Ten undescribed sesquiterpenoids were isolated from Chloranthus japonicus Sieb., including (4R,5S,6R,8R,10R)-4- hydroxy-6-O-(3-D-glucosyleudesman-7(11)-en-8,12-olide (1), (1R,4R,5R,8S,10R)-1,4-dihydroxy-15-(2-methyl- butyryloxy)eudesman-7(11)-en-8,12-olide (2),(1R,4S,5R,8S,10R)-1,4-dihydroxy-15-(2-methylbutyryloxy)eudes- man-7(11)-en-8,12-olide (3), (1R,3S,4R,5S,8S,9S,10S)-8,9-epoxy-15-hydroxylindenran-7(11)-en-8,12-olide (4), (1R,3S,4R,5S,8S,9S,10S)-8,9,15-trihydroxylindenran-7(11)-en-8,12-olide (5), (1R,3S,4R,5S,6R,8S,10S)-6-ace- toxyl-4-hydroxy-15-O-(3-D-glucosyllindenran-7(11)-en-8,12-olide (6), (1R,3S,4R,5S,6R,8S,10S)-15-hydroxy-4-O- (3-D-glucosyllindenran-7(11),8(9)-dien-8,12-olide (7), japonilides A-C (8-10), along with 19 known compounds. Compounds 8-10 are rare 5,6-seco-germacrane-type sesquiterpenoids, and only one of this type sesquiterpenoid has been reported to be isolated from C. anhuiensis. 9-Ketocurzerene (27) was first reported from a natural source. The structures and absolute configurations of the compounds were elucidated through a combination of spectroscopic data interpretation, quantum-chemical calculation, DP4+ probability analysis, and single-crystal X-ray diffraction analysis. Compounds 8, 12, 16 and 22 exhibited significant inhibitory effects on NO production in lipopolysaccharide-stimulated RAW 264.7 macrophages, with IC50 values of 22.99 +/- 2.71, 24.34 +/- 1.36, 23.69 +/- 2.83, and 21.23 +/- 1.34 mu mol/L, respectively. Western blotting studies demonstrated that compound 8 inhibited the expression of nitric oxide synthase and cyclooxygenase-2, which act as key mediators in the inflammatory response.

Three unreported ent-abietane-type norditerpene lactones, euphohelides A-C (1-3), and 11 known analogs (4-14) were isolated from the whole plants of Euphorbia helioscopia L. Euphohelide A (1) is an unprecedented 2-nor-ent-abietane lactone bearing a unique 5/6/6/5 tetracyclic system. Euphohelides B (2) and C (3) possess 2-nor-6/6/6/5 and 2,3-dinor-5/6/6/5 dilactone tetracyclic moieties, respectively. Their structures were established by spectroscopic methods, computational ECD, and X-ray crystallographic analyses. A biomimetic synthesis of 1 was achieved from precursor 4 based on the speculative biogenetic pathway. Compounds 1 and 5 significantly alleviated the release of LPS-induced NO with IC50 values of 32.98 ± 1.13 and 33.82 ± 3.25 μM, which might be related to the regulation of the NF-κB signaling pathway.

A bioactivity-guided isolation from the aerial parts of Phyllanthus rheophyticus obtained 17 undescribed ent-cleistanthane-type diterpenoids, namely phyllarheophols A-Q, as well as 12 known analogs. Their structures were characterized by a combination of spectroscopic data interpretation, single-crystal X-ray diffraction and ECD analysis. The anti-inflammatory activities of these compounds were evaluated by measuring their inhibitory effects on NO production in LPS-stimulated RAW264.7 macrophages, and their preliminary structure-activity relationships were also discussed. Further study showed that promising compounds phyllarheophol D and phyacioid B significantly suppressed the expressions of cytokines and nitric oxide synthase through the NF-κB signaling pathway.

This paper proposes a novel hybrid optimization algorithm based biogeography-based optimization (BBO) and ant colony optimization (ACO). Specifically, BBO is utilized for preliminary search and then the final search is conducted by using ACO on the preliminary results, which makes the hybrid algorithm have powerful search ability in the solution space. Moreover, the algorithm is tested on 6 well-known benchmarks for comparing with the 4 others existing optimization algorithms, including 2 algorithms were proposed by the coauthor earlier. Obviously, the simulation results show that the proposed hybrid BBO-ACO has better performance than the existing others.

Plant-specific NAC (NAM, ATAF, CUC) transcription factor (TF) family plays important roles in biological processes such as plant growth and response to stress. Nevertheless, no information is known about NAC TFs in Cleistogenes songorica, a prominent xerophyte desert grass in northwestern China. In this study, 162 NAC genes were found from the Cleistogenes songorica genome, among which 156 C. songoricaNAC (CsNAC) genes (96.3%) were mapped onto 20 chromosomes. The phylogenetic tree constructed by CsNAC and rice NAC TFs can be separated into 14 subfamilies. Syntenic and Ka/Ks analyses showed that CsNACs were primarily expanded by genomewide replication events, and purifying selection was the primary force driving the evolution of CsNAC family genes. The CsNAC gene expression profiles showed that 36 CsNAC genes showed differential expression between cleistogamous (CL) and chasmogamous (CH) flowers. One hundred and two CsNAC genes showed differential expression under heat, cold, drought, salt and ABA treatment. Twenty-three CsNAC genes were commonly differentially expressed both under stress responses and during dimorphic floret development. Gene Ontology (GO) annotation, coexpression network and qRT-PCR tests revealed that these CsNAC genes may simultaneously regulate dimorphic floret development and the response to stress. Our results may help to characterize the NAC transcription factors in C. songorica and provide new insights into the functional research and application of the NAC family in crop improvement, especially in dimorphic floret plants.

Background As global warming continues, heat stress (HS) is becoming an increasingly significant factor limiting plant growth and reproduction, especially for cool-season grass species. The objective of this study was to determine the transcriptional regulatory network of Cleistogenes songorica under HS via transcriptome profiling, identify of gene families and comparative analysis across major Poaceae species. Results Physiological analysis revealed significantly decreased leaf relative water content (RWC) but increased proline (Pro) content in C. songorica under 24 h of HS. Transcriptome profiling indicated that 16,028 and 14,645 genes were differentially expressed in the shoots and roots of C. songorica under HS, respectively. Two subgenomes of C. songorica provide equal contribution under HS on the basis of the distribution and expression of differentially expressed genes (DEGs). Furthermore, 216 DEGs were identified as key evolutionarily conserved genes involved in the response to HS in C. songorica via comparative analysis with genes of four Poaceae species; these genes were involved in the ‘response to heat’ and ‘heat acclimation’. Notably, most of the conserved DEGs belonged to the heat-shock protein (HSP) superfamily. Similar results were also obtained from co-expression analysis. Interestingly, hub-genes of co-expression analysis were found to overlap with conserved genes, especially heat-shock protein (HSP). In C. songorica , 84 HSP and 32 heat-shock transcription factor ( HSF ) genes were identified in the allotetraploid C. songorica genome, and might have undergone purifying selection during evolutionary history based on syntenic and phylogenetic analysis. By analysing the expression patterns of the CsHSP s and CsHSF s, we found that the transcript abundance of 72.7% of the CsHSP genes and of 62.5% of the CsHSF genes changed under heat stress in both the shoots and roots. Finally, a core regulatory network of HS was constructed on the basis of the CsHSP , CsHSF and other responsive genes in C. songorica . Conclusions Regulatory network and key genes were comprehensively analysed and identified in C. songorica under HS. This study improves our knowledge of thermotolerance mechanisms in native grasses, and also provides candidate genes for potential applications in the genetic improvement of grasses.

Background Transcription factors act as important regulators of transcription networks. Basic leucine zipper (bZIP) transcription factors have been shown to be involved in multiple biological processes in plants. However, no information is available for the bZIP family in Cleistogenes songorica, which is an important xerophytic and allotetraploid grass in desert grasslands. Results In this study, 86 CsbZIPs were identified in the allotetraploid C. songorica genome. For location analysis, CsbZIPs were distributed evenly across two subgenomes of C. songorica. Phylogenetic tree analysis among three species indicated that CsbZIPs were evolutionarily more closely related to OsbZIPs than AtbZIPs. Syntenic and phylogenetic analyses confirmed that the CsbZIPs were mainly expanded by whole-genome duplication events. Furthermore, it was determined that rice and C. songorica might have undergone purified selection during their long evolutionary history by calculating the Ks values and Ka/Ks ratios of orthologous gene pairs. By analysing the expression patterns of CsbZIPs in different tissues and under abiotic stresses, 21 CsbZIP genes were differentially expressed between chasmogamous (CH) and cleistogamous (CL) flowers, including two FLOWERING LOCUS D (FD) genes. In shoots and roots, 79.1 and 87.2% of the CsbZIP genes, respectively, displayed transcript changes under at least one stress treatment, such as heat, cold, drought and salt. Strikingly, 17 common CsbZIP genes showed differential expression under stress response and during CL flowering. Co-expression network, GO annotation and real-time quantitative reverse transcription PCR (qRT-PCR) analyses revealed a close relationship between CL flowering-associated genes and abiotic stress-related genes. Conclusions BZIP TFs were comprehensively analysed and identified in allotetraploid C. songorica. Our results provide insights into the evolutionary history of the bZIP family in C. songorica and provide abiotic stress-responsive and CL-associated candidate CsbZIP genes for potential applications in the genetic improvement of plants.