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The most characteristic feature of membranous nephropathy (MN) is the presence of subepithelial electron dense deposits and the consequential thickening of the glomerular basement membrane. There have been great advances in the understanding of the destiny of immune complexes in MN by the benefit of experimental models represented by Heymann nephritis. Subepithelial immune complexes are formed in situ by autoantibodies targeting native autoantigens or exogenous planted antigens such as the phospholipase A2 receptor (PLA2R) and cationic BSA respectively. The nascent immune complexes would not be pathogenic until they develop into immune deposits. Podocytes are the major source of autoantigens in idiopathic membranous nephropathy. They also participate in the modulation and removal of the immune complexes to a large extent. The balance between deposition and clearance is regulated by a wide range of factors such as the composition and physicochemical properties of the immune complexes and the complement system. Complement components such as C3 and C1q have been reported to be precipitated with the deposits whereas a complement regulatory protein CR1 expressed by podocytes is involved in the phagocytosis of immune complexes by podocytes. Podocytes regulate the dynamic change of immune complexes which is disturbed in membranous nephropathy. To elucidate the precise fate of the immune complexes is essential for developing more rational and novel therapies for membranous nephropathy.

Dichloroquinolinic acid is a hormone-type herbicide widely used to control barnyard grass during crop cultivation. However, it can seriously inhibit the growth of susceptible crops, including tobacco, because it degrades slowly under field conditions. Additionally, the mechanism by which it damages crops is unclear. More specifically, the transcriptional changes in plants induced by dichloroquinolinic acid remain unknown. In this study, differentially expressed genes (DEGs) in tobacco treated with dichloroquinolinic acid (varying concentrations and durations) were analyzed and validated to explore the global transcriptome changes. The number of DEGs, which were determined according to the FPKM, varied from 758 to 21,340. The KEGG analysis revealed that many DEGs were involved in starch and sucrose metabolism, phenylpropanoid biosynthesis, photosynthesis, porphyrin and chlorophyll metabolism, and glutathione metabolism. Transcriptomic analyses indicated that dichloroquinolinic acid can inhibit tobacco growth by inhibiting photosynthesis and storage of energy. We discovered that the toxicity mechanism of the hormone herbicide dichloroquinolinic acid differs from that of high concentrations of IAA (Indoleacetic acid), despite studies confirming that the effects of hormone herbicides are consistent with the physiological disturbances and growth inhibition exhibited by plants in IAA overdose. Particularly, dichloroquinolinic acid suppresses photosynthesis while high concentration IAA stimulates nucleotide synthesis and photosynthesis. More importantly, we found by editing the IAA-responsive gene IAA16, tobacco could develop resistance to dichloroquinolinic acid. The results will help clarify plant responses to hormone-type herbicides at the transcriptional level, thereby providing insights into the diversity in the gene’s response to herbicides, the molecular targets of hormone-type herbicides, and the mechanism underlying the susceptibility of tobacco to dichloroquinolinic acid. Accordingly, this study may be helpful for future research to enhance crop resistance to herbicides residues.

Abstract Tobacco bacterial wilt has seriously affected tobacco production. Ethyl methanesulfonate (EMS) induced tobacco bacterial wilt resistant mutants are important for the control of tobacco bacterial wilt. High-throughput sequencing technology was used to study the rhizosphere bacterial community assemblages of bacterial wilt resistant mutant tobacco rhizosphere soil (namely KS), bacterial wilt susceptible tobacco rhizosphere soil (namely GS) and bulk soil (namely BS) in Xuancheng, Huanxi, Yibin and Luzhou. Alpha analysis showed that the bacterial community diversity and richness of KS and GS in the four regions were not significantly different. However, analysis of intergroup variation in the top 15 bacterial communities in terms of abundance showed that the bacterial communities of KS and GS were significantly different from BS, respectively. In addition, pH, alkali-hydrolysable nitrogen (AN) and soil organic carbon (SOC) were positively correlated with the bacterial community of KS and negatively correlated with GS in the other three regions except Huanxi. Network analysis showed that the three soils in the four regions did not show a consistent pattern of network complexity. PICRUSt functional prediction analysis showed that the COG functions were similar in all samples. All colonies were involved in RNA processing and modification, chromatin structure and dynamics, etc. In conclusion, our experiments showed that rhizosphere bacterial communities of tobacco in different regions have different compositional patterns, which are strongly related to soil factors.

Plants respond to Ralstonia solanacearum infestation through two layers of immune system (PTI and ETI). This process involves the production of plant-induced resistance. Strategies for inducing resistance in plants include the formation of tyloses, gels, and callose and changes in the content of cell wall components such as cellulose, hemicellulose, pectin, lignin, and suberin in response to pathogen infestation. When R. solanacearum secrete cell wall degrading enzymes, plants also sense the status of cell wall fragments through the cell wall integrity (CWI) system, which activates deep-seated defense responses. In addition, plants also fight against R. solanacearum infestation by regulating the distribution of metabolic networks to increase the production of resistant metabolites and reduce the production of metabolites that are easily exploited by R. solanacearum. We review the strategies used by plants to induce resistance in response to R. solanacearum infestation. In particular, we highlight the importance of plant-induced physical and chemical defenses as well as cell wall defenses in the fight against R. solanacearum.

The more axillary growth (MAX) gene family is a group of key genes involved in the synthesis and signal transduction of strigolactones (SLs) in plants. Although MAX genes play vital roles in plant growth and development, characterization of the MAX gene family has been limited in solanaceous crops, especially in tobacco. In this study, 74 members of the MAX family were identified in representative Solanaceae crops and classified into four groups. The physicochemical properties, gene structure, conserved protein structural domains, cis-acting elements, and expression patterns could be clearly distinguished between the biosynthetic and signal transduction subfamilies; furthermore, MAX genes in tobacco were found to be actively involved in the regulation of meristem development by responding to hormones. MAX genes involved in SL biosynthesis were more responsive to abiotic stresses than genes involved in SL signaling. Tobacco MAX genes may play an active role in stress resistance. The results of this study provide a basis for future in-depth analysis of the molecular mechanisms of MAX genes in tobacco meristem development and stress resistance.

Abstract Genetic map is a linear arrangement of the relative positions of sites in the chromosome or genome based on the recombination frequency between genetic markers. It is the important basis for genetic analysis. Several kinds of software have been designed for genetic mapping, but all these tools require users to write or edit code, making it time-costing and difficult for researchers without programming skills to handle with. Here, MG2C, a new online tool was designed, based on PERL and SVG languages. Users can get a standard genetic map, only by providing the location of genes (or quantitative trait loci) and the length of the chromosome, without writing additional code. The operation interface of MG2C contains three sections: data input, data output and parameters. There are 33 attribute parameters in MG2C, which are further divided into 8 modules. Values of the parameters can be changed according to the users’ requirements. The information submitted by users will be transformed into the genetic map in SVG file, which can be further modified by other image processing tools. MG2C is a user-friendly and time-saving online tool for drawing genetic maps, especially for those without programming skills. The tool has been running smoothly since 2015, and updated to version 2.1. It significantly lowers the technical barriers for the users, and provides great convenience for the researchers.

Relation extraction (RE) is a fundamental NLP task that aims to identify relations between some entities regarding a given text. RE forms the basis for many advanced NLP tasks, such as question answering and text summarization, and thus its quality is critical to the relevant downstream applications. However, evaluating the quality of RE models is non-trivial. On the one hand, obtaining ground truth labels for individual test inputs is tedious and even difficult. On the other hand, there is an increasing need to understand the characteristics of RE models in terms of various aspects. To mitigate these issues, this study proposes evaluating RE models by applying metamorphic testing (MT). A total of eight metamorphic relations (MRs) are identified based on three categories of transformation operations, namely replacement, swap, and combination. These MRs encode some expected properties of different aspects of RE. We further apply MT to three popular RE models. Our experiments reveal a large number of prediction failures in the subject RE models, confirming that MT is effective for evaluating RE models. Further analysis of the experimental results reveals the advantages and disadvantages of our subject models and also uncovers some typical issues of RE models.

Many tobacco (Nicotiana tabacum) cultivars are salt-tolerant and thus are potential model plants to study the mechanisms of salt stress tolerance. The CALCINEURIN B-LIKE PROTEIN (CBL) is a vital family of plant calcium sensor proteins that can transmit Ca2+ signals triggered by environmental stimuli including salt stress. Therefore, assessing the potential of NtCBL for genetic improvement of salt stress is valuable. In our studies on NtCBL members, constitutive overexpression of NtCBL5A was found to cause salt supersensitivity with necrotic lesions on leaves. NtCBL5A-overexpressing (OE) leaves tended to curl and accumulated high levels of reactive oxygen species (ROS) under salt stress. The supersensitivity of NtCBL5A-OE leaves was specifically induced by Na+, but not by Cl−, osmotic stress, or drought stress. Ion content measurements indicated that NtCBL5A-OE leaves showed sensitivity to the Na+ accumulation levels that wild-type leaves could tolerate. Furthermore, transcriptome profiling showed that many immune response-related genes are significantly upregulated and photosynthetic machinery-related genes are significantly downregulated in salt-stressed NtCBL5A-OE leaves. In addition, the expression of several cation homeostasis-related genes was also affected in salt-stressed NtCBL5A-OE leaves. In conclusion, the constitutive overexpression of NtCBL5A interferes with the normal salt stress response of tobacco plants and leads to Na+-dependent leaf necrosis by enhancing the sensitivity of transgenic leaves to Na+. This Na+ sensitivity of NtCBL5A-OE leaves might result from the abnormal Na+ compartmentalization, plant photosynthesis, and plant immune response triggered by the constitutive overexpression of NtCBL5A. Identifying genes and pathways involved in this unusual salt stress response can provide new insights into the salt stress response of tobacco plants.