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Objective To develop a questionnaire on social media content production among adolescents and to test its reliability and validity. Methods This study was an empirical investigation that recruited middle school students from a secondary school in Tai’an City, Shandong Province, China. The preliminary questionnaire was developed based on a combination of semi-structured interviews and a comprehensive review of the relevant literature. A total of 672 adolescents served as the initial test subjects, with 336 questionnaires undergoing item analysis and exploratory factor analysis, and the remaining 336 questionnaires undergoing confirmatory factor analysis. A reliability test was conducted using a retest questionnaire administered to 62 adolescent retest subjects. Results The adolescent social media sports content production questionnaire comprises two dimensions—user-generated content (UGC) and professional-generated content (PGC)—and nine items. The results of the confirmatory factor analysis indicated that the questionnaire had good fit indices (CMIN/DF = 4.352, RMSEA = 0.031, RMR = 0.024, CFI = 0.994, TLI = 0.992); The internal consistency of the total questionnaire reached 0.883, with Cronbach’s Alpha coefficients for each dimension exceeding 0.7, and test-retest reliability at 0.792; validity analysis showed significant correlations between dimensions and between sub-dimensions and the total questionnaire. Conclusion The questionnaire developed in this study for assessing social media content production among adolescents demonstrates good reliability, validity, and discriminative power, and can serve as an evaluation tool for social media sports content production among adolescents.

In tomato (Solanum lycopersicum), as in other plants, the immunity hormone jasmonate (JA) triggers genome-wide transcriptional changes in response to pathogen and insect attack. These changes are largely regulated by the basic helix-loop-helix (bHLH) transcription factor MYC2. The function of MYC2 depends on its physical interaction with the MED25 subunit of the Mediator transcriptional coactivator complex. Although much has been learned about the MYC2-dependent transcriptional activation of JA-responsive genes, relatively less studied is the termination of JA-mediated transcriptional responses and the underlying mechanisms. Here, we report an unexpected function of MYC2 in regulating the termination of JA signaling through activating a small group of JA-inducible bHLH proteins, termed MYC2-TARGETED BHLH1 (MTB1), MTB2, and MTB3. MTB proteins negatively regulate JA-mediated transcriptional responses via their antagonistic effects on the functionality of the MYC2-MED25 transcriptional activation complex. MTB proteins impair the formation of the MYC2-MED25 complex and compete with MYC2 to bind to its target gene promoters. Therefore, MYC2 and MTB proteins form an autoregulatory negative feedback circuit to terminate JA signaling in a highly organized manner. We provide examples demonstrating that gene editing tools such as CRISPR/Cas9 open up new avenues to exploit MTB genes for crop protection.

The hormone jasmonate (JA), which functions in plant immunity, regulates resistance to pathogen infection and insect attack through triggering genome-wide transcriptional reprogramming in plants. We show that the basic helix-loop-helix transcription factor (TF) MYC2 in tomato (Solanum lycopersicum) acts downstream of the JA receptor to orchestrate JA-mediated activation of both the wounding and pathogen responses. Using chromatin immunoprecipitation sequencing (ChIP-seq) coupled with RNA sequencing (RNA-seq) assays, we identified 655 MYC2-targeted JA-responsive genes. These genes are highly enriched in Gene Ontology categories related to TFs and the early response to JA, indicating that MYC2 functions at a high hierarchical level to regulate JA-mediated gene transcription. We also identified a group of MYC2-targeted TFs (MTFs) that may directly regulate the JA-induced transcription of late defense genes. Our findings suggest that MYC2 and its downstream MTFs form a hierarchical transcriptional cascade during JA-mediated plant immunity that initiates and amplifies transcriptional output. As proof of concept, we showed that during plant resistance to the necrotrophic pathogen Botrytis cinerea, MYC2 and the MTF JA2-Like form a transcription module that preferentially regulates wounding-responsive genes, whereas MYC2 and the MTF ETHYLENE RESPONSE FACTOR.C3 form a transcription module that preferentially regulates pathogen-responsive genes.

The phytohormone auxin promotes the growth of plant shoots by stimulating cell expansion via plasma membrane (PM) H⁺-ATPase activation, which facilitates cell wall loosening and solute uptake. Mechanistic insight was recently obtained by demonstrating that auxin-induced SMALL AUXIN UP RNA (SAUR) proteins inhibit D-CLADE TYPE 2C PROTEIN PHOSPHATASE (PP2C.D) activity, thereby trapping PM H⁺-ATPases in the phosphorylated, activated state, but how SAURs bind PP2C.D proteins and inhibit their activity is unknown. Here, we identified a highly conserved motif near the C-terminal region of the PP2C.D catalytic domain that is required for SAUR binding in Arabidopsis (Arabidopsis thaliana). Missense mutations in this motif abolished SAUR binding but had no apparent effect on catalytic activity. Consequently, mutant PP2C.D proteins that could not bind SAURs exhibited constitutive activity, as they were immune to SAUR inhibition. In planta expression of SAUR-immune pp2c.d2 or pp2c.d5 derivatives conferred severe cell expansion defects and corresponding constitutively low levels of PM H⁺-ATPase phosphorylation. These growth defects were not alleviated by either auxin treatment or 35S:StrepII-SAUR19 coexpression. In contrast, a PM H⁺-ATPase gain-of-function mutation that results in a constitutively active H1 pump partially suppressed SAUR-immune pp2c.d5 phenotypes, demonstrating that impaired PM H⁺-ATPase function is largely responsible for the reduced growth of the SAUR-immune pp2c.d5 mutant. Together, these findings provide crucial genetic support for SAUR-PP2C.D regulation of cell expansion via modulation of PM H⁺-ATPase activity. Furthermore, SAUR-immune pp2c.dderivatives provide new genetic tools for elucidating SAUR and PP2C.D functions and manipulating plant organ growth.

To restrict pathogen entry, plants close stornata as an integral part of innate immunity. To counteract this defense, Pseudomonas syringae pv tomato produces coronatine (COR), which mimics jasmonic acid (JA), to reopen stornata for bacterial entry. It is believed that abscisic acid (ABA) plays a central role in regulating bacteria-triggered stomatal closure and that stomatal reopening requires the JA/COR pathway, but the downstream signaling events remain unclear. We studied the stomatal immunity of tomato (Solanum lycopersicum) and report here the distinct roles of two homologous NAC (for NAM, ATAF1,2, and CUC2) transcription factors, JA2 (for jasmonic acid2) and JA2L (for JA2-like), in regulating pathogen-triggered stomatal movement. ABA activates JA2 expression, and genetic manipulation of JA2 revealed its positive role in ABA-mediated stomatal closure. We show that JA2 exerts this effect by regulating the expression of an ABA biosynthetic gene. By contrast, JA and COR activate JA2L expression, and genetic manipulation of JA2L revealed its positive role in JA/COR-mediated stomatal reopening. We show that JA2L executes this effect by regulating the expression of genes involved in the metabolism of salicylic acid. Thus, these closely related NAC proteins differentially regulate pathogen-induced stomatal closure and reopening through distinct mechanisms.

In response to insect attack and mechanical wounding, plants activate the expression of genes involved in various defense-related processes. A fascinating feature of these inducible defenses is their occurrence both locally at the wounding site and systemically in undamaged leaves throughout the plant. Wound-inducible proteinase inhibitors (PIs) in tomato (Solanum lycopersicum) provide an attractive model to understand the signal transduction events leading from localized injury to the systemic expression of defense-related genes. Among the identified intercellular molecules in regulating systemic wound response of tomato are the peptide signal systemin and the oxylipin signal jasmonic acid (JA). The systemin/JA signaling pathway provides a unique opportunity to investigate, in a single experimental system, the mechanism by which peptide and oxylipin signals interact to coordinate plant systemic immunity. Here we describe the characterization of the tomato suppressor of prosystemin-mediated responses8 (spr8) mutant, which was isolated as a suppressor of (pro)systemin-mediated signaling. spr8 plants exhibit a series of JA-dependent immune deficiencies, including the inability to express wound-responsive genes, abnormal development of glandular trichomes, and severely compromised resistance to cotton bollworm (Helicoverpa armigera) and Botrytis cinerea. Map-based cloning studies demonstrate that the spr8 mutant phenotype results from a point mutation in the catalytic domain of TomLoxD, a chloroplast-localized lipoxygenase involved in JA biosynthesis. We present evidence that overexpression of TomLoxD leads to elevated wound-induced JA biosynthesis, increased expression of wound-responsive genes and, therefore, enhanced resistance to insect herbivory attack and necrotrophic pathogen infection. These results indicate that TomLoxD is involved in wound-induced JA biosynthesis and highlight the application potential of this gene for crop protection against insects and pathogens.

Key messagesGray leaf spot (GLS) resistance in tomato is controlled by one major dominant locus, Sm. Sm was fine mapped, and the nucleotide-binding site-leucine-rich repeat (NBS-LRR) gene Solyc11g020100 was identified as a candidate gene for Sm. Further functional analysis indicated that this gene confers high resistance to Stemphylium lycopersici in tomato.Tomato (Solanum Lycopersicum) is widely consumed and cultivated in the world. Gray leaf spot (GLS), caused by Stemphylium lycopersici (S. lycopersici), is one of the most devastating diseases in tomato production. To date, only one resistance gene, Sm, which confers high resistance against GLS disease, has been identified in the wild tomato species Solanum pimpinellifolium. This resistance locus (comprising the Sm gene) has been transferred into the cultivated variety ‘Motelle’. Although several studies have reported the mapping of the Sm gene, it has not been cloned, limiting the utilization in tomato breeding. Here, we cloned Sm using a map-based cloning strategy. The Sm gene was mapped in a region of 160 kb at chromosome 11 between two markers, namely, M390 and M410, by using an F2 population from a cross between the resistant cultivar ‘Motelle’ (Mt) and susceptible line ‘Moneymaker’ (Mm). Three clustered NBS-LRR (nucleotide-binding site-leucine-rich repeat) resistance genes, namely, Solyc11g020080 (R1), Solyc11g020090 (R2), and Solyc11g020100 (R3) were identified in this interval. Nonsynonymous SNPs were identified in only the open reading frame (ORF) of R3, suggesting it as a strong candidate for the Sm gene. Furthermore, gene silencing of R3 abolished the high resistance to S. lycopersici in Motelle, demonstrating that this gene confers high resistance to S. lycopersici. The cloning of Sm may speed up its utilization for breeding resistant tomato varieties and represents an important step forward in our understanding of the mechanism underlying the resistance to GLS.

Background Venous thromboembolism (VTE) is most prevalent among parturients following a cesarean section (CS). The objective of this study was to assess the practical utility of bilateral compression ultrasonography (CUS) of the lower limbs, coupled with D-dimer monitoring, in the early diagnosis of VTE within the Han Chinese population. Methods Our prospective observational study included 742 women who underwent CUS and D-dimer testing on the first day post-CS. Subsequently, telephone or outpatient follow-ups were conducted until 42 days postpartum. States of hypercoagulation and thrombosis, as indicated by CUS, were classified as CUS abnormal. A D-dimer level ≥ 3 mg/l was considered the D-dimer warning value. Early ambulation and mechanical prophylaxis were universally recommended for all parturients post-CS. A sequential diagnostic strategy, based on the 2015 RCOG VTE risk-assessment tool, was employed. Therapeutic doses of low-molecular-weight heparin (LMWH) were administered for the treatment of thromboembolic disease. Prophylactic doses of LMWH were given for VTE prophylaxis in parturients with hypercoagulative status accompanied by D-dimer levels ≥ 3 mg/l. All high-risk women (RCOG score ≥ 4 points) were additionally treated with preventive LMWH. Statistical analyses were conducted using the R statistical software, with a two-sided P value < 0.05 considered statistically significant. Results Fifteen cases of VTE and 727 instances without VTE were observed. The overall VTE rate post-CS was 2.02% (15/742), with 66.7% (10/15) being asymptomatic. Eleven patients received a VTE diagnosis on the first postpartum day. Among the 41 parturients exhibiting hypercoagulation ultrasound findings and D-dimer levels ≥ 3 mg/l, despite receiving pharmacological VTE prophylaxis with LMWH, 4.88% (2/41) in the high-risk group were eventually diagnosed with VTE. A total of 30.86% (229/742) exhibited normal ultrasound findings and D-dimer levels < 3 mg/l on the first day post-CS, with no VTE occurrences in the postpartum follow-up. According to RCOG’s recommendation, 78.03% (579/742) of cesarean delivery women should receive prophylactic anticoagulation, while only 20.62% (153/742) met our criterion for prophylactic anticoagulation. Conclusion The strategy of timely routine bilateral CUS and D-dimer monitoring is conducive to the early diagnosis and treatment of VTE, significantly reducing the use of LMWH in the Chinese Han population.

Male sterility can reduce cost and enable high seed purity during hybrid seed production. However, the commercial application of male sterility in hybrid seed production has not been widely used in tomatoes. CRISPR/Cas9-mediated gene editing can facilitate acceleration for the practical application of male sterility in hybrid seed production. Here, by using the CRISPR-Cas9 system, two genes DYSFUNCTIONAL TAPETUM1 (SlDYT1) and Glutathione S-transferase (SlGSTAA), which underly the two closely linked loci Male sterile 10 (Ms10) and Anthocyanin absent (AA), were knocked out simultaneously in two tomato parental lines. The generated dyt1gstaa double mutants developed green hypocotyl owing to anthocyanin deficiency and exhibited stable male sterility. Up to 92% effectiveness in selecting male sterility was achieved using green hypocotyl as a morphological marker, and thereafter an efficient and stable propagation strategy of male sterility with the aid of the morphological marker selection was developed. Furthermore, dyt1gstaa-derived hybrid seeds were produced and found to have comparable yield, weight, and germination rate with the corresponding WT-derived F1 seeds. The dyt1gstaa system not only increased hybrid seed purity to 100% but also facilitated its rapid and cost-effective determination. Moreover, this system was discovered to have no evident side effects on important agronomic traits. This study suggested that our CRISPR/Cas9-created dyt1gstaa system can be deployed in tomato hybrid seed production.