Upgrading the genome of an elite japonica rice variety Kongyu 131 for lodging resistance improvement

Developing a new rice variety requires tremendous efforts and years of input. To improve the defect traits of the excellent varieties becomes more cost and time efficient than breeding a completely new variety. Kongyu 131 is a high-performing japonica variety with early maturity, high yield, wide adaptability and cold resistance, but the poor-lodging resistance hinders the industrial production of Kongyu 131 in the Northeastern China. In this study, we attempted to improve the lodging resistance of Kongyu 131 from perspectives of both gene and trait. On the one hand, by QTL analysis and fine mapping we discovered the candidate gene loci. The following CRISPR/Cas9 and transgenic complementation study confirmed that Sd1 dominated the lodging resistance and favourable allele was mined for precise introduction and improvement. On the other hand, the Sd1 allelic variant was identified in Kongyu 131 by sequence alignment, then introduced another excellent allelic variation by backcrossing. Then, the two new resulting Kongyu 131 went through the field evaluation under different environments, planting densities and nitrogen fertilizer conditions. The results showed that the plant height of upgraded Kongyu 131 was 17%–26% lower than Kongyu 131 without penalty in yield. This study demonstrated a precise and targeted way to update the rice genome and upgrade the elite rice varieties by improving only a few gene defects from the perspective of breeding.     

Equilibria of polyoxometalates in aqueous solution

In most aqueous polyoxometalate systems, numerous, often highly negatively charged species, are formed. To establish the speciation in such complex polyanion systems, many experimental methods and techniques must be used. Moreover, it is of vital importance that the experimental data are of the highest accuracy and that the data collected from different methods are treated simultaneously with an appropriate computer program. In systems containing one or more sensitive NMR nuclei, a combined EMF-NMR method has been shown to be extremely powerful.This article firstly gives some general comments on equilibria in aqueous polyoxometalate systems including ionic medium effects, and then describes an equilibrium EMF-NMR (³¹P and⁵¹V) study of the five component system H⁺-Mo(VI)-V(V)-P(V)-e^–. The study has been focused on so-called Keggin ratio solutions, Mo+V):P=12:1, since these are commonly used in selective oxidation processes. Special attention has been given to Mo₁₀V₂P and Mo₉V₃P solutions, where positional isomers occur. We have been able to identify and characterize all the five possible isomers of -Mo₁₀V₂PO ₄₀ ^5– at 25 and 90 °C. Besides the results from the five component system, some interesting findings from the binary, ternary and quarternary sybsystems are also reported.     

拟南芥ACOL8基因在乙烯合成与响应中的功能分析

植物激素乙烯在多种生理生化过程中发挥重要作用,但其在特定组织器官中的合成机制尚不完全清楚。拟南芥中存在12个功能未知的ACC氧化酶类似蛋白（ACO-like homolog,ACOL）,运用基因定点编辑技术构建了ACOL8的功能丧失型突变体,发现该基因的突变削弱了经典的乙烯“三重反应”。与野生型相比,突变体黄化幼苗下胚轴及主根的长度显著增加,这与突变体对外源ACC的敏感性下降现象一致。同时还发现ACOL8基因的表达受乙烯信号的正反馈调控,EIN3过表达增强其表达水平,而etr1-3的突变则产生相反效应。再者,在正常条件下,ACOL8基因的突变并未影响拟南芥的生长;但在盐胁迫条件下,突变体的根冠比显著下降,这说明该基因参与植物的盐胁迫响应。综上,这些结果说明ACOL8可能具有ACC氧化酶的功能,参与乙烯的合成与响应。     

Epigenetic and pharmacological control of pigmentation via Bromodomain Protein 9 (BRD9)

Lineage-specific differentiation programs are activated by epigenetic changes in chromatin structure. Melanin-producing melanocytes maintain a gene expression program ensuring appropriate enzymatic conversion of metabolites into the pigment, melanin, and transfer to surrounding cells. During neuroectodermal development, SMARCA4 (BRG1), the catalytic subunit of SWItch/Sucrose Non-Fermentable (SWI/SNF) chromatin remodeling complexes, is essential for lineage specification. SMARCA4 is also required for development of multipotent neural crest precursors into melanoblasts, which differentiate into pigment-producing melanocytes. In addition to the catalytic domain, SMARCA4 and several SWI/SNF subunits contain bromodomains which are amenable to pharmacological inhibition. We investigated the effects of pharmacological inhibitors of SWI/SNF bromodomains on melanocyte differentiation. Strikingly, treatment of murine melanoblasts and human neonatal epidermal melanocytes with selected bromodomain inhibitors abrogated melanin synthesis and visible pigmentation. Using functional genomics, iBRD9, a small molecule selective for the bromodomain of BRD9 was found to repress pigmentation-specific gene expression. Depletion of BRD9 confirmed a requirement for expression of pigmentation genes in the differentiation program from melanoblasts into pigmented melanocytes and in melanoma cells. Chromatin immunoprecipitation assays showed that iBRD9 disrupts the occupancy of BRD9 and the catalytic subunit SMARCA4 at melanocyte-specific loci. These data indicate that BRD9 promotes melanocyte pigmentation whereas pharmacological inhibition of BRD9 is repressive.     

2型糖尿病伴慢性牙周炎患者龈沟液Omentin-1、MMP-9、OPG/RANKL比值与牙周指标、氧化应激和NLRP3炎症小体的关系

摘要 目的：探讨2型糖尿病（T2DM）伴慢性牙周炎（CP）患者龈沟液网膜素-1（Omentin-1）、基质金属蛋白酶-9（MMP-9）、骨保护素（OPG）/细胞核因子κB受体活化因子配体（RANKL）比值与牙周指标、氧化应激和核苷酸结合寡聚化结构域样受体蛋白3（NLRP3）炎症小体的关系。方法：选择2020年6月至2022年6月首都医科大学附属北京康复医院收治的73例T2DM患者（T2DM组）,77例CP患者（CP组）,83例T2DM伴CP患者（T2DM伴CP组）。检测所有患者龈沟液中Omentin-1、MMP-9、OPG/RANKL比值,分析其与牙周指标、氧化应激和NLRP3炎症小体相关分子信使核糖核酸（mRNA）表达的相关性。结果：T2DM伴CP组龈沟液中Omentin-1,OPG/RANKL比值、总抗氧化能力（TAC）、超氧化物歧化酶（SOD）低于T2DM组和CP组（P＜0.05）,MMP-9、丙二醛（MDA）、NLRP3mRNA、凋亡相关斑点样蛋白（ASC）mRNA、半胱氨酸蛋白酶-1（caspase-1）mRNA表达以及出血指数（SBI）、菌斑指数（PLI）、牙周袋探诊深度（PD）、附着丧失（AL）高于T2DM组和CP组（P＜0.05）。T2DM伴CP患者龈沟液中Omentin-1、OPG/RANKL比值与TAC、SOD呈正相关（P＜0.05）,与MDA、NLRP3mRNA、ASC mRNA、caspase-1mRNA表达以及PLI、SBI、AL、PD呈负相关（P＜0.05）,MMP-9与TAC、SOD呈负相关（P＜0.05）,与MDA、NLRP3mRNA、ASC mRNA、caspase-1mRNA表达以及PLI、SBI、AL、PD呈正相关（P＜0.05）。结论：T2DM伴CP患者龈沟液中Omentin-1水平、OPG/ RANKL比值降低,MMP-9水平升高,与牙周组织破坏加重、氧化应激、NLRP3炎症小体激活有关。     

Stimulation of shoot elongation in Salix pentandra by gibberellin A9; activity appears to be dependent upon hydroxylation to GAl via GA20

Cessation of shoot elongation in seedlings of Salix pentandra L. is induced by short photoperiod. Gibbereliin A₉ (GA₉) applied either to the apical bud or injected into a mature leaf, induced shoot elongation under a short photoperiod of 12 h, and GA₉ could completely substitute for a transfer to a long photoperiod. When [³H]GA₉ or [²H₂]GA₉ was injected into a leaf, no [³H]GA₉ was detected in the elongating apex and only traces of [³H]GA₉ were found in the shoot above the treated leaf. By the use of gas chromatography-mass spectrometry (GC-MS), [²H₂]GA₂₀ was identified as the main metabolite of [²H₂]GA₉ in both the shoot and the treated leaf. In addition, [²H₂]GA₁ and [²H₂]GA₂₉ were also identified as metabolites of [²H₂]GA₉. These results are consistent with the hypothesis that exogenous GA, promotes shoot elongation in Salix through its metabolism to GA₂₀ and GA,.     

Tachykinin NK-1 receptor probed with constrained analogues of substance P

The action of rotameric probes introduced either in position 7 or 8 in the sequence of substance P (SP) was investigated, i.e. -tetrahydroisoquinoleic acid (Tic), -fluorenylglycine (Flg), -diphenylalanine (Dip), the diastereoisomers of -1-indanylglycine (Ing) and -benz[ƒ]indanylglycine (Bfi), the Z- and E-isomers of dehydrophenylalanine and dehydronaphthylalanine (Δ^ZPhe, Δ^EPhe, Δ^ZNal, Δ^ENal) and (Dmp). The aim of this study was the topographical characterization of the binding subsites of human NK-1 receptor expressed in CHO cells, especially the S₇ and S₈ subsites, corresponding to residues Phe⁷ and Phe⁸ of substance P. According to the binding potencies of these substituted-SP analogues, the S₇ binding subsite is smaller than the S₈ subsite: the S₇ subsite accepts only one aromatic nucleus, while the S₈ can accommodate three coplanar nuclei altogether. These findings are compatible with the idea that the S₈ binding subsite may reside in the extracellular loops of the hNK-1 receptor. NK-1 agonists bind to human NK-1 receptor and activate the production of both inositol phosphates and cyclic AMP. As already quoted for septide, [pGlu⁶, Pro⁹]SP(6–11), discrepancies are observed between affinity (K_i) and activity (EC₅₀) values for IPs production. While a weak correlation between K_i and EC₅₀ values for IPs production could be found (r = 0.70), an excellent correlation could be demonstrated between their affinities (K_i) and their potencies (EC₅₀) for cAMP production (r = 0.97). The high potency (EC₅₀) observed for ‘septide-like’ molecules on PI hydrolysis, compared to their affinity is not an artefact related to the high level of NK-1 receptors expressed on CHO cells since a good correlation was found between EC₅₀ values obtained for PI hydrolysis and those measured for spasmogenic activity in guinea pig ileum bioassay (r = 0.94).

According to the binding potencies of constrained analogues of phenylalanine, the S₇ binding subsite of human NK-1 receptor is small, whereas the S₈, which can accommodate three coplanar nuclei, might probably reside in the extracellular loop. The discrepancies observed between affinity (K_i) and activity (EC₅₀) values for IPs production are not an artefact of CHO cells since a good correlation was found between EC₅₀ for PI hydrolysis and those measured in guinea pig ileum bioassay.