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Full time adult credential students?instructional preferences at California State University, Long Beach: pedagogy or andragogy?
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作者 WANG Victor 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2004年第3期116-121,共6页
This study investigated the instructional preferences of full time adult credential students after they took a live course called Principles of Adult Education at California State University, Long Beach (CSULB) in the... This study investigated the instructional preferences of full time adult credential students after they took a live course called Principles of Adult Education at California State University, Long Beach (CSULB) in the fall semester of 2002. These full time adult credential students had been working on their adult teaching credentials to meet the competencies specified by the California Commission on Teacher Credentialing. The course introduced students to Andragogy developed by Malcolm Knowles out of the andragogical model developed by Lindeman (1926). The study used Principles of Adult Learning Scales (PALS), advanced by Gary Conti in 1983 to measure instructional preferences. Data were collected from 30 (100% of 30) full time adult credential students enrolled in a live course to determine their instructional preferences of helping adults learn. The results of the study showed in most cases these adult learning professionals taught adult students andragogically; in some cases they taught adult students pedagogically. 展开更多
关键词 ANDRAGOGY Principles of Adult Learning Scales (PALS) Instructional preferences california State university
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Team California Santa Clara University,California College of the Arts
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作者 李昭君 《建筑技艺》 2011年第5期182-185,共4页
折屋说明当代建筑学与工程学的完美结合能够为我们创造出美丽、舒适的可持续住房.该项目在室内外设计中融入了加州的生活方式,建筑的开窗很多.我们在试图建造一个能效最大的房子的同时,优先处理视线、空间、功能与周围环境的连接问题.... 折屋说明当代建筑学与工程学的完美结合能够为我们创造出美丽、舒适的可持续住房.该项目在室内外设计中融入了加州的生活方式,建筑的开窗很多.我们在试图建造一个能效最大的房子的同时,优先处理视线、空间、功能与周围环境的连接问题.我们用这种策略将预制房转变成一个宽敞、包容的房间.大面积的室外生活空间通过有效地模糊室内外界限与室内保持着亲密的联系.建筑的朝向与大面积玻璃使室内分区相当明确.不同房间在最有可能被使用的时间段确保能有大量的天然光射入.每时每刻,光影都处于动态的韵律变化之中.我们采用了两种基本策略来增加这个小房子的空间感以便给住户带来更多乐趣:通过加长并弯曲的建筑平面,空间各有不同;谨慎运用光与开口来创造出与周围环境强烈的视觉连接与功能联系. 展开更多
关键词 分解图 加州 景观设计 建筑设计 Team california Santa Clara university california College of the Arts 室内设计 室内装饰 住宅 甲板 船舶结构
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Liver transplantation for hepatocellular carcinoma in India: Are we ready for 2040?
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作者 Hirak Pahari Amruth Raj +6 位作者 Ambreen Sawant Dipak S Ahire Raosaheb Rathod Chetan Rathi Tushar Sankalecha Sachin Palnitkar Vikram Raut 《World Journal of Transplantation》 2024年第1期141-153,共13页
BACKGROUND Liver transplantation(LT)for hepatocellular carcinoma(HCC)has been widely researched and is well established worldwide.The cornerstone of this treatment lies in the various criteria formulated by expert con... BACKGROUND Liver transplantation(LT)for hepatocellular carcinoma(HCC)has been widely researched and is well established worldwide.The cornerstone of this treatment lies in the various criteria formulated by expert consensus and experience.The variations among the criteria are staggering,and the short-and long-term outcomes are controversial.AIM To study the differences in the current practices of LT for HCC at different centers in India and discuss their clinical implications in the future.METHODS We conducted a survey of major centers in India that performed LT in December 2022.A total of 23 responses were received.The centers were classified as high-and low-volume,and the current trend of care for patients undergoing LT for HCC was noted.RESULTS Of the 23 centers,35%were high volume center(>500 Liver transplants)while 52%were high-volume centers that performed more than 50 transplants/year.Approximately 39%of centers had performed>50 LT for HCC while the percent distribution for HCC in LT patients was 5%–15%in approximately 73%of the patients.Barring a few,most centers were divided equally between University of California,San Francisco(UCSF)and center-specific criteria when choosing patients with HCC for LT,and most(65%)did not have separate transplant criteria for deceased donor LT and living donor LT(LDLT).Most centers(56%)preferred surgical resection over LT for a Child A cirrhosis patient with a resectable 4 cm HCC lesion.Positron-emission tomography-computed tomography(CT)was the modality of choice for metastatic workup in the majority of centers(74%).Downstaging was the preferred option for over 90%of the centers and included transarterial chemoembolization,transarterial radioembolization,stereotactic body radiotherapy and atezolizumab/bevacizumab with varied indications.The alphafetoprotein(AFP)cut-off was used by 74%of centers to decide on transplantation as well as to downstage tumors,even if they met the criteria.The criteria for successful downstaging varied,but most centers conformed to the UCSF or their center-specific criteria for LT,along with the AFP cutoff values.The wait time for LT from downstaging was at least 4–6 wk in all centers.Contrast-enhanced CT was the preferred imaging modality for post-LT surveillance in 52%of the centers.Approximately 65%of the centers preferred to start everolimus between 1 and 3 months post-LT.CONCLUSION The current predicted 5-year survival rate of HCC patients in India is less than 15%.The aim of transplantation is to achieve at least a 60%5-year disease free survival rate,which will provide relief to the prediction of an HCC surge over the next 20 years.The current worldwide criteria(Milan/UCSF)may have a higher 5-year survival(>70%);however,the majority of patients still do not fit these criteria and are dependent on other suboptimal modes of treatment,with much lower survival rates.To make predictions for 2040,we must prepare to arm ourselves with less stringent selection criteria to widen the pool of patients who may undergo transplantation and have a chance of a better outcome.With more advanced technology and better donor outcomes,LDLT will provide a cutting edge in the fight against liver cancer over the next two decades. 展开更多
关键词 Hepatocellular carcinoma Liver transplant INDIA DOWNSTAGING Survey MILAN university of california San Francisco Portal vein tumor thrombus Expanded criteria
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University of California Santa Barbara 2007 Global Medicine Conference——Integrating Chinese and Western Medicine:The View from China 被引量:1
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作者 夏亦嗣 《Chinese Journal of Integrative Medicine》 SCIE CAS 2007年第3期233-234,共2页
From May 3 through May 6, 2007, the University of California, Santa Barbara (UCSB)'s Global Medicine Project, and Santa Barbara Cottage Hospital cosponsored a conference entitled, “Integrating Chinese and Western ... From May 3 through May 6, 2007, the University of California, Santa Barbara (UCSB)'s Global Medicine Project, and Santa Barbara Cottage Hospital cosponsored a conference entitled, “Integrating Chinese and Western Medicine: The View from China”. A select group of the most prominent doctors in China accepted an invitation to visit UCSB to share their research, case studies, and specific treatment protocols that successfully combine Western medicine and ancient Chinese healing practices to alleviate the suffering caused by some of the most difficult diseases confronting humanity. In China, this type of treatment has been used effectively for more than four decades, and was presented by a group of doctors and research scholars who are the central figures in the evolution of this important paradigm for healing in the 21st Century. 展开更多
关键词 Integrating Chinese and Western Medicine university of california Santa Barbara 2007 Global Medicine Conference
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The President of the California Institute of Technology and the Chancellor of the University of California at Santa Barbara Visit Tsinghua
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《Tsinghua Science and Technology》 SCIE EI CAS 2009年第6期731-731,共1页
The President of the Califomia Institute of Technology Professor Jean-Lou Chameau and the Chancellor of the University of California at Santa Barbara Professor Henry Yang both delivered speeches in the Tsinghua Global... The President of the Califomia Institute of Technology Professor Jean-Lou Chameau and the Chancellor of the University of California at Santa Barbara Professor Henry Yang both delivered speeches in the Tsinghua Global Vision Lecture Series during their Tsinghua University visit on August 25, 2009. 展开更多
关键词 Vision The President of the california Institute of Technology and the Chancellor of the university of california at Santa Barbara Visit Tsinghua
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The University of California,Berkeley 被引量:1
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作者 李琳 《科技英语学习》 2007年第11期53-,共1页
The roots of the University of California go back to the gold rush days of 1849,when the drafters of the State Constitution,a group of vigorous and farsighted people,required the legislature to "encourage by all ... The roots of the University of California go back to the gold rush days of 1849,when the drafters of the State Constitution,a group of vigorous and farsighted people,required the legislature to "encourage by all suitable means the promotion of intellectual,scientific,moral and agricultural improvement"of the people of California.These 展开更多
关键词 The university of california Berkeley
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University of Southern California Professor Kai Hwang Delivers Tsinghua Global Vision Lecture
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《Tsinghua Science and Technology》 SCIE EI CAS 2009年第2期280-280,共1页
University of Southern California (USC) Professor Kai Hwang delivered the Tsinghua Global Vision Lecture “Global Advances in Computer and Information Technology: Can China Take the Lead?” in the FIT Lecture Hall... University of Southern California (USC) Professor Kai Hwang delivered the Tsinghua Global Vision Lecture “Global Advances in Computer and Information Technology: Can China Take the Lead?” in the FIT Lecture Hall on January 6, 2009. During his lecture, Professor Hwang shared his ideas about several global advances in computer, networking, and information technology and discussed the great challenges yet to be confronted in information and technology in academia and in industry and the building of world-class universities. In his address, 展开更多
关键词 VISION university of Southern california Professor Kai Hwang Delivers Tsinghua Global Vision Lecture
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President of the California Institute of Technology and Chancellor of the University of California at Santa Barbara Visit Tsinghua University
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《Tsinghua Science and Technology》 SCIE EI CAS 2009年第5期600-600,共1页
The President of the California Institute of Technology Professor Jean-Lou Chameau and the Chancellor of the University of California at Santa Barbara Professor Henry Yang both delivered speeches in the Tsinghua Globa... The President of the California Institute of Technology Professor Jean-Lou Chameau and the Chancellor of the University of California at Santa Barbara Professor Henry Yang both delivered speeches in the Tsinghua Global Vision Lecture Series during their Tsinghua University visit on August 25, 2009. Tsinghua University President Gu Binglin welcomed Professor Chameau and Professor Yang and outlined for them the latest developments at Tsinghua University. The three university presidents expressed the hope that more cooperation in the future could be built between their universities. They discussed collaboration in research and student exchange during their talks. 展开更多
关键词 President of the california Institute of Technology and Chancellor of the university of california at Santa Barbara Visit Tsinghua university
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University of California, Berkeley
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作者 郭大任 《科技英语学习》 2007年第8期45-,共1页
The University of California, Berkeley, is the oldest and flagship campus of the ten-campus University of California system.
关键词 BERKELEY university of california
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Sucrose transporters and plasmodesmal regulation in passive phloem loading 被引量:9
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作者 Johannes Liesche 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2017年第5期311-321,共11页
An essential step for the distribution of carbon throughout the whole plant is the loading of sugars into the phloem in source organs. In many plants, accumulation of sugars in the sieve element-companion cell (SE-CC... An essential step for the distribution of carbon throughout the whole plant is the loading of sugars into the phloem in source organs. In many plants, accumulation of sugars in the sieve element-companion cell (SE-CC) complex is mediated and regulated by active processes. However, for poplar and many other tree species, a passive symplasmic mechanism of phloem loading has been proposed, characterized by symplasmic continuity along the pre-phloem pathway and the absence of active sugar accumulation in the SE-CC complex. A high overall leaf sugar concentration is thought to enable diffusion of sucrose into the phloem. In this review, we critically evaluate current evidence regarding the mechanism of passive syrnplasmic phloem loading, with a focus on the potential influence of active sugar transport and plasmo- desmal regulation. The limited experimental data, com- bined with theoretical considerations, suggest that a concomitant operation of passive symplasmic and active phloem loading in the same minor vein is unlikely. However, active sugar transport could well play an important role in how passively loading plants might modulate the rate of sugar export from leaves. Insights into the operation of this mechanism has direct implications for our understanding of how these plants utilize assimilated carbon. 展开更多
关键词 William J. Lucas university of california DAVIS USA
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Molecular regulation of sucrose catabolism and sugar transport for development~ defence and phloem function 被引量:8
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作者 Jun Li Limin Wu +1 位作者 Ryan Foster Yong-Ling Ruan 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2017年第5期322-335,共14页
Sucrose (Suc) is the major end product of photosynthesis in mesophyll cells of most vascular plants. It is loaded into phloem of mature leaves for long-distance translocation to non-photosynthetic organs where it is... Sucrose (Suc) is the major end product of photosynthesis in mesophyll cells of most vascular plants. It is loaded into phloem of mature leaves for long-distance translocation to non-photosynthetic organs where it is unloaded for diverse uses. Clearly, Suc transport and metabolism is central to plant growth and development and the functionality of the entire vascular system. Despite vast information in the literature about the physiological roles of individual sugar metabolic enzymes and transporters, there is a lack of systematic evaluation about their molecular regulation from transcriptional to post-translational levels. Knowledge on this topic is essential for understanding and improving plant development, optimizing resource distri- bution and increasing crop productivity. We therefore focused our analyses on molecular control of key players in Suc metabolism and transport, including: (i) the identifica- tion of promoter elements responsive to sugars and hormones or targeted by transcription factors and micro- RNAs degrading transcripts of target genes; and (ii) modulation of enzyme and transporter activities through protein-protein interactions and other post-translational modifications. We have highlighted major remaining questions and discussed opportunities to exploit current understanding to gain new insights into molecular control of carbon partitioning for improving plant performance. 展开更多
关键词 William J. Lucas university of california DAVIS USA
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A novel wheat NAC transcription factor,Ta NAC_(30), negatively regulates resistance of wheat to stripe rust 被引量:7
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作者 Bing Wang Jinping Wei +3 位作者 Na Song Ning Wang Jing Zhao Zhensheng Kang 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2018年第5期432-443,共12页
NAC transcription factors are widespread in the plant kingdom and play essential roles in the transcriptional regulation of defense responses. In this study, we isolated a novel NAC transcription factor gene, TaNAC30,... NAC transcription factors are widespread in the plant kingdom and play essential roles in the transcriptional regulation of defense responses. In this study, we isolated a novel NAC transcription factor gene, TaNAC30, from a cDNA library constructed from wheat (Triticum aestivum) plants inoculated with the stripe rust pathogen Puccinia striiformis f. sp. tritici (Pst). TaNAC30 contains a typical NAM domain and localizes to the nucleus. Yeast one-hybrid assays revealed that TaNAC30 exhibits transcriptional activity and that its C-terminus is necessary for the activation of transcription. Expression of TaNAC30 increased when host plants were infected with a virulent race (CYR31) of the rust fungus Pst. Silencing of TaNAC30 by virus-induced gene silencing inhibited colonization of the virulent Psi isolate CYR31. Moreover, detailed histological analyses showed that silencing of TaNAC30 enhanced resistance to Pst by inducing a significant increase in the accumulation of H2O2. Finally, we overexpressed TaNAC30 in fission yeast and determined that cell viability was severely reduced in TaNAC30-transformed cells grown on medium containing H2O2. These results suggest that TaNAC30 negatively regulates plant resistance in a compatible wheat-Psi interaction. 展开更多
关键词 Gitta L. Coaker university of california DAVIS USA
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Plant xylem hydraulics:What we understand,current research,and future challenges 被引量:22
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作者 Martin D. Venturas John S. Sperry Uwe G. Hacke 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2017年第6期356-389,共34页
Herein we review the current state-of-the-art of plant hydraulics in the context of plant physiology, ecology, and evolution, focusing on current and future research opportunities. We explain the physics of water tran... Herein we review the current state-of-the-art of plant hydraulics in the context of plant physiology, ecology, and evolution, focusing on current and future research opportunities. We explain the physics of water transport in plants and the limits of this transport system, highlighting the relationships between xylem structure and function. We describe the great variety of techniques existing for evaluating xylem resistance to cavitation. We address several methodological issues and their connec- tion with current debates on conduit refilling and exponentially shaped vulnerability curves. We analyze the trade-offs existing between water transport safety and efficiency. We also stress how little information is available on molecular biology of cavitation and the potential role of aquaporins in conduit refilling. Finally, we draw attention to how plant hydraulic traits can be used for modeling stomatal responses to environmental variables and climate change, including drought mortality. 展开更多
关键词 William J. Lucas university of california Davis USAReceived Jan. 10 2017 Accepted Mar. 9 2017 Online on Mar. 14 2017
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Transport of chemical signals in systemic acquired resistance 被引量:3
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作者 Archana Singh Gah-Hyun Lim Pradeep Kachroo 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2017年第5期336-344,共9页
Systemic acquired resistance (SAR) is a form of broad-spectrum resistance induced in response to local infections that protects uninfected parts against subsequent secondary infections by related or unrelated pathog... Systemic acquired resistance (SAR) is a form of broad-spectrum resistance induced in response to local infections that protects uninfected parts against subsequent secondary infections by related or unrelated pathogens. SAR signaling requires two parallel branches, one regulated by salicylic acid (SA). and theother by azelaic acid (AzA) and glycerol-3-phosphate (G3P). AzA and G3P function downstream of the free radicals nitric oxide (NO) and reactive oxygen species (ROS). During SAR, SA, AzA and G3P accumulate in the infected leaves, but only a small portion of these is transported to distal uninfected leaves. SA is preferen- tially transported via the apoplast, whereas phloem loading of AzA and G3P occurs via the symplast. The symplastic transport of AzA and G3P is regulated by gating of the plasmodesmata (PD). The PD localizing proteins, PDLP1 and PDLP5, regulate SAR by regulating PD gating as well as the subcellular partitioning of a SAR-associated protein. 展开更多
关键词 William J. Lucas university of california DAVIS USA
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Nicotiana attenuata's capacity to interact with arbuscular mycorrhiza alters its competitive ability and elicits major changes in the leaf transcriptome 被引量:2
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作者 Ming Wang Julia Wilde +1 位作者 Ian T.Baldwin Karin Groten 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2018年第3期242-261,共20页
To study the local and systemic effects of arbuscular mycorrhizal fungal (AMF) colonization, Nicotiana attenuata plants impaired in their interactions with AMF due to silencing of a calcium- and calmodulin dependent... To study the local and systemic effects of arbuscular mycorrhizal fungal (AMF) colonization, Nicotiana attenuata plants impaired in their interactions with AMF due to silencing of a calcium- and calmodulin dependent protein kinase (inverted repreat (ir)CCaMK) were grown competitively in pairs with empty vector (EV) plants, with and without two different types of inoculum. When inoculated, EV plants strongly outperformed irCCaMK plants. Foliar transcript profiling revealed that AMF colonization significantly changed gene expression of P-starvation and -transporter genes in irCCaMK plants. The Phtl family phosphate transporter NaPT5 was not only specifically induced in roots after AMF colonization, but also in leaves of AMF-colonized irCCaMK plants, and in plants grown under low Pi conditions in the absence of AMF. The P-starvation signature of inoculated irCCaMK plants corresponded with increases in selected amino acids and phenolic compounds in leaves. We also found a strong AMF-induced increase in amino acids and phenolic metabolites in roots. Plants impaired in their interactions with AMF clearly have a fitness disadvantage when competing for limited soil nutrients with a fully functional isogenic line. The additional role of the AMF-induced Phtl family transporter NaPT5 in leaves under P-starvation conditions will require further experiments to fully resolve. 展开更多
关键词 William J. Lucas university of california DAVIS USA
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The fungal UmSrt1 and maize ZmSUT1 sucrose transporters battle for plant sugar resources 被引量:7
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作者 Anke Wittek Ingo Dreyer +3 位作者 Khaled A.S. Al-Rasheid Norbert Sauer Rainer Hedrich Dietmar Geiger 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2017年第6期422-435,共14页
The biotrophic fungus Ustilago maydis causes corn smut disease, inducing tumor formation in its host Zea mays. Upon infection, the fungal hyphae invaginate the plasma membrane of infected maize ceils, establishing an ... The biotrophic fungus Ustilago maydis causes corn smut disease, inducing tumor formation in its host Zea mays. Upon infection, the fungal hyphae invaginate the plasma membrane of infected maize ceils, establishing an interface where pathogen and host are separated only by their plasma membranes. At this interface the fungal and maize sucrose transporters, UmSrtl and ZmSUT1, compete for extracellular sucrose in the corn smut/maize pathos- ystem. Here we biophysically characterized ZmSUT1 and UmSrtl in Xenopus oocytes with respect to their voltage-, pH- and substrate-dependence and determined affinities toward protons and sucrose. In contrast to ZmSUT% UmSrtl has a high affinity for sucrose and is relatively pH- and voltage-independent. Using these quantitative parameters, we developed a mathematical model to simulate the competition for extracellular sucrose at the contact zone between the fungus and the host plant. This approach revealed that UmSrtl exploits the apoplastic sucrose resource, which forces the plant transporter into a sucrose export mode providing the fungus with sugar from the phloem. Importantly, the high sucrose concen- tration in the phloem appeared disadvantageous for the ZmSUT1 preventing sucrose recovery from the apoplastic space in the fungus/plant interface. 展开更多
关键词 William J. Lucas university of california Davis USAReceived Mar. 1 2017 Accepted Mar. 10 2017 Online on Mar. 15 2017
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Sucrose transporter2 contributes to maize growth,development,and crop yield 被引量:13
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作者 Kristen A.Leach Thu M.Tran +2 位作者 Thomas L.Slewinski Robert B.Meeley David M.Braun 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2017年第6期390-408,共19页
During daylight, plants produce excess photo- synthates, including sucrose, which is temporarily stored in the vacuole. At night, plants remobilize sucrose to sustain metabolism and growth. Based on homology to other ... During daylight, plants produce excess photo- synthates, including sucrose, which is temporarily stored in the vacuole. At night, plants remobilize sucrose to sustain metabolism and growth. Based on homology to other sucrose transporter (SUT) proteins, we hypothesized the maize (Zea mays) SUCROSE TRANSPORTER2 (ZmSUT2) protein functions as a sucrose/H^+ symporter on the vacuolar membrane to export transiently stored sucrose. To understand the biological role of ZmSut2, we examined its spatial and temporal gene expression, determined the protein subcellular localization, and characterized loss-of- function mutations. ZmSut2 mRNA was ubiquitously expressed and exhibited diurnal cycling in transcript abundance. Expressing a translational fusion of ZmSUT2 fused to a red fluorescent protein in maize mesophyll cell protoplasts revealed that the protein localized to the tonoplast. Under field conditions, zmsut2 mutant plants grew slower, possessed smaller tassels and ears, and produced fewer kernels when compared to wild-type siblings, zmsut2 mutants also accumulated two-fold more sucrose, glucose, and fructose as well as starch in source leaves compared to wild type. These findings suggest (i) ZmSUT2 functions to remobilize sucrose out of the vacuole for subsequent use in growing tissues; and (ii) its function provides an important contribution to maize development and agronomic yield. 展开更多
关键词 William J. Lucas university of california Davis USAReceived Dec. 30 2016 Accepted Feb. 10 20171 Online on Feb. 16 2017
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Plant genetics enters the nano age? 被引量:1
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作者 dirk joldersma zhongchi liu 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2018年第6期446-447,共2页
Plant transformation has for many years relied on agrobacterium infection or biolistic particle delivery. However, these two methods are limited to model plant systems or a small number of crop species. This commentar... Plant transformation has for many years relied on agrobacterium infection or biolistic particle delivery. However, these two methods are limited to model plant systems or a small number of crop species. This commentary highlights recent developments in the nanoparticle-mediated transformation that havethe potential to revolutionize how plants are trans- formed. 展开更多
关键词 William J. Lucas university of california DAVIS USA
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What actually is the Münch hypothesis?A short history of assimilate transport by mass flow 被引量:1
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作者 Michael Knoblauch Winfried S.Peters 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2017年第5期292-310,共19页
In the 192os, the German forestry scientist Ernst M{Jnch postulated that photo-assimilate transport is a mass flow driven by osmotically induced pressure gradients between source organs (high turgot) and sink organs... In the 192os, the German forestry scientist Ernst M{Jnch postulated that photo-assimilate transport is a mass flow driven by osmotically induced pressure gradients between source organs (high turgot) and sink organs (lower turgor). Two crucial components of MOnch's hypothesis, the translocation by mass flow from sources to sinks and the osmotic mechanism of pressure flow, were established notions at the time, but had been developed by two institutionally separated groups of scholars. A conceptual separation of wholepplant biology from cellular physiology had followed the institutional separation of forestry science from botany in German-speaking central Europe during the so-called Humboldtian reforms, and was reinforced by the delayed institutionalization of plant physiology as an academic discipline. Munch did not invent a novel concept, but accomplished an integration of the organism-focused and the cell-focused research traditions, reducing the polarization that had evolved when research universities emerged in central Europe. Post-Munch debates about the validity of his hypothesis focused increasingly on the suitability of available research methodologies, especially the electron microscope and the proper interpretation of the results it produced. The present work reconstructs the influence of the dynamic scientific and non-scientific context on the history of the Munch hypothesis. 展开更多
关键词 William J. Lucas university of california DAVIS USA
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Implications of nitrogen phloem loading for carbon metabolism and transport during Arabidopsis development 被引量:1
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作者 James P. Santiago Mechthild Tegeder 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2017年第6期409-421,共13页
Metabolite transport processes and primary metabolism are highly interconnected. This study exam- ined the importance of source-to-sink nitrogen partition- ing, and associated nitrogen metabolism for carbon capture, t... Metabolite transport processes and primary metabolism are highly interconnected. This study exam- ined the importance of source-to-sink nitrogen partition- ing, and associated nitrogen metabolism for carbon capture, transport and usage. Specifically, Arabidopsis aap8 (AMINO ACID PERMEASE 8) mutant lines were analyzed to resolve the consequences of reduced amino acid phloem loading for source leaf carbon metabolism, sucrose phloem transport and sink development during vegetative and reproductive growth phase. Results showed that decreased amino acid transport had a negative effect on sink development of aap8 lines throughout the life cycle, leading to an overall decrease in plant biomass. During vegetative stage, photosynthe- sis and carbohydrate levels were decreased in aap8 leaves, while expression of carbon metabolism and transport genes, as well as sucrose phloem transport were not affected despite reduced sink strength. However, when aap8 plants transitioned to reproductive phase, carbon fixation and assimilation as well as sucrose partitioning to siliques were strongly decreased. Overall, this work demonstrates that phloem loading of nitrogen has varying implications for carbon fixation, assimilation and source-to-sink allocation depending on plant growth stage. It further suggests alterations in source-sink relationships, and regulation of carbon metabolism and transport by sink strength in a development-dependent manner. 展开更多
关键词 William J. Lucas university of california Davis USA Received Feb. 25 2017 Accepted Mar. 9 2017 Online on Mar. 14 2017
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