OsbZIP72 Is Involved in Transcriptional Gene-Regulation Pathway of Abscisic Acid Signal Transduction by Activating Rice High-Affinity Potassium Transporter OsHKT1;1

We created CRISPR-Cas9 knock-out and overexpressing OsbZIP72 transgenic rice plants to gain a better understanding of the role and molecular mechanism of OsbZIP72 gene in stress tolerance,which has remained largely elusive.OsbZIP72 was expressed and integrated into rice transgenic plant genomes,and the OsbZIP72 transcript in overexpression lines was elicited by salinity,abscisic acid(ABA)and drought stresses.OsbZIP72 overexpressing plants showed higher tolerance to drought and salinity stresses,while knock-out transgenic lines showed higher sensitivity to these stresses.The differentially expressed genes(DEGs)from RNA-sequencing data encompassed several abiotic stress genes,and the functional classification of these DEGs demonstrated the robust transcriptome diversity in OsbZIP72.Yeast one-hybrid,along with luciferase assay,indicated that OsbZIP72 acted as a transcriptional initiator.Remarkably,electrophoresis mobility assay revealed that OsbZIP72 bound directly to the ABAresponsive element in the OsHKT1;1 promoter region and activated its transcription.Overall,our findings revealed that OsbZIP72 can act as a transcriptional modulator with the ability to induce the expression of OsHKT1;1 in response to environmental stress through an ABA-dependent regulatory pathway,indicating that OsbZIP72 can play a crucial role in the ABA-mediated salt and drought tolerance pathway in rice.

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.

Influences of external nutrient conditions on the transcript levels of a nitrate transporter gene in Skeletonema costatum

To verify the feasibility of high-affinity nitrate transporter gene （Nrt2） as an indicator of nitrogen status, changes in the transcript levels of transcripts associated with phosphate starvation and different nitrate concentrations were studied using real-time quantitative reverse-transcription PCR （QRT-PCR） technology in batch cultures of Skeletonema costatum. The results show that compared with P-replete condition, P starvation could reduce the Nrt2 transcript levels apparently. Nrt2 transcript levels had a significant negative linear correlation with nitrate concentrations below 40 pmol/L. The results of 48 h short-term incubation experiment under different nitrate concentrations confirmed this correlation, and the following regression equation is built： y = -3.305x ＋ 98.95, R2 = 0.988, where x represents nitrate concentrations （〈40 btmol/L） and y represents the Nrt2 transcript levels.

Baicalin protects neonatal rat brains against hypoxicischemic injury by upregulating glutamate transporter 1 via the phosphoinositide 3-kinase/protein kinase B signaling pathway

Baicalin is a flavonoid compound extracted from Scutellaria baicalensis root.Recent evidence indicates that baicalin is neuroprotective in models of ischemic stroke.Here,we investigate the neuroprotective effect of baicalin in a neonatal rat model of hypoxic-ischemic encephalopathy.Seven-day-old pups underwent left common carotid artery ligation followed by hypoxia（8% oxygen at 37°C） for 2 hours,before being injected with baicalin（120 mg/kg intraperitoneally） and examined 24 hours later.Baicalin effectively reduced cerebral infarct volume and neuronal loss,inhibited apoptosis,and upregulated the expression of p-Akt and glutamate transporter 1.Intracerebroventricular injection of the phosphoinositide 3-kinase/protein kinase B（PI3 K/Akt） inhibitor LY294002 30 minutes before injury blocked the effect of baicalin on p-Akt and glutamate transporter 1,and weakened the associated neuroprotective effect.Our findings provide the first evidence,to our knowledge that baicalin can protect neonatal rat brains against hypoxic-ischemic injury by upregulating glutamate transporter 1 via the PI3 K/Akt signaling pathway.

Ipomoea batatas HKT1 transporter homolog mediates K^+ and Na^+ uptake in Saccharomyces cerevisiae

Soil salinity causes the negative effects on the growth and yield of crops. In this study, two sweet potato （Ipomoea batatas L.） cultivars, Xushu 28 （X-28） and Okinawa 100 （O-100）, were examined under 50 and 100 mmol L-1 NaCI stress. X-28 cultivar is relatively high salt tolerant than O-100 cultivar. Interestingly, real-time quantitative polymerase chain reaction （RT-qPCR） results indicated that sweet potato high-affinity K^＋ transporter 1 （IbHKT1） gene expression was highly induced by 50 and 100 mmol L-1 NaCI stress in the stems of X-28 cultivar than in those of O-100 cultivar, but only slightly induced by these stresses in the leaves and fibrous roots in both cultivars. To characterize the function of IbHKT1 transporter, we performed ion-flux analysis in tobacco transient system and yeast complementation. Tobacco transient assay showed that IbHKT1 could uptake sodium （Na^＋）. Yeast complementation assay showed that IbHKT1 could take up K^＋ in 50 mmol L^-1 K^＋ medium without the presence of NaCI. Moreover, Na^＋ uptake significantly increased in yeast overexpressing IbHKTI. These results showed that IbHKT1 transporter could have K^＋-Na^＋ symport function in yeast. Therefore, the modes of action of IbHKT1 in transgenic yeast could differ from the mode of action of the other HKT1 transporters in class I. Potentially, IbHKT1 could be used to improve the salt tolerance nature in sweet potato.

Genome-Wide Identification and Expression Profiling of the Shaker K+ Channel and HAK/KUP/KT Transporter Gene Families in Grape (Vitis vinifera L.)

Potassium(K+)is an essential macronutrient for plants to maintain normal growth and development.Shaker-like K+channels and HAK/KUP/KT transporters are critical components in the K+acquisition and translocation.In this study,we identified 9 Shaker-like K+channel(VvK)and 18 HAK/KUP/KT transporter(VvKUP)genes in grape,which were renamed according to their distributions in the genome and relative linear orders among the distinct chromosomes.Similar structure organizations were found within each group according to the exon/intron structure and protein motif analysis.Chromosomal distribution analysis showed that 9 VvK genes and 18 VvKUP genes were unevenly distributed on 7 or 10 putative grape chromosomes.Three pairs of tandem duplicated genes and one pair of segmental duplicated genes were observed in the expansion of the grape VvKUP genes.Gene expression omnibus(GEO)data analysis showed that VvK and VvKUP genes were expressed differentially in distinct tissues.Various cis-acting regulatory elements pertinent to phytohormone responses and abiotic stresses,including K+deficiency response and drought stress,were detected in the promoter region of VvK and VvKUP genes.This study provides valuable information for further functional studies of VvK and VvKUP genes,and lays a foundation to explore K+uptake and utilization in fruit trees.

复杂社会网络与N-K模型的氢能储运系统风险因素耦合分析

将复杂社会网络(SNA)与N-K模型的融合风险因素分析体系引入氢能储运系统安全风险评价中。收集整理国内外近20年来氢能储运事故案例;运用N-K模型计算风险耦合值并确定事故耦合形式,利用SNA构建关联网络计算风险度量;结合复杂社会网络可达性分析与N-K模型修正出接近中心度以确定关键风险因素,并提出相关对策措施。结果表明:避免人-设-环-管多因素风险耦合形式是降低事故发生概率的关键方式;设-环-管三因素风险耦合形式最易引起事故的发生;人才队伍、管理执行力度、规章制度、文化水平、专业技能是需要重点防范的关键风险因素。

基于K-means与GRNN的高原山区高速公路短时交通流预测

为了研究可适用于高原山区高速公路短时交通流的预测方法,以及预测方法思路对绩效的影响,提出基于广义回归神经网络(General Regression Neural Network,GRNN),构建K均值聚类算法(K-means clustering algorithm,K-means)与GRNN混合预测方法思路,即通过K-means和绩效指标判断GRNN模型参数最佳值,进而建立最佳预测模型。与传统上通过经验或一定指标判断模型参数值的思路相比,采用K-means和GRNN混合预测思路得出的模型参数值更佳,且模型RMSE、MAE最高可分别改善45.92%、45.05%,则构建的混合预测方法思路是科学有效的,可为高原山区交通流预测方法优化提供借鉴。

Influence of K + on the Coupling Between ATP Hydrolysis and Proton Transport by the Plasma Membrane H +_ATPase from Soybean Hypocotyls

The plasma membrane vesicles were purified from soybean (Glycine max L.) hypocotyls by two_phase partitioning methods. The stimulatory effects of K + on the coupling between ATP hydrolysis and proton transport by the plasma membrane H +_ATPase were studied. The results showed that the proton transport activity was increased by 850% in the presence of 100 mmol/L KCl, while ATP hydrolytic activity was only increased by 28.2%. Kinetic studies showed that K m of ATP hydrolysis decreased from 1.14 to 0.7 mmol/L, while V max of ATP hydrolysis increased from 285.7 to 344.8 nmol Pi·mg -1 protein·min -1 in the presence of KCl. Experiments showed that the optimum pH was 6.5 and 6.0 in the presence and absence of KCl, respectively. Further studies revealed that K + could promote the inhibitory effects of hydroxylamines and vanadates on the ATP hydrolytic activity. The above results suggested that K + could regulate the coupling between ATP hydrolysis and proton transport of the plasma membrane H +_ATPase through modulating the structure and function of the kinase and phosphatase domains of the plasma membrane H +_ATPase.

Abnormal electric transport property and magnetoresistance stability of La-Sr-K-Mn-O system

The perovskite samples La1-x（Sr1-yKy）xMnO3 （y = 0.0, 0.2, 04, 0.6, 0.8） were prepared by the solid-state reaction method with comparatively low sintering tem- perature and with comparatively short sintering time, and the electric transport property and temperature stability of MR of this system were studied. The p-T curves show the abnormal phenomenon that with the increase of K doping amount, resistivity increases, and the insulator-metal transition temperature decreases, which is because the influence of the occupation disorder degree of A-site ions σ2 on the electric transport property of perovskite manga- nites is larger than that of the radius of A-site ions （rA）. In the temperature range below 225 K, MR increases contin- uously with the decrease of temperature, which is the characteristic of low-field magnetoresistance; in the com- paratively wide temperature range near 250 K, the MR- T curves of all the samples are comparatively fiat, and the value of MR almost does not change with temperature, which shows the temperature stability of magnetoresis- tance, and can be explained by the competition between the low-field magnetoresistance induced by spin-dependent tunneling of surface phase and the intrinsic magnetoresis- tance of grain phase. The magnetoresistance value of the sample with y = 0.8 keeps at （7.92 ±0.36） % in the very wide temperature range of 225-275 K, and this is a goodreference for the preparation of this kind of sample with practical application value in the future.

基于LOADEST模型和M K检验的淮河入洪泽湖氮磷污染通量分析

基于2015-2020年淮河入洪泽湖断面的水文水质数据,利用LOADEST模型建立污染物通量与河流流量之间的统计回归模型,并估算淮河入洪泽湖总氮(TN)、总磷(TP)污染物通量。结果表明,2005-2020年间淮河TN、TP年平均输移通量分别为(4730.14±1893.32)t、(257.56±108.53)t;受流量变幅影响,TN、TP输移通量与河流流量均呈极显著性相关关系(p<0.01)。采用M K检验分析发现,研究期间淮河TN和TP的输移通量总体上呈下降趋势,2018年12月后受入湖水量与氮磷浓度双重影响氮磷输移通量下降趋势更为明显。

HKT在植物离子稳态和响应非生物逆境胁迫中的作用

K^(+)在植物生长发育及抵御非生物胁迫中扮演着重要角色。高亲和性K^(+)转运蛋白(high-affinity K^(+)transporter,HKT)是最重要的阳离子转运蛋白家族之一,广泛参与植物K^(+)和Na^(+)吸收与转运。大量研究表明,HKT家族基因表达受Ca^(2+)、腐植酸和胞嘧啶甲基化等调控;其介导植物体内Na^(+)长距离运输以及维持K^(+)和Mg^(2+)稳态平衡,在植物抗逆性中发挥着关键作用。本研究对HKT家族的发现、结构与分类、生物学功能、表达与调控机制及其响应非生物胁迫等方面的研究成果加以综述,并对其未来研究方向进行展望,以期为农作物抗逆性遗传改良提供理论依据和基因资源。

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。

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^(+).

基于N-K模型的铁路运输安全风险耦合分析

为探究我国铁路运输安全事故的关键因素,采用N-K模型从人、设、环、管四个子系统风险进行分析,将风险耦合分为单因素、双因素和多因素三类,并以我国1950~2020年发生的铁路运输安全事故统计数据为基础,进行N-K模型实证分析。结果表明:安全事故发生的概率与风险值耦合值呈现正相关,其中人的因素对耦合影响最大。因此主观因素是铁路部门应当着重注意并改善的方向,以避免各因素耦合作用发生在铁路安全运输系统中较为薄弱环节。

基于K-means聚类与PLS回归模型的交通速度短时预测

为实现对交通流局部特征的有效提取,提高交通速度预测模型的可解释性,提出基于K-means聚类与偏最小二乘(Partial Least Squares,PLS)回归的交通速度短时预测模型。模型采用时空相关矩阵挖掘路网中相邻路段交通速度之间的关联性,利用K-means聚类算法划分历史数据集,并选取实测出租车GPS数据验证模型对交通速度短时预测的准确性。实验结果表明,与ARIMA、PLS回归和LSTM模型相比,该模型的预测误差减少了约30%。

基于深度强化学习和历史轨迹的船舶路径规划

为减少船舶在航行过程中人为操作不当或者没有及时对障碍风险做出反应而造成的船舶碰撞事故,增加船舶航行的安全性,提出一种船舶路径规划方法。将船舶历史的船舶自动识别系统(AIS)数据进行相应的预处理后,运用K-means聚类算法对相应数据进行聚类,得到的一条特征轨迹,并将其作为船舶在该区域的全局静态路径规划轨迹。设计一种基于深度确定性策略梯度(DDPG)算法的局部路径避碰方法和基于深度强化学习(DQN)的局部路径回归方法,使船舶可对局部动态风险做出有效的反应。分析全局静态路径的效果,并对局部动态路径规划方法做了仿真验证,结果表明:该方法可得到一条较为安全的全局路径,并且可规避航行时的局部动态风险,为船舶安全航行提供一定的参考。

城市客运交通方式碳排放强度比较

为比较不同城市客运交通方式的碳排放水平,提出城市客运交通碳排放强度评价指标,构建城市客运交通碳排放强度测算模型,结合Kruskal-Wallis检验和Bonferroni校正方法,分析不同城市客运交通方式碳排放强度的显著差异性,并采用k-means聚类方法,研究不同运营里程轨道交通的碳排放强度.研究表明:(1)定员人公里碳排放因子(RPCF)和实际人公里碳排放因子(APCF)指标均能有效评估城市客运方式的碳排放强度,但2个指标之间具有明显、不可忽略的差异.(2)从RPCF和APCF的平均水平来看,城市公共交通相较私人交通均具有明显的低碳优势.RPCF均值由大到小排序为:汽油小汽车、纯电动小汽车、柴油公交车、天然气公交车、城市轨道交通、纯电动公交车,取值分别为40.69,21.26,14.86,11.63,8.81,5.28gCO_(2)/(人·km);APCF均值由大到小排序为:汽油小汽车、纯电动小汽车、城市轨道交通、柴油公交车、天然气公交车、纯电动公交车,取值分别为113.02,59.06,43.14,42.47,33.24,15.07gCO_(2)/(人·km).相较于RPCF,城市轨道交通APCF的低碳优势减弱.(3)总体水平来看,城市轨道交通、柴油公交车相较于纯电动小汽车不具有低碳优势,天然气公交车和纯电动公交车相较城市轨道交通具有明显低碳优势,纯电动公交车是最低碳的客运方式,汽油小汽车是最不低碳的客运方式.(4)相较于低运营里程轨道交通,目前高运营里程轨道交通发挥出了更大的低碳优势.运营里程为0~70,70~200,200~400,400~600,600~800km的轨道交通对应的APCF分别为86.03,57.43,51.71,34.11,33.41gCO_(2)/(人·km).

葡萄基因组中 KUP 蛋白的生物信息学分析(英文)

植物钾（K＋）转运体蛋白在K＋的跨膜运输中起重要作用，进而维持植物体正常生长和代谢活动。本研究中，通过隐马尔科夫模型（HMM）和葡萄蛋白质库搜索，共找到18个葡萄钾转运体蛋白（VvKUPs）。利用生物信息学方法，我们对葡萄家族12条KUP蛋白序列的系统发生和KUP基因组定位进行分析，然后对其氨基酸组成成分、理化性质以及二级结构进行预测和分析，同时还分析了葡萄与拟南芥、水稻和杨树的K卯基因家族之间的联系。基因组定位结果发现其分布在至少9条染色体上。二级结构预测结果发现不同成员间氨基酸数目、氨基酸序列间的疏水性存在一定的差异；仅一螺旋和无规则卷曲为主要二级结构组成部分。基因结构分析表明，KUP基因家族成员分别含有7～10个内含子。葡萄KUP蛋白的亚细胞定位分析表明VvKUP主要定位于膜结构上。电子表达图谱分析结果表明：12条K卯基因有对应的EST序列，其中的11条KUP有相应的电子表达谱，并主要在花、果实、花序和花蕾等组织部位表达。

高等植物K^+吸收及转运的分子机制研究进展

K^+是植物生长必需的营养元素。K^+被植物根系吸收后,有效地向地上部转运,在跨膜转运的过程中主要由次级K^+转运蛋白和K^+通道介导。KT/HAK/KUP和HKT家族是参与植物体内K+吸收及转运的两类主要K+转运蛋白,其中HKT家族参与K^+转运的成员仅存在于单子叶植物中,它们在植物生长发育、渗透调节等过程中均发挥重要作用。Shaker家族是K^+通道中最早发现且研究最为深入的一类电压门控型通道,是植物K^+吸收的重要途径之一。本研究从结构特征、定位和组织表达、功能调控等方面对植物KT/HAK/KUP家族、HKT家族和Shaker通道进行综述,最后对未来的主要研究方向做了展望。