Yong Wang

Solar radiation is the foundation of efficient greenhouse production. Studying how structural parameters affect light transmission and solar energy utilization efficiency is crucial for optimizing greenhouse design and increasing crop yields. This study constructed a full-process solar radiation model using ray tracing technology. It examined the solar radiation energy intercepted, captured, and distributed by the greenhouse. The simulation yielded high prediction accuracy and rapid subsequent computation after pre-calculation of the shape factor matrix. The coefficient of determination R² was at least 0.95 for four observation points, with computations for 51 time points completed within 125 s. Subsequently, a comparative analysis of large-span insulated plastic greenhouses with different parameters was conducted during the cold and warm seasons based on eight representative solar terms. The results indicated that for a 20-m-span greenhouse at 35° N, an east-west orientation with a 15 m south roof and a 6 m ridge was better for the cold season. For comprehensive seasonal adaptability, a north-south orientation with a 5 m ridge was recommended. This study provides seasonal-oriented decision support for the structural parameter design of large-span insulated plastic greenhouses.

Although peanut shells represent an abundant agricultural waste, their high-value utilization potential as a horticultural substrate has not been fully recognized. Meanwhile, horticultural crops such as tomatoes are in urgent demand for high-quality and innovative cultivation substrates. This study investigated the effects of different ratios of peanut shell–substrate on tomato yield and rhizosphere bacterial community structure, aiming to provide a theoretical basis for the utilization of agricultural waste and the development of novel growth substrates for tomato cultivation. Results showed that peanut shell–substrate improved tomato yield and quality, and enhanced soil urease, sucrase, and catalase activities. High-throughput 16S rRNA gene sequencing revealed significant differences in rhizosphere bacterial alpha diversity between peanut shell substrates and the control. Proteobacteria, Acidobacteria, and Actinobacteriota were the dominant phyla, while unclassified genera, Devosia A_501803 and Bauldia, were identified as the core genera at the genus level. In conclusion, peanut shell substrates enriched dominant functional bacterial genera and enhanced the ecological functions of the substrate.

Leaf angle is a key agronomic trait for improving planting density and yield in lettuce, particularly in controlled‐environment agriculture and high‐density field cultivation. Leaf angle regulation is well studied in monocots; however, the genetic and molecular mechanisms in dicots remain largely unknown. Here, we genetically clone and functionally characterize LsOFP6a , an OVATE family protein gene, as a key regulator of leaf angle in lettuce. A nonsense mutation in LsOFP6a in large‐leaf‐angle cultivars produces a truncated protein with impaired function. CRISPR/Cas9 knockout and complementary tests confirmed that LsOFP6a negatively regulates leaf angle in lettuce. LsOFP6a physically interacts with the BELL‐like homeodomain transcription factor LsBLH2. Genetic analyses revealed that LsOFP6a regulates leaf angle through an LsBLH2 ‐dependent pathway, and LsBLH2 is recessive‐epistatic to LsOFP6a . LsBLH2 directly upregulates the expression of the cytokinin oxidase gene LsCKX5a . LsOFP6a represses the transcriptional activity of LsBLH2 on LsCKX5 , leading to elevated cytokinin levels and small leaf angle. Furthermore, LsOFP6a inhibits the effects of LsBLH2 on repressing abaxial gene LsYAB1 , leading to enhanced abaxial cell elongation and erect leaves. Loss of function of LsOFP6a decreases the cytokinin level and represses abaxial cells, resulting in large leaf angles. In summary, the LsOFP6a–LsBLH2 module orchestrates cytokinin catabolism and leaf dorsiventrality to regulate lettuce leaf angle. Our study suggests potential novel strategies for the breeding of lettuce with compact architecture and suitable for high‐density planting in the open field and plant factories.

Pumpkin is widely used as a functional food for people and rootstock for other Cucurbitaceae crops. Se-enriched pumpkin can be used as an important Se source for humans. However, the boundary between beneficial and phytotoxic levels of Se is narrow. Here, effects of selenite with different concentrations (2–80 μM) on pumpkin growth and Se accumulation in pumpkin seedlings were explored. Our results revealed that Se accumulations in both shoots and roots of C. moschata were closely related to selenite doses. Selenite seemed to have no positive effects on C. moschata growth. The root activity increased at 2–20 μM of selenite, but significantly decreased at higher doses. High concentrations of selenite (above 40 μM) resulted in serious O₂^•– accumulation, growth inhibiting and even symptoms of toxicity, which could be alleviated by melatonin. Transcriptome analysis revealed that a series of defense mechanisms, including Ca²⁺ signaling, ET and JA signaling, antioxidant defense systems, MAPK cascade, proteostasis protection, could be activated in roots of C. moschata in response to 40 μM selenite. Additionally, we identified some important genes probably involved in Se absorption and conversion in C. moschata, such as PHT, SULTR, APS, APK, APR, SiR, GR, and CS genes. These results may help our understanding of the physiological and molecular mechanisms of Se accumulation and tolerance to Se toxicity in C. moschata, which may provide genetic resources and a theoretical basis for the breeding and cultivation of Se-rich pumpkin or rootstocks.

Members of homeodomain-leucine zipper (HD-Zip) transcription factors can play their roles by modulating abscisic acid (ABA) signaling in Arabidopsis. So far, our knowledge of the functions of HD-Zips in woodland strawberries (Fragaria vesca), a model plant for studying ABA-mediated fruit ripening, is limited. Here, we identified a total of 31 HD-Zip genes (FveHDZ1-31) in F. vesca, and classified them into four subfamilies (I to IV). Promoter analyses show that the ABA-responsive element, ABRE, is prevalent in the promoters of subfamily I and II FveHDZs. RT-qPCR results demonstrate that 10 of the 14 investigated FveHDZs were consistently >1.5-fold up-regulated or down-regulated in expression in response to exogenous ABA, dehydration, and ABA-induced senescence in leaves. Five of the six consistently up-regulated genes are from subfamily I and II. Thereinto, FveHDZ4, and 20 also exhibited significantly enhanced expression along with increased ABA content during fruit ripening. In yeast one-hybrid assays, FveHDZ4 proteins could bind the promoter of an ABA signaling gene FvePP2C6. Collectively, our results strongly support that the FveHDZs, particularly those from subfamilies I and II, are involved in the ABA-mediated processes in F. vesca, providing a basis for further functional characterization of the HD-Zips in strawberry and other plants.

As a glycophyte plant, pepper (Capsicum annuum L.) is widely cultivated worldwide, but its growth is susceptible to salinity damage, especially at the seedling stage. Here, we conducted a study to determine the physiological and transcriptional differences between two genotype seedlings (P300 and 323F3) with contrasting tolerance under salt stress. The P300 seedlings were more salt-tolerant and had higher K⁺ contents, higher antioxidase activities, higher compatible solutes, and lower Na⁺ contents in both their roots and their leaves than the 323F3 seedlings. During RNA-seq analysis of the roots, more up-regulated genes and fewer down-regulated genes were identified between salt-treated P300 seedlings and the controls than between salt-treated 323F3 and the controls. Many ROS-scavenging genes and several SOS pathway genes were significantly induced by salt stress and exhibited higher expressions in the salt-treated roots of the P300 seedlings than those of 323F3 seedlings. Moreover, biosynthesis of the unsaturated fatty acids pathway and protein processing in the endoplasmic reticulum pathway were deeply involved in the responses of P300 to salt stress, and most of the differentially expressed genes involved in the two pathways, including the genes that encode mega-6 fatty acid desaturases and heat-shock proteins, were up-regulated. We also found differences in the hormone synthesis and signaling pathway genes in both the P300 and 323F3 varieties under salt stress. Overall, our results provide valuable insights into the physiological and molecular mechanisms that affect the salt tolerance of pepper seedlings, and present some candidate genes for improving salt tolerance in pepper.

The excessive accumulation of copper (Cu²⁺) has become a threat to worldwide crop production. Recently, it was revealed that melatonin (MT) could play a crucial role against heavy metal (HM) stresses in plants. However, the underlying mechanism of MT function acted upon by Cu²⁺ stress (CS) has not been substantiated in tomatoes. In the present work, we produced MT-rich tomato plants by foliar usage of MT, and MT-deficient tomato plants by employing a virus-induced gene silencing methodology and exogenous foliar application of MT synthesis inhibitor para-chlorophenylalanine (pCPA). The obtained results indicate that exogenous MT meaningfully alleviated the dwarf phenotype and impeded the reduction in plant growth caused by excess Cu²⁺. Furthermore, MT effectively restricted the generation of reactive oxygen species (ROS) and habilitated cellular integrity by triggering antioxidant enzyme activities, especially via CAT and APX, but not SOD and POD. In addition, MT increased nonenzymatic antioxidant activity, including FRAP and the GSH/GSSG and ASA/DHA ratios. MT usage improved the expression of several defense genes (CAT, APX, GR and MDHAR) and MT biosynthesis-related genes (TDC, SNAT and COMT). Taken together, our results preliminarily reveal that MT alleviates Cu²⁺ toxicity via ROS scavenging, enhancing antioxidant capacity when subjected to excessive Cu²⁺. These results build a solid foundation for developing new insights to solve problems related to CS.

Simple sequence repeats (SSRs) are widely used in mapping constructions and comparative and genetic diversity analyses. Here, 103,056 SSR loci were found in Cucurbita species by in silico PCR. In general, the frequency of these SSRs decreased with the increase in the motif length, and di-nucleotide motifs were the most common type. For the same repeat types, the SSR frequency decreased sharply with the increase in the repeat number. The majority of the SSR loci were suitable for marker development (84.75% in Cucurbita moschata, 94.53% in Cucurbita maxima, and 95.09% in Cucurbita pepo). Using these markers, the cross-species transferable SSR markers between C. pepo and other Cucurbitaceae species were developed, and the complicated mosaic relationships among them were analyzed. Especially, the main syntenic relationships between C. pepo and C. moschata or C. maxima indicated that the chromosomes in the Cucurbita genomes were highly conserved during evolution. Furthermore, 66 core SSR markers were selected to measure the genetic diversity in 61 C. pepo germplasms, and they were divided into two groups by structure and unweighted pair group method with arithmetic analysis. These results will promote the utilization of SSRs in basic and applied research of Cucurbita species.