Evolution of NLR Resistance Genes in Magnoliids: Dramatic Expansions of CNLs and Multiple Losses of TNLs

Magnoliids are the third-largest group of angiosperms and occupy a critical position in angiosperm evolution. In the past years, due to the lack of sequenced genomes, the disease resistance gene (R gene) profile of magnoliids remains poorly understood. By the genome-wide identification of 1,832 NLR genes from seven magnoliid genomes, we built a framework for the evolution of magnoliid R genes. TNL genes were completely absent from five magnoliids, presumably due to immune pathway deficiencies. A total of 74 ancestral R genes (70 CNLs, 3 TNLs, and 1 RNL) were recovered in a common ancestor of magnoliids, from which all current NLR gene repertoires were derived. Tandem duplication served as the major drive for NLR genes expansion in seven magnoliid genomes, as most surveyed angiosperms. Due to recent rapid expansions, most magnoliids exhibited “a first expansion followed by a slight contraction and a further stronger expansion” evolutionary pattern, while both Litsea cubeba and Persea americana showed a two-times-repeated pattern of “expansion followed by contraction.” The transcriptome analysis of seven different tissues of Saururus chinensis revealed a low expression of most NLR genes, with some R genes displaying a relatively higher expression in roots and fruits. Overall, our study sheds light on the evolution of NLR genes in magnoliids, compensates for insufficiency in major angiosperm lineages, and provides an important reference for a better understanding of angiosperm NLR genes.

Development of the petaloid bracts of a paleoherb species, Saururus chinensis

Saururus chinensis is a core member of Saururaceae, an ancient, perianthless (lacking petals or sepals) family of the magnoliids in the Mesangiospermae, which is important for understanding the origin and evolution of early flowers due to its unusual floral composition and petaloid bracts. To compare their transcriptomes, RNA-seq abundance analysis identified 43,463 genes that were found to be differentially expressed in S. chinensis bracts. Of these, 5,797 showed significant differential expression, of which 1,770 were up-regulated and 4,027 down-regulated in green compared to white bracts. The expression profiles were also compared using cDNA microarrays, which identified 166 additional differentially expressed genes. Subsequently, qRT-PCR was used to verify and extend the cDNA microarray results, showing that the A and B class MADS-box genes were up-regulated in the white bracts. Phylogenetic analysis was performed on putative S. chinensis A and B-class of MADS-box genes to infer evolutionary relationships within the A and B-class of MADS-box gene family. In addition, nature selection and protein interactions of B class MADS-box proteins were inferred that B-class genes free from evolutionary pressures. The results indicate that petaloid bracts display anatomical and gene expression features normally associated with petals, as found in petaloid bracts of other species, and support an evolutionarily conserved developmental program for petaloid bracts.

Purification Efficiency of Three Combinations of Native Aquatic Macrophytes in Artificial Wastewater in Autumn

Water pollution caused by excessive nutrient and biological invasion is increasingly widespread in China, which can lead to problems with drinking water as well as serious damage to the ecosystem if not be properly treated. Aquatic plant restoration (phytoremediation) has become a promising and increasingly popular solution. In this study, eight native species of low-temperature-tolerant aquatic macrophytes were chosen to construct three combinations of aquatic macrophytes to study their purification efficiency on eutrophic water in large open tanks during autumn in Guangzhou City. The total nitrogen (TN) removal rates of group A (Vallisneria natans + Ludwigia adscendens + Monochoria vaginalis + Saururus chinensis), group B (V. natans + Ipomoea aquatica + Acorus calamus + Typha orientalis), and group C (V. natans + L. adscendens + Schoenoplectus juncoides + T. orientalis) were 79.10%, 46.39%, and 67.46%, respectively. The total phosphorus (TP) removal rates were 89.39%, 88.37%, and 91.96% in groups A, B, and C, respectively, while the chemical oxygen demand (COD) removal rates were 93.91%, 96.48%, and 92.78%, respectively. In the control group (CK), the removal rates of TN, TP, and COD were 70.42%, 86.59%, and 87.94%, respectively. The overall removal rates of TN, TP, and COD in the plant groups were only slightly higher than that in CK group, which did not show a significant advantage. This may be related to the leaf decay of some aquatic plants during the experiment, whereby the decay of V. natans was the most obvious. The results suggest that a proper amount of plant residue will not lead to a significant deterioration of water quality.

Molecular mechanisms of a traditional Chinese medicine in the treatment of dysfunctional uterine bleeding

Dysfunctional uterine bleeding (DUB) is a common gynecological disease regulated by multiple hormones, which seriously affects female physical and mental health. Some drugs have been prompted to cure this disease, but most drugs have certain side effects and limitations. In the present study, we demonstrated an unexploited Chinese traditional medicine, a combination of Saururus chinensis, Celosia cristata and Spatholobus suberectus (Referred to as XBR), was capable of exerting hemostatic, coagulation and anti-inflammatory effects on SD rats. Furthermore, the XBR decreased the value of erythrocyte, hemoglobin, and hematocrit in serum for lowering blood stasis caused by DUB. Further studies were conducted to provide direct evidence that the recovery of endometrial hyperplasia was associated with the modulation of the hormones (follicle-stimulating hormone, luteinizing hormone, estradiol and progesterone). Besides, XBR altered mRNA expression levels of matrix metalloproteinase-1 and tissue inhibitor of matrix metalloproteinase-1 on the uterine endometrium, thereby promoting the repair of proliferating endometrium in the rats. Collectively, our study indicates that XBR harbors a profoundly curative effect on the treatment of DUB, and explains the mechanism at the molecular and genes expression levels.

Responses of inflammation signaling pathway by saucerneol D from elicitor-treated Saururus chinensis on pro-inflammatory responses in LPS-stimulated Raw 264.7 cell

This study confirmed the association with inflammation-related proteins, mediators, and cytokines using saucerneol D from Saururus chinensis leaf, a useful ingredient increased through elicitor treatment. To confirm the anti-inflammatory effect, saucerneol D were treated with lipopolysaccharide, which induces pro-inflammatory factors in Raw 264.7 cell. The pro-inflammatory influences were measured by dint of chemical assay and western blotting as well as ELISA. As a result, the content of saucerneol D was changed when eicitor was treated by various concentration (1.5, and 3 mg/mL) in S. chinensis leaves. In addition, the expression levels of hyaluronidase and pro-inflammatory-related factors [nitric oxide (NO), inducible NO synthase (iNOS), and cyclooxygenase-2 (COX-2)] were regulated according to the saucerneol D content in the elicitor-treated and non-treated groups. Therefore, after confirming that saucerneol D has an inhibitory effect on pro-inflammatory-related factors, saucerneol D was adjusted by concentration and compared with the control substance to verify the efficacy. Saucerneol D was adjusted to a concentration that did not toxic to macrophages through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Saucerneol D controlled at various concentrations inhibited iNOS and COX-2 proteins. NO produced by iNOS activity, prostaglandin E2 (PGE2), an inflammatory mediator produced by COX-2 activity, and pro-inflammatory cytokines [interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α)] were significantly suppressed. Therefore, it was confirmed that saucerneol D, an active ingredient increased by the elicitor treatment, could be used as a functional material that controls inflammatory factors.

Saururus chinensis Prevents Estrogen Deficiency-Induced Osteoporosis in Rats: A Metabolomic Study Using UPLC/Q-TOF MS

Saururus chinensis (SC), a traditional medicine, has been used for the treatment of edema, jaundice, gonorrhea, and several inflammatory diseases in China and Korea. Our previous studies reported the anti-osteoporotic activity of SC extract (SCE) in ovariectomized (OVX) rats but the mechanism of this effect was unclear. The aim of this study was to explore the anti-osteoporotic effect of SCE and elucidate the underlying mechanisms in ovariectomized rats using a metabolomics approach based on ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC/ESI-Q-TOF MS) to analyze metabolic changes. Female Sprague-Dawley (SD) rats were divided into sham, OVX, and SCE treatment groups. Partial least squares-discriminant analysis (PLS-DA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) score plots separated OVX and sham groups fairly well. Further, 22 potential biomarkers were identified in the rat models of estrogen deficiency-induced osteoporosis, and SCE showed regulatory effects on three vital metabolic pathways associated with these biomarkers, namely, glycerophospholipid metabolism, glycosylphosphatidylinositol-anchor biosynthesis, and linoleic acid metabolism. The metabolomics approach reliably confirmed that SCE exerted its anti-osteoporotic effect by intervening with lipid metabolism, thus preventing osteoporosis. This study also showed the promising potential of this approach in an evaluation of natural medicine efficacy.