Symplocos paniculate is an oil plant exhibiting tissue-specific variations in oil content and fatty acid composition across the whole fruit (mainly pulp and seed). And its oil synthesis is intricately linked to the accumulation and transformation of sugars. Nevertheless, there remains a dearth of understanding regarding how sugar metabolism impacts oil synthesis in S. paniculate fruit. To unravel the intricate mechanism underlying the impact of sugar metabolism on lipid biosynthesis in S. paniculata fruit, a comparative analysis was conducted on the transcriptome and metabolite content of pulp and seed throughout fruit development. The findings revealed that the impact of sugar metabolism on oil synthesis varied across different stages of fruit development. Notably, during the early fruit developmental stage (from 90 to 120 DAF), pivotal genes involved in sugar metabolism, such as PGK3, PKP1, PDH-E1, MDH, and malQ, along with key genes associated with oil synthesis like KAR, HAD, and PAP were predominantly expressed in the pulp. Consequently, this preferential expression led to earlier accumulation of oil in the pulp tissue compared to the seed. Whereas, during the fruit maturity stage (from 120 DAF to 140 DAF), these genes exhibited a high level of expression in seed, thereby facilitating the rapid and substantial accumulation of seed oil compared to pulp. The sugar metabolism activity in various parts of S. paniculata fruit plays a pivotal role in oil synthesis and is contingent upon the developmental stage. These findings can offer alternative genes for further gene enhancement through molecular biotechnology, thereby augmenting fruit oil yield and altering fatty acid composition.

Litsea cubeba Pers., a dioecious species, is an important tree species for the bioenergy industry with great potential for lead (Pb)-polluted soil phytoremediation. However, the sex-specific morphological and physiological characteristics of L. cubeba under Pb stress remain largely unknown. In this study, L. cubeba was used as a study model to identify sex differences in leaf traits, chlorophyll, photosynthetic gas parameters, chlorophyll fluorescence, Pb subcellular distribution, and photosynthesis-related nutrient contents in chloroplasts and cell nuclei under three different Pb concentrations [0 (CK), 1 (P1), 2 (P2), and 3 (P3) mmol/kg]. The results indicate that Pb stress significantly decreases photosynthetic leaf pigments in both sexes, mainly caused by changes in Ca, Mg, and Mn contents. Furthermore, L. cubeba male plants exhibited greater adaptability to Pb stress by enlarging their leaf area, enhancing photosynthesis and excess light energy in the form of heat dissipation when compared to female plants. Notably, we observed that more Pb reached the organelle fraction and damaged chloroplasts and mitochondria in female leaves under high-level Pb treatments compared to those of the opposite sex. Transcriptome analysis demonstrated that Pb stress could significantly up-regulate more genes involved in photosynthetic antenna proteins and photosynthesis pathways in male leaves than in female leaves. Taken together, L. cubeba male plants are clearly more resistant to Pb toxicity than female plants—at least under the described Pb treatments—which is most likely due to differences in Pb allocation. This research offers a theoretical foundation for the utilization of male and female L. cubeba as suitable plants for the remediation of Pb-polluted soil.

The aim of present study was to develop an optimum extraction method for high quality edible oil from Symplocos paniculata fruit. S. paniculata fruit oils were extracted by three methods viz., cold pressing (PCP), subcritical extraction (SBE) and Soxhlet extraction (SE). A comparative analysis was performed for their physiochemical properties, fatty acid composition and bioactive substances. The oil extraction rate from SE, SBE and PCP was 36.6, 35.7 and 8.4%, respectively. Total unsaturated fatty acids present were in the range of 79.04-79.35% with 48.13-48.52% oleic acid, and 30.08-30.18% linoleic acid. The ratio of saturated fatty acids to total unsaturated fatty acids was 0.26025~0.2652. PCP extraction oil had the highest content of polyunsaturated fatty acids, while SBE extracted oil had highest content of unsaturated fatty acids, along with rich bioactive substances. Based on the criterion of extraction rate, oil composition and bioactive substances, the SBE method appeared optimum method for extracting high quality edible oil from S. paniculata fruits.

Premise Phosphorus (P) limitation in subtropical red soil is a major constraint on plant productivity. Understanding how plant species adapt to nutrient-poor conditions is a fundamental question in plant ecology. This study addresses this question by investigating the nutrient utilization strategies of four common subtropical tree species. Methods We conducted a homogeneous garden experiment on phosphorus-limited red soil with four subtropical tree species (Pinus massoniana, Liquidambar formosana, Elaeocarpus decipiens, and Schima superba). We systematically evaluated their leaf functional traits, nitrogen (N) and phosphorus (P) resorption efficiencies (NRE and PRE), and their interrelationships among these parameters. Results (1) Leaf functional traits varied significantly among species, forming a continuous resource-use spectrum from acquisitive (L. formosana) to conservative (P. massoniana), with. E. decipiens and S. superba showed intermediate strategies.2) The trait differentiation was strongly linked to nutrient resorption: the conservative species, P. massoniana exhibited the highest NRE and PRE (54.25% and 54.78%, respectively). Among broadleaved species, E. decipiens and S. superba had significantly higher NRE than L. formosana. All species exhibited strong P limitation (leaf N/P > 20), resulting in generally higher PRE than NRE, supporting the Relative Resorption Hypothesis. 3) Redundancy analysis further confirmed that conservative traits were positively correlated with resorption efficiency, identifying leaf carbon, litter nitrogen, leaf N/P ratio, and thickness as key regulatory factors. Conclusions These findings demonstrate how subtropical trees adapt to nutrient-poor soils through functional trait differentiation and nutrient resorption plasticity, offering a scientific basis for species selection in restoring degraded red soil ecosystems.