Cytotoxic lymphocyte-monocyte complex reflects the dynamics of COVID-19 systemic immune response.

SARS-CoV-2 infection causes a variety of clinical manifestations, many of which originate from altered immune responses, either locally or systemically. Immune cell crosstalk occurs mainly in lymphoid organs. However, systemic cell interaction specific to COVID-19 has not been well characterized. Here, by employing single cell RNA sequencing and imaging flow cytometry analysis, we unraveled, in peripheral blood, a heterogeneous group of cell complexes formed by the adherence of CD14+ monocytes to different cytotoxic lymphocytes, including SARS-CoV-2-specific CD8+ T cells, γδT and NKT cells. These lymphocytes attached to CD14+ monocytes that showing enhanced inflammasome activation and pyroptosis-induced cell death in progression stage, whereas in convalescent phase, CD14+ monocytes with elevated antigen presentation potential were targeted by cytotoxic lymphocytes, thereby restricting the excessive immune activation. Collectively, our study reports previously unrecognized cell-cell interplay in SARS-CoV-2 specific immune response, providing new insight into the intricacy of dynamic immune cell interaction representing anti-viral defense.

The wheat basic helix-loop-helix gene TabHLH123 positively modulates the formation of crown roots and is associated with plant height and 1000-grain weight under various conditions.

Crown roots are the main components of the fibrous root system in cereal crops and play critical roles in plant adaptation; however, the molecular mechanisms underlying their formation in wheat (Triticum aestivum) have not been fully elucidated. In this study, we identified a wheat basic helix-loop-helix (bHLH) protein, TabHLH123, that interacts with the essential regulator of crown root initiation, MORE ROOT in wheat (TaMOR). TabHLH123 is expressed highly in shoot bases and roots. Ectopic expression of TabHLH123 in rice resulted in more roots compared with the wild type. TabHLH123 regulates the expression of genes controlling crown-root development and auxin metabolism, responses, and transport. In addition, we analysed the nucleotide sequence polymorphisms of TabHLH123s in the wheat genome and identified a superior haplotype, TabHLH123-6B, that is associated with high root dry weight and 1000-grain weight, and short plant height. Our study reveals the role of TabHLH123 in controlling the formation of crown roots and provides beneficial insights for molecular marker-assisted breeding in wheat.

Genome-wide identification, evolutionary and functional analyses of KFB family members in potato.

BACKGROUND: Kelch repeat F-box (KFB) proteins play vital roles in the regulation of multitudinous biochemical and physiological processes in plants, including growth and development, stress response and secondary metabolism. Multiple KFBs have been characterized in various plant species, but the family members and functions have not been systematically identified and analyzed in potato. RESULTS: Genome and transcriptome analyses of StKFB gene family were conducted to dissect the structure, evolution and function of the StKFBs in Solanum tuberosum L. Totally, 44 StKFB members were identified and were classified into 5 groups. The chromosomal localization analysis showed that the 44 StKFB genes were located on 12 chromosomes of potato. Among these genes, two pairs of genes (StKFB15/16 and StKFB40/41) were predicted to be tandemly duplicated genes, and one pair of genes (StKFB15/29) was segmentally duplicated genes. The syntenic analysis showed that the KFBs in potato were closely related to the KFBs in tomato and pepper. Expression profiles of the StKFBs in 13 different tissues and in potato plants with different treatments uncovered distinct spatial expression patterns of these genes and their potential roles in response to various stresses, respectively. Multiple StKFB genes were differentially expressed in yellow- (cultivar 'Jin-16'), red- (cultivar 'Red rose-2') and purple-fleshed (cultivar 'Xisen-8') potato tubers, suggesting that they may play important roles in the regulation of anthocyanin biosynthesis in potato. CONCLUSIONS: This study reports the structure, evolution and expression characteristics of the KFB family in potato. These findings pave the way for further investigation of functional mechanisms of StKFBs, and also provide candidate genes for potato genetic improvement.

Overexpression of Sweet Potato Carotenoid Cleavage Dioxygenase 4 (IbCCD4) Decreased Salt Tolerance in Arabidopsis thaliana.

Salt stress has a serious impact on normal plant growth and yield. Carotenoid cleavage dioxygenase (CCD) degrades carotenoids to produce apocarotenoids, which are involved in plant responses to biotic and abiotic stresses. This study shows that the expression of sweet potato IbCCD4 was significantly induced by salt and dehydration stress. The heterologous expression of IbCCD4 in Arabidopsis was induced to confirm its salt tolerance. Under 200 mM NaCl treatment, compared to wild-type plants, the rosette leaves of IbCCD4-overexpressing Arabidopsis showed increased anthocyanins and carotenoid contents, an increased expression of most genes in the carotenoid metabolic pathway, and increased malondialdehyde (MDA) levels. IbCCD4-overexpressing lines also showed a decreased expression of resistance-related genes and a lower activity of three antioxidant enzymes: peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT). These results indicate that IbCCD4 reduced salt tolerance in Arabidopsis, which contributes to the understanding of the role of IbCCD4 in salt stress.

Uncovering anthocyanin biosynthesis related microRNAs and their target genes by small RNA and degradome sequencing in tuberous roots of sweetpotato.

BACKGROUND: Compared with white-fleshed sweetpotato (WFSP), purple-fleshed sweetpotato (PFSP) is a desirable resource for functional food development because of the abundant anthocyanin accumulation in its tuberous roots. Some studies have shown that the expression regulation mediated by miRNA plays an important role in anthocyanin biosynthesis in plants. However, few miRNAs and their corresponding functions related to anthocyanin biosynthesis in tuberous roots of sweetpotato have been known. RESULTS: In this study, small RNA (sRNA) and degradome libraries from the tuberous roots of WFSP (Xushu-18) and PFSP (Xuzishu-3) were constructed, respectively. Totally, 191 known and 33 novel miRNAs were identified by sRNA sequencing, and 180 target genes cleaved by 115 known ib-miRNAs and 5 novel ib-miRNAs were identified by degradome sequencing. Of these, 121 miRNAs were differently expressed between Xushu-18 and Xuzishu-3. Integrated analysis of sRNA, degradome sequencing, GO, KEGG and qRT-PCR revealed that 26 differentially expressed miRNAs and 36 corresponding targets were potentially involved in the anthocyanin biosynthesis. Of which, an inverse correlation between the expression of ib-miR156 and its target ibSPL in WFSP and PFSP was revealed by both qRT-PCR and sRNA sequencing. Subsequently, ib-miR156 was over-expressed in Arabidopsis. Interestingly, the ib-miR156 over-expressing plants showed suppressed abundance of SPL and a purplish phenotype. Concomitantly, upregulated expression of four anthocyanin pathway genes was detected in transgenic Arabidopsis plants. Finally, a putative ib-miRNA-target model involved in anthocyanin biosynthesis in sweetpotato was proposed. CONCLUSIONS: The results represented a comprehensive expression profiling of miRNAs related to anthocyanin accumulation in sweetpotato and provided important clues for understanding the regulatory network of anthocyanin biosynthesis mediated by miRNA in tuberous crops.

Physiological responses to low temperature in spring and winter wheat varieties.

BACKGROUND: Northward expansion of winter wheat is an efficient means to improve crop yield and quality in many countries. However, inadequate cold hardiness restricts the northward expansion of winter wheat. This study aimed to investigate cold adaption of different wheat varieties and underlying physiological mechanism. RESULTS: In the field experiment, soluble sugar and proline content, relative electric conductivity (EC) and malondialdehyde (MDA) content were higher in wheat varieties in the overwintering period than those in the pre-wintering period. Superoxide dismutase (SOD) activity was lower in the overwintering period than in the pre-wintering period and spring growth period. Photosynthetic rate was reduced dramatically in the winter variety (Suyin 10), weak winter variety (Lumai 22) and spring (Jinchun 9) variety after low-temperature treatment. Cold treatment inhibited stomatal conductance (Gs) and transpiration rate (Tr). Influences of high-temperature treatment and cold acclimation after vernalization were further analyzed in the greenhouse in wheat variety Jinghe 1. High-temperature treatment after vernalization significantly inhibited SOD and peroxidase activities in the vernalized plants, while cold acclimation after vernalization enhanced peroxidase activity. CONCLUSION: Cold tolerance of wheat varieties may be associated with effective osmoregulation ability, photosynthetic capacity, Gs and Tr , as well as activity of antioxidant enzymes.

Sulforaphane decreases oxidative stress and inhibits NLRP3 inflammasome activation in a mouse model of ulcerative colitis.

Excessive oxidative stress and NLRP3 inflammasome activation are considered the main drivers of inflammatory bowel disease (IBD), and inhibition of inflammasomes ameliorates clinical symptoms and morphological manifestations of IBD. Herein, we examined the roles of NLRP3 activation in IBD and modulation of NLRP3 by sulforaphane (SFN), a compound with multiple pharmacological activities that is extracted from cruciferous plants. To simulate human IBD, we established a mouse colitis model by administering dextran sodium sulfate in the drinking water. SFN (25, 50 mg·kg-1·d-1, ig) or the positive control sulfasalazine (500 mg/kg, ig) was administered to colitis-affected mice for 7 days. Model mice displayed pathological alterations in colon tissue as well as classic symptoms of colitis beyond substantial tissue inflammation. Expression of NLRP3, ASC, and caspase-1 was significantly elevated in the colonic epithelium. The expression of NLRP3 inflammasomes led to activation of downstream proteins and increases in the cytokines IL-18 and IL-1ß. SFN administration either fully or partially reversed these changes, thus restoring IL-18 and IL-1ß, substantially inhibiting NLRP3 activation, and decreasing inflammation. SFN alleviated the inflammation induced by LPS and NLRP3 agonists in RAW264.7 cells by decreasing the levels of reactive oxygen species. In summary, our results revealed the pathological roles of oxidative stress and NLRP3 in colitis, and indicated that SFN might serve as a natural NLRP3 inhibitor, thereby providing a new strategy for alternative colitis treatment.

Retraction notice to "Genome-wide analysis of the B-box gene family in the sweet potato wild ancestor Ipomoea trifida and determination of the function of IbBBX28 in the regulation of flowering time of Arabidopsis" [Plant Physiol. Biochem. 188 (2022) 109-122].

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editors-in-Chief. A large part of the article is highly similar to the paper previously published by Wenqian Hou, Lei Ren, Yang Zhang, Haoyun Sun, Tianye Shi, Yulan Gu, Aimin Wang, Daifu Ma, Zongyun Li and Lei Zhang in Scientia Horticulturae 288 (2021) 110374 https://doi.org/10.1016/j.scienta.2021.110374. In particular, a large part of the two articles shows a study on the same gene family in the same plant, with similar methodological approaches, resulting in a series of highly similar figures. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

Integrated metabolic and transcriptional analysis reveals the role of carotenoid cleavage dioxygenase 4 (IbCCD4) in carotenoid accumulation in sweetpotato tuberous roots.

BACKGROUND: Plant carotenoids are essential for human health, having wide uses in dietary supplements, food colorants, animal feed additives, and cosmetics. With the increasing demand for natural carotenoids, plant carotenoids have gained great interest in both academic and industry research worldwide. Orange-fleshed sweetpotato (Ipomoea batatas) enriched with carotenoids is an ideal feedstock for producing natural carotenoids. However, limited information is available regarding the molecular mechanism responsible for carotenoid metabolism in sweetpotato tuberous roots. RESULTS: In this study, metabolic profiling of carotenoids and gene expression analysis were conducted at six tuberous root developmental stages of three sweetpotato varieties with different flesh colors. The correlations between the expression of carotenoid metabolic genes and carotenoid levels suggested that the carotenoid cleavage dioxygenase 4 (IbCCD4) and 9-cis-epoxycarotenoid cleavage dioxygenases 3 (IbNCED3) play important roles in the regulation of carotenoid contents in sweetpotato. Transgenic experiments confirmed that the total carotenoid content decreased in the tuberous roots of IbCCD4-overexpressing sweetpotato. In addition, IbCCD4 may be regulated by two stress-related transcription factors, IbWRKY20 and IbCBF2, implying that the carotenoid accumulation in sweeetpotato is possibly fine-tuned in responses to stress signals. CONCLUSIONS: A set of key genes were revealed to be responsible for carotenoid accumulation in sweetpotato, with IbCCD4 acts as a crucial player. Our findings provided new insights into carotenoid metabolism in sweetpotato tuberous roots and insinuated IbCCD4 to be a target gene in the development of new sweetpotato varieties with high carotenoid production.

BBIBP-CorV vaccination accelerates anti-viral antibody responses in heterologous Omicron infection: A retrospective observation study in Shanghai.

OBJECTIVES: To investigate how BBIBP-CorV vaccination affecting antibody responses upon heterologous Omicron infection. METHODS: 440 Omicron-infected patients were recruited in this study. Antibodies targeting SARS-CoV-2 spike protein receptor binding domain (RBD) and nucleoprotein of both wild-type (WT) and Omicron were detected by ELISA. The clinical relevance was further analyzed. RESULTS: BBIBP-CorV vaccinated patients exhibited higher anti-RBD IgG levels targeting both WT and Omicron than non-vaccinated patients at different stages. By using a 3-day moving average analysis, we found that BBIBP-CorV vaccinated patients exhibited the increases in both anti-WT and Omicron RBD IgG from the onset and reached the plateau at Day 8 whereas those in non-vaccinated patients remained low during the disease. Significant increase in anti-WT RBD IgA was observed only in vaccinated patients. anti-Omicron RBD IgA levels remained low in both vaccinated and non-vaccinated patients. Clinically, severe COVID-19 only occurred in non-vaccinated group. anti-RBD IgG and IgA targeting both WT and Omicron were negatively correlated with virus load, hospitalization days and virus elimination in vaccinated patients. CONCLUSIONS: BBIBP-CorV vaccination effectively reduces the severity of Omicron infected patients. The existence of humoral memory responses established through BBIBP-CorV vaccination facilitates to induce rapid recall antibody responses when encountering SARS-CoV-2 variant infection.

An Early Warning Intelligent Algorithm System for Forest Resource Management and Monitoring.

The development of remote sensing technology has passed an effective means for forest resource management and monitoring, but remote sensing technology is limited by sensor hardware equipment, and the quality of remote sensing image data is low, which is difficult to meet the needs of forest resource change monitoring. This paper presents a remote sensing image classification method based on the combination of the SSIF algorithm and wavelet denoising. Forest information is extracted from PALSAR/PALSAR-2 radar remote sensing data. The forest distribution map is generated by pixel level fusion algorithm, and the accuracy of the forest distribution map is evaluated by a confusion matrix. The remote sensing image is spatio-temporal fused by the SSIF algorithm to capture more details of forest distribution. The simulation analysis shows that the overall accuracy of the forest classification results obtained by the fusion algorithm is 96% ± 1, and the kappa coefficient is 0.66. The accuracy of forest recognition meets the requirements.

The sweet potato B-box transcription factor gene IbBBX28 negatively regulates drought tolerance in transgenic Arabidopsis.

B-box (BBX) which are a class of zinc finger transcription factors, play an important role in regulating of photoperiod, photomorphogenesis, and biotic and abiotic stresses in plants. However, there are few studies on the involvement of BBX transcription factors in response to abiotic stresses in sweet potato. In this paper, we cloned the DNA and promoter sequences of IbBBX28. There was one B-box conserved domain in IbBBX28, and the expression of IbBBX28 was induced under drought stress. Under drought stress, compared to wild type Arabidopsis, the protective enzyme activities (SOD, POD, and CAT) were all decreased in IbBBX28-overexpression Arabidopsis but increased in the mutant line bbx28, while the MDA content was increased in the IbBBX28-overexpression Arabidopsis and decreased in the bbx28. Moreover, the expression levels of the resistance-related genes showed the same trend as the protective enzyme activities. These results showed that IbBBX28 negatively regulates drought tolerance in transgenic Arabidopsis. Additionally, the yeast two-hybrid and BiFC assays verified that IbBBX28 interacted with IbHOX11 and IbZMAT2. The above results provide important clues for further studies on the role of IbBBX28 in regulating the stress response in sweet potato.

A Locus Controlling Leaf Rolling Degree in Wheat under Drought Stress Identified by Bulked Segregant Analysis.

Drought stress frequently occurs, which seriously restricts the production of wheat (Triticum aestivum L.). Leaf rolling is a typical physiological phenomenon of plants during drought stress. To understand the genetic mechanism of wheat leaf rolling, we constructed an F2 segregating population by crossing the slight-rolling wheat cultivar "Aikang 58" (AK58) with the serious-rolling wheat cultivar ″Zhongmai 36″ (ZM36). A combination of bulked segregant analysis (BSA) with Wheat 660K SNP Array was used to identify molecular markers linked to leaf rolling degree. A major locus for leaf rolling degree under drought stress was detected on chromosome 7A. We named this locus LEAF ROLLING DEGREE 1 (LERD1), which was ultimately mapped to a region between 717.82 and 720.18 Mb. Twenty-one genes were predicted in this region, among which the basic helix-loop-helix (bHLH) transcription factor TraesCS7A01G543300 was considered to be the most likely candidate gene for LERD1. The TraesCS7A01G543300 is highly homologous to the Arabidopsis ICE1 family proteins ICE/SCREAM, SCREAM2 and bHLH093, which control stomatal initiation and development. Two nucleotide variation sites were detected in the promoter region of TraesCS7A01G543300 between the two wheat cultivars. Gene expression assays indicated that TraesCS7A01G543300 was higher expressed in AK58 seedlings than that of ZM36. This research discovered a candidate gene related to wheat leaf rolling under drought stress, which may be helpful for understanding the leaf rolling mechanism and molecular breeding in wheat.

Genome-wide analysis of the B-box gene family in the sweetpotato wild ancestor Ipomoea trifida and determination of the function of IbBBX28 in the regulation of flowering time of Arabidopsis.

B-box (BBX) proteins constitute a class of transcription factors that play vital roles in the regulation of photoperiod flowering, photomorphogenesis, and the response to biotic and abiotic stresses. In this paper, a total of 32 BBX genes were identified in Ipomoea trifida, a wild ancestor of sweetpotato. Chromosome localization analysis showed that these 32 ItfBBX genes were distributed unevenly across 12 chromosomes. The ItfBBX gene family members were classified into five groups according to their phylogenetic relationships and structural features. Predictions of cis-elements revealed that the promoter sequences of the ItfBBX genes contain light response, stress response, hormone response and other elements. Synteny analysis revealed evidence of 26 segmental duplication events and only one tandem duplication event. Tissue-specific and abiotic stress-response expression profiles were analysed, and the results were confirmed via RT-qPCR. Overall, ItfBBX genes may play vital roles in the stress response. We chose IbBBX28 for further study and revealed that IbBBX28 negatively regulates the flowering time of IbBBX28-overexpressing Arabidopsis under long-day conditions. Our study provides references for characterizing the function of BBX genes in sweetpotato.

Mismatch Between Specific and Genetic Diversity in an Evergreen Broadleaf Forest in Southeast China: A Study Case of 10.24 ha Forest Dynamics Plot of Huangshan.

For a long time, forestry management has often focused on the protection of species diversity, and mistakenly believed that protecting species diversity protects genetic diversity. Therefore, research that integrates community ecology and population genetics has become important because it can help elucidate whether the targets for protecting specific and genetic diversity are congruent. In this study, we have emphasized the impact of the community on the population because no previous studies have considered the community composition of a place a priori. Based on the Huangshan 10.24 ha dynamics forest plot, we a priori considered the community composition in the plot to test species-genetic diversity among the tree layers. Firstly, a redundancy analysis (RDA) found that Castanopsis eyrei and Pinus massoniana were the dominant species. Secondly, specific and genetic diversity are not congruent in Huang Shan. Finally, the structural equation model (SEM) showed that the different degrees of response by community composition and population structure to environmental heterogeneity are the main reasons for the mismatch between species diversity and genetic diversity. The results suggest that we must focus on genetic diversity, as well as on protecting species diversity.

Transcriptomic and targeted metabolomic analysis identifies genes and metabolites involved in anthocyanin accumulation in tuberous roots of sweetpotato (Ipomoea batatas L.).

Purple-fleshed sweetpotato (PFSP) accumulates high amounts of anthocyanins that are beneficial to human health. Although biosynthesis of such secondary metabolites has been well studied in aboveground organs of many plants, the mechanisms underlying anthocyanin accumulation in underground tuberous roots of sweetpotato are less understood. To identify genes and metabolites involved in anthocyanin accumulation in sweetpotato, we performed comparative transcriptomic and metabolomic analysis of (PFSP) and white-fleshed sweetpotato (WFSP). Anthocyanin-targeted metabolome analysis revealed that delphinidin, petunidin, and rosinidin were the key metabolites conferring purple pigmentation in PFSP as they were highly enriched in PFSP but absent in WFSP. Transcriptomic analysis identified 358 genes that were potentially implicated in multiple pathways for the biosynthesis of anthocyanins. Although most of the genes were previously known for their roles in anthocyanin biosynthesis, we identified 26 differentially expressed genes that are involved in Aux/IAA-ARF signaling. Gene-metabolite correlation analysis also revealed novel genes that are potentially involved in the anthocyanin accumulation in sweetpotato. Taken together, this study provides insights into the genes and metabolites underlying anthocyanin enrichment in underground tuberous roots of sweetpotato.

Optimization of reference genes for qRT-PCR analysis of microRNA expression under abiotic stress conditions in sweetpotato.

Sweetpotato (Ipomoea batatas. L) is an important food crop, harvested for its nutrient-rich tuberous roots. Drought and salt stresses are two major factors limiting the sweetpotato production. Since microRNAs (miRNAs) are well known to play crucial roles in regulation of plant stress responses, quantitative profiling of miRNA expression under stress conditions will facilitate identification and genetic manipulation of novel miRNAs to improve stress tolerance. Real-time quantitative reverse transcription PCR (qRT-PCR) is a commonly used tool for this purpose, but not without challenges. Although stem-loop and poly(A)-tail modified qRT-PCR methods were developed for characterizing miRNA expression, accurate profiling of miRNAs is still difficult in many plant species because of a lack of reliable reference genes for normalizing miRNA transcripts. To identify reference genes that are suitable for normalizing miRNA expression in sweetpotato, the expression stability of eight candidate miRNAs and two commonly used reference genes were tested in 96 samples involving four tissues and two cultivars under drought and salt stress treatments. Data analysis using the geNorm, NormFinder and Bestkeeper algorithms demonstrated that miRn60, miR482, and their combination were reliable references. We further validated the reference genes by expression analysis of the well-characterized miR319 and miR156 that regulate drought and salt stress responses, respectively. The reference genes identified in this study will facilitate future miRNA analysis under abiotic stress conditions in sweetpotato.

The art of microRNA: various strategies leading to gene silencing via an ancient pathway.

MicroRNAs (miRNAs), an endogenous type of small RNAs of approximately 22 nucleotides (nt), have long resided in the cells of plants and animals including humans, constituting an ancient pathway of gene regulation in eukaryotes. They have a simple structure in their mature form but carry enormous information that may regulate up to 90% of the human transcriptome. Furthermore, the multi-facets of a miRNA are tightly associated with diverse cellular proteins that make it broadly connected to various physiological and pathological processes. This review aims to examine miRNAs briefly from their biogenesis to their general functions with an emphasis on working mechanisms in regulation of their target mRNAs.

Calreticulin: conserved protein and diverse functions in plants.

Calreticulin (CRT) is a key Ca2+-binding protein mainly resident in the endoplasmic reticulum (ER), which is highly conserved and extensively expressed in all eukaryotic organisms investigated. The protein plays important roles in a variety of cellular processes including Ca2+ signaling and protein folding. Although calreticulin has been well characterized in mammalian systems, increased investigations have demonstrated that plant CRTs have a number of specific properties different from their animal counterparts. Recent developments on plant CRTs have highlighted the significance of CRTs in plants growth and development as well as biotic and abiotic stress responses. There are at least two distinct groups of calreticulin isoforms in higher plants. Glycosylation of CRT was uniquely observed in plants. In this article, we will describe our current understanding of plant calreticulin gene family, protein structure, cellular localization, and diverse functions in plants. We also discuss the prospects of using this information for genetic improvements of crop plants.