Sunflower Verticillium wilt (SVW) is a vascular disease caused by root infection with Verticillium dahliae (V. dahlia). It is a serious threat to the yield and quality of sunflower. However, chemical and agronomic measures for controlling this disease are not effective. The selection of more resistant genotypes is a desirable strategy to reduce contamination. A deeper knowledge of the molecular mechanisms and genetic basis underlying sunflower Verticillium wilt is necessary to accelerate breeding progress. An RNA-Seq approach was used to perform global transcriptome profiling on the roots of resistant (S18) and susceptible (P77) sunflower genotypes infected with V. dahlia. Different pairwise transcriptome comparisons were examined over a time course (6, 12 and 24 h, and 2, 3, 5 and 10 d post inoculation). In RD, SD and D datasets, 1231 genes were associated with SVW resistance in a genotype-common transcriptional pattern. Moreover, 759 and 511 genes were directly related to SVW resistance in the resistant and susceptible genotypes, respectively, in a genotype-specific transcriptional pattern. Most of the genes were demonstrated to participate in plant defense responses; these genes included peroxidase (POD), glutathione peroxidase, aquaporin PIP, chitinase, L-ascorbate oxidase, and LRR receptors. For the up-regulated genotype-specific differentially expressed genes (DEGs) in the resistant genotype, higher average fold-changes were observed in the resistant genotype compared to those in the susceptible genotype. An inverse effect was observed in the down-regulated genotype-specific DEGs in the resistant genotype. KEGG analyses showed that 98, 112 and 52 genes were classified into plant hormone signal transduction, plant-pathogen interaction and flavonoid biosynthesis categories, respectively. Many of these genes, such as CNGC, RBOH, FLS2, JAZ, MYC2 NPR1 and TGA, regulate crucial points in defense-related pathway and may contribute to V. dahliae resistance in sunflower. The transcriptome profiling results provided a clearer understanding of the transcripts associated with the crosstalk between sunflower and V. dahliae. The results identified several differentially expressed unigenes involved in the hyper sensitive response (HR) and the salicylic acid (SA)/jasmonic acid (JA)-mediated signal transduction pathway for resistance against V. dahliae. These results are useful for screening resistant sunflower genotypes.

The number of vertebrae is a crucial economic trait that can significantly impact the carcass length and meat production in animals. However, our understanding of the quantitative trait loci (QTLs) and candidate genes associated with the vertebral number in sheep (Ovis aries) remains limited. To identify these candidate genes and QTLs, we collected 73 Ujimqin sheep with increased numbers of vertebrae (T13L7, T14L6, and T14L7) and 23 sheep with normal numbers of vertebrae (T13L6). Through high-throughput genome resequencing, we obtained a total of 24,130,801 effective single-nucleotide polymorphisms (SNPs). By conducting a selective-sweep analysis, we discovered that the most significantly selective region was located on chromosome 7. Within this region, we identified several genes, including VRTN, SYNDIG1L, LTBP2, and ABCD4, known to regulate the spinal development and morphology. Further, a genome-wide association study (GWAS) performed on sheep with increased and normal vertebral numbers confirmed that ABCD4 is a candidate gene for determining the number of vertebrae in sheep. Additionally, the most significant SNP on chromosome 7 was identified as a candidate QTL. Moreover, we detected two missense mutations in the ABCD4 gene; one of these mutations (Chr7: 89393414, C > T) at position 22 leads to the conversion of arginine (Arg) to glutamine (Gln), which is expected to negatively affect the protein’s function. Notably, a transcriptome expression profile in mouse embryonic development revealed that ABCD4 is highly expressed during the critical period of vertebral formation (4.5–7.5 days). Our study highlights ABCD4 as a potential major gene influencing the number of vertebrae in Ujimqin sheep, with promising prospects for future genome-assisted breeding improvements in sheep.

Introduction: There is a knowledge gap regarding the effects of sowing date and nitrogen (N) management on the grain quality, as well as the relationship between grain quality and leaf carbon (C) and N status in high-quality hybrid rice.Methods: This study aimed to compare the grain quality of high-quality hybrid rice and evaluate the relationships between grain quality and leaf C and N content, as well as the C/N ratio, across different sowing dates and N management strategies in 2022 and 2023. Two sowing dates were employed for each year, and for each sowing date and year, rice cultivars were subjected to two N rates and three N split-application ratios.Results and discussion: Results showed that delaying the sowing date increased head rice rate, amylose content, setback viscosity and leaf N content at the maturity stage while decreasing protein content, peak and breakdown viscosity, and leaf C/N ratio. Increasing N rate and delaying N application boosted head rice rate, amylose and protein content, setback viscosity, and leaf N content at both the heading and maturity stages but reduced peak and breakdown viscosity, and leaf C/N ratio. When leaf N content was below 2.92% and 1.44% at the heading and maturity stages, and the leaf C/N ratio was above 14.9 and 29.5, respectively, it enhanced the eating quality but did not improve milling and nutritional quality. These findings suggest that delaying the sowing date can improve milling quality but deteriorate the eating and nutritional quality of high-quality hybrid rice. Increasing N rate and delaying N application are beneficial to milling and nutritional quality but are unfavorable for improving eating quality. The leaf N content and C/N ratio at the heading and maturity stages are effective indicators for diagnosing grain quality.

[Objective] Soil microorganisms are the most active parts in soil and are sensitive to soil additives. This study aimed to clarify the impacts of the addition of biomass materials (corn straw and biochar) and nitrogen application on the compositions of the soil microbial community in moderately saline soils (salt content was 0.4%). [Method] Indoor constant-temperature cultivation experiments were conducted to study the effects of biomass materials and nitrogen application on the microbial diversity and community structure in moderately saline soils. This experiment had a two-way factorial design, with the biomass materials and nitrogen application rates as the treatments. The biomass materials included no addition of biomass materials as a control (C0), corn straw (C1, 0.64 g/pot), and biochar (C2, 0.85 g/pot), and the nitrogen application rates included 0 g N (N0), 0.015 g N (N1), and 0.03 g N (N2). There were nine treatments, as follows: C0N0, C0N1, C0N2, C1N0, C1N1, C1N2, C2N0, C2N1, and C2N2. [Results] (1) The different biomass materials and nitrogen application levels significantly influenced the α-diversity and composition of the bacterial community. At the initial stage of cultivation, the soil bacterial diversity was relatively high, and it significantly decreased after 35 days of cultivation. Moreover, the improvement of the bacterial community structure by the biochar treatment was better than that of corn straw. After 35 days of cultivation, the relative abundance of Actinobacteria, Bacteroidetes, and Firmicutes in the soil significantly increased, while the relative abundance of Gemmatimonadete, Chloroflexi, Acidobacteria, Planctomycetes, and Patescibacteria significantly decreased. Ammonium nitrogen, nitrate nitrogen, and nitrate reductase were the main environmental factors affecting the bacterial community. (2) The different biomass materials and nitrogen treatments significantly affected the richness of the fungal communities. The fungal richness index significantly increased after adding the corn straw and biochar treatments, and the addition of corn straw promoted an increase in the beneficial bacterial abundance in the moderately saline soil. Soil nitrate reductase and ammonium nitrogen were the main environmental factors affecting the fungal community. [Conclusions] In summary, biomass materials and nitrogen application can effectively increase the diversity of soil microbial communities and optimize the structure of microbial communities, thereby ameliorating the ecosystem health of moderately saline soil.

Sunflowers (Helianthus annuus L.), a vital oil crop, are facing a severe challenge from broomrape (Orobanche cumana), a parasitic plant that seriously jeopardizes the growth and development of sunflowers, limits global production and leads to substantial economic losses, which urges the development of resistant sunflower varieties. This study aims to identify resistance genes from a comprehensive transcriptomic profile of 103 sunflower varieties based on gene expression data and then constructs predictive models with the key resistant genes. The least absolute shrinkage and selection operator (LASSO) regression and random forest feature importance ranking method were used to identify resistance genes. These genes were considered as biomarkers in constructing machine learning models with Support Vector Machine (SVM), K-Nearest Neighbours (KNN), Logistic Regression (LR), and Gaussian Naive Bayes (GaussianNB). The SVM model constructed with the 24 key genes selected by the LASSO method demonstrated high classification accuracy (0.9514) and a robust AUC value (0.9865), effectively distinguishing between resistant and susceptible varieties based on gene expression data. Furthermore, we discovered a correlation between key genes and differential metabolites, particularly jasmonic acid (JA). Our study highlights a novel perspective on screening sunflower varieties for broomrape resistance, which is anticipated to guide future biological research and breeding strategies.

Background/Objectives: Sunflower (Helianthus annuus L.) is one of the four major oil crops worldwide and possesses strong stress tolerance. However, salt stress remains limiting in the improvement of sunflower yield and quality. Methods: In this study, the salt-tolerant cultivar P50 and salt-sensitive cultivar P29 were used as experimental materials to conduct transcriptome sequencing on root and leaf samples treated with NaCl. Subsequently, the molecular mechanisms underlying salt tolerance in sunflower were revealed through assembly and splicing, functional annotation, differential expression analysis, enrichment analysis, and transcription factors (TFs) prediction. Results: Results showed that 54,860,184 and 60,601,572 high-quality clean reads were obtained from the two cultivars, respectively. A total of 110,751 all-unigenes were generated after assembly and clustering, of which 77,536 were functionally annotated. A total of 21,332 differentially expressed genes (DEGs) were identified, including 10,306 upregulated and 11,026 downregulated genes. Quantitative real-time PCR validation of 15 DEGs showed a 93.33% consistency rate with the sequencing data. GO enrichment analysis indicated that DEGs were significantly enriched in pathways related to antioxidant enzyme activities. KEGG enrichment analysis demonstrated that DEGs were primarily involved in 15 carbohydrate metabolism pathways, especially starch and sucrose metabolism. In addition, 67 differentially expressed TF families containing 528 DEGs were identified, including bHLH, AP2/ERF-ERF, MYB, C3H, WRKY, EREBP, B3-ARF, and NAC. Conclusions: Our study constructed a comprehensive transcription map of the sunflower response to salt stress and systematically elucidated the molecular mechanisms underlying salt tolerance. The salt-tolerant sunflower cultivar P50 exhibits an efficient salt stress defense system via three core strategies: (i) activating the antioxidant system to rapidly scavenge excess reactive oxygen species and mitigate oxidative damage; (ii) regulating carbohydrate metabolism through starch and sucrose redistribution to provide energy and osmotic protection against physiological drought; and (iii) mobilizing multiple TF families to establish a complex regulatory network for the precise control of downstream functional genes.