Light is one of the important environmental factors affecting the growth and development of facility vegetables. In this experiment, we investigated the effects of different light intensities on the growth, nutritional quality and flavonoid accumulation of celery under hydroponic and full LED light conditions. Four light intensities of 40, 100, 200, or 300 µmol·m^-2·s^-1 were set up in the experiment, and three harvest periods were set up on the basis of different light intensities, which were 15, 30, and 45 d after treatment (labeled as S1, S2, and S3, respectively). The results showed that the plant height and aboveground biomass of celery increased with the increase of light intensity, and the light intensity of 200 μmol·m^-2·s^-1 was beneficial to increase the contents of chlorophyll, carotenoids, total phenols, vitamin C, cellulose, total flavones and apigenin in celery. During the S1-S3 period, the activities of PAL, CHS, CHI and ANS increased gradually under 200 and 300 μmol·m^-2·s^-1 light intensity treatments, and the activities of FNS and CHS enzymes were the highest under 200 μmol·m^-2·s^-1 light intensity treatment. The expression and ANS activity of Ag3GT, a key gene for anthocyanin synthesis, reached the maximum value at 300 μmol·m^-2·s^-1, and the expression level and FNS activity of AgFNS, a key gene for apigenin synthesis, reached a maximum value at 200 μmol·m^-2·s^-1. In general, the anthocyanin content was the highest at 300 μmol·m^-2·s^-1, and the apigenin content was the highest at 200 μmol·m^-2·s^-1. In conclusion, light intensity of 200 µmol·m^-2·s^-1 treatment was more favorable for celery growth and nutrient synthesis.

The plant growth, stem sap flow, Na⁺ and Cl⁻ content, and the expression of vacuolar Na⁺/H⁺ antiporter gene (LeNHX1) in the leaves and roots of tomato under different NaCl stresses (0.5% and 1%) were studied to analyze the effect of arbuscular mycorrhizal fungi (AMF) on Na⁺ and Cl⁻ accumulation and ion exchange. The results showed that arbuscular mycorrhizal (AM) plant growth and stem sap flow increased and salt tolerance improved, whereas Na⁺ and Cl⁻ accumulated. Na⁺ significantly decreased, and no significant decline was detected in Cl⁻ content after AMF inoculation compared with the non-AM plants. The LeNHX1 gene expression was induced in the AM and non-AM plants by NaCl stress. However, AMF did not improve the LeNHX1 level, and low expression was observed in the AM tomato. Hence, the mechanism that reduced the Na⁺ damage to tomato induced by AMF has little relation to LeNHX1, which can export Na⁺ from the cytosol to the vacuole across the tonoplast.

Background: Chayote is a high economic crop in the Cucurbitaceae family, playing an important role in food production, disease treatment and the production of degradable materials in industries. Due to the harsh environment, such as high temperature, drought and frost, some chayote resources are gradually disappearing. It is crucial to collect, characterize, and conserve chayote resources. However, the genetic diversity of chayote resources in China has not been studied so far. Results: In this study, we collected 35 individuals of chayote from 14 provinces in China. Subsequently, we found 363,156 SSR motifs from the chayote genome and designed 57 pairs of SSR primers for validation. Out of these, 48 primer pairs successfully amplified bands, with 42 of them showing polymorphism. These 42 primer pairs detected a total of 153 alleles, averaging 3.64 alleles per locus. The polymorphic information content ranged from 0.03 to 0.78, with an average value of 0.41, indicating a high level of polymorphism. Based on the analysis using STRUCTURE, PCoA, and UPGMA methods, the 35 chayote individuals were divided into two major clusters. Through further association analysis, 7 significantly associated SSR markers were identified, including four related to peel color and three related to spine. Conclusions: These molecular markers will contribute to the analysis of genetic diversity and genetic breeding improvement of chayote in the future.

Cadmium (Cd) in farmland soils has severely hindered agricultural production. Our previous studies have found that the combined application of silicon (Si) and iron (Fe) can effectively alleviate cadmium toxicity in tomatoes. But the underlying mechanisms remain unclear. In this study, authors investigated the effects of individual or combined application of silicon and iron by physiological, biochemical (mainly on cell wall components) and transcriptomic analysis under cadmium stress. The results showed that the application of silicon and iron under cadmium stress effectively reduced cadmium accumulation in the roots of tomato seedlings, with the combined application of silicon and iron showing the best effect. It also significantly reduced cadmium accumulation in the stems and leaves of the aboveground parts. The cadmium content in the cell wall was significantly higher than that in the soluble fraction and organelles. Compared to the cadmium treatment alone, the application of silicon and iron increased the content of pectin and hemicellulose in the root cell wall, decreased cellulose content, downregulated the expression of ABCA1, and upregulated the expression of HMA5. However, the application of silicon alone resulted in higher cadmium accumulation in pectin and hemicellulose in the root cell wall, while the combined application of Silicon and Iron reduced cadmium content in the cell wall components and resulted in the highest expression of HMA5, which reduced the accumulation of cadmium in roots and its translocation to the aboveground parts. Based on transcriptome KEGG differential enrichment analysis, CSF vs Cd phenylpropane synthesis pathway and pectin metabolism gene expression were up-regulated and down-regulated, respectively, suggesting that the application of Si and Fe may remodel the cell wall and enhance Cd fixation by alleviating excessive cellular lignification as well as sustaining pectin methyl esterification. This indicated that the combined application of silicon and iron could reduce cadmium uptake and accumulation in tomato seedlings by regulating cell wall components and cadmium transport-related gene expression. The synergistic application of silicon and iron effectively reduces cadmium uptaking and accumulation in tomato seedlings by modifying cell wall composition and regulating key metal transport genes. This strategy presents a promising approach for mitigating cadmium toxicity in crops.

Two pot experiments were conducted to study the effects of intercropping with cadmium (Cd) accumulator plant Eclipta prostrata and hyperaccumulator plant Crassocephalum crepidioides on the growth and Cd accumulation of tomato seedlings. In the preliminary experiment, intercropping with E. prostrata and C. crepidioides promoted the growth and decreased the Cd content in roots and shoots of tomato seedlings. In the further experiment, intercropping with E. prostrata and C. crepidioides had the same effects on the growth and Cd content of tomato seedlings as the preliminary experiment. In the further experiment, when three plant species (E. prostrate, C. crepidioides and tomato) intercropping together, the root and shoot biomasses of tomato seedlings got the maximum, and the Cd content in tomato seedlings got the minimum. Compared with the monoculture of tomato, three plant species intercropping increased the root and shoot biomasses of tomato seedlings by 49.28% and 64.19%, respectively, and decreased the Cd contents in roots and shoots of tomato seedlings by 17.35% and 22.35%, respectively. Intercropping with E. prostrata and C. crepidioides also increased the photosynthetic pigment content and enhanced the antioxidant enzyme activity of tomato seedlings. For accumulator and hyperaccumulator plants, intercropping with tomato inhibited the growth of E. prostrata and C. crepidioides, while increased the Cd content in two plant species. Therefore, intercropping with E. prostrata and C. crepidioides could promote the growth and reduce the Cd uptake of tomato seedlings, and three plant species intercropping together was the best combination.