The PYR/PYL/RCAR (PYL) gene family (Pyrabactin Resistance 1/PYR1-Like/Regulatory Component of ABA Receptor), as core receptors of abscisic acid (ABA), play a pivotal regulatory role in the signaling pathways of plant responses to abiotic stresses such as drought. Saccharum spontaneum L. (wild sugarcane), an important wild relative for sugarcane stress-resistant breeding, harbors abundant drought-tolerant genetic resources. However, systematic identification and functional analysis of its PYL gene family remain unreported to date. Based on the S. spontaneum genome data (Saccharum spontaneum Np-X2021), the study identified members of the SsPYL gene family using bioinformatics approaches, and systematically analyzed the physicochemical properties, chromosomal localization, phylogenetic relationships, gene structures, conserved motifs, and cis-acting elements in promoters. Additionally, quantitative real-time PCR (qRT-PCR) was employed to investigate the expression patterns of core members under drought stress. The results showed that 32 SsPYL genes, designated as SsPYL1 to SsPYL32, were identified in the S. spontaneum genome. The encoded proteins ranged in length from 149 to 385 amino acids, with most being acidic and hydrophilic proteins primarily localized in the cytoplasm. The secondary structure was dominated by α-helices and random coils. Furthermore, SsPYLs exhibited uneven distribution across chromosomes, and segmental duplication was the dominant mechanism driving family expansion. A total of 54 pairs of syntenic genes were identified between SsPYLs and rice OsPYL genes, reflecting the evolutionary conservation of this family among monocotyledonous plants. Phylogenetic analysis clustered the 32 SsPYLs into three subfamilies, with members of the same subfamily sharing similar conserved motif compositions and gene structures. All SsPYL proteins contained the signature PYR_PYL_RCAR_like domain. The promoter regions of SsPYL genes were enriched in hormone-responsive and abiotic stress-related cis-acting elements, such as ABRE (ABA-responsive element), ARE (anaerobic responsive element), and LTR (low-temperature responsive element). Under drought stress, the expression levels of eight SsPYL genes (SsPYL1, SsPYL3, SsPYL4, SsPYL6, SsPYL8, SsPYL14, SsPYL19 and SsPYL24) were extremely significantly upregulated (P<0.01), among which SsPYL8, SsPYL14 and SsPYL19 showed more than 5-fold upregulation. The genes are thus speculated to be key candidate genes regulating drought tolerance in S. spontaneum. The study represents the first systematic characterization of the molecular features and drought-responsive patterns of the SsPYL gene family in S. spontaneum. It would provide a theoretical basis for further exploring the functional mechanisms in ABA-mediated drought stress signaling pathways and offer important gene targets for the genetic improvement of drought tolerance in sugarcane.

The widely targeted metabolisms of fruit pericarp was determined, the differential metabolites were screened and the metabolic pathway was analyzed to understand the metabolomics difference of fruit pericarp at its different growth and development stages in wax apple (Syzygium samarangense). The samples were picked at 15 d (S₁), 30 d (S₂), 45 d (S₃) and 60 d (S₄) after flower respectively. A total of 946 metabolites were detected from wax apple fruit pericarp, including 177 amino acids and their derivatives, 140 flavonoids, 96 sugars and their derivatives, 96 organic acids and their derivatives, 89 lipids, 65 nucleotides and their derivatives, and 283 other metabolites. There were 65, 88, 59, 88, 112, and 103 differential metabolites in S₁ vs S₂, S₂ vs S₃, S₃ vs S₄, S₁ vs S₃, S₁ vs S₄, and S₂ vs S₄ respectively. There were only 6 common differential metabolites in six groups, of which 5 metabolites belonged to amino acids and derivatives and 1 belonged to flavonoid. The differential metabolites of fruit pericarp at different growth and development stages mainly included amino acids and their derivatives, flavonoids, sugars and their derivatives, lipids. The number of differential metabolites of flavonoids, sugars and their derivatives decreased first and then increased, while the number of lipid metabolites increased first and then decreased with the growth and development of fruit. Most flavonoid metabolites were down-regulated, while sugars and their derivatives were up-regulated. There were more lipid differential metabolites in S₂ vs S₃, and only 1 in S₃ vs S₄. The most significant enrichment pathway of differential metabolites of wax apple fruit pericarp were biosynthesis of starch and sucrose, phenylalanine, D-amino acid, galactose, terpenoids and steroids. This study would provide theoretical support and data references for the regulation of fruit quality and harvest period of wax apple.

Granule-bound starch synthase I (MeGBSSI) is the key enzyme for amylose synthesis in cassava, primarily responsible for catalyzing the formation of amylose through α-1,4-glucosidic linkages on the surface of starch granules. However, how MeGBSSI cooperates with other starch-synthetic enzymes to orchestrate starch biosynthesis remains unclear. In the previous stage of this research group, through yeast two-hybrid technology, it was hypothesized that the soluble starch synthase MeSSV was a potential binding protein of MeGBSSI. In this study, the MeGBSSI and MeSSV genes were cloned using the main cultivated variety of cassava, Huanshan 8 (SC8), as the material. Yeast two-hybrid vectors pGBKT7-MeGBSSI and pGADT7-MeSSV were constructed. Through yeast two-hybrid point-to-point experiments, the interaction relationship between MeGBSSI and MeSSV was preliminarily verified. The luciferase complementation (LCA) and double-molecule fluorescence complementation (BiFC) techniques were used to further clarify the direct protein interaction between the two. The results showed that the protein sequences encoded by the MeGBSSI and MeSSV genes, compared with the sequenced variety AM560, respectively, had 4 and 2 amino acid substitutions; the MeGBSSI protein was non-toxic to yeast cells and had no self-activation activity; this protein interacted with the soluble starch synthase MeSSV in yeast; the LCA experiment showed that the chemical signals significantly enhanced after co-expression of MeGBSSI and MeSSV; the BiFC experiment further proved that the two could form a complex in plant cells, and the interaction signal was located in the chloroplast. The findings would provide new insight into the synergistic regulation among cassava starch-synthetic enzymes.

Dwarfism is a key trait for Litchi chinensis breeding and cultivation. Focusing on the candidate gene LcGAMYB23 implicated in dwarfism by prior quantitative trait locus (QTL) mapping, we evaluated the MYB transcription factor family background and its molecular application potential. A genome-wide bioinformatic survey identified 151 members of the LcMYB gene family. Conserved motif and domain analyses showed that all family members harbored the canonical Myb_DNA-binding domain, indicating high sequence conservation in litchi. We further cloned and sequenced LcGAMYB23 from three standard (non-dwarf) cultivars (9918, Feizixiao, FZX; Sanyuehong, SYH) and three dwarf cultivars (Nuomici, NMC; Yamulong, YML; Ziniangxi, ZNX), and detected consistent sequence differences between the two groups. Based on the divergent single-nucleotide polymorphism (SNP) sites, we developed molecular markers and validated them across 70 cultivars. The markers effectively discriminated standard versus dwarf types at the cDNA level, with concordant results at the genomic DNA level. The findings would provide practical tools for molecular typing and marker-assisted selection of dwarfism in litchi and lay the groundwork for functional elucidation of LcGAMYB23.

Tomato ripening involves the coordinated regulation of key agronomic traits such as color transformation, texture softening, and flavor compound accumulation. Elucidating its molecular mechanisms is not only a central goal in postharvest biology but also crucial for improving fruit quality and achieving precise control of storage duration. In this study, the functions of SlBEL1, SlBEL2 and SlBEL11, members of the BEL family of transcription factors in tomato, were systematically investigated through multi-dimensional experiments. Phylogenetic and amino acid sequence alignment analyses revealed that SlBEL1, SlBEL2 and SlBEL11 possessed highly conserved protein domains, suggesting potential functional similarities. Spatiotemporal expression profiling showed that the genes were synchronously highly expressed during critical stages of fruit ripening, from the breaker to the full ripening stage. Using CRISPR-Cas9 technology, single-gene and triple-gene editing lines of SlBEL1, SlBEL2 and SlBEL11 were generated. The single-gene editing lines CR-SlBEL1, CR-SlBEL2 and CR-SlBEL11 all exhibited a delayed fruit ripening phenotype, while the triple editing line resulted in impaired reproductive development, failing to proceed to flowering and fruit setting. Furthermore, reverse transcription quantitative real-time PCR (qRT-PCR) analysis revealed that SlBEL1/2/11 modulated the expression of multiple ripening-related genes in tomato. Collectively, the results demonstrate that SlBEL1/2/11 functioned redundantly to coordinately control the fruit ripening process. This study identified novel targets for the genetic improvement of tomato fruit ripening.

Germplasm resources are the key material support for the breeding of new mango varieties and the sustainable development of the industry, and the efficient conservation and utilization are of great significance for mango research. In the study, 431 mango germplasm accessions were used. Combining different sampling strategies and genetic distances, the optimal sampling strategy combination for constructing the mango core collection was screened by the UPGMA clustering method, and the core collection was subsequently established. The results showed that the average effective number of alleles (Ne), average Shannon's information index (I), and average Nei's diversity index (H) of 12 pairs of primers was 4.0993, 1.534 and 0.7361, respectively, indicating that the mango germplasm possessed rich genetic diversity. The t-test results of genetic diversity parameters revealed that the core collection constructed by the combination of the locus priority sampling strategy and Nei & Li genetic distance had the highest Ne, H and I among all tested groups, with value of 4.2603, 0.7486 and 1.5855, respectively, demonstrating that the combination was the optimal method for constructing the mango core collection. The established core collection comprised 85 accessions, accounting for 19.72% of the original germplasm. The retention rate of Ne, I and H in the core collection reached 103.93%, 103.35% and 101.45%, respectively, indicating that although the core collection was much smaller in quantity than the original germplasm, it exhibited superior performance in genetic diversity-related indicators. Principal coordinate analysis (PCoA) showed that the distribution of the core collection uniformly covered the distribution range of the original germplasm in the principal coordinate space, suggesting that the core collection could comprehensively retain the genetic diversity characteristics of the original germplasm and had good representativeness.

To clarify the genetic diversity characteristics of pollen morphology and the genetic relationships among pitaya germplasm resources, 63 pitaya germplasm accessions were used as the research materials in this study. Scanning electron microscopy (SEM) was applied to observe pollen micromorphology, 8 traits including polar axis length, equatorial axis length, and polar-equatorial ratio were systematically measured, and the diversity patterns of these traits were investigated through correlation analysis, principal component analysis (PCA), and cluster analysis. The results showed that the pollen grains of all 63 pitaya germplasms were N3P4C3 type, with tricolporate apertures and spiny exine ornamentation. The differences in pollen among the germplasms were mainly reflected in subtle aspects such as shape, size, germinal furrow traits and exine ornamentation. The pollen grains were prolate or subspheroidal in shape. The polar axis length ranged from 58.82 to 101.00 μm, the equatorial axis length ranged from 52.50 to 86.54 μm, the germinal furrow length ranged from 37.03 to 82.25 μm, the germinal furrow width ranged from 1.31 to 8.53 μm, the furrow spacing ranged from 25.14 to 53.88 μm, and the surface spine density ranged from 1.30 to 3.11 per μm². Among the quantitative traits, the coefficient of variation (CV) of germinal furrow width was the largest, while that of equatorial axis length was the smallest. Correlation analysis revealed that polar axis length had an extremely significant positive correlation with germinal furrow length and polar-equatorial ratio, and polar-equatorial ratio had an extremely significant negative correlation with furrow spacing. Cluster analysis showed that the 63 germplasms were divided into 3 major clusters at a Euclidean distance of 20. The first cluster contained 30 accessions including Yuhonglong, the second cluster contained 15 accessions including Yunnan No.5, and the third cluster contained 18 accessions including Bama Red Flesh. This study confirmed that pitaya pollen morphology presents abundant genetic diversity, and established a palynology-based technique for the classification and identification of pitaya germplasms, which can provide important theoretical support for the identification and genetic breeding of pitaya germplasm resources.

Date palm (Phoenix dactylifera), a nutrient-rich crop of significant economic importance, serves as a staple food in many Arab countries and regions, offering considerable potential for further development and utilization. Its genetic resources play a crucial role in driving innovation and enhancing the competitiveness of the date palm industry, garnering increasing attention from the scientific community in recent years. While phased research progress has been achieved, overall studies remain in an exploratory stage. Currently, the global date palm industry faces severe challenges, including climate change, cultivar deterioration, loss of genetic diversity, and threats from pest and disease. Therefore, there is an urgent need to accelerate in-depth research on the preservation, identification, evaluation and innovative utilization of date palm germplasm resources to overcome bottlenecks in achieving simultaneous improvements in yield, stress resistance and quality. This paper systematically reviewed the current status of date palm germplasm resources, encompassing core areas such as resource collection and conservation technologies, identification and evaluation systems, and strategies for innovative utilization. It further examined existing bottlenecks and challenges, proposed targeted solutions, and outlined future directions for development. This study aims to provide theoretical support and strategic guidance for the efficient development and innovative utilization of date palm germplasm resources, thereby enhancing agricultural productivity and optimizing resource management.

The comprehensive effects of different fertilization treatments on soil fertility, enzyme activity and microbial community structure in rubber plantations were systematically investigated to provide a theoretical basis for sustainable nutrient management of rubber plantation soils. Using the rubber clone Reyan 7-33-97 as the research subject, five treatments were set, no fertilization (CK), conventional chemical fertilizer (CF), organic-inorganic compound fertilizer (OF), and two slow-release fertilizers with different release ratios (SF 25% and SF 50%). Soil chemical properties, enzyme activity and microbial community structure were measured to systematically explore the relationships among the factors. Compared with CF, OF treatment significantly increased soil organic matter (35.40%), available phosphorus (40.00%), pH (10.86%) and urease activity (54.84%). SF 25% significantly increased available phosphorus (43.00%) and catalase activity (19.23%). The available phosphorus content in SF 50% treatment showed no significant difference from CF, but was significantly lower than that in OF and SF 25% treatments. Microbial community analysis revealed that there were no significant differences in bacterial and fungal α-diversity across the treatments, but β-diversity analysis showed that fertilization treatments had a significant effect on the fungal community structure. Furthermore, both OF and SF 25% treatments significantly increased the relative abundance of Acidobacteria (93.47%, 64.58%), Chujaibacter (351.56%, 222.53%) and Ascomycota (38.43%, 11.13%) while decreasing the relative abundance of Rozellomycota. The SF 50% treatment significantly decreased the relative abundance of Glomeromycota (53.70%). In conclusion, organic-inorganic compound fertilizer (OF) and slow-release fertilizer (SF 25%) were more effective in improving soil fertility, enzyme activity and microbial community structure, and can be recommended as fertilization strategies for soil health management in rubber plantations.

We have discovered and reported a litchi male sterile line MS1 recently but the characteristics of this male sterile was still unclear. In this study, grafted litchi male sterile line MS1 was used as the experimental materials and all the materials were planted in plastic pots. Anther fertility of the litchi male-sterile line MS1, characterized by off-season flowering, was assessed via morphological observation and paraffin sectioning. The results demonstrated that MS1 produced a low proportion of male flowers during high-temperature seasons. Moreover, both male and female flowers lacked viable pollen grains yet exhibited parthenocarpic ability. This study confirmed the stable male sterility of the MS1 line under high-temperature conditions, which lays the groundwork for determining its sterility type, and provides preliminary strategies for achieving off-season flowering in litchi.