriptional and post-transcriptional levels. CONCLUSION: Reference-guided transcriptome assembly and the identification of novel transcripts fine-tune the annotation of the cotton genome and predicted the landscape of fiber development. Our approach provided a high-throughput method, based on multi-omics, for discovering unannotated ORFs, hidden translational control, and complex regulatory mechanisms in crop plants.

Effect of perioperative application of dexmedetomidine on post-operative stress reaction, pain and prognostic adverse effects in patients undergoing gynaecological laparoscopy.

Introduction: The aim of this study was to analyse the effect of perioperative dexmedetomidine (DEX) application on stress response, post-operative pain and prognosis in patients undergoing gynaecologic laparoscopy. Patients and Methods: One hundred and sixty-eight patients admitted for gynaecologic laparoscopic surgery from May 2020 to November 2022 were included in the study. The patients were randomly divided into pre-operative DEX group (n = 56), intraoperative DEX group (n = 56) and post-operative DEX group (n = 56) according to the application of DEX in the perioperative period. The visual analogue scale (VAS), time awake, extubation time, pneumoperitoneum time, post-anaesthesia care unit (PACU) stay time and Richmond agitation-sedation scale score (RASS) were recorded. Results: Patients in both the pre-operative and intraoperative DEX groups had substantially shorter wakeup and extubation times than those in the post-operative DEX group. Patients in the pre-operative DEX group had considerably shorter wakeup and extubation times than those in the intraoperative DEX group, and their pneumoperitoneum time was significantly shorter than that of the post-operative DEX group (P < 0.001). The RASS scores of the pre-operative DEX group and intraoperative DEX group were significantly lower than those of the post-operative DEX group at 1 h, 6 h and 12 h after surgery. Meanwhile, at all time periods, the RASS scores of patients in the pre-operative DEX group were considerably lower than those in the intraoperative DEX group (P < 0.01). The VAS scores of patients in the pre-operative DEX group and intraoperative DEX group were evidently lower than those in the post-operative DEX group at 0.5 h, 2 h and 12 h postoperatively, and the VAS scores of patients in the pre-operative DEX group were markedly lower than those in the intraoperative DEX group (P < 0.001). The incidence of nausea and vomiting was significantly lower in the pre-operative DEX group than in the intraoperative DEX group and the post-operative DEX group at 0-2 h, >2-12 h and >12-24 h postoperatively (P < 0.001). The incidence of nausea and vomiting in the intraoperative DEX group was significantly lower than that in the post-operative DEX group from 0 to 2 h after surgery (P < 0.05). The incidence of adverse reactions was not significantly different amongst the three groups of patients (P > 0.05). Conclusion: Pre-operative and intraoperative application of DEX can help reduce post-operative pain and stress responses, help patients recover quickly after surgery and improve patient prognosis, especially the pre-operative application of DEX.

Intraoperative use of tranexamic acid to reduce blood loss during cytoreductive surgery for advanced ovarian cancer: A randomized controlled clinical trial.

INTRODUCTION: Tranexamic acid reduces blood loss and allogeneic transfusion requirements in various surgical procedures. The role of tranexamic acid during cytoreductive procedures in advanced ovarian cancer is not clear. MATERIAL AND METHODS: This was a single center randomized, controlled, three-armed clinical trial. A total of 150 ovarian cancer patients undergoing cytoreductive surgery were recruited and assigned to three groups (n = 50/group): the control group (normal saline), low-dose group (10 mg/kg bolus + 1 mg/kg continuous infusion of tranexamic acid), and high-dose group (20 mg/kg bolus + 5 mg/kg continuous infusion of tranexamic acid). The primary endpoint was intraoperative blood loss volume and total blood loss volume, and secondary endpoints included intraoperative blood transfusion volumes, vasoactive agent consumption, admission into the intensive care unit, and incidence of postoperative complications within postoperative 30 days. The study was registered at ClinicalTrials.gov ID: NCT04360629. RESULTS: The patients in the high-dose group had less intraoperative (median [IQR]: 625.3 mL [343.5-1210.5]) and total blood loss volume (748.9 mL [292.2-1650.2]) than those in the control group (1015.5 mL [679.4-1015.5], p = 0.012; and 1700.7 mL [458.7-2419.8], p = 0.004, respectively). In contrast, the intraoperative (992.5 mL [539.0-1404.0], p = 0.874) and total blood loss volume (1025.0 mL [381.8-1819.9], p = 0.113) was not significantly reduced in the low-dose group when compared with the control group. Correspondingly, the relative risk of blood transfusion (RR [95% CI], 0.405 [0.180-0.909], p = 0.028) was reduced in the high-dose group and required less intraoperative noradrenaline (881.0 ± 438.3 mg) to maintain stable hemodynamics than the control group (1548.0 ± 349.8 mg, p = 0.001). Furthermore, compared with the control group, the two tranexamic acid groups had decreased intensive care unit admission rates (p = 0.016) without increasing the incidence of postoperative seizure, acute kidney injury, and thromboembolism. CONCLUSIONS: High-dose tranexamic acid is more effective in reducing blood loss and blood transfusion without increasing the risk of postoperative complications. The high-dose regime tended to have a better risk-benefit profile.

The Capparis spinosa var. herbacea genome provides the first genomic instrument for a diversity and evolution study of the Capparaceae family.

BACKGROUND: The caper bush Capparis spinosa L., one of the most economically important species of Capparaceae, is a xerophytic shrub that is well adapted to drought and harsh environments. However, genetic studies on this species are limited because of the lack of its reference genome. FINDINGS: We sequenced and assembled the Capparis spinosa var. herbacea (Willd.) genome using data obtained from the combination of PacBio circular consensus sequencing and high-throughput chromosome conformation capture. The final genome assembly was approximately 274.53 Mb (contig N50 length of 9.36 Mb, scaffold N50 of 15.15 Mb), 99.23% of which was assigned to 21 chromosomes. In the whole-genome sequence, tandem repeats accounted for 19.28%, and transposable element sequences accounted for 43.98%. The proportion of tandem repeats in the C. spinosa var. herbacea genome was much higher than the average of 8.55% in plant genomes. A total of 21,577 protein-coding genes were predicted, with 98.82% being functionally annotated. The result of species divergence times showed that C. spinosa var. herbacea and Tarenaya hassleriana separated from a common ancestor 43.31 million years ago. CONCLUSIONS: This study reported a high-quality reference genome assembly and genome features for the Capparaceae family. The assembled C. spinosa var. herbacea genome might provide a system for studying the diversity, speciation, and evolution of this family and serve as an important resource for understanding the mechanism of drought and high-temperature resistance.

Systematic analysis of CNGCs in cotton and the positive role of GhCNGC32 and GhCNGC35 in salt tolerance.

BACKGROUND: Cyclic nucleotide-gated ion channels (CNGCs) are calcium-permeable channels that participate in a variety of biological functions, such as signaling pathways, plant development, and environmental stress and stimulus responses. Nevertheless, there have been few studies on CNGC gene family in cotton. RESULTS: In this study, a total of 114 CNGC genes were identified from the genomes of 4 cotton species. These genes clustered into 5 main groups: I, II, III, IVa, and IVb. Gene structure and protein motif analysis showed that CNGCs on the same branch were highly conserved. In addition, collinearity analysis showed that the CNGC gene family had expanded mainly by whole-genome duplication (WGD). Promoter analysis of the GhCNGCs showed that there were a large number of cis-acting elements related to abscisic acid (ABA). Combination of transcriptome data and the results of quantitative RT-PCR (qRT-PCR) analysis revealed that some GhCNGC genes were induced in response to salt and drought stress and to exogenous ABA. Virus-induced gene silencing (VIGS) experiments showed that the silencing of the GhCNGC32 and GhCNGC35 genes decreased the salt tolerance of cotton plants (TRV:00). Specifically, physiological indexes showed that the malondialdehyde (MDA) content in gene-silenced plants (TRV:GhCNGC32 and TRV:GhCNGC35) increased significantly under salt stress but that the peroxidase (POD) activity decreased. After salt stress, the expression level of ABA-related genes increased significantly, indicating that salt stress can trigger the ABA signal regulatory mechanism. CONCLUSIONS: we comprehensively analyzed CNGC genes in four cotton species, and found that GhCNGC32 and GhCNGC35 genes play an important role in cotton salt tolerance. These results laid a foundation for the subsequent study of the involvement of cotton CNGC genes in salt tolerance.

Bifidobacterium longum relieves constipation by regulating the intestinal barrier of mice.

Constipation is a major health concern worldwide, requiring effective and safe treatment options. This study mainly focused on three species and nine strains of bifidobacteria from different sources to study their abilities to relieve constipation induced by loperamide in BALB/C mice. By monitoring constipation-related indicators, it was found that only Bifidobacterium longum (B. longum) relieved constipation, which indicated that bifidobacteria had inter-species differences in relieving constipation. Furthermore, through the detection of biological, chemical, mechanical, and immune barriers in mice, it was discovered that B. longum upregulates the relative abundance of 22 genera that were positively related to faecal water content, small intestinal propulsion rate, acetate, propionate, and intestinal mechanical barrier and negatively correlated with inflammatory factors, AQP8 and the time of first black stool and downregulates the relative abundance of Akkermansia. Furthermore, it increased the level of acetate in faeces and reduced the expression of AQP8 in the colon. This enhances intestinal motility and improves water and electrolyte metabolism. Meanwhile, it inhibited inflammation and prevented loperamide-induced intestinal barrier damage in constipated mice by upregulating occludin and downregulating IL-1ß and TNF-α. In summary, B. longum relieved constipation by regulating the intestinal barrier in constipated mice.

GRAND: An Integrated Genome, Transcriptome Resources, and Gene Network Database for Gossypium.

With the increasing amount of cotton omics data, breeding scientists are confronted with the question of how to use massive cotton data to mine effective breeding information. Here, we construct a Gossypium Resource And Network Database (GRAND), which integrates 18 cotton genome sequences, genome annotations, two cotton genome variations information, and also four transcriptomes for Gossypium species. GRAND allows to explore and mine this data with the help of a toolbox that comprises a flexible search system, BLAST and BLAT suite, orthologous gene ID, networks of co-expressed genes, primer design, Gbrowse and Jbrowse, and drawing instruments. GRAND provides important information regarding Gossypium resources and hopefully can accelerate the progress of cultivating cotton varieties.

Genome sequence and transcriptome of Sorbus pohuashanensis provide insights into population evolution and leaf sunburn response.

Sorbus pohuashanensis (Hance) Hedl. is a potential horticulture and medicinal plant, but its genomic and genetic backgrounds remain unknown. Here, we sequence and assemble the S. pohuashanensis reference genome using PacBio long reads. Based on the new reference genome, we resequence a core collection of 22 Sorbus spp. samples, which are divided into 2 groups (G1 and G2) based on phylogenetic and PCA analyses. These phylogenetic clusters are highly consistent with their classification based on leaf shape. Natural hybridization between the G1 and G2 groups is evidenced by a sample (R21) with a highly heterozygous genotype. Nucleotide diversity (π) analysis shows that G1 has a higher diversity than G2 and that G2 originated from G1. During the evolution process, the gene families involved in photosynthesis pathways expanded and the gene families involved in energy consumption contracted. RNA-seq data suggests that flavonoid biosynthesis and heat-shock protein (HSP)-heat-shock factor (HSF) pathways play important roles in protection against sunburn. This study provides new insights into the evolution of Sorbus spp. genomes. In addition, the genomic resources, and the identified genetic variations, especially those related to stress resistance, will help future efforts to produce and breed Sorbus spp.

Different Bifidobacterium bifidum strains change the intestinal flora composition of mice via different mechanisms to alleviate loperamide-induced constipation.

Constipation is a condition with a high prevalence rate worldwide and may occur in men and women of any age. Bifidobacterium bifidum has been shown to have a relieving effect on constipation, but the underlying mechanism is still unknown. This study explored the effects of gavage of three strains of B. bifidum (CCFM668, FHNFQ25M12 and FXJCJ32M2) from different sources in mice with loperamide-induced constipation. After 38 days of intervention, B. bifidum CCFM668, FHNFQ25M12 and FXJCJ32M2 showed the ability to modify the levels of gastrointestinal active peptides and promote the expression of 5-hydroxytryptamine (5-HT or serotonin) receptor 4 (5-HT4R), thereby promoting small intestinal peristalsis. The strains could also effectively increase the thickness of the colonic mucosa. However, what was different from previous studies was that these results were independent of the levels of short-chain fatty acids (SCFAs) and 5-HT. Further analysis of the intestinal flora revealed that the relative abundances of the genera Faecalibaculum and Ruminococcaceae_UCG_014 in the constipated mice increased significantly, whereas that of Erysipelatoclostridium decreased. A correlation analysis between the intestinal flora and evaluated gastrointestinal indicators demonstrated that the relative abundances of the genera Anaerotruncus, Angelakisella, Erysipelatoclostridium and Ruminococcaceae_UCG_014 were negatively correlated with the levels of gastrointestinal active peptides. B. bifidum FXJCJ32M2 can increase the relative abundances of Turicibacter and Dubosiella, and this was positively correlated with the expression of aquaporin 8 and vasoactive intestinal peptide receptor 1 but could not effectively alleviate faecal dryness or promote colonic motility. These findings suggest that B. bifidum shows significant intraspecific differences in the remission mechanism and provides a theoretical basis for subsequent population experiments and personalised treatment for constipation.

Maize microRNA166 Inactivation Confers Plant Development and Abiotic Stress Resistance.

MicroRNAs are important regulators in plant developmental processes and stress responses. In this study, we generated a series of maize STTM166 transgenic plants. Knock-down of miR166 resulted in various morphological changes, including rolled leaves, enhanced abiotic stress resistance, inferior yield-related traits, vascular pattern and epidermis structures, tassel architecture, as well as abscisic acid (ABA) level elevation and indole acetic acid (IAA) level reduction in maize. To profile miR166 regulated genes, we performed RNA-seq and qRT-PCR analysis. A total of 178 differentially expressed genes (DEGs) were identified, including 118 up-regulated and 60 down-regulated genes. These DEGs were strongly enriched in cell and intercellular components, cell membrane system components, oxidoreductase activity, single organism metabolic process, carbohydrate metabolic process, and oxidation reduction process. These results indicated that miR166 plays important roles in auxin and ABA interaction in monocots, yet the specific mechanism may differ from dicots. The enhanced abiotic stress resistance is partly caused via rolling leaves, high ABA content, modulated vascular structure, and the potential changes of cell membrane structure. The inferior yield-related traits and late flowering are partly controlled by the decreased IAA content, the interplay of miR166 with other miRNAs and AGOs. Taken together, the present study uncovered novel functions of miR166 in maize, and provide insights on applying short tandem target mimics (STTM) technology in plant breeding.

MicroRNA1917-CTR1-LIKE PROTEIN KINASE 4 impacts fruit development via tuning ethylene synthesis and response.

MicroRNA1917 (miR1917) is a newly identified miRNAs that regulate ethylene responses in tomato. However, evidence is still limited about its functions in fruit development and ripening. Here, we investigated the possible roles of miR1917-SlCTR4 module in tomato fruit development. We generated miR1917 knock-down mutants by expressing Short Tandem Target Mimic (STTM1917). qRT-PCR and northern-blot analyses suggested that the expression of miR1917 are down-regulated in STTM1917. Concomitantly, miR1917-targeted SlCTR4 gene was up-regulated. STTM1917 plants showed a series of developmental phenotypes, including larger biomass, longer terminal leaflet, bigger floral organ and enhanced fruit and seed size. RNA-seq and qRT-PCR analyses suggested that the expression levels of numerous miRNAs and genes in the transgenic line were significantly altered compared to the wild type. These miRNAs and genes include fruit development-related miRNAs, fruit ripening-related transcription factors and ethylene metabolism genes. Altogether, our results demonstrated that working in concert with ripening regulators, miR1917 might regulate multiple genes in ethylene pathway, thereby modulating fruit development. Our results further indicated that fine-tuning miRNAs expression via STTM can be deployed for agronomic improvement of tomato.

Dissecting the Regulatory Network of Leaf Premature Senescence in Maize (Zea mays L.) Using Transcriptome Analysis of ZmELS5 Mutant.

Leaf premature senescence largely determines maize (Zea mays L.) grain yield and quality. A natural recessive premature-senescence mutant was selected from the breeding population, and near-isogenic lines were constructed using Jing24 as the recurrent parent. In the near-isogenic lines, the dominant homozygous material was wild-type (WT), and the recessive material of early leaf senescence was the premature-senescence-type ZmELS5. To identify major genes and regulatory mechanisms involved in leaf senescence, a transcriptome analysis of the ZmELS5 and WT near-isogenic lines (NILs) was performed. A total of 8,796 differentially expressed transcripts were identified between ZmELS5 and WT, including 3,811 up-regulated and 4,985 down-regulated transcripts. By combining gene ontology, Kyoto Encyclopedia of Genes and Genomes, gene set, and transcription factor enrichment analyses, key differentially expressed genes were screened. The senescence regulatory network was predicted based on these key differentially expressed genes, which indicated that the senescence process is mainly regulated by bHLH, WRKY, and AP2/EREBP family transcription factors, leading to the accumulations of jasmonic acid and ethylene. This causes stress responses and reductions in the chlorophyll a/b-binding protein activity level. Then, decreased ATP synthase activity leads to increased photosystem II photodamage, ultimately leading to leaf senescence.

Effect of vitamin B12 on cleft palate induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin and dexamethasone in mice.

The purpose of this study was to investigate the effect of vitamin B12 on palatal development by co-administration of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and dexamethasone (DEX). We examined the morphological and histological features of the palatal shelf and expression levels of key signaling molecules (transforming growth factor-ß3 (TGF-ß3) and TGF-ß type I receptor (activin receptor-like kinase 5, ALK5)) during palatogenesis among a control group (Group A), TCDD+DEX exposed group (Group B), and TCDD+DEX+vitamin B12 exposed group (Group C). While we failed to find that vitamin B12 decreased the incidence of cleft palate induced by TCDD+DEX treatment, the expression levels of key signaling molecules (TGF-ß3 and ALK5) during palatogenesis were significantly modulated. In TCDD+DEX exposed and TCDD+DEX+vitamin B12 exposed groups, palatal shelves could not contact in the midline due to their small sizes. Our results suggest that vitamin B12 may inhibit the expression of some cleft palate inducers such as TGF-ß3 and ALK5 in DEX+TCDD exposed mice, which may be beneficial against palatogenesis to some degree, even though we were unable to observe a protective role of vitamin B12 in morphological and histological alterations of palatal shelves induced by DEX and TCDD.

The immune response of a recombinant fowlpox virus coexpressing the HA gene of the H5N1 highly pathogenic avian influenza virus and chicken interleukin 6 gene in ducks.

Ducks have played an important role in the emergence of H5N1 subtype of highly pathogenic avian influenza (HPAI), and the development of an effective vaccine against HPAI in ducks is a top priority. It has been shown that a recombinant fowlpox virus (FPV)-vectored vaccine can provide protection against HPAI in ducks. In this study, a recombinant fowlpox virus (rFPV-AIH5AIL6) coexpressing the haemagglutinin (HA) gene of the H5N1 subtype of the avian influenza virus (AIV) and chicken interleukin 6 gene was constructed and tested in Gaoyou and cherry valley ducks to evaluate the immune response in ducks. These animal studies demonstrated that rFPV-AIH5AIL6 induced a higher anti-AIV HI antibody response, an enhanced lymphocyte proliferation response, an elevated immune protection, and a reduction in virus shedding compared to a recombinant fowlpox virus expressing the HA gene alone (rFPV-SYHA). These data indicate that rFPV-AIH5AIL6 may be a potential vaccine against the H5 subtype of avian influenza in ducks and chicken interleukin 6 may be an effective adjuvant for increasing the immunogenicity of FPV-vectored AIV vaccines in ducks.

[The preliminary study on transforming growth factor-beta 3, activin receptor-like kinase 5 expression in 2, 3, 7, 8-tetrachloro-p-dibenzodioxin and dexamethasone induced palatal cleft in mice].

OBJECTIVE: To establish a good animal model of cleft palate and confirm whether 2, 3, 7, 8-tetrachloro-p-dibenzodioxin (TCDD) and Dexamethasone (DEX) induced palatal cleft in mice is related to the fold change of transforming growth factor-beta 3 (TGF-beta3) and activin receptor-like kinase 5 (Alk5). METHODS: Pregnant mice were treated with oral medication of TCDD and intraperitoneal injection with DEX on GD10-12 in experimental group while the control group without any treatment. Then embryos were examined on GD17.5 under stereomicroscope for calculating the incidence of cleft palate and palatal shelves were dissected from the staged embryos respectively for RNA extraction on GD13.5, GD14.5 and GD15.5. At last the real-time PCR and SYBR Green I detection were used for RNA relative quantification. RESULTS: Cleft palate could be induced 100% in C57BL/6J fetal mice with TCDD and DEX, thus established a stable animal model for further molecular studies of cleft palate. There were no significant difference in expression level of TGF-beta3 and Alk5 on GD13.5 among the groups, but the differences were statistically significant on GD14.5 and GD15.5 (P < 0.05). On the contrary, the expression level of Alk5 were significantly higher in experimental group (P < 0.05). CONCLUSION: Combined effects of TCDD and DEX could induce a stable formation of cleft palate and down-regulated mRNA of TGF-beta3 and up-regulated Alk5 may contribute to the occurrence of cleft palate.

Tomato protein kinase 1b mediates signaling of plant responses to necrotrophic fungi and insect herbivory.

The tomato protein kinase 1 (TPK1b) gene encodes a receptor-like cytoplasmic kinase localized to the plasma membrane. Pathogen infection, mechanical wounding, and oxidative stress induce expression of TPK1b, and reducing TPK1b gene expression through RNA interference (RNAi) increases tomato susceptibility to the necrotrophic fungus Botrytis cinerea and to feeding by larvae of tobacco hornworm (Manduca sexta) but not to the bacterial pathogen Pseudomonas syringae. TPK1b RNAi seedlings are also impaired in ethylene (ET) responses. Notably, susceptibility to Botrytis and insect feeding is correlated with reduced expression of the proteinase inhibitor II gene in response to Botrytis and 1-aminocyclopropane-1-carboxylic acid, the natural precursor of ET, but wild-type expression in response to mechanical wounding and methyl-jasmonate. TPK1b functions independent of JA biosynthesis and response genes required for resistance to Botrytis. TPK1b is a functional kinase with autophosphorylation and Myelin Basis Protein phosphorylation activities. Three residues in the activation segment play a critical role in the kinase activity and in vivo signaling function of TPK1b. In sum, our findings establish a signaling role for TPK1b in an ET-mediated shared defense mechanism for resistance to necrotrophic fungi and herbivorous insects.

AtMTM1, a novel mitochondrial protein, may be involved in activation of the manganese-containing superoxide dismutase in Arabidopsis.

Mtm1p is essential for the posttranslational activation of manganese-containing superoxide dismutase (SOD2) in Saccharomyces cerevisiae; however, whether the same holds true for Arabidopsis thaliana is unknown. In this study, by using the yeast mtm1 mutant complementation method, we identified a putative MTM gene (AtMTM1, At4g27940) that is necessary for SOD2 activation. Further, analysis of SOD activity revealed that an SOD2 defect is rescued in the yeast mutant Y07288 harboring the AtMTM1 gene. Related mRNA-level analysis showed the AtMTM1 gene is induced by paraquat but not by hydrogen peroxide, which indicates that this gene is related to the superoxide scavenger SOD. In addition, an AtMTM1::GFP fusion construct was transiently expressed in the protoplasts, and it was localized to the mitochondria. Furthermore, sequence deletion analysis of AtMTM1 revealed that the code region (amino acid (aa) 60-198) of Mtm1p plays an important role in localization of the protein to the mitochondria. Regulation of AtMTM1 gene expression was analyzed using a fusion construct of the 1,766 bp AtMTM1 promoter and the GUS (beta-glucuronidase) reporter gene. The screen identified GUS reporter gene expression in the developing cotyledons, leaves, roots, stems, and flowers but not in the siliques. Our results suggest that AtMTM1 encodes a mitochondrial protein that may be playing an important role in activation of MnSOD1 in Arabidopsis.