The pecan is a salt-alkali-tolerant plant, and its fruit and wood have high economic value. This study aimed to explore the molecular mechanisms responsible for salt stress tolerance in the pecan grown under hydroponic conditions to simulate salt stress. The results showed that the photosynthetic rate (Pn) was reduced in response to salt stress, while the intercellular carbon dioxide concentrations (Ci) increased. The response of the pecan to salt stress was measured using iTRAQ (isobaric tags for relative or absolute quantitation) and LC/MS (liquid chromatography and mass spectrometry) non-targeted metabolomics technology. A total of 198 differentially expressed proteins (65 down-regulated and 133 up-regulated) and 538 differentially expressed metabolites (283 down-regulated and 255 up-regulated) were identified after exposure to salt stress for 48 h. These genes were associated with 21 core pathways, shown by Kyoto Encyclopedia of Genes and Genomes annotation and enrichment, including the metabolic pathways involved in nucleotide sugar and amino sugar metabolism, amino acid biosynthesis, starch and sucrose metabolism, and phenylpropane biosynthesis. In addition, analysis of interactions between the differentially expressed proteins and metabolites showed that two key nodes of the salt stress regulatory network, L-fucose and succinate, were up-regulated and down-regulated, respectively, suggesting that these metabolites may be significant for adaptations to salt stress. Finally, several key proteins were further verified by parallel reaction monitoring. In conclusion, this study used physiological, proteomic, and metabolomic methods to provide an important preliminary foundation for improving the salt tolerance of pecans.

The Gly-Asp-Ser-Leu (GDSL)-lipase family is a large subfamily of lipolytic enzymes that plays an important role in plant growth and defense against environmental stress. However, little is known about their function in pecans (Carya illinoensis K. Koch). In this study, 87 CilGDSLs were identified and divided into 2 groups and 12 subgroups using phylogenetic analysis; members of the same sub-branch had conserved gene structure and motif composition. The majority of the genes had four introns and were composed of an α-helix and a β-strand. Subcellular localization analysis revealed that these genes were localized in the extracellular matrix, chloroplasts, cytoplasm, nucleus, vacuole, and endoplasmic reticulum, and were validated by transient expression in tobacco mesophyll cells. Furthermore, the analysis of the promoter cis-elements for the CilGDSLs revealed the presence of plant anaerobic induction regulatory, abscisic acid response, light response elements, jasmonic acid (JA) response elements, etc. The qRT-PCR analysis results in “Pawnee” with salt treatment showed that the CilGDSL42.93 (leaf) and CilGDSL39.88 (root) were highly expressed in different tissues. After salt stress treatment, isobaric tags for relative and absolute quantitation (iTRAQ) analysis revealed the presence of a total of ten GDSL proteins. Moreover, the weighted gene co-expression network analysis (WGCNA) showed that one set of co-expressed genes (module), primarily CilGDSL41.11, CilGDSL39.49, CilGDSL34.85, and CilGDSL41.01, was significantly associated with salt stress in leaf. In short, some of them were shown to be involved in plant defense against salt stress in this study.

The purpose of this study is to develop a new remote sensing method to assess the area of cultivated land illegally converted to nurseries and orchards in the Yangtze River Delta region of China over the past 40 years (1980–2020), and then estimate the increase in grain yield based on this area. Our result showed that 2.23 × 10⁴ km² of cultivated land was reduced by 11.8% over the past 40 years. About 14,521.40 km² of cultivated land was converted to nursery and orchard from 1980 to 2020. The conversion area was unevenly distributed among different administrative regions. Zhejiang and Anhui Provinces had higher conversion rate and area than Jiangsu Province and Shanghai Municipalities. After the illegal nurseries and orchards return to cultivated land, if rotation farming mode is adopted, in which each grain crop is planted only once a year, the increased production of rice, wheat, corn, beans and tubers will reach (632.57 ± 13.08) × 10⁴, (0~531.05 ± 33.25) × 10⁴, (0~556.19 ± 30.36) × 10⁴, (0~249.85 ± 13.14) × 10⁴ and (0~489.11 ± 28.14) × 10⁴ tons at most in each year, respectively. Our results provide theoretical guidance for implementing food security policies and alleviating contradiction between grain production and rural labor shortages in the Yangtze River Delta region.

Ilex verticillata (winterberry) is a valuable ornamental shrub increasingly threatened by leaf blight, a disease that compromises its aesthetic and economic value. While fungal pathogens like Alternaria alternata are known to cause leaf blight in horticultural crops, their role in I. verticillata and the host’s defense mechanisms have not been fully characterized. Our study investigated the pathogen-host interaction by identifying the causal agent and examining the physiological and molecular defense mechanisms of I. verticillata. Through morphological and multi-locus molecular analyses (ITS, TEF1-α, G3PDH, RPB2), A. alternata was confirmed as the primary pathogen, fulfilling Koch’s postulates. Pathogenicity assays revealed distinct disease progression stages, from necrotic lesions to tissue degradation. Transcriptomic profiling uncovered dynamic host responses, with early upregulation of pattern recognition receptors (PRRs) and transcripts encoding antioxidant enzymes (SOD, CAT), followed by downregulation of metabolic pathway genes. Phytohormone analysis highlighted intricate crosstalk, with salicylic acid (SA) peaking during mid-infection and jasmonic acid (JA) rebounding later, reflecting a coordinated defense strategy. Additionally, the oxidative stress marker malondialdehyde (MDA), an indicator of membrane lipid peroxidation, surged early, indicating membrane damage, while sustained induction of antioxidant enzymes suggested adaptive responses. The key finding was distinct phytohormone crosstalk, characterized by a mid-infection SA peak followed by a late JA rebound, alongside an early oxidative burst marked by MDA accumulation and sustained antioxidant enzyme activity. These findings provide a framework for understanding I. verticillata’s defense mechanisms and offer insights for developing targeted disease management strategies, such as resistant cultivar breeding or hormone-mediated interventions.

Ilex vomitoria Ait. is a star substitute for “tea” in recent years. At present, research on I. vomitoria mainly focuses on its breeding and cultivation, and there are few reports on the seasonal changes of important components such as leaf nutrients. This study focuses on the leaves of the topmost annual branches of I. vomitoria. Leaves were harvested at different stages, and the nutrient elements, antioxidant substances, antioxidant capacity, and aroma components in the leaves were measured and analyzed. The results showed that the content of mineral elements, soluble sugars, vitamin C, amino acids, flavonoids, polyphenols, saponins, caffeine, and catechins, as well as the DPPH free radical scavenging ability, ABTS cation free radical scavenging ability, and FRAP iron ion reduction ability in the leaves of I. vomitoria showed significant differences with seasonal changes. The mineral element content in spring leaves is relatively high. Flavonoids and polyphenols are the main antioxidant substances in the leaves of I. vomitoria, indicating that the antioxidant capacity of spring leaves is the strongest. The content of aroma components in the leaves of I. vomitoria in spring is the highest, with alcohols ranging from 54.93% to 66.08%, followed by ketones from 17.63% to 48.07%, and aldehydes from 21.27% to 38.51%. Overall, spring leaves are more suitable for harvesting, development, and utilization.