Potassium nutrition of maize:Uptake,transport,utilization,and role in stress tolerance

Potassium(K) is an essential macronutrient for plant growth and development and influences yield and quality of agricultural crops.Maize(Zea mays) is one of the most widely distributed crops worldwide.In China,although maize consumes a large amount of K fertilizer,the K uptake/utilization efficiency(KUE)of maize cultivars is relatively low.Elucidation of KUE mechanisms and development of maize cultivars with higher KUE are needed.Maize KUE is determined by K+uptake,transport,and remobilization,which depend on a variety of K+channels and transporters.We review basic information about K+channels and transporters in maize,their functions and regulation,and the roles of K+in nitrogen transport,sugar transport,and salt tolerance.We discuss challenges and prospects for maize KUE improvement.

Identification of the HAK gene family reveals their critical response to potassium regulation during adventitious root formation in apple rootstock

Adventitious root formation is a bottleneck during vegetative proliferation.Potassium(K^(+))is an essential macronutrient for plants.K^(+)accumulation from the soil and its distribution to the different plant organs is mediated by K^(+)transporters named K^(+)transporter(KT),K^(+)uptake(KUP),or high-affinity K^(+)(HAK).This study aimed to identify members of the HAK gene family in apples and to characterize the effects of K^(+)supply on adventitious root formation and on the expression of HAK genes and the genes that putatively control auxin transport,signaling,and cell fate during adventitious root formation.In this study,34 HAK genes(MdHAKs)were identified in the apple(Malus×domestica‘Golden Delicious’)genome.A phylogenetic analysis divided MdHAKs into four clusters(Ⅰ,Ⅱ,Ⅲ,andⅣ),comprising 16,1,4,and 13 genes,respectively.The syntenic relationships revealed that 62.5%of the total MdHAK genes arise from genomic duplication events.Chromosome location,domain structure,motif analysis,and physico-chemical characteristics were subsequently investigated.Furthermore,the application of K^(+)indicated the emergence of adventitious roots at 8 d and produced more adventitious roots at 16 d than the K^(+)-free control(CK)treatment.In addition,various MdHAKs showed root-specific expression in B9 apple rootstock stem cuttings and enhanced expression during the initiation and emergence stages of adventitious root formation in response to K^(+)treatment.Additionally,K^(+)treatment enhanced the expression levels of MdPIN1,MdPIN2,and MdAUX1.Further data indicated that a higher expression of MdWOX11,MdLBD16,and MdLBD29 and of cell cycle-related genes contributed to the auxin-stimulated adventitious root formation in response to K^(+).

电/高锰酸钾/过一硫酸盐体系降解活性黄K-RN及其机理

印染废水中的有机染料处理在水处理技术中长久以来都是一大难题,电/高锰酸钾/过一硫酸盐体系(EC/PM/PMS体系)可以高效地降解活性黄K-RN等难降解有机污染物,但其降解机制还尚未明确,且锰类物质能否活化PMS产生活性物质以及PMS活化机理还需进一步探究。因此,本文研究了EC/PM/PMS体系在降解印染废水时活性物质的类别和产生途径,同时确定了锰类物质在其中的作用机理和PMS的活化过程。结果表明,EC/PM/PMS体系是一种包含自由基氧化和非自由基氧化的复合体系,体系中由PM还原生成五价锰、六价锰和无定形二氧化锰活化PMS。此外,明确了活性氧类自由基氧化是活性黄K-RN降解的主要路径,占比为95.3%,电极直接氧化占比2.1%,非自由基氧化占比仅为2.6%。

Associations between serum potassium and sodium levels and risk of hypertension： a community-based cohort study

Objective Several studies have examined the relationships between dietary potassium and sodium and hypertension, but few have evaluated the association between serum potassium or sodium and risk of incident hypertension. We therefore investigated the associations between serum potassium and sodium and risk of incident hypertension in a Chinese community-based population. Methods A total of 839 normotensive individuals without cardiovascular disease from the Chinese Multi-Provincial Cohort Study who took part in the baseline examination in 2007-2008 and the follow-up survey in 2012-2013 were included in this study. Odds ratios （OR） and 95% confidence intervals （95%CI） for baseline serum potassium and sodium in relation to the risk of new-onset hypertension were evaluated using multivari- ate logistic regression models. Results During five years of follow-up, 218 （26.0%） individuals progressed to hypertension. Logistic re- gression adjusting for multiple confounders showed that every 1 mEq/L increment in baseline serum potassium level was associated with a 75% increased risk of hypertension （OR： 1.75; 95%CI： 1.01-3.04; P = 0.04）. Compared with adults with serum potassium level of 4.20-4.79 mEq/L, adults with level 〉 4.80 mEq/L had an 84% increased risk of hypertension （OR： 1.84; 95%CI： 1.14-2.96; P = 0.01）. There was no significant association between serum sodium and risk of hypertension （OR： 0.96; 95%CI： 0.89-1.04; P = 0.33）. Conclusions Base- line serum potassium level, but not baseline serum sodium level, was positively related to the risk of incident hypertension in the Chinese population.

Relationship between Obesity, Serum Uric Acid, Serum Potassium and Glomerular Filtration Rate with Electric Left Ventricular Hypertrophy in Blacks Central Africans with High Blood Pressure

The authors conducted a retrospective study over a period of 6 months in a hypertensive population in order to determine the correlation between serum uric acid on glomerular filtration rate (GFR) and estimated serum potassium with left ventricular hypertrophy (LVH) and obesity. This study enrolled 122 patients including 63 women (51.6%). The mean age was 55.9 ± 10.6 years (range 30 to 74 years). Obesity weight was found in 38 cases (31.1%) of which 20?were men (33.9%) and 18 women (28.6%). Abdominal obesity was found in 104 cases (85.2%). The average serum uric acid in patients with obesity weight was 63.3 ± 18.9 mg/L vs 62.4 ± 14.2 mg/L for no-obese patients (p?= 0.63). The average serum potassium in obese patients was 4.06 ± 0.42 mEq/L vs 4.02 ± 0.46 mEq/L for no-obese (p?= 0.65). The average GFR was 73.4 ± 21.4 ml/L in obese patients vs 66.6 ± 22.6 ml/min in no-obese (p?= 0.03). The LVH was found in 81 cases (66.4%). The LVH was found in 65 (62.5%) obese patients vs?16 (88%) non-obese patients (OR = 4.8, 95% 1.04?-?22?p?= 0.02). Only abdominal?obesity has been correlated with left ventricular hypertrophy after multivariate analysis. Emphasis must be focused on public health actions for effective and appropriate measures against obesity and hypertension, whose prevalence is increasing in our region.

血清学标志物甲胎蛋白、PIVKA-Ⅱ和磷脂酰肌醇蛋白聚糖3联合诊断肝癌的meta分析

目的:探讨血清生物标志物甲胎蛋白(AFP)、维生素K缺失或拮抗剂Ⅱ诱导的蛋白质(PIVKA-Ⅱ)和磷脂酰肌醇蛋白聚糖3(GPC-3)单独或联合用于肝细胞癌(以下简称肝癌)诊断的价值。方法:检索PubMed、Web of Science、Embase三个数据库,收集2002年以来发表的AFP、PIVKA-Ⅱ和GPC-3单独或联合用于诊断肝癌的文献。根据纳入和排除标准筛选文献并提取相关数据。利用诊断准确性研究的质量评价(QUADAS)检查表对纳入的文献进行质量评价,并采用Meta DiSc软件、Review Manager 5.4软件和Stata 15.1软件对AFP、PIVKA-Ⅱ和GPC-3单用和联合使用诊断肝癌的受试者工作特征曲线下面积(AUC)、敏感度、特异度等指标进行数据分析。结果:共纳入32篇文献。Meta分析结果显示,单个标志物用于诊断肝癌时,PIVKA-Ⅱ的AUC值最高,为0.88(95%CI:0.85~0.91),其次是GPC-3和AFP;多个标志物联合用于诊断肝癌的AUC均高于单个标志物,其中PIVKA-Ⅱ联合GPC-3诊断的AUC值最高,为0.90(95%CI:0.87~0.92)。单个标志物用于诊断肝癌时,PIVKA-Ⅱ和GPC-3的敏感度相对较高(分别为0.75和0.76),但GPC-3的特异度不如PIVKA-Ⅱ和AFP(AFP、PIVKA-Ⅱ和GPC-3分别为0.87、0.88和0.81);多个标志物联合用于诊断肝癌的敏感度较单个标志物诊断时有所提高,但特异度无明显提高。单个标志物用于诊断肝癌时,PIVKA-Ⅱ的诊断比值比(DOR)最高,为22(95%CI:13~36),其次是GPC-3和AFP;两个标志物联合用于诊断肝癌的DOR均高于单个标志物,其中AFP联合GPC-3诊断的DOR最高,为25(95%CI:9~67);三个标志物联合用于诊断肝癌时的DOR明显降低,为10(95%CI:7~45)。结论:单个标志物用于肝癌诊断时,PIVKA-Ⅱ的诊断价值更高。两种标志物联合能显著提高肝癌诊断的敏感度,三种标志物联合未能进一步提高诊断价值。结合临床实际,推荐AFP联合PIVKA-Ⅱ用于肝癌的诊断。

Comparison on serum biomarkers for anovulatory and ovulatory dysfunctional uterine bleeding in Lizu females

Objective:To screen,identify,and compare the serum biomarkers between anovulatory dysfunctional uterine bleeding(ADUB)and ovulatory dysfunctional uterine bleeding(ODUB)in Lizu females.Methods:The subjects included 128 ADLB patients,63 ODUB patients,and 93controls.The serum and supernate of the subjects'mense were collected and stored at-80°C until use.Differential proteins in the sera of three groups were screened using surface-enhaneed laser desorption ionization time-of-flight mass spectrometry.The screened proteins were then identified by tricine-SDS-PAGE gel and spectrometry.Protein expression levels in the menses of ADUB,ODUB,and control subjects were determined using ELISA,RT-PCR,and Western blotting.SPSS 14.1 was used for statistical analysis and chart drawing(a=0.05),Results:Three differentia)protein peaks with peak values of 11.80,13.59,and 14.68 km/z were,screened and identified as serum amyploid protein A(SAA),vascular endothelial growth factor,and vitamin K epoxide reductase,respectively.The SAA was highly expressed in the menses of ADUB and ODUB patients but poorly expressed in the controls.The vascular endothelial growth factor was highly expressed in the menses of ODUB and controls but poorly expressed in ADUB patients.Meanwhile,the vitamin K epoxide reductase was highly expressed in the menses of ADUB and control subjects but poorly expressed in ODUB patients.Conclusions:The SAA is the common serum biomarker of ADUB and ODUB.ADUB may be related to angiogenesis impairment,whereas ODUB may be associated with blood coagulation disruption.

Effect of Potassium on Ultrastructure of Maize Stalk Pith and Young Root and Their Relation to Stalk Rot Resistance

To study the mechanism of potassium （K） application on improvement of maize resistance to stalk rot at cellular level, scanning electron microscope and transmission electron microscope were used to observe the effect of K on the ultrastructure of maize stalk pith tissue and young root tip cell influenced by K and pathogen. In K deficient treatment, parenchyma cells of stalk pith had abnormal structure, and the cell wall between upper and lower adjacent cell was damaged, resulting in the loss of connections between vascular cells and insufficient supporting capacity. However, an improved K nutrition helped to keep a quite tight arrangement of root cell with thick cell wall, and prevent the invasion of pathogen effectively. Moreover, K treated root cell had abundant golgi apparatus, which could excrete large amount of secretions to degrade mycelium. Papillary and highly electronic intensity dot were accumulated at the invading point to prevent the deveJopment of the mycelium. Improved K nutrition could increase the resistant ability of maize plant to stalk rot, through keeping cell structure stability, preventing the expansion of intracellular space to reduce the chances of pathogen invasions, and through reinforcing cell wall and formation of intercellular and intracellular material to restrict further development of pathogen in host cell.

Baeyer-Villiger oxidation of cyclic ketones utilizing potassium peroxydisulfate(K_2S_2O_8) or sodium perborate(NaBO_3) in acidic media

The efficient, green, facile, mild and straightforward conversion procedure for the oxidation of cyclic ketones to lactones at room temperature utilizing potassium peroxydisulfate （K2S2O8） in acidic media is satisfactory to high yields without using traditional chlorinated solvents is reported. This oxidative reagent is cheap and friendly environmental procedure for industrial purposes than use of organic peracids.

Preparation of Layered Potassium Titanate Whiskers with Large Length-diameter Ratio by KDC Method

Pure K2Ti4O9 whiskers were prepared by KDC（Kneading-Drying-Calcination） method with TiO2 and K2CO3 as raw materials. The influences of TiO2/K2CO3 molar ratio（RT/K）, calcination temperature（TC） and cooling process on phase composition and morphology of the whiskers were investigated by TG-DSC（thermo gravimetric-differential scanning calorimeter）, XRD（X-ray diffraction）, and SEM（scanning electron microscope）. Pure K2Ti4O9 potassium titanate whiskers with large length-diameter ratio（r）（over 250） can be obtained at RT/K = 2.9 and TC = 950 ℃.

20 Years Advances in Preparation of Potassium Salts from Potassic Rocks:A Review

Long-term research on key techniques of clean utilization of potassic rocks from over twenty localities has been performed to settle the shortage of soluble potassium resources in China. The results show that K-feldspar as the principal mineral enriched in potassium could be decomposed in the media of Ca（OH）_2, NaOH, KOH-H_2O solution via hydrothermal treatment, into tobermorite, hydroxylcancrinite, and kalsilite respectively. By further processing, these compounds are feasible for being as slow-release carrier of potassium nitrate, extracting alumina, and preparing farm-oriented fertilizers of potassium sulphate and nitrate. Correspondingly, the filtrate is KOH,（Na, K）_2SiO_3, and K_2SiO_3 solution, from which potassium carbonate, sulphate, nitrate, and phosphate could be easily fabricated. As NaO H and KOH are recycled in the processing chains by causticizing sodium and/or potassium metasilicate solutions, the hydrothermal alkaline techniques as developed in this research have several advantages as lower consumption of disposable mineral resources and energy, maximized utilization of potassic mineral resources, as well as clean productions etc. Based on the approaches presented in this paper, the technical system of efficiently utilizing insoluble potassium resources has been established. The hydrothermal alkaline methods are feasible to be industrialized on a large scale, thus resulting in decreasing imports of potash fertilizers, improving the pattern of potassium fertilizer consumption, and enhancing the supplying guarantee of potassium resource in China.

萝卜HAK/KUP/KT基因家族鉴定与表达特性分析

钾元素是植物生长发育过程中必需的主要矿质营养元素之一,对作物的产量和品质有决定性影响,细胞内K+含量水平在很大程度上受K+转运蛋白控制。通过生物信息学方法从全基因组水平鉴定出萝卜K^(+)转运蛋白HAK/KUP/KT基因家族成员,并对其基因结构、蛋白质特性、保守基序、染色体定位、启动子顺式作用元件、系统进化及表达特性等进行分析。结果表明,鉴定出的17个萝卜HAK/KUP/KT基因不均等地分布在萝卜6条染色体及Scaffold00840上,根据与拟南芥的同源关系将其命名为RsHAK1~RsHAK17;RsHAKs基因结构、保守基序、蛋白质理化特性等均具有高度保守性,启动子区域存在大量与环境因素、植物激素、逆境胁迫应答等有关的顺式作用元件;系统进化分析结果显示,17个RsHAKs基因聚为4个亚家族,全基因组复制事件是RsHAKs基因扩张的主要驱动力。转录组和qRT-PCR表达分析结果表明,除RsHAK5仅在萝卜根部表达外,其他RsHAKs在萝卜各器官及发育过程中均有特异性表达,且在高钾渗透胁迫下在叶片中相对表达量显著上调,RsHAK3、RsHAK9、RsHAK11和RsHAK12在根部呈现明显的缺钾诱导表达模式。研究结果为进一步全面解析HAK/KUP/KT基因在萝卜中的生物学功能以及提高萝卜栽培品质提供了一定理论依据。

Potassium forms in calcareous soils as affected by clay minerals and soil development in Kohgiluyeh and Boyer-Ahmad Province,Southwest Iran

Potassium（K） is known as one of the essential nutrients for the growth of plant species. The relationship between K and clay minerals can be used to understand the K cycling, and assess the plant uptake and potential of soil K fertility. This study was conducted to analyze the K forms（soluble, exchangeable, non-exchangeable and structural） and the relationship of K forms with clay minerals of calcareous soils in Kohgiluyeh and Boyer-Ahmad Province, Southwest Iran. The climate is hotter and drier in the west and south of the province than in the east and north of the province. A total of 54 pedons were dug in the study area and 32 representative pedons were selected. The studied pedons were mostly located on calcareous deposits. The soils in the study area can be classified into 5 orders including Entisols, Inceptisols, Mollisols, Alfisols and Vertisols. The main soil clay minerals in the west and south of the study area were illite, chlorite and palygorskite, whereas they were smectite, vermiculite and illite in the north and east of the province. Due to large amount of smectite and high content of organic carbon in soil surface, the exchangeable K in surface soils was higher than that in subsurface soils. It seems that organic matter plays a more important role than smectite mineral in retaining exchangeable K in the studied soils. Non-exchangeable K exhibited close relationships with clay content, illite, vermiculite and smectite. Although the amount of illite was the same in almost all pedons, amounts of structural and non-exchangeable K were higher in humid regions than in arid and semi-arid regions. This difference may be related to the poor reservoir of K~＋ minerals like palygorskite and chlorite together with illite in arid and semi-arid regions. In humid areas, illite was accompanied by vermiculite and smectite as the K~＋ reservoir. Moreover, the mean cumulative non-exchangeable K released by CaCl_2 was higher than that released by oxalic acid, which may be due to the high buffering capacity resulting from high carbonates in soils.

The diagnosis of hyperkalemia induced by potassium chloride in experimental rabbits

Objective： To observe the electrocardiogram （ECG） and heart rate in a rabbit model ofhyperkalemia induced by potassium chloride, and provide theoretical and experimental reference for timely diagnosis of hyperkalemia clinically. Methods： Forty rabbits were randomly assigned into four groups. 0.9% isotonic saline solution was perfused in the group I , while 1.0%, 4.0% and 10.0% potassium chloride solutions were perfused in the other groups, respectively, to induce hyperkalemia. Results： The changes of serum potassium, ECG and heart rate before perfusion were significantly （P〈 0.05） different from those after perfusion in the other groups compared with group I . The effect of ECG variability rates was well consistent （Kappa = 0.724, P〈0.01） with that of serum potassium on diagnostic tests in the other groups. The area under ROC curve in diagnosis effect of ECG variability rates and sermn potassium on hyperkalaemia was much significantly larger （P〈0.01 and P〈0.05） compared with 0.5. There was asignificantly positive correlation between ECG variability rates and serum potassium （r= 0.865, P〈0.05 for bilateral Pearson test）. There was certain positive correlation between heart rate and serum potassium, but the correlation was poor （r= 0.526, R2=0.277）. Conclusion： A combination of serum potassium, ECG variability rates and heart rate should be considered and analyzed by synthesis to establish an accurate and timely diagnosis for hyperkalemia.

Ion channels in neurodevelopment:lessons from the Integrin-KCNB1 channel complex

Ion channels modulate cellular excitability by regulating ionic fluxes across biological membranes.Pathogenic mutations in ion channel genes give rise to epileptic disorders that are among the most frequent neurological diseases affecting millions of individuals worldwide.Epilepsies are trigge red by an imbalance between excitatory and inhibitory conductances.However,pathogenic mutations in the same allele can give rise to loss-of-function and/or gain-of-function va riants,all able to trigger epilepsy.Furthermore,certain alleles are associated with brain malformations even in the absence of a clear electrical phenotype.This body of evidence argues that the underlying epileptogenic mechanisms of ion channels are more diverse than originally thought.Studies focusing on ion channels in prenatal cortical development have shed light on this apparent paradox.The picture that emerges is that ion channels play crucial roles in landmark neurodevelopmental processes,including neuronal migration,neurite outgrowth,and synapse formation.Thus,pathogenic channel mutants can not only cause epileptic disorders by alte ring excitability,but further,by inducing morphological and synaptic abnormalities that are initiated during neocortex formation and may persist into the adult brain.

A novel luminol-based chemiluminescence method for the determination of amikacin sulfate in serum by using trivalent copper-periodate complex

A novel chemiluminescence （CL） reaction was based on the oxidizing reaction of luminol by the trivalent copper-periodate complex （Ks[Cu（HIO6）2], DPC） in alkaline medium. The CL intensity could be enhanced in the presence of amikacin sulfate （AKS）. A new CL method was developed for the determination of AKS by coupling with flow injection （FI） technology. Because of the distinctive oxidative effect of DPC, the luminol-based CL reaction could occur at a low concentration of 10-7 M. The relative CL intensity was proportional to the concentration of AKS in the range of 4.0 x 10-9-4.0 x 10-6 g/mL with the detection limit of 1.2 x 10-9 g/mL. The relative standard deviation was 2.1% for 8.0xl0-9g/mL AKS （n=9）. The proposed method was successfully applied to the direct determination of AKS at the level of ng/mL in serum samples. The recovery varied from 97.0% to 106.3%. A possible mechanism of the CL reaction was discussed in detail by relating to the CL kinetic characteristics and electrochemical activities of the oxidant DPC.

STRUCTURE OF POTASSIUM ∝-TRIVANADOENNEATUNGSTOGERMANATE ∝-K_3H_4 GeW_9 V_3 O_(40)·8H_2O

The complex K_3H_4GeW_9V_3O_(40)·8H_2O crystallized in a monocliinie system with space group P2, Mr=2784.67, a=11.099(3), b=16.452(4), c=13.534(4) , β=108.14(2)°, Z=2,V=2348.49 ~3, F(000):2456, μ=239.7cm^(-1), De=3.932 g/cm^3. The final R=0.083 for 4528 non-zero reflexions. The structure of anions GeW_9V_3O_(40)~and GeW_9O_(34)~belongs to A-type.

Enhanced Loading of ^(40)K from Natural Abundance Potassium Source with a High Performance 2D^+ MOT

40K is one of the most important atomic species for ultra-cold atomic physics. Due to the extremely low con- centration （0.012%） of 40K in natural abundance of potassium, most experiments use 4-10% enriched potassium source, which have greatly suffered from the extremely low annual production and significant price hikes in recent years. Using naturally abundant potassium source, we capture 5.4 × 10 6 cold 40K atoms with the help of a high performance of two-dimensional magneto-optical trap （2D＋ MOT）, which is almost three orders of magnitude greater than previous results without the 2D＋ MOT. The number of the 40K atoms is sufficient for most ultra-cold 40K experiments, and our approach provides an ideal alternative for the field.

An Experimental Study on RBC Count and Serum Potassium Concentration Changes During Compression Transfusion of WBC-removal Whole Blood

Objective： To observe changes in RBC count, changes, RBC morphology, and serum potassium during compressed transfusion of WBC-removal whole blood. Methods： Prepared human WBC-removal whole blood and connected transfusion apparatus with different sizes of intravenous detaining needles （18G, 20G, 22G and 24G）. Observed RBC count and serum potassium concentration under different pressures （100 mmHg, 200 mmHg, and 300 mmHg） as blood flowed out of the pinhead end of the intravenous detaining needle. Samples obtained with the 20G needle were smeared on glass slides, and RBC morphologic changes were observed under an oil immersion lens. Results： RBC count and serum potassium changed slightly under different pressures with different sizes of intravenous detaining needles as blood flowed through the transfusion apparatus. In addition, the observation of blood samples under a common light microscope revealed that coarse- prick, oblong, and spindle cell counts in the visual fields increased gradually as the pressure increased. Additionally, a portion of cells had undergone splintering. Conclusions： While applying 18G, 20G, 22G and 24G intravenous detaining needles for blood transfusion under less than 300 mmHg of pressure, no significant RBC count change was found in blood samples in the short term. However, there were significant RBC morphologic changes. The results could offer more basis to ensure the clinical safetv of oatients undereoing blood transfilsion.

Solid–liquid Phase Equilibria in the Aqueous Ternary System Containing Lithium,Potassium,and Sulfate ions at 288.15 K

1 Introduction Salt lakes are widely distributed in the western of China,especially in the area of Qinghai-Xizang(Tibet)Plateau.A series of salt lakes in the Qaidam Basin,located in Qinghai Province,China,is famous for their abundance of lithium,potassium and boron resources(Zheng et al,1988;Deng et al,2012).It is well known that the