Microplastics and nanoplastics (MPs/NPs) are posing emerging potential threats to global ecosystems and human health. Recently, the individual effects of MPs/NPs and combined effects of MPs/NPs-coexisting pollutants on soil–terrestrial plant systems have attracted increasing attention. Based on the latest research progress, this review firstly summarized the sources of MPs/NPs and the interaction between MPs/NPs and coexisting pollutants in soil environment, and then systematically induced their multilevel impacts on soil properties and terrestrial plants. Soil and agroecosystem are major long-term sinks of primary and secondary MPs/NPs, with extensive sources. MPs/NPs exhibit universal adsorption capacities and can further serve as the vectors for varied heavy metal, organic and biological contaminants. Generally, MPs/NPs and the combination with coexisting contaminants may affect soil physical, chemical and microbiological properties, soil structure and functions, while the specific impacts and degree depend on MP/NP characteristics including polymer type, size, shape, concentration and degradability. Increasing evidence confirmed the uptake and translocation of MPs/NPs in terrestrial plants and proved their influence on growth performance, metabolism and physiological toxicity, as well as cytotoxicity and genotoxicity. The specific effects vary as a function of MP/NPs properties, plant species and environmental conditions. The joint effects of MPs/NPs and coexisting pollutants are complex, and synergistic, antagonism and neutralization effects have been reported at different circumstances. Further comprehensive and in-depth studies are urgently needed to fulfill the current knowledge gaps, especially the deficiency in the inherent mechanisms.

Camellia chekiangoleosa has a higher oleic acid content and a shorter reproductive cycle than typical oil tea plants. It was intensively sampled over six C. chekiangoleosa seed development stages. The content of fatty acids determined by GC showed that the accumulation of fatty acids gradually increased from the S1 to S5 stages, and the maximum concentration was reached in S5. Then, fatty acids declined slightly in S6. The main fatty acid component showed the same accumulation trend as the total fatty acids, except linolenic acid, which remained at a low level throughout seed developmental stages. Changes in the expression of fatty acid accumulation-related genes were monitored using second-generation and SMRT full-length transcriptome sequencing. Finally, 18.92 G accurate and reliable data were obtained. Differential expression analysis and weighted coexpression analysis revealed two "gene modules" significantly associated with oleic acid and linoleic acid contents, and the high expression of ENR, KAS I, and KAS II, which accumulate substrates for oleic acid synthesis, was thought to be responsible for the rapid accumulation of fatty acids in the early stage. The rapid increase in fatty acids in the second stage may be closely related to the synergy between the high expression of SAD and low expression of FAD2. In addition, many transcription factors, such as ERF, GRAS, GRF, MADS, MYB and WRKY, may be involved in the fatty acid synthesis. Our data provide a rich resource for further studies on the regulation of fatty acid synthesis in C. chekiangoleosa.

Tilia miqueliana Maxim., a tall deciduous tree in the Malvaceae family, is native to china and is cultivated in the Jiangsu, Zhejiang, Anhui, and Jiangxi provinces as an ornamental plant. T. miqueliana has currently received increased attention because of its value as timber, a source plant for honey, and in formal landscape architecture (Wang et al. 2022). In the last three years, symptoms of leaf spot disease were observed in T. miqueliana fields （9-year-old tree）and a breeding nursery _(1-year-old saplings) in Nanjing, Jiangsu Province, China. Field surveys showed that, the disease incidence was approximately 10% and 40% in the fields and breeding nursery, respectively. Symptoms of leaf spot disease on T. miqueliana appeared as small, circular, or near-circular/irregular black lesions on the upper surfaces of the leaves. As the disease progressed, the spots expanded into irregular shapes with the center turning yellow to black and leaves wilted from margins to centers. In severe cases, the yellow necrotic area extended to the margin, which ultimately led to leaf curling and death. To analyze the presence of the pathogenic microorganism, pieces of leaf at the junction of diseased and healthy tissue (about 3x3 mm) were taken from symptomatic plants, sterilized with 75% ethanol for 1 min and 2% sodium hypochlorite (NaClO) for 2 min, and washed 3 times with ddH2O. The leaf pieces were transferred onto Potato Dextrose Agar (PDA) plates and incubated at 28°C for 3 days in the dark. Colonies were observed and transferred to fresh PDA plates. Sixteen fungal isolates were obtained and one (named D4-2) of them was verified using Koch's assumption. Single spores of D4-2 were cultured in PDA medium, while its initial colony morphology was fluffy white colonies, which then gradually turned dark yellow from the centre to the edge. To further analyze the form of the spores, a hypha was incubated on fresh synthetic low-nutrient agar (SNA) using cellophane and inverted cultivation was performed for 20 days in the dark. Obclavate or obpyriform conidia (10 to 30 × 2 to 18 µm, n=5) were produced in chains and were pale brown to brown in color. The morphology was consistent with that of Alternaria sp.. The molecular identification of the isolated representative fungus D4-2 was conducted via the amplification of the internal transcribed spacer (ITS) (White et al. 1990),translation elongation factor 1 alpha (TEF) (Carbone and Kohn. 1999), glyceraldehyde-3-dehydrogenase (GAPDH) (Berbee et al. 1999) and RNA polymerase II beta subunit (RPB2) using the primer pairs ITS1/ITS4, EF1-728F/EF1-986R, GPD1/GPD2, and RPB2-5F2/fRPB2-7cR (Sung et al. 2007) respectively. All these sequences were deposited in GenBank under accession numbers OP108438 (ITS), OP168372 (RPB2), OQ473880 (TEF), and OP168374 (GAPDH). Based on the GAPDH, RPB2, and TEF regions of D4-2, MEGA-11 was used to construct a neighbor-joining tree (1000 replications) with 31 other known species that had a relatively close evolutionary relationship with species from the Alternaria genus (Woudenberg et al. 2013). The phylogenetic tree indicated 100% bootstrap support between D4-2 and A. alternata. The branches showing the distribution of other species were exactly the same as that of the consensus tree based on the Bayesian 50 % majority rule that represented the Alternaria-complex (Woudenberg et al. 2013). The initial Koch's Postulates was verified using PDA slices with mycelium (pure PDA slices were used as control) that were inverted on the leaves at 25℃ for 3 days before removing slices and observing the phenotype after 7 days. Only leaves infected with D4-2 showed the same symptoms. Moreover, the spore suspension (at a concentration of 107 spores/mL) of D4-2 was applied to the leaves of T. miqueliana seedlings. After 15 days of incubation at 26 ℃ , the leaves showed the same symptoms. Subsequently, the pathogen was reisolated and cultured from these invaded leaves using the same method described above. Morphological and molecular identifications were consistent with those of D4-2. Above all, the pathogenic fungus (D4-2) isolated from T. miqueliana leaves was confirmed to be A. alternata. T. miqueliana is considered to be an endangered species due to the deep dormancy of its seeds that result in a low natural germination rate (Wu and Shen. 2021). At present, research on T. miqueliana mainly focuses on seed germination and breeding technology, and there is hardly any research on the diseases occurring in T. miqueliana. Therefore, we believe that this is the first report of leaf spot disease caused by A. alternata on T. miqueliana in China.