Branching Shoots and Spikes from Lateral Meristems in Bread Wheat

Wheat grain yield consists of three components: spikes per plant, grains per spike (i.e. head or ear), and grain weight; and the grains per spike can be dissected into two subcomponents: spikelets per spike and grains per spikelet. An increase in any of these components will directly contribute to grain yield. Wheat morphology biology tells that a wheat plant has no lateral meristem that forms any branching shoot or spike. In this study, we report two novel shoot and spike traits that were produced from lateral meristems in bread wheat. One is supernumerary shoot that was developed from an axillary bud at the axil of leaves on the elongated internodes of the main stem. The other is supernumerary spike that was generated from a spikelet meristem on a spike. In addition, supernumerary spikelets were generated on the same rachis node of the spike in the plant that had supernumerary shoot and spikes. All of these supernumerary shoots/spikes/spikelets found in the super wheat plants produced normal fertility and seeds, displaying huge yield potential in bread wheat.     

Milky spot macrophages remodeled by gastric cancer cells promote peritoneal mesothelial cell injury

Peritoneal dissemination (PD) is the most frequent metastatic pattern of advanced gastric cancer (GC) and the main cause of death in GC patients. Human peritoneal mesothelial cell (HPMC) injury induced by gastric cancer cells (GCCs) and GCC outgrowths supported by peritoneal milky spot macrophages (PMSMs) are the key events during gastric cancer peritoneal dissemination (GCPD). In this study, we investigated whether PMSMs remodeled by GCC can induce HPMC injury and create a favorable microenvironment for GCPD. We established a tumor-associated macrophage (TAM) model using in vitro cell coculture. Normal macrophages cocultured with GCCs down-regulated expression of antigen-presenting surface molecules CD80, CD86, and MHC-II, but, notably, they up-regulated expression of phagocytic scavenger receptor CD206, which is similar to the M2 macrophage phenotype. In further experiments, various experimental methods were applied to detect the injurious effect of TAMs on HPMCs in another TAM–HPMC coculture. Our results showed that GCCs can induce HPMC apoptosis by unregulated apoptosis associated with cleaved caspase3, cleaved caspase9, and p21 proteins. HPMC growth ceased, and both early- and late-stage apoptosis were observed. Additionally, GCCs can induce HPMC fibrosis via increased expression of epithelial cell marker E-cadherin and decreased expression of mesenchymal cell marker α-SMA. Our results demonstrate that, in the GCPD process, PMSMs were remodeled by GCCs, resulting in phenotypic and functional transformation. In turn, this transformation induced HPMC injury and provided a favorable microenvironment for GCC anchorage and growth. These results may provide new insight into the mechanisms of GCPD.     

Surgical trauma-induced CCL18 promotes recruitment of regulatory T cells and colon cancer progression

Background: Surgical stress has been suggested to facilitate colon cancer growth and metastasis. However, the precise mechanisms by which surgical trauma promotes colon cancer progression remain poorly understood. Methods: To unravel the mechanisms underlying surgery-induced colon cancer progression, a syngenic transplantation tumor model was established with CT26 cells, and the effect of laparotomy on tumor progression was investigated. Especially, the expression of several chemokines was assessed, and their roles in recruiting CD4+ CD25+ regulatory T cells (Tregs) after surgery were analyzed. Results: Tregs population was significantly increased in the tumor tissue and peripheral blood of tumor-bearing mice after laparotomy. C-C motif chemokine ligand 18 (CCL18) expression was significantly upregulated after laparotomy in tumor tissue and the peritoneal cavity of tumor-bearing mice, and it was positively correlated with the recruitment of Tregs. Functionally, CCL18 knockdown significantly reduces tumor growth and angiogenesis compared with control. Through analysis of Tregs, we found an upregulated proportion of Tregs in tumor tissue, peritoneal cavity, and peripheral blood after laparotomy, but this enhancement was blocked after CCL18 knockdown. In patients with colon cancer, a higher Tregs proportion is positively correlated to more advanced clinical TNM stages and shorter survival. Furthermore, a positive correlation was found between the serum CCL18 level and the Treg proportion in clinical samples. Conclusion: Surgical trauma contributes to colon cancer progression by increasing CCL18 expression and hence promotes Treg recruitment, which leads to an immunosuppressive environment.     

粉美人萱草的快繁技术和大田种植

以粉美人萱草(Hemerocallis fulva cv. ‘Fenmeiren’)的花茎为外植体进行离体培养, 该研究成功建立了粉美人萱草组培快繁技术。结果表明, 6月获得的外植体用浓度为15% (v/v)的次氯酸钠溶液消毒8分钟, 外植体存活率达95%; 最佳增殖培养基为MS+1.0 mg·L^-1 6-BA+0.004 mg·L^-1 TDZ+0.1 mg·L^-1 NAA, 培养30天后, 月增殖系数达2.9; 壮苗培养基为MS+0.1 mg·L^-1 6-BA+0.1 mg·L^-1 IBA, 在该培养基中, 组培苗不再分化, 长势健壮; 最佳生根培养基为1/2MS+0.4 mg·L^-1 IBA+20 g·L^-1蔗糖, 生根率达95%; 移栽基质采用珍珠岩:草炭=1:2 (v/v), 通过精细化管理, 成活率可达85%, 出圃合格率为75%。目前已实现规模化繁殖, 并生产组培苗2.0×10⁵株, 大田种植表现良好。     

Bacteria-based nanosystems for enhanced antitumor therapy

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