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The importance of allopolyploidy in plant evolution has been widely recognized. The genetic changes triggered by allopolyploidy, however, are not yet fully understood due to inconsistent phenomena reported across diverse species. The construction of synthetic polyploids offers a controlled approach to systematically reveal genomic changes that occur during the process of polyploidy. This study reports the first fully sequenced synthetic allopolyploid constructed from a cross between Cucumis sativus and C. hystrix, with high‐quality assembly. The two subgenomes are confidently partitioned and the C. sativus‐originated subgenome predominates over the C. hystrix‐originated subgenome, retaining more sequences and showing higher homeologous gene expression. Most of the genomic changes emerge immediately after interspecific hybridization. Analysis of a series of genome sequences from several generations (S0, S4–S13) of C. ×hytivus confirms that genomic changes occurred in the very first generations, subsequently slowing down as the process of diploidization is initiated. The duplicated genome of the allopolyploid with double genes from both parents broadens the genetic base of C. ×hytivus, resulting in enhanced phenotypic plasticity. This study provides novel insights into plant polyploid genome evolution and demonstrates a promising strategy for the development of a wide array of novel plant species and varieties through artificial polyploidization. [ABSTRACT FROM AUTHOR]

Heat stress has become a major threat to crop production due to global warming; however, the mechanisms underlying plant high-temperature sensing are not well known. In plants, the membrane-anchored receptor-like kinases (RLKs) relay environmental signals into the cytoplasm. In a previous study, we isolated a wall-associated RLK-like (WAKL) gene CaWAKL20 from pepper (Capsicum annuum L.). Here, the amino acid sequence of CaWAKL20 was characterized and found to consist of conserved domains of WAK/WAKL family, including an extracellular region containing a GUB-WAK binding domain and a degenerated EGF2-like domain; a transmembrane region; and an intercellular region with an STKc catalytic domain. Moreover, CaWAKL20 transcription was inhibited by heat stress, whereas it was induced by both ABA and H2O2 treatments. Silencing of CaWAKL20 enhanced pepper thermotolerance, while overexpression decreased Arabidopsis thermotolerance. Additionally, Arabidopsis lines overexpressing CaWAKL20 showed less sensitivity to ABA during seed germination and root growth. Finally, the survival rate of Arabidopsis seedlings under heat stress treatment was enhanced by ABA pre-treatment, while it was compromised by the overexpression of CaWAKL20. Furthermore, the heat-induced expression of several ABA-responsive genes and some key regulator genes for thermotolerance was decreased in Arabidopsis CaWAKL20- overexpression lines. These results suggest that CaWAKL20 negatively modulates plant thermotolerance by reducing the expression of ABA-responsive genes, laying a foundation for further investigation into the functional mechanisms of WAKs/WAKLs in plants undergoing environmental stresses. [ABSTRACT FROM AUTHOR]

Codonopsis Pilosula (CP), as a well-known traditional Chinese medicine (TCM) with medicinal and edible herb, is one of the most representative tonic Chinese herbal medicine. It has been widely used for regulating immune function with hardly any adverse effects in clinical practice. This study aimed to elucidate the immunomodulatory effect and to explore probable mechanism of Codonopsis Pilosula Extract (CPE) in septic rats. The model of septic rat was established by cecal ligation and perforation (CLP). The thymus index, spleen index and cerebral index were calculated. Histological changes were observed by Hematoxylin-eosin (HE). The positive expression of CD4+ T cells was determined in the thymus and spleen by immunohistochemical (IHC). The expression level of 24 h CD4 was corroborated by real-time quantitative polymerase chain reaction (RT-QPCR). Infectious factors, immune factors and inflammatory factors were determined by enzyme-linked immunosorbent assay (ELISA). Blood cells were detected by automatic biochemical analyzer. The metabolite changes and gene expression levels, the potential targets and pathways of CPE in regulating immune function of thymus were analyzed by integrative analysis of transcriptomic and metabolomic methods. High dose of CPE increased the thymus index and spleen index of septic rats at different stages, and the brain index at different stages could be increased at medium dose and high dose. Medium and high doses of CPE reduced the pathological changes of thymus, spleen and brain tissue. CPE promoted the expression levels of CD4 in the thymus and spleen. CPE improved the levels of red blood cells (RBC), lymphocytes (LYM) and hemoglobin (HGB), and decreased the levels of neutrophils (NEUT), NLR (NEUT/LYM) and PLR (PLT/LYM). CPE dynamically regulated the levels of white blood cells (WBC) and PLT (platelet). CPE dynamically regulated the expression levels of infectious factors, immune factors, and inflammatory factors related to disease severity. CPE has the ability to dynamically modulate the expression levels of infectious factors, immune factors, and inflammatory factors related to disease severity, and alleviate the damages of immune organs. The research has provided a global view of the integration of metabolomics and transcriptomics to elucidate the immunomodulatory effects and mechanisms of CPE. CPE could affect a series of biological processes in glycerophospholipid metabolism by interfering with the B cell receptor (BCR) signaling pathway in the thymus, to maintain immune homeostasis of septic rats on the whole, especially humoral immunity. [Display omitted] [ABSTRACT FROM AUTHOR]