Explore the vast range of titles available.

Freezing stress is the main obstacle affecting the geographical distribution, growth, development, quality, and productivity of rapeseed ( Brassica napus ) in northern China. However, there is a little knowledge of rapeseed freezing tolerance mechanism. Here, 289 core germplasms collected from 36 countries were used to identify SNPs associated with freezing tolerance. We used RNA-seq data to narrow down the candidate genes identified by genome-wide association studies. The frequency distributions of phenotypic values and best linear unbiased estimates (BLUE) values for each trait conform to normal or approximately normal distributions, with good repeatability across various locations. The results showed that 594, 513, 7, and 45 SNPs were significantly associated with malondialdehyde, peroxidase, soluble protein, and relative electrolyte leakage, respectively. Based on these significantly associated SNPs, we identified 4,998 associated genes. Crossover analysis indicated that 73 genes were overlapped between GWAS and RNA-seq datasets, and 13 candidate genes involved in transmission and perception of freeze stress signals, lipid metabolism, reactive oxygen species (ROS) homeostasis, antifreeze proteins synthesis, and other metabolic processes. These results reveal novel genes associated with freezing tolerance in rapeseed, and provide a basis for further research and improvement of freezing tolerance in rapeseed.

The cold tolerance of winter rapeseed cultivars is critically important for winter survival and yield formation in northern area. BrAFP1, an antifreeze protein in , is hypothesized to stabilize membranes and inhibit ice crystal formation. we cloned the promoter from the cold-tolerant cultivar Longyou 7 (L7) and constructed the expression vector to investigate the impact of membrane state changes on BrAFP1 expression and the cold tolerance in winter rapeseed. Ten independent transgenic T3 lines were generated, among which T3-5 and T3-7 were selected for subsequent analysis. The dimethyl sulfoxide (DMSO) treatment in the absence of cold exposure activated the transcriptional activity of proBrAFP1, a cold-inducible promoter; in contrast, benzyl alcohol (BA) treatment eliminated its cold-induced activation. The expression levels of cold-responsive genes, including cyclic nucleotide-gated channel 1 ( ), open stomata 1 ( ), and inducer of CBF expression 1 ( ), as well as membrane fluidity-related genes, such as acyl-lipid desaturase 2 ( ), fatty acid desaturase 2 ( ), and sensitive to freezing 2 ( ), were significantly increased following DMSO pretreatment, while BA treatment significantly inhibited the expression of these genes. Furthermore, ABA and SA levels are closely linked to alterations in the membrane state, compared to untreated plants, the levels of ABA and SA in the leaves markedly increased at 4°C after DMSO and BA treatment but decreased at -4°C. Collectively, DMSO pretreatment enhanced cold tolerance, while BA pretreatment improved cell survival under cold stress, which is important for practise of keeping the rapeseed yields.

Currently, the widely used active form of plant elicitor peptide 1 (PEP1) from Arabidopsis thaliana is composed of 23 amino acids, hereafter AtPEP1(1–23), serving as an immune elicitor. The relatively less conserved N-terminal region in AtPEP family indicates that the amino acids in this region may be unrelated to the function and activity of AtPEP peptides. Consequently, we conducted an investigation to determine the necessity of the nonconserved amino acids in AtPEP1(1–23) peptide for its functional properties. By assessing the primary root growth and the burst of reactive oxygen species (ROS), we discovered that the first eight N-terminal amino acids of AtPEP1(1–23) are not crucial for its functionality, whereas the conserved C-terminal aspartic acid plays a significant role in its functionality. In this study, we identified a truncated peptide, AtPEP1(9–23), which exhibits comparable activity to AtPEP1(1–23) in inhibiting primary root growth and inducing ROS burst. Additionally, the truncated peptide AtPEP1(13–23) shows similar ability to induce ROS burst as AtPEP1(1–23), but its inhibitory effect on primary roots is significantly reduced. These findings are significant as they provide a novel approach to explore and understand the functionality of the AtPEP1(1–23) peptide. Moreover, exogenous application of AtPEP1(13–23) may enhance plant resistance to pathogens without affecting their growth and development. Therefore, AtPEP1(13–23) holds promise for development as a potentially applicable biopesticides.

Currently, the widely used active form of plant elicitor peptide 1 (PEP1) from Arabidopsis thaliana is composed of 23 amino acids, hereafter AtPEP1[sup.(1–23)], serving as an immune elicitor. The relatively less conserved N-terminal region in AtPEP family indicates that the amino acids in this region may be unrelated to the function and activity of AtPEP peptides. Consequently, we conducted an investigation to determine the necessity of the nonconserved amino acids in AtPEP1[sup.(1–23)] peptide for its functional properties. By assessing the primary root growth and the burst of reactive oxygen species (ROS), we discovered that the first eight N-terminal amino acids of AtPEP1[sup.(1–23)] are not crucial for its functionality, whereas the conserved C-terminal aspartic acid plays a significant role in its functionality. In this study, we identified a truncated peptide, AtPEP1[sup.(9–23)], which exhibits comparable activity to AtPEP1[sup.(1–23)] in inhibiting primary root growth and inducing ROS burst. Additionally, the truncated peptide AtPEP1[sup.(13–23)] shows similar ability to induce ROS burst as AtPEP1[sup.(1–23)], but its inhibitory effect on primary roots is significantly reduced. These findings are significant as they provide a novel approach to explore and understand the functionality of the AtPEP1[sup.(1–23)] peptide. Moreover, exogenous application of AtPEP1[sup.(13–23)] may enhance plant resistance to pathogens without affecting their growth and development. Therefore, AtPEP1[sup.(13–23)] holds promise for development as a potentially applicable biopesticides.