【Objective】This study aimed to systematically characterize the BZR1 transcription factor family in yellowhorn (Xanthoceras sorbifolium) and elucidate its functional roles in abiotic stress response, thereby providing insights for breeding stress-resistant cultivars.【Method】Genome-wide identification of XsBZR1 genes was performed using bioinformatics tools. Subcellular localization of XsBZR1 proteins was validated via 35S::XsBZR1-eYFP fusion constructs. Expression profiles under abiotic stresses (low temperature, salt, drought) and abscisic acid (ABA) treatment were analyzed by qRT-PCR. Functional validation was conducted by overexpressing XsBZR1- 9 in Arabidopsis thaliana and assessing salt tolerance phenotypes.【Result】Nine XsBZR1 genes (XsBZR1-1 to XsBZR1-9) were identified and distributed unevenly across six chromosomes. Phylogenetic and synteny analyses revealed close evolutionary relationships with dicotyledonous BZR1 orthologs. Promoter regions harbored abundant cis-regulatory elements associated with light responsiveness (48.9%), hormone signaling (35.0%) and stress adaptation (24.6%). The nuclear localization of all XsBZR1 proteins was experimentally confirmed. Differential expression patterns were observed under stress conditions: low temperature (4 ℃) rapidly induced eight XsBZR1 genes (1.3- to 6.0-fold upregulation at 3 h; P<0.05), except XsBZR1-7. Salt stress (150 mmol/L NaCl) suppressed XsBZR1-3/4/5/7 but strongly upregulated XsBZR1-1 (26.1-fold) and XsBZR1-9 (19.6-fold) at 9 h (P<0.001). Drought stress (mass fraction 25% PEG6000) elevated XsBZR1- 3/7/8/9 expression (>1.9-fold at 9 h), while others remained stable. ABA treatment (100 μmol/L) universally induced XsBZR1 genes, with XsBZR1-8 showing a 35.4-fold increase (P<0.001).Transgenic Arabidopsis overexpressing XsBZR1-9 exhibited enhanced salt tolerance, with taproot lengths twice that of the wild-type under 100 mmol/L NaCl (P<0.01).【Conclusion】The XsBZR1 gene family plays pivotal roles in yellowhorn’s abiotic stress response, with XsBZR1-9 demonstrating significant potential for improving salt tolerance. These findings advance the molecular understanding of stress adaptation mechanisms in woody plants and provide targets for precision breeding.
【Objective】This study aimed to characterize the sequence identity, transcriptional activation potential, and functional domains of the WRINKLED1 (WRI1) transcription factor in Xanthoceras sorbifolium (yellowhorn), providing insights into its regulatory role in seed oil biosynthesis. 【Method】The full-length cDNA of XsWRI1 was cloned from endosperm tissues of mature yellowhorn using rapid amplification of cDNA ends (RACE). Bioinformatics tools were employed to analyze protein sequence properties. A recombinant pGBKT7-XsWRI1 vector was constructed and transformed into Y2HGold yeast cells to assess transcriptional activation activity. Tissue-specific expression patterns were quantified via quantitative real-time PCR (qRT-PCR) across the root, stem, leaf, petal, stamen and developing embryo tissues. 【Result】The XsWRI1 gene (GenBank accession: OR500287) spans 1 688 bp, encoding a hydrophilic and unstable protein of 414 amino acids. Yeast activity testing confirmed strong transcriptional activation activity of XsWRI1. Tissue-specific expression analysis revealed predominant XsWRI1 expression in developing embryos, with negligible levels in vegetative organs (root, stem, leaf) and reproductive structures (petal, stamen). Structural prediction identified two conserved AP2/EREBP DNA-binding domains (residues 76-148 and 177-238) and a nuclear localization signal. 【Conclusion】This study elucidates the molecular characteristics and tissue-specific regulatory role of XsWRI1 in yellowhorn, highlighting its potential function in lipid biosynthesis pathways. These findings establish a foundation for targeted genetic manipulation to enhance seed oil accumulation in woody oil crops.
【Objective】 Xanthoceras sorbifolium is a unique woody oil-bearing tree species native to China. In addition to the value of its seed oil, the saponins in the fruit husk also have significant utilization values in production. This study aims to analyze the dynamic changes in fruit morphological traits, kernel oil content, saponin, soluble sugar, and starch content during the growth and development of fruits from superior clonal lines of X. sorbifolium, intending to provide a scientific basis for the efficient cultivation and fruit harvesting strategies. 【Method】 The study observed the dynamic changes in the growth and development of the fruits and their internal content and constructed a growth model accordingly. 【Result】 (1) The development processes of fruit transverse and longitudinal diameters followed sigmoid growth curves. Fruit development can be divided into four stages: the initial growth stage (1-16 days after flowering), the rapid growth stage (17-38 days after flowering), the late growth stage (39-45 days after flowering), and the fruit maturity stage (46-80 days after flowering). (2) The key periods for accumulating seed oil and fruit peel saponins were 45-80 days and 55-65 days after flowering, respectively. The peak values appeared at 80 days (62.75%) and 65 days (1.599%). Peak values for soluble sugars and starch occurred at 75 and 65 days after flowering. (3) The contents of saponin, soluble sugar, and starch in the fruit showed a highly significant positive correlation with the transverse and longitudinal diameters and the fruit’s fresh weight. 【Conclusion】 The optimal harvesting period for X. sorbifolium fruits for oil usage is 75-80 days after flowering, during which the transverse diameter of the fruit ranges from 64.82 to 66.47 mm, and the longitudinal diameter from 67.26 to 69.97 mm. For saponin usage, 60-65 days after flowering is suitable for fruit harvest, at which time the transverse diameter of fruits is 62.64 to 63.63 mm, and the longitudinal diameter is 65.57 to 65.94 mm.
【Objective】 This study aimed to evaluate the variation in phenotypic traits, leaf nutrient content, and enzyme activities among 23 clonal lines of Xanthoceras sorbifolium, and to examine their interrelations. The findings aim to provide a scientific foundation for the targeted cultivation, introduction and promotion of superior clonal lines of leaf-use X. sorbifolium. 【Method】 Twenty-three clonal lines of X. sorbifolia, introduced to Yancheng Forest Farm in Jiangsu Province, were used as research subjects. Variation was assessed by analyzing the coefficient of variation across 15 key indicators. Pearson correlation coefficients were calculated to determine the relationships between phenotypic traits, leaf nutrients and enzyme activities. Principal component analysis and hierarchical clustering were applied to comprehensively evaluate and classify the clonal lines. 【Result】 The 15 indicators exhibited varying degrees of variation, with coefficients ranging from 6.17% to 43.00%. Significant correlations were identified: nine pairs of indicators showed extremely significant correlations (P<0.01), while five pairs demonstrated significant correlations (P<0.05).【 Conclusion】 Leaf traits among the clonal lines of X. sorbifolium display substantial variation, indicating strong potential for selective improvement. The superior clonal lines identified were 50, Y8 and Y11, which are recommended for further cultivation and introduction in the Yancheng region.
