Molecular Characterization of Magnesium Chelatase in Soybean [Glycine max (L.) Merr.]

Soybean (Glycine max) seed yields rely on the efficiency of photosynthesis, which is poorly understood in soybean. Chlorophyll, the major light harvesting pigment, is crucial for chloroplast biogenesis and photosynthesis. Magnesium chelatase catalyzes the insertion of Mg2+ into protoporphyrin IX in the first committed and key regulatory step of chlorophyll biosynthesis. It consists of three types of subunits, ChlI, ChlD, and ChlH. To gain a better knowledge of chlorophyll biosynthesis in soybean, we analyzed soybean Mg-chelatase subunits and their encoding genes. Soybean genome harbors 4 GmChlI genes, 2 GmChlD genes, and 3 GmChlH genes, likely evolved from two rounds of gene duplication events. The qRT-PCR analysis revealed that GmChlI, GmChlD, and GmChlH genes predominantly expressed in photosynthetic tissues, but the expression levels among paralogs are different. In silicon promoter analyses revealed these genes harbor different cis-regulatory elements in their promoter regions, suggesting they could differentially respond to various environmental and developmental signals. Subcellular localization analyses illustrated that GmChlI, GmChlD, and GmChlH isoforms are all localized in chloroplast, consistent with their functions. Yeast two hybrid and bimolecular fluorescence complementation (BiFC) assays showed each isoform has a potential to be assembled into the Mg-chelatase holocomplex. We expressed each GmChlI, GmChlD, and GmChlH isoform in Arabidopsis corresponding mutants, and results showed that 4 GmChlI and 2 GmChlD isoforms and GmChlH1 could rescue the severe phenotype of Arabidopsis mutants, indicating that they maintain normal biochemical functions in vivo. However, GmChlH2 and GmChlH3 could not completely rescue the chlorotic phenotype of Arabidopsis gun5-2 mutant, suggesting that the functions of these two proteins could be different from GmChlH1. Considering the differences shown on primary sequences, biochemical functions, and gene expression profiles, we conclude that the paralogs of each soybean Mg-chelatase subunit have diverged more or less during evolution. Soybean could have developed a complex regulatory mechanism to control chlorophyll content to adapt to different developmental and environmental situations

An Overview of Laser Metal Deposition for Cladding: Defect Formation Mechanisms, Defect Suppression Methods and Performance Improvements of Laser-Cladded Layers

With the development of society and the economy, there is an increasing demand for surface treatment techniques that can efficiently utilize metal materials to obtain good performances in the fields of mechanical engineering and the aerospace industry. The laser metal deposition (LMD) technique for cladding has become a research focus in recent years because of its lower dilution rate, small heat-effect zone and good metallurgical bonding between the coating and substrate. This paper reviews the simulation technology for the melt pool’s grain growth mechanism, temperature and stress distribution that are directly related to defect formation in LMD technology. At the same time, the defect suppression method and the performance improvement method of the cladded layer in LMD technology are introduced. Finally, it is pointed out that the active selection of materials according to the required performance, combined with the controllable processing technology, to form the corresponding microstructure, and finally, to actively realize the expected function, is the future development direction of LMD technology

Global trends in research of mitophagy in liver diseases over past two decades: A bibliometric analysis

Increasing evidence indicated that mitophagy might play a crucial role in the occurrence and progression of liver diseases. In order to enhance our understanding of the intricate relationship between mitophagy and liver diseases, a comprehensive bibliometric analysis of the existing literature in this field was conducted. This analysis aimed to identify key trends, potential areas of future research, and forecast the development of this specific field. We systematically searched the Web of Science Core Collection (WoSCC) for publications related to mitophagy in liver diseases from 2000 to 2022. We conducted the bibliometric analysis and data visualization through VOSviewer and CiteSpace. The analysis of publication growth revealed a substantial increase in articles published in this field over the past years, indicating mitophagy's growing interest and significance in liver diseases. China and USA emerged as the leading contributors in the number of papers, with 294 and 194 independent papers, respectively. Exploring the mechanism of mitophagy in the initiation and procession of liver diseases was the main content of studies in this field, and Parkin-independent mediated mitophagy has attracted much attention recently. “Lipid metabolism,” “cell death,” “liver fibrosis” and “oxidative stress” were the primary keywords clusters. Additionally, “nlrp3 inflammasome”, “toxicity” and “nonalcoholic steatohepatitis” were emerging research hotspots in this area and have the potential to continue to be focal areas of investigation in the future. This study represents the first systematic bibliometric analysis of research on mitophagy in liver diseases conducted over the past 20 years. By providing an overview of the existing literature and identifying current research trends, this analysis sheds light on the critical areas of investigation and paves the way for future studies in this field

Oral delivery of bi-autoantigens by bacterium-like particles (BLPs) against autoimmune diabetes in NOD mice

AbstractInduction of oral tolerance by vaccination with type 1 diabetes mellitus (T1DM)-associated autoantigens exhibits great potential in preventing and treating this autoimmune disease. However, antigen degradation in the gastrointestinal tract (GIT) limits the delivery efficiency of oral antigens. Previously, bacterium-like particles (BLPs) have been used to deliver a single-chain insulin (SCI-59) analog (BLPs-SCI-59) or the intracellular domain of insulinoma-associated protein 2 (IA-2ic) (BLPs-IA-2ic). Both monovalent BLPs vaccines can suppress T1DM in NOD mice by stimulating the corresponding antigen-specific oral tolerance, respectively. Here, we constructed two bivalent BLPs vaccines which simultaneously deliver SCI-59 and IA-2ic (Bivalent vaccine-mix or Bivalent vaccine-SA), and evaluated whether there is an additive beneficial effect on tolerance induction and suppression of T1DM by treatment with BLPs-delivered bi-autoantigens. Compared to the monovalent BLPs vaccines, oral administration of the Bivalent vaccine-mix could significantly reduce morbidity and mortality in T1DM. Treatment with the bivalent BLPs vaccines (especially Bivalent vaccine-mix) endowed the mice with a stronger ability to regulate blood glucose and protect the integrity and function of pancreatic islets than the monovalent BLPs vaccines treatment. This additive effect of BLPs-delivered bi-autoantigens on T1DM prevention may be related to that SCI-59- and IA-2-specific Th2-like immune responses could be induced, which was more beneficial for the correction of Th1/Th2 imbalance. In addition, more CD4+CD25+Foxp3+ regulatory T cells (Tregs) were induced by treatment with the bivalent BLPs vaccines than did the monovalent BLPs vaccines. Therefore, multiple autoantigens delivered by BLPs maybe a promising strategy to prevent T1DM by efficiently inducing antigen-specific immune tolerance

Data_Sheet_1_Molecular Characterization of Magnesium Chelatase in Soybean [Glycine max (L.) Merr.].pdf

<p>Soybean (Glycine max) seed yields rely on the efficiency of photosynthesis, which is poorly understood in soybean. Chlorophyll, the major light harvesting pigment, is crucial for chloroplast biogenesis and photosynthesis. Magnesium chelatase catalyzes the insertion of Mg²⁺ into protoporphyrin IX in the first committed and key regulatory step of chlorophyll biosynthesis. It consists of three types of subunits, ChlI, ChlD, and ChlH. To gain a better knowledge of chlorophyll biosynthesis in soybean, we analyzed soybean Mg-chelatase subunits and their encoding genes. Soybean genome harbors 4 GmChlI genes, 2 GmChlD genes, and 3 GmChlH genes, likely evolved from two rounds of gene duplication events. The qRT-PCR analysis revealed that GmChlI, GmChlD, and GmChlH genes predominantly expressed in photosynthetic tissues, but the expression levels among paralogs are different. In silicon promoter analyses revealed these genes harbor different cis-regulatory elements in their promoter regions, suggesting they could differentially respond to various environmental and developmental signals. Subcellular localization analyses illustrated that GmChlI, GmChlD, and GmChlH isoforms are all localized in chloroplast, consistent with their functions. Yeast two hybrid and bimolecular fluorescence complementation (BiFC) assays showed each isoform has a potential to be assembled into the Mg-chelatase holocomplex. We expressed each GmChlI, GmChlD, and GmChlH isoform in Arabidopsis corresponding mutants, and results showed that 4 GmChlI and 2 GmChlD isoforms and GmChlH1 could rescue the severe phenotype of Arabidopsis mutants, indicating that they maintain normal biochemical functions in vivo. However, GmChlH2 and GmChlH3 could not completely rescue the chlorotic phenotype of Arabidopsis gun5-2 mutant, suggesting that the functions of these two proteins could be different from GmChlH1. Considering the differences shown on primary sequences, biochemical functions, and gene expression profiles, we conclude that the paralogs of each soybean Mg-chelatase subunit have diverged more or less during evolution. Soybean could have developed a complex regulatory mechanism to control chlorophyll content to adapt to different developmental and environmental situations.</p