Flg22 is an artificially synthesized 22-amino-acid peptide derived from the conserved N-terminal region of bacterial flagellin, playing a crucial role in regulating plant immune responses. Due to the high cost of artificially synthesized flg22 short peptides and limitations for large-scale application, this study aimed to determine the suitable conditions for prokaryotic induction expression of the flg22 protein and to verify its function, thereby determining whether it could replace the commercially used flg22 short peptides. In this study, the pET32a-flg22 prokaryotic expression vector was synthesized, and we then compared protein expression efficiency under induction at 28 ℃ and 37 ℃. Additionally, we detected the dynamic burst of reactive oxygen species (ROS) in cassava treated with flg22 peptides and flg22 proteins at different concentrations to validate the functions. The results indicated that 28 ℃ was the optimal induction temperature for inducing flg22 protein expression. ROS measurements showed that within a specific concentration range, the peak intensity of ROS increased with the increase in flg22 protein concentration. Furthermore, after spraying cassava leaves with 60 μg/mL and 600 μg/mL of flg22 recombinant proteins, as well as 2.27 μg/mL of flg22 peptides, for three days, we inoculated plants with the pathogen Xam (Xanthomonas axonopodis pv. manihotis, Xam). Compared to treatment with sterile water, both flg22 protein and flg22 peptide treatments showed significant antibacterial effects against Xam in cassava plants, with the 60 μg/mL and 600 μg/mL flg22 protein treatments showing notably stronger antibacterial activity than the flg22 peptide. The results preliminarily identified the prokaryotic expression conditions of flg22 recombinant protein and verified that its function in inducing plant defense responses is consistent with that of the peptide, providing a theoretical basis for substituting commercial peptides with flg22 recombinant protein.

The regulatory effects of exogenous homogentisic acid (HGA) on plant growth, anthocyanin synthesis, and the antioxidant system at phenotypic, physiological and gene expression levels using one-leaf seedlings of Wushansimiao (R534) were studied to explore the role of HGA in rice salt stress response. The results showed that under 140 mmol/L NaCl stress and treatment with 0.25 mmol/L HGA significantly improved the salt tolerance of rice seedlings. On the 3^rd day after treatment, plant height, root length, fresh weight and dry weight increased by 43.95%, 60.00%, 41.86% and 76.38%, respectively, compared to the control without HGA. After 7 days of treatment and 7 days of rewatering, the survival rate of seedlings increased by 56.69%. RT-qPCR analysis revealed that HGA significantly upregulated the key genes involved in anthocyanin biosynthesis in leaves, including OsPAL3, OsCHS8, OsCHI, OsF3H, OsDFR6, OsANS1 and OsUF3GT. Anthocyanin content increased by 15.18%, 24.58% and 39.56% on the 3^rd, 5^th and 7^th day, respectively. On the 3^rd day, the accumulation of reactive oxygen species (H₂O₂ and ) and malondialdehyde (MDA) content decreased, while the activities of antioxidant enzymes SOD, POD and CAT significantly increased. This study preliminarily clarified that HGA could activate the anthocyanin biosynthesis pathway under salt stress to enhance antioxidant capacity, laying a foundation for further understanding the physiological role of HGA.

S-adenosylmethionine synthase (SAMS) is a key enzyme catalyzing the synthesis of S-adenosylmethionine (SAM, S-adenosylmethionine), widely involved in various biological processes in plants, such as epigenetic regulation, oxidative stress, and growth and development. In this study, the full-length cDNA sequence of CaSAMS3 was successfully cloned from coffee, and the physicochemical properties, protein structure, conserved domains, and evolutionary characteristics of the encoded CaSAMS3 protein were analyzed. Through cis-acting element analysis and protein interaction network prediction, and the metabolic processes involving CaSAMS3 were explored, and its expression pattern was analyzed in combination with qPCR and subcellular localization studies. The results showed that the open reading frame length of CaSAMS3 was 1173 bp, encoding a hydrophilic protein (molecular weight 42.57 kDa, theoretical isoelectric point 6.07), with a secondary structure mainly composed of α- helices and irregular curls, and located on cell membrane and nucleus. The protein contained a typical SAMS conserved domain and had the highest homology with SAMS in kiwifruit. Its promoter contained response elements related to light, hormones, stress, and growth and development, including MYB and MYC binding sites. CaSAMS3 exhibited tissue-specific expression, and its expression trend during developmental stages was consistent with accumulation pattern of caffeine. This study would provide an important theoretical basis for elucidating the biological function of CaSAMS3 in the regulation of caffeine synthesis, and provides a potential target for improving coffee quality and resistance.

Date palm (Phoenix dactylifera) is a key economic crop in arid and semi-arid regions, which possesses ecological functions of sand fixation and water conservation, economic value driven by deep processing, as well as profound religious and cultural significance. This paper reviews the research progress in its genetic breeding from the following aspects. In germplasm resources, core germplasm banks have been established by institutions such as King Faisal University of Saudi Arabia, the National Plant Gene Bank of Iran, and the Chinese Academy of Tropical Agricultural Sciences. The institutions preserve germplasm resources by combining technologies like smart irrigation and cryopreservation, while molecular marker technologies including SSR and SNP have been applied to reveal genetic differences among date palm varieties. In breeding methods, traditional selection and hybrid breeding have laid the foundation for date palm breeding. Modern biotechnologies such as high-throughput sequencing, somatic embryogenesis, and CRISPR/Cas9 have accelerated the process of precision breeding. The current core challenges in date palm breeding include difficulty in early sex identification due to dioecy, a complete growth cycle exceeding 10 years, highly heterozygous genome, and lagging molecular research. Future breeding efforts should focus on developing varieties resistant to abiotic stresses such as hot temperature, drought and salinity-alkalinity, preventing and controlling pests and diseases including red palm weevil, Fusarium spp., and leaf spot disease, and optimizing fruit yield and quality. Meanwhile, it is necessary to deepen research on genetic mechanisms, break through bottlenecks in gene editing technology, and strengthen international exchange and cooperation of germplasm resources, to promote the sustainable development of the global date palm industry.

Determining the appropriate nitrogen application rate for Ficus hirta Vahl. is one of the key cultivation techniques for establishing an efficient and ecological "rubber-Ficus hirta Vahl." agroforestry system. This study evaluated five nitrogen application treatments, 0, 150, 225, 300 and 375 kg/hm² (denoted as CK, N₁₅₀, N₂₂₅, N₃₀₀ and N₃₇₅), and conducted a comprehensive analysis of the suitable nitrogen rate from the perspectives of productivity, resource use efficiency, and ecological footprint. The results showed that, compared with the CK treatment, nitrogen application significantly increased the yield, biomass, and economic benefits. Among the treatments, N₂₂₅ and N₃₀₀ performed the best, achieving a yield of 15 438 and 15 150 kg/hm² and an economic benefit of 60 950 and 57 555 yuan/hm², respectively (P<0.05). Compared with CK, nitrogen application significantly improved solar utilization efficiency by 59.1%-76.9%, but significantly reduced carbon efficiency by 46.2%-73.7%. The partial factor productivity from applied nitrogen also decreased significantly with increasing nitrogen application (P<0.05). N₁₅₀ exhibited the best overall performance in resource use efficiency, followed by N₂₂₅. Similarly, N₁₅₀ showed the best overall performance in terms of carbon and nitrogen footprints, followed by N₂₂₅. Nitrogen uptake in Ficus hirta Vahl. across different treatments ranged from 117.8 to 174.0 kg/hm², with the CK and N₁₅₀ showing higher nitrogen uptake than nitrogen input. Taking into account the productivity, resource use efficiency, ecological footprint and sustainability of nitrogen supply, this study concludes that N₂₂₅ is the suitable nitrogen application rate for establishing an efficient and ecological "rubber-Ficus hirta Vahl." agroforestry system.

Ocimum gratissimum is widely utilized due to its significant medicinal and culinary value. However, substantial variations in volatile components and medicinal metabolite content exist among different germplasms, influenced by geographical origin, cultivation conditions, and environmental factors. The variations directly impact the stability of pharmacological efficacy and industrial-scale production. To address this, the present study employed an integrated metabolomics and transcriptomics approach to systematically investigate the aroma profiles, metabolite composition, and regulatory mechanisms of two distinct O. gratissimum germplasms (G096 and G134). Sensory evaluation confirmed that both accessions exhibited a characteristic clove-like aroma. Metabolomic analysis identified 1094 volatile metabolites, with 784 showing significant differential accumulation between the two germplasms. Correlation analysis between differential metabolites and sensory attributes revealed that eugenol was the key metabolite responsible for the distinctive flavor of O. gratissimum. Transcriptomic profiling identified 54 936 differentially expressed genes (DEGs), including 27 220 upregulated and 27 716 downregulated genes. Through metabolic pathway prediction, a biosynthetic pathway for eugenol in O. gratissimum was constructed, identifying PAL, C4H, 4CL, HCT and C3'H as critical regulatory genes governing eugenol biosynthesis. This study would not only elucidate the biosynthetic mechanism of the primary flavor compounds in O. gratissimum, but also provide a crucial molecular theoretical foundation for quality improvement and standardized production. The findings would hold significant scientific and practical value for advancing the industrial development of O. gratissimum.

Pineapple (Ananas comosus) ranks as the world's third most important tropical fruit and is a significant economic crop in China's tropical regions. To investigate the role of the dihydroflavonol 4-reductase (DFR) gene family in anthocyanin accumulation in pineapple and provide a theoretical foundation for germplasm improvement, this study identified and preliminary functionally analyzed members of the pineapple DFR gene family. A total of 17 dihydroflavonol 4-reductase genes were identified in the whole genome of pineapple, which were named AcDFR1 to AcDFR17 and distributed unevenly on 10 chromosomes. AcDFRs encoded proteins ranging from 313 to 378 amino acids (aa) in length, with molecular weights between 34.73 and 47.74 kDa and isoelectric points (pI) from 5.10 to 8.9. The secondary structure of AcDFR proteins primarily consisted of α-helices and β-sheets, with α-helix content ranging from 38.73% to 43.07% and β-sheet content from 13.24% to 15.64%. Phylogenetic analysis revealed that the 17 AcDFRs formed four subfamilies. The motif arrangement and number of exons were similar among AcDFRs. The AcDFR genes promoter regions contained multiple cis-acting elements responsive to light, hormones, abiotic stress, growth and development. Real-time quantitative PCR analysis revealed significant expression variations of AcDFRs genes across different pineapple tissues (roots, stems, leaves, flowers, pulp, peel), though most genes exhibited high expression in both pulp and peel. Cloning and identification of AcDFRs revealed sequences largely consistent with predicted sequences. Subcellular localization studies of the AcDFR1 in tobacco leaves via transient expression indicated localization to the cytoplasm and cell membrane. The findings would provide theoretical references for further investigation into the functions of the dihydroflavonol-4-reductase gene family in pineapple and for pineapple quality improvement.

This study systematically analyzed the nutritional composition, active ingredient content, and antioxidant activity of Camellia oleifera Abel. seed cake (COSC) from Yunnan and Jiangxi provinces. The results revealed significant differences in nutritional composition between the two regional samples. COSC from Jiangxi exhibited higher moisture (8.57%), ash (12.31%), and total dietary fiber content (62.73 g/100 g), whereas the Yunnan sample possessed higher levels of crude fat (11.47%), crude protein (12.14%), and total amino acids (0.99 g/100 g). Both samples were rich in beneficial compounds, including vitamin E, vitamin K₃, oleic acid, and linolenic acid. The Yunnan sample contained higher levels of mineral elements such as phosphorus, sulfur, and potassium. Regarding bioactive compounds, Jiangxi COSC showed higher total phenolic (3.29 μg/mg) and total flavonoid (66.75 μg/mg) content, while Yunnan COSC exhibited higher polysaccharide (48.32 μg/mg) and tea saponin (222.10 μg/mg) content. Antioxidant activity analysis indicated that Jiangxi COSC demonstrated stronger DPPH radical scavenging capacity and ferric reducing antioxidant power (FRAP), whereas Yunnan COSC showed superior ABTS cation radical scavenging activity. In summary, Yunnan COSC is suitable for developing high-protein supplements, while Jiangxi COSC is more appropriate for high-fiber feed applications. Both samples exhibited promising antioxidant activity, indicating potential for functional product development. This study would provide a theoretical foundation for the resource utilization and value-added applications of C. oleifera seed cake.

This study investigated the quality variation and climatic adaptation mechanisms of Hainan large-leaf and Yunnan large-leaf black tea through multi-component analysis and aroma characterization of tea samples from Wuzhishan, Wanning, and Baisha. The results demonstrated that Hainan large-leaf tea exhibited superior photosynthetic performance in Wanning and Wuzhishan, with maximum net photosynthetic rate reaching 7.28 μmol/(m²·s), accompanied by high amino acid content (up to 93.50 μmol/g) and moderate caffeine levels (3.93%-4.31%), forming a distinctive "high amino acid-moderate astringency" flavor profile. Aroma component analysis revealed significant regional differences in Hainan large-leaf tea, with Wanning characterized by benzaldehyde (14.51%)-dominant fruity notes and Baisha featuring linalool (31.18%)-rich floral aroma. Climatic adaptability analysis indicated that higher temperatures in Wanning (annual average 24.40 ℃) promoted the synthesis of tea polyphenols and catechins, while the cooler climate of Baisha (annual average 22.30 ℃) was more conducive to theaflavins formation and aroma compound accumulation. Compared with Yunnan large-leaf tea, Hainan large-leaf tea showed significant advantages in photosynthetic efficiency, amino acid accumulation, and aroma composition. The findings would provide theoretical support for optimizing production regions and developing characteristic products of Hainan black tea, with important implications for enhancing its market competitiveness.

To establish a regeneration system for somatic embryo-derived plants from the anthers of the triploid rubber tree clone Yunyan 73-46, this study utilized anthers as explants and employed an orthogonal experimental design to examine the effects of various hormone combinations on callus and somatic embryo induction efficiency. Furthermore, the morphological characteristics and differentiation capacity of callus under different culture duration were analyzed. Hormones were crucial for callus induction. In the absence of hormones, anthers failed to dedifferentiate and underwent browning and necrosis after 10d. In media containing 2,4-D, NAA, KT and TDZ, anther dedifferentiation to produce callus occurred with induction rates ranging from 15% to 91.56%, with a mean of (69.41±30.37)%. The impact of 2,4-D, NAA, KT and TDZ on callus induction rate and subsequent somatic embryogenesis rate were all highly significant (P<0.01), with the order of influence being 2,4-D>TDZ>NAA>KT. The optimal combination identified through comprehensive screening was 2,4-D 1.0 mg/L+NAA 0.8 mg/L+TDZ 0.02 mg/L. Upon verification, the callus induction rate and subsequent somatic embryogenesis rate was (86.15±1.53)% and (14.46±0.89)%, respectively, marking significant improvements of 2.31% and 5.40% over the best experimental combination (G7). The somatic embryogenesis capacity of this clone was generally low, with somatic embryo formation rates ranging from 6.91% to 19.31%, with a mean of (10.58±3.95)%. The effects of 6-BA, ABA, NAA and KT on somatic embryogenesis rate were highly significant (P<0.01), with the order of influence being ABA>6-BA>NAA>KT. The optimal combination was 6-BA 0.4 mg/L+ABA 0.2 mg/L+NAA 0.2 mg/L+KT 0.2 mg/L (M9), achieving a somatic embryogenesis rate of (19.31±0.60)%, which was significantly higher than other treatments. The optimal culture duration for callus was determined to be 55 d, which exhibited superior growth status without browning and the strongest somatic embryo differentiation capacity. The somatic embryogenesis rate was (30.83±1.67)%, the cotyledonary embryo formation rate was (18.33±0.83)%, and the average number of somatic embryos was (0.63±0.03), all of which were extremely significantly higher than those at other culture durations. By optimizing the hormone ratios during callus induction and somatic embryogenesis stages of Yunyan 73-46 anthers, coupled with adjusting the duration of callus induction culture, the production efficiency of anther-derived somatic embryo plantlets can be significantly enhanced. This approach would provide technical support for establishing a large-scale propagation system of somatic embryo plantlets for triploid rubber tree clones.