Impact of Different Rates of Nitrogen Supplementation on Soil PhysicochemicalProperties and Microbial Diversity in Goji Berry

Goji berry(Lycium barbarum L.)is substantially dependent on nitrogen fertilizer application,which can signifi-cantly enhance fruit yield and Goji berry industrial development in Ningxia,China.This study aimed to analyze the functions of differential nitrogen application rates including low(N1),medium(N2),and high(N3)levels in soil microbial community structure(bacterial and fungal)at 2 diverse soil depths(0-20,20-40 cm)through high-throughput sequencing technology by targeting 16S RNA gene and ITS1&ITS2 regions.All the observed physicochemical parameters exhibited significant improvement(p<0.05)with increased levels of nitrogen and the highest values for most parameters were observed at N2.However,pH decreased(p<0.05)gradually.The alpha and beta diversity analyses for bacterial and fungal communities’metagenome displayed more similarities than differences among all groups.The top bacterial and fungal phyla and genera suggested no obvious(p>0.05)differences among three group treatments(N1,N2,and N3).Furthermore,the functional enrichment analysis demonstrated significant(p<0.05)enrichment of quorum sensing,cysteine and methionine metabolism,and transcriptional machinery for bacterial communities,while various saprotrophic functional roles for fungal communities.Conclusively,moderately reducing the use of N-supplemented fertilizers is conducive to increasing soil nitrogen utilization rate,which can contribute to sustainable agriculture practices through improved soil quality,and microbial community structure and functions.

ERF5.1 modulates carotenoid accumulation by interacting with CCD4.1 in Lycium

Carotenoids are important natural pigments and have medical and health functions for humans.Carotenoid cleavage dioxygenase 4(CCD4)and ethylene responsive factor(ERF)participate in carotenoid metabolism,but their roles in Lycium have not been discovered.Here,we annotated LbCCDs from the Lycium reference genome and found that LbCCD4.1 expression was significantly correlated with the carotenoid metabolites during Lycium five fruit developmental stages.Over-expression of LbCCD4.1 in NQ’s leaves resulted in a series of significantly lower contents of carotenoid metabolites,includingβ-carotene andβ-cryptoxanthin.Moreover,LbERF5.1,a transcription factor belonging to the ERF family that was located in the nucleus,was isolated.Significant reductions in the carotenoids,especially lutein,violaxanthin and their derivatives,were observed in over-expressing ERF5.1 transgenic NQ’s leaves.Over-expression or virus-induced gene silencing of LbERF5.1 in NQ’s leaves induced a consistent up-or down-expression,respectively,of LbCCD4.1.Furthermore,yeast one-hybrid and dual-luciferase reporter assays showed that ERF5.1 interacted with the promoter of CCD4.1 to increase its expression,and LbERF5.1 could bind to any one of the three predicted binding sites in the promoter of LbCCD4.1.A transcriptome analysis of LbERF5.1 and LbCCD4.1 over-expressed lines showed similar global transcript expression,and geranylgeranyl diphosphate synthase,phytoene synthase,lycopeneδ-cyclase cytochrome,cytochrome P450-type monooxygenase 97A,cytochrome P450-type monooxygenase 97C,and zeaxanthin epoxidase in the carotenoid biosynthesis pathway were differentially expressed.In summary,we uncovered a novel molecular mechanism of carotenoid accumulation that involved an interaction between ERF5.1 and CCD4.1,which may be used to enhance carotenoid in Lycium.

模块化装配式钢框架结构简化计算模型及动力特性分析

模块化建筑作为预制程度最高的一种建筑结构体系,以其装配化程度高、施工速度快、环境干扰少、模块质量可控且隔声、防火、保温性能优良、可拆卸重复利用、绿色环保等显著优势成为建筑工业化的研究热点。我国在模块化建筑的研究与应用方面取得了一定成果,但针对模块化结构的研究大多集中在模块化节点和构件上,缺乏多高层模块结构在风、地震等荷载工况下的整体性能研究。为此,将对采用板式内套筒节点的模块化装配式钢框架进行整体结构的设计与分析,研究地震作用下结构的抗震性能。为便于整体结构建模分析,根据模块间连接节点构造形式和传力特点对节点简化方式进行了研究,提出了模块化板式内套筒节点简化计算模型并与相应的实体模型做对比以进行合理性验证;采用MIDAS/Gen 2020建立模块化钢框架整体结构计算模型,对结构进行反应谱分析,并将计算结果与现行国家标准限值进行对比;研究了地震作用下模块化钢框架的结构动力响应,采用弹性及弹塑性时程分析法对结构进行抗震性能分析,探讨结构的屈服机制及塑性铰开展情况。研究结果表明:1)提出的模块化节点简化计算模型与实体模型应力分布规律一致,破坏形态相同,二者破坏模式均为模块梁屈服,梁端产生塑性铰破坏,且两者的荷载-位移曲线相近,弹性阶段的刚度相差不大,简化模型的初始刚度约为实体模型的0.84~0.91倍,在相同荷载作用下,简化模型的位移变形更大;进入弹塑性阶段后,实体模型的屈服荷载和极限承载力均大于简化模型,验证了简化计算模型是合理且偏于安全的;2)反应谱分析得到的模块化钢框架结构的周期振型、顶点位移、层间位移角和应力比等相关力学性能指标均满足抗震设计要求,结构的用钢量为84.02 kg/m^(2),处在合理用钢量范围内,整体结构的设计是合理的;3)模块化钢框架结构的弹塑性分析表明,罕遇地震下大部分结构构件仍处在线弹性阶段,只有少量构件达到屈服,塑性铰主要集中在模块梁端且模块梁先于模块柱屈服,结构属于“强柱弱梁”体系,在罕遇地震下具有良好的抗震性能。