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Search Results: 1 - 10 of 23427 matches for " Zuyu Zheng "
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Roles of Arabidopsis WRKY3 and WRKY4 Transcription Factors in Plant Responses to Pathogens
Zhibing Lai, KM Vinod, Zuyu Zheng, Baofang Fan, Zhixiang Chen
BMC Plant Biology , 2008, DOI: 10.1186/1471-2229-8-68
Abstract: Both WRKY3 and WRKY4 are nuclear-localized and specifically recognize the TTGACC W-box sequences in vitro. Expression of WRKY3 and WRKY4 was induced rapidly by stress conditions generated by liquid infiltration or spraying. Stress-induced expression of WRKY4 was further elevated by pathogen infection and SA treatment. To determine directly their role in plant disease resistance, we have isolated T-DNA insertion mutants and generated transgenic overexpression lines for WRKY3 and WRKY4. Both the loss-of-function mutants and transgenic overexpression lines were examined for responses to the biotrophic bacterial pathogen Pseudomonas syringae and the necrotrophic fungal pathogen Botrytis cinerea. The wrky3 and wrky4 single and double mutants exhibited more severe disease symptoms and support higher fungal growth than wild-type plants after Botrytis infection. Although disruption of WRKY3 and WRKY4 did not have a major effect on plant response to P. syringae, overexpression of WRKY4 greatly enhanced plant susceptibility to the bacterial pathogen and suppressed pathogen-induced PR1 gene expression.The nuclear localization and sequence-specific DNA-binding activity support that WRKY3 and WRKY4 function as transcription factors. Functional analysis based on T-DNA insertion mutants and transgenic overexpression lines indicates that WRKY3 and WRKY4 have a positive role in plant resistance to necrotrophic pathogens and WRKY4 has a negative effect on plant resistance to biotrophic pathogens.Upon pathogen infection, pathogen-associated molecular patterns (PAMPs) such as bacterial flagellin and lipopolysaccharides are recognized by plant receptors to activate PAMP-triggered immunity through a mitogen-activated protein kinase signaling cascade [1]. Gram-negative bacterial pathogens such as Pseudomonas syringae can deliver effector proteins to plant cells to interfere PAMP-triggered resistance to promote pathogen virulence. As a result, the remaining basal defense is usually insuffi
Spiral rainband in a numerically simulated tropical cyclone
Peijun Zhu,Yongguang Zheng,Hongqing Wang,Zuyu Tao
Chinese Science Bulletin , 2005, DOI: 10.1007/BF03183682
Abstract: Spiral rainband is a prominent structure of tropical cyclone. Though its forming mechanism, vortex Rossby wave theory, has been widely accepted in recent years, its internal structural features are still not well known. The spiral rainband in the severe tropical storm Kammuri (2002), which caused heavy rainfall in southeast China, is simulated using the mesoscale model MM5 (V3). Results show that the simulated spiral rainband propagates azimuthally at a speed close to that of vortex Rossby wave in theory, and is accompanied with energy dispersion in the radial direction. The structural features of simulated spiral rainband are analyzed with the high-resolution model output including the full physical process. Positive vorticity, ascending motion, horizontal momentum and so on are highly concentrated in the spiral rainband. The convergent moisture of spiral rainband comes mostly from the planetary boundary layer under 1 km. Airflow from the outside of spiral rainband is convective instability, which can provide instability energy for convection development. However, the atmospheric stratification in the inside of spiral rainband is neutral, implying that the instability energy has been released. There is a mesoscale strong wind band just near the spiral rainband in the outer side with a maximum wind speed exceeding 30 m/s, which results from the pressure force acceleration when the air flows into the spiral rainband along the gradient of pressure.
A Study of the Extratropical Transformation of Typhoon Winnie (1997)
A Study of the Extratropical Transformation of Typhoon Winnie (1997)

ZHU Peijun,ZHENG Yongguang,ZHANG Chunxi,TAO Zuyu,
ZHU Peijun
,ZHENG Yongguang,ZHANG Chunxi,TAO Zuyu

大气科学进展 , 2005,
Abstract: The complicated evolutive process of how a tropical cyclone transforms into an extratropical cyclone is still an unresolved issue to date, especially one which arises in a weakly baroclinic environment. Typhoon Winnie (1997) is studied during its extratropical transformation stage of extratropical transition (ET)with observational data and numerical simulations. Results show that Winnie experienced its extratropical transformation to the south of the subtropical high without intrusion of the mid-latitude baroclinic zone.This is significantly different from previous studies. Analyses reveal that the cold air, which appeared in the north edge of Winnie circulation, resulted from the precipitation drag and cooling effect of latent heat absorption associated with the intense precipitation there. The cooling only happened below 3 km and the greatest cooling was below 1 km. With the cold air and its advection by the circulation of Winnie, a front was formed in the lower troposphere. The front above is related not only to the cooling in the lower level but also to the warming effect of latent heat release in the middle-upper levels. The different temperature variation in the vertical caused the temperature gradient over Winnie and resulted in the baroclinicity.
Functional analysis of Arabidopsis WRKY25 transcription factor in plant defense against Pseudomonas syringae
Zuyu Zheng, Stephen L Mosher, Baofang Fan, Daniel F Klessig, Zhixiang Chen
BMC Plant Biology , 2007, DOI: 10.1186/1471-2229-7-2
Abstract: We analyzed the role of the WRKY25 transcription factor from Arabidopsis in plant defense against the bacterial pathogen Pseudomonas syringae. WRKY25 protein recognizes the TTGACC W-box sequences and its translational fusion with green fluorescent protein is localized to the nucleus. WRKY25 expression is responsive to general environmental stress. Analysis of stress-induced WRKY25 in the defense signaling mutants npr1, sid2, ein2 and coi1 further indicated that this gene is positively regulated by the salicylic acid (SA) signaling pathway and negatively regulated by the jasmonic acid signaling pathway. Two independent T-DNA insertion mutants for WRKY25 supported normal growth of a virulent strain of P. syringae but developed reduced disease symptoms after infection. By contrast, Arabidopsis constitutively overexpressing WRKY25 supported enhanced growth of P. syringae and displayed increased disease symptom severity as compared to wild-type plants. These WRKY25-overexpressing plants also displayed reduced expression of the SA-regulated PR1 gene after the pathogen infection, despite normal levels of free SA.The nuclear localization and sequence-specific DNA-binding activity support that WRKY25 functions as a transcription factor. Based on analysis of both T-DNA insertion mutants and transgenic overexpression lines, stress-induced WRKY25 functions as a negative regulator of SA-mediated defense responses to P. syringae. This proposed role is consistent with the recent finding that WRKY25 is a substrate of Arabidopsis MAP kinase 4, a repressor of SA-dependent defense responses.Plants are subjected to constant attack by a variety of microbial pathogens and herbivores and they have evolved a complex battery of defense mechanisms that are activated by multiple defense signaling pathways. Thus, in response to infection by some microbial pathogens, the interacting EDS1 and PAD4 proteins are induced and activated; these proteins positively regulate biosynthesis of salicylic ac
Analysis of Indian Monsoon and Associated Low-Level Circulation in 1980 and 1981

Tao Zuyu,

大气科学进展 , 1989,
Abstract: In this paper, Indian monsoon of 1980 and 1981 is analysed based on the seasonal and half-month averaged data of 850 hPa of ECMWF analysis. The results show that Indian monsoon is related to Somali jet, the low-latitude easterlies and the mid-latitude westerlies over southern Indian Ocean, which are associated with the stationary wave of Southern Hemisphere. The forces affecting on the low-level flow are diagnosed, which display the relationship between Indian monsoon and the associated low-level flow.
failure mechanisms and calculation of bearing capacity of a strip footing on soil considering joined influnces of cohesion,surcharge and gravity
wang yujie,in jinhua chen zuyu
岩石力学与工程学报 , 2001,
Abstract:
Numerical study on structure of meso-β scale rainstorm system during IOP523 of HUAMEX
Qingli Wu,Min Chen,Hongqing Wang,Zuyu Tao
Chinese Science Bulletin , 2002, DOI: 10.1007/BF03183318
Abstract: One of the scientific goals of HUAMEX (Torrential Rainfall Experiment over Both Sides of the Taiwan Strait and Adjacent Area), a special project in the National “863” Scientific Project, is to reveal meso-β scale structure of heavy rainfall. However, limited by the observational instruments, the resolution of the data attained from the outfield scientific observation network cannot reveal the meso-β scale structure. A 36-h numerical simulation of heavy rainfall case from May 23 to May 24, 1998 during IOP523 of HUAMEX was performed by the mesoscale numerical model of PSU/NCAR MM5, and the meso-β scale structure of convective system was examined based on the model output in this note. The results point out that the meso-β scale features of the heavy rainfall are clear considerably at low, middle and upper levels, respectively. There is a strong ageostrophic feature between the geopotential height field and the wind field on the upper level. The vertical cross sections of 54 km coarse grid and 18 km fine grid both show the vertical circulation cells of the rainstorm clearly, which include a descending middle-level rear inflow and strong ascending low-level inflow. More importantly, the 18 km fine grid vertical section reveals another shallow vertical circulation cell in the planetary boundary layer (PBL) below 900 h Pa, which relates to the draggle flow resulting from the falling raindrops.
Analysis and Physical Interpretation on Cloud System Structure for the Cold vortex with Severe Weather
强天气冷涡云系结构的分析和物理解释

Yang Hongmei,Tao Zuyu,
杨红梅
,陶祖钰

大气科学 , 1992,
Abstract: In this paper, the satellite images of three cases of cold vortices, which caused the severe convective weathers, are studied. The structure of cold vortex cloud system is catalogued by two types, the simple vortex structure and the occluded cyclone structure. The physical interpretation of various constituent parts of the cold vortex cloud system, i.e. the eddy cloud area, the instable cloud area, the positive vorticity advection cloud area, the cold front cloud area and the warm front cloud area, are discussed with diagnostic data.
A Case Study of Cold Air Activity during Meiyu Period in July of 1991
1991年梅雨期中冷空气活动的个例分析

Huang Wei,Tao Zuyu,
黄伟
,陶祖钰

大气科学 , 1995,
Abstract: The trajectories of cold air in heaVy rainfall Period of Jiang-Huai district July 4-6, 1991 show the cold air, which confront with the warm moist air in the Yangtze myer basin, came from the Northwest.The formation of 500 hpa trough on the set of Tibet Plateau, which cause the cyclone to develop in the Meiyu front, is related to the cold air activity.
强天气冷涡云系结构的分析和物理解释
杨红梅 Yang Hongmei,陶祖钰 Tao Zuyu
大气科学 , 1992, DOI: 10.3878/j.issn.1006-9895.1992.01.12
Abstract: 本文分析了三个产生强对流天气冷涡过程的卫星云图.冷涡云系的结构可归纳为单纯的冷涡结构和具有锢囚气旋结构两类.利用诊断分析对冷涡云系中各个组成部分,即涡旋云区、不稳定云区、正涡度平流云区、冷涡云区及暖锋云区与有关物理量的配置关系进行了讨论.
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