Host-induced gene silencing of the Verticillium dahliae thiamine transporter protein gene(VdThit)confers resistance to Verticillium wilt in cotton

Verticillium wilt(VW),induced by the soil-borne fungus Verticillium dahliae(Vd),poses a substantial threat to a diverse array of plant species.Employing molecular breeding technology for the development of cotton varieties with heightened resistance to VW stands out as one of the most efficacious protective measures.In this study,we successfully generated two stable transgenic lines of cotton(Gossypium hirsutum L.),VdThitRNAi-1 and VdThit-RNAi-2,using host-induced gene silencing(HIGS)technology to introduce double-stranded RNA(dsRNA)targeting the thiamine transporter protein gene(VdThit).Southern blot analysis confirmed the presence of a single-copy insertion in each line.Microscopic examination showed marked reductions in the colonization and spread of Vd-mCherry in the roots of VdThit-RNAi cotton compared to wild type(WT).The corresponding disease index and fungal biomass of VdThit-RNAi-1/2 also exhibited significant reductions.Real-time quantitative PCR(qRT-PCR)analysis demonstrated a substantial inhibition of VdThit expression following prolonged inoculation of VdThit-RNAi cotton.Small RNA sequencing(sRNA-Seq)analysis revealed the generation of a substantial number of VdThit-specific siRNAs in the VdThit-RNAi transgenic lines.Additionally,the silencing of VdThit by the siVdThit produced by VdThit-RNAi-1/2 resulted in the elevated expression of multiple genes involved in the thiamine biosynthesis pathway in Vd.Under field conditions,VdThit-RNAi transgenic cotton exhibited significantly enhanced disease resistance and yield compared with WT.In summary,our findings underscore the efficacy of HIGS targeting VdThit in restraining the infection and spread of Vd in cotton,thereby potentially enabling the development of cotton breeding as a promising strategy for managing VW.

Existence of Forced Waves and Their Asymptotic for Leslie-Gower Prey-Predator Model with Nonlocal Effects under Shifting Environment

In this paper, we prove the existence of forced waves for Leslie-Gower prey-predator model with nonlocal effects under shifting environment. By constructing a pair of upper and lower solutions with the method of monotone iteration, we can obtain the existence of forced waves for any positive constant shifting speed. Finally, we show the asymptotical behavior of traveling wave fronts in two tails.

面向室内定位的WIFI探针数据预处理研究

为验证依据多探针同时感知到的同一WIFI终端的RSSI值辨识WIFI终端是否在指定区域内的可行性,本文围绕多探针数据集的构造将将WIFI终端数据预处理流程划分为探针探测数据集解析、探针探测数据时间帧编号、面向室内人员定位的探针数据构造等三个阶段,并设计了相关预处理任务的流程并进行了实现。实验结果表明,以预处理后的数据为输入,基于BP神经网络的判别器可以以很高的准确率判别WIFI终端是否在指定的区域内,依据多探针同时感知到的同一WIFI终端的RSSI值辨识WIFI终端是否在指定区域内是可行的。

Numerical simulation and damage analysis of fissure field evolution law in a single coal seam mining

Based on the different deformation and failure laws of coal and rock materials under tensile or compressive loads,the damage variable was defined to divide three phases from the damage and rupture point of view in order to reveal the fissured field evolution characteristics and spatial distribution of coal and rock in the single coal seam mining with low permeability and rich methane.According to the corresponding damage constitutive equations,the secondary development of the finite element program was completed.The fissures field evolution law of a coal mine with single coal seam mining was calculated and analyzed by this new program and the distribution areas and failure degree of the surrounding coal and rock structures with damage,fissure or rupture are given on the condition of mining.This paper provides a scientific basis for quantitative research and evaluation of the safe simultaneous production of coal and gas.

THREE-DIMENSIONAL STATIC ANALYSES FOR FGM PLATES WITH MEDIUM COMPONENTS AND DIFFERENT NET STRUCTURES

A new microelement method for the analyses of functionally graded structures was proposed. The key of this method is the maneuverable combination of two kinds of elements. Firstly, the macro elements are divided from the functionally graded material structures by the normal finite elements. In order to reflect the functionally graded distributions of materials and the microconstitutions in each macro-element, the microelement method sets up the dense microelements in every macro-element, and translates nodes to the same as the normal finite elements by the degrees of freedom of all microelemental the compatibility conditions. This microelement method can fully reflect the micro constitutions and different components of materials, and its computational elements are the same as the normal finite elements, so it is an effective numerical method for the analyses of the functionally graded material structures. The three-dimensional analyses of functionally graded plates with medium components and different micro net structures are given by using the microelement method in this paper. The differences of the stress contour in the plane of functionally graded plates with different net microstructures are especially given in this paper.

锌、镉及其复合胁迫下白花泡桐幼苗的生理及富集特征

采用水培培养的试验方法,研究白花泡桐幼苗在锌(Zn)、镉(Cd)单一及复合胁迫下的生理生化响应及对重金属的富集、转移特征变化。结果表明,单一及复合重金属胁迫下,白花泡桐的生物量、株高及过氧化物酶(Peroxidase,POD)活性均随处理浓度的增加而降低。在复合污染下,Zn、Cd在植株的株高及生物量上表现出拮抗作用。与对照比,单一胁迫下,随着Zn浓度的增加,白花泡桐叶绿素含量和过氧化氢酶(Catalase,CAT)活性先增加后减小,超氧化物歧化酶(Superoxide dismutase,SOD)活性升高,地上部丙二醛(Malondialdehyde,MDA)含量先减小后增加;随着Cd浓度的增加,叶绿素含量和过氧化氢酶(CAT)活性升高,超氧化物歧化酶(SOD)活性及地上部丙二醛(MDA)含量先增加后减小,复合胁迫下,则表现出更加复杂的生理响应。白花泡桐幼苗对Cd的富集部位集中在根部;对Zn的富集部位集中在地上部,且转移系数大于1.00;Zn的加入会促进重金属向地上部分的转移;白花泡桐具有对复合重金属污染地进行有效的生态恢复的潜力。