期刊：
Science (New York, N.Y.),2014年345(6199):950-953 ISSN：0036-8075
通讯作者：
Chalhoub, Boulos;Parkin, Isobel A P;Edwards, David;Zhou, Yongming;Hua, Wei;Sharpe, Andrew G;Paterson, Andrew H;Guan, Chunyun;Wincker, Patrick
作者机构：
[Samans, Birgit; Snowdon, Rod J] Department of Plant Breeding, Research Center for Biosystems, Land Use and Nutrition, Justus Liebig University, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany;[Deniot, Gwenaelle; Lassalle, Gilles; Schnel, Nicolas; Falentin, Cyril; Delourme, Regine; Renard, Michel] INRA, Institut de Genetique, Environnement et Protection des Plantes (IGEPP) UMR1349, BP35327, 35653 Le Rheu Cedex, France;[Hua, Wei] Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture of People's Republic of China, Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430062, China. chalhoub@evry.inra.fr;[Chauveau, Aurelie; Le Paslier, Marie-Christine; Charles, Mathieu; Brunel, Dominique; Berard, Aurelie] INRA, Etude du Polymorphisme des Genomes Vegetaux, US1279, Centre National de Genotypage, CEA-IG, 2 rue Gaston Cremieux, 91057 Evry, France;[Guo, Hui; Lee, Tae-Ho] Plant Genome Mapping Laboratory, University of Georgia, Athens, GA 30602, USA
通讯机构：
[Parkin, Isobel A P] Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK S7N 0X2, Canada.;[Paterson, Andrew H] Plant Genome Mapping Laboratory, University of Georgia, Athens, GA 30602, USA.;[Edwards, David] Australian Centre for Plant Functional Genomics, School of Agriculture and Food Sciences, University of Queensland, St. Lucia, QLD 4072, Australia. School of Plant Biology, University of Western Australia, WA 6009, Australia.;[Hua, Wei] Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture of People's Republic of China, Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430062, China.;[Guan, Chunyun] College of Agronomy, Hunan Agricultural University, Changsha 410128, China.
摘要：
Oilseed rape (Brassica napus L.) was formed similar to 7500 years ago by hybridization between B. rapa and B. oleracea, followed by chromosome doubling, a process known as allopolyploidy. Together with more ancient polyploidizations, this conferred an aggregate 72x genome multiplication since the origin of angiosperms and high gene content. We examined the B. napus genome and the consequences of its recent duplication. The constituent A(n) and C-n subgenomes are engaged in subtle structural, functional, and epigenetic cross-talk, with abundant homeologous exchanges. Incipient gene loss and expression divergence have begun. Selection in B. napus oilseed types has accelerated the loss of glucosinolate genes, while preserving expansion of oil biosynthesis genes. These processes provide insights into allopolyploid evolution and its relationship with crop domestication and improvement.
通讯机构：
[Liu, SY] Chinese Acad Agr Sci, Oil Crops Res Inst, Key Lab Biol & Genet Improvement Oil Crops, Minist Agr PRC, Wuhan 430062, Peoples R China.
摘要：
Polyploidization has provided much genetic variation for plant adaptive evolution, but the mechanisms by which the molecular evolution of polyploid genomes establishes genetic architecture underlying species differentiation are unclear. Brassica is an ideal model to increase knowledge of polyploid evolution. Here we describe a draft genome sequence of Brassica oleracea, comparing it with that of its sister species B. rapa to reveal numerous chromosome rearrangements and asymmetrical gene loss in duplicated genomic blocks, asymmetrical amplification of transposable elements, differential gene co-retention for specific pathways and variation in gene expression, including alternative splicing, among a large number of paralogous and orthologous genes. Genes related to the production of anticancer phytochemicals and morphological variations illustrate consequences of genome duplication and gene divergence, imparting biochemical and morphological variation to B. oleracea. This study provides insights into Brassica genome evolution and will underpin research into the many important crops in this genus.
摘要：
The ideotype approach has been used in breeding programs at the International Rice Research Institute (IRRI) and in China to improve rice yield potential. First-generation new plant type (NPT) lines developed from tropical japonica at IRRI did not yield well because of limited biomass production and poor grain filling. Progress has been made in second-generation NPT lines developed by crossing elite indica with improved tropical japonica. Several second-generation NPT lines outyielded the first-generation NPT lines and indica check varieties. China's "super" rice breeding project has developed many F(1) hybrid varieties using a combination of the ideotype approach and intersubspecific heterosis. These hybrid varieties produced grain yield of 12 t ha(-1) in on-farm demonstration fields, 8-15% higher than the hybrid check varieties. The success of China's "super" hybrid rice was partially the result of assembling the good components of IRRI's NPT design in addition to the use of intersubspecific heterosis. For example, both designs focused on large panicle size, reduced tillering capacity, and improved lodging resistance. More importantly, improvement in plant type design was achieved in China's "super" hybrid rice by emphasizing the top three leaves and panicle position within a canopy in order to meet the demand of heavy panicles for a large source supply. The success of "super" hybrid rice breeding in China and progress in NPT breeding at IRRI suggest that the ideotype approach is effective for breaking the yield ceiling of an irrigated rice crop. (C) 2008 Elsevier B.V. All rights reserved.
作者机构：
[Wang, Zhenlin; He, Mingrong; Zhang, Jiwang] Shandong Agr Univ, Coll Agron, Tai An 271000, Shandong, Peoples R China.;[Zhang, Weifeng; Cui, Zhenling; Chen, Xinping; Wang, Guiliang; Wu, Liang; Zhang, Fusuo; Wu, Liangquan; Fan, Mingsheng; Ma, Lin; An, Ning] China Agr Univ, Coll Resources & Environm Sci, Beijing 100193, Peoples R China.;[Ma, Wenqi] Agr Univ Hebei, Coll Resources & Environm Sci, Baoding 071001, Peoples R China.;[Yan, Xiaoyuan] Chinese Acad Sci, Inst Soil Sci, Nanjing 210008, Peoples R China.;[Ren, Jun] Jilin Acad Agr Sci, Res Ctr Agr Environm & Resources, Changchun 130033, Peoples R China.
通讯机构：
[Zhang, FS] China Agr Univ, Coll Resources & Environm Sci, Beijing 100193, Peoples R China.
摘要：
Agriculture faces great challenges to ensure global food security by increasing yields while reducing environmental costs(1,2). Here we address this challenge by conducting a total of 153 site-year field experiments covering the main agro-ecological areas for rice, wheat and maize production in China. A set of integrated soil-crop system management practices based on a modern understanding of crop ecophysiology and soil biogeochemistry increases average yields for rice, wheat and maize from 7.2 million grams per hectare (Mg ha(-1)), 7.2 Mg ha(-1) and 10.5 Mg ha(-1) to 8.5 Mg ha(-1), 8.9 Mg ha(-1) and 14.2 Mg ha(-1), respectively, without any increase in nitrogen fertilizer. Model simulation and life-cycle assessment(3) show that reactive nitrogen losses and greenhouse gas emissions are reduced substantially by integrated soil-crop system management. If farmers in China could achieve average grain yields equivalent to 80% of this treatment by 2030, over the same planting area as in 2012, total production of rice, wheat and maize in China would be more than enough to meet the demand for direct human consumption and a substantially increased demand for animal feed, while decreasing the environmental costs of intensive agriculture.
关键词：
Biotic and abiotic stresses;Crop improvement;Crop management;Grain yield;Rice research;Stress tolerance
摘要：
Rice production in China has more than tripled in the past five decades mainly due in increased grain yield rather than increased planting area. This increase has come from the development of high-yielding varieties and improved crop management practices such as nitrogen fertilization and irrigation. However, yield stagnation of rice has been observed in the past ten years in China. As its population rises, China will need to produce about 20% more rice by 2030 in order to meet is domestic needs if rice consumption per capita stays at the current level. This is not an easy task because several trends and problems in the Chinese rice production system constrain the sustainable increase in total rice production. Key trends include a decline in arable land, increasing water scarcity, global climate change, labor shortages, and increasing comsumer demand for high-quality rice (which often comes from low-yielding varieties). The major problems confronting rice production in China are narrow genetic background, overuse of fertilizers and pesticides, breakdown of irrigation infrastructure, oversimplified crop management, and a weak extension system. Despite these challenges, good research strategies call drive increased rice production in China. These include the development of the new rice varieties with high yield potential, improvement of resistances to major diseases and insects, and to major abiotic stresses such as drought and heat, and the establishment of integrated crop management. We believe that a sustainable increase in rice production is achievable in China with the development of new technology through rice research.
期刊：
AGRONOMY FOR SUSTAINABLE DEVELOPMENT,2010年30(03):649-656 ISSN：1774-0746
通讯作者：
Peng, SB
作者机构：
[Dobermann, Achim; Buresh, Roland J.; Peng, Shaobing] Int Rice Res Inst, Crop & Environm Sci Div, Manila, Philippines.;[Liu, Yuanying] NE Agr Univ, Coll Resources & Environm Sci, Harbin 150030, Heilongjiang, Peoples R China.;[Yang, Jianchang] Yangzhou Univ, Coll Agr, Dept Agron, Yangzhou 225009, Jiangsu, Peoples R China.;[Zhong, Xuhua] Guangdong Acad Agr Sci, Rice Res Inst, Guangzhou 510640, Guangdong, Peoples R China.;[Zhang, Fusuo] China Agr Univ, Coll Resources & Environm Sci, Beijing 100094, Peoples R China.
通讯机构：
[Peng, SB] Int Rice Res Inst, Crop & Environm Sci Div, DAPO Box 7777, Manila, Philippines.
关键词：
site-specific nitrogen management;nitrogen use efficiency;grain yield;nitrogen response;rice;China
摘要：
Excessive nitrogen (N) application to rice (Oryza sativa L.) crop in China causes environmental pollution, increases the cost of rice farming, reduces grain yield and contributes to global warming. Scientists from the International Rice Research Institute have collaborated with partners in China to improve rice N fertilization through site-specific N management (SSNM) in China since 1997. Field experiments and demonstration trials were conducted initially in Zhejiang province and gradually expanded to Guangdong, Hunan, Jiangsu, Hubei and Heilongjiang provinces. On average, SSNM reduced N fertilizer by 32% and increased grain yield by 5% compared with farmers' N practices. The yield increase was associated with the reduction in insect and disease damage and improved lodging resistance of rice crop under the optimal N inputs. The main reason for poor fertilizer N use efficiency of rice crop in China is that most rice farmers apply too much N fertilizer, especially at the early vegetative stage. We observed about 50% higher indigenous N supply capacity in irrigated rice fields in China than in other major rice-growing countries. Furthermore, yield response of rice crop to N fertilizer application is low in China, around 1.5 t ha(-1) on average. However, these factors were not considered by rice researchers and extension technicians in determining the N fertilizer rate for recommendation to rice farmers in China. After a decade of research on SSNM in China and other Asian rice-growing countries, we believe SSNM is a matured technology for improving both fertilizer N use efficiency and grain yield of rice crop. Our challenges are to further simplify the procedure of SSNM and to convince policy-makers of the effectiveness of this technology in order to facilitate a wider adoption of SSNM among rice farmers in China.
摘要：
Rice blast, caused by the fungal pathogen Magnaporthe oryzae, is the most devastating disease of rice and severely affects crop stability and sustainability worldwide. This disease has advanced to become one of the premier model fungal pathosystems for host-pathogen interactions because of the depth of comprehensive studies in both species using modern genetic, genomic, proteomic and bioinformatic approaches. Many fungal genes involved in pathogenicity and rice genes involved in effector recognition and defence responses have been identified over the past decade. Specifically, the cloning of a total of nine avirulence (Avr) genes in M. oryzae, 13 rice resistance (R) genes and two rice blast quantitative trait loci (QTLs) has provided new insights into the molecular basis of fungal and plant interactions. In this article, we consider the new findings on the structure and function of the recently cloned R and Avr genes, and provide perspectives for future research directions towards a better understanding of the molecular underpinnings of the rice-M. oryzae interaction.
关键词：
Radiation use efficiency;"Super" hybrid rice;Yield components;Yield potential
摘要：
China's "super" hybrid rice breeding project has developed many new varieties using a combination of the ideotype approach and intersubspecific heterosis. It is controversial whether these "super" hybrid varieties have increased the yield potential of irrigated rice. This study was conducted to compare grain yield and yield attributes among "super" hybrid, ordinary hybrid, and inbred varieties. Field experiments were done in Liuyang (moderate-yielding site) and Guidong (high-yielding site) counties. Hunan Province, China, in 2007 and 2008. Two varieties from each varietal group were grown in each field experiment under moderate and high N rates. Grain yield, yield components, aboveground total dry weight, harvest index, total N uptake, and crop radiation use efficiency (RUE) were measured for each variety. A significant difference in grain yield was observed among the varieties and varietal groups but not between the two N rates. "super" hybrid varieties have increased rice yield potential by 12% compared with ordinary hybrid and inbred varieties. The higher grain yield of "super" hybrid varieties was attributed to improvement in both source and sink. "super" hybrid varieties produced more biomass than ordinary hybrid and inbred varieties. Long growth duration and high accumulated incident radiation were partially responsible for high biomass production for the "super" hybrid varieties. "super" hybrid varieties had significantly larger panicle size (spikelets per panicle) than ordinary hybrid and inbred varieties, which resulted in larger sink size (spikelets per m(2)). Crop RUE did not explain the yield superiority of "super" hybrid rice. Our study suggests that "super" hybrid rice varieties do not necessarily require more N fertilizer to produce high grain yield. (C) 2009 Elsevier B.V. All rights reserved.
作者：
Rang, Z. W.;Jagadish, S. V. K.;Zhou, Q. M.;Craufurd, P. Q.;Heuer, S.
期刊：
Environmental and Experimental Botany,2011年70(01):58–65 ISSN：0098-8472
通讯作者：
Jagadish, SVK
作者机构：
[Rang, Z. W.; Jagadish, S. V. K.; Heuer, S.] Int Rice Res Inst, Manila, Philippines.;[Rang, Z. W.; Zhou, Q. M.] Hunan Agr Univ, Coll Agron, Changsha 410128, Hunan, Peoples R China.;[Craufurd, P. Q.] Int Crops Res Inst Semi Arid Trop, Patancheru 502324, Andhra Pradesh, India.
通讯机构：
[Jagadish, SVK] Int Rice Res Inst, DAPO Box 7777, Manila, Philippines.
摘要：
In future climates, rice could more frequently be subjected to simultaneous high temperature and water stress during sensitive developmental stages such as flowering. In this study, five rice genotypes were exposed to high temperature, water stress and combined high temperature and water stress during flowering to quantify their response through spikelet fertility. Microscopic analyses revealed significant differences in anther dehiscence between treatments and genotypes, with a moderately high association with the number of germinated pollen grains on the stigma. There was a strong relationship between spikelet fertility and the number of germinated pollen on stigmas. Although, all three stress treatments resulted in spikelet sterility, high-temperature stress caused the highest sterility in all five genotypes. A cumulative linear decline in spikelet fertility with increasing duration of independent high-temperature stress and in combination with water stress was quantified. Better anther dehiscence, higher in vivo pollen germination, and higher spikelet fertility were observed in both the N22 accessions compared with IR64, Apo and Moroberekan under high temperature, water stress and combined stress, indicating its ability to tolerate multiple abiotic stresses. (C) 2010 Elsevier B.V. All rights reserved.
摘要：
Rice feeds more than half of the world's population. Rice blast, caused by the fungal pathogen Magnaporthe oryzae, and bacterial blight, caused by the bacterial pathogen Xanthomonas oryzae pv. oryzae, are major constraints to rice production worldwide. Genome sequencing and extensive molecular analysis has led to the identification of many new pathogen-associated molecular patterns (PAMPs) and avirulence and virulence effectors in both pathogens, as well as effector targets and receptors in the rice host. Characterization of these effectors, host targets, and resistance genes has provided new insight into innate immunity in plants. Some of the new findings, such as the binding activity of X. oryzae transcriptional activator-like (TAL) effectors to specific rice genomic sequences, are being used for the development of effective disease control methods and genome modification tools. This review summarizes the recent progress toward understanding the recognition and signaling events that govern rice innate immunity.
关键词：
flag leaf;grain filling;grain quality;high night temperature (HNT);nonstructural carbohydrate (NSC);proteome;rice (Oryza sativa);spikelets
摘要：
High night temperatures (HNTs) can reduce significantly the global rice (Oryza sativa) yield and quality. A systematic analysis of HNT response at the physiological and molecular levels was performed under field conditions. Contrasting rice accessions, N22 (highly tolerant) and Gharib (susceptible), were evaluated at 22 degrees C (control) and 28 degrees C (HNT). Nitrogen (N) and nonstructural carbohydrate (NSC) translocation from different plant tissues into grains at key developmental stages, and their contribution to yield, grain-filling dynamics and quality aspects, were evaluated. Proteomic profiling of flag leaf and spikelets at 100% flowering and 12 d after flowering was conducted, and their reprogramming patterns were explored. Grain yield reduction in susceptible Gharib was traced back to the significant reduction in N and NSC translocation after flowering, resulting in reduced maximum and mean grain-filling rate, grain weight and grain quality. A combined increase in heat shock proteins (HSPs), Ca signaling proteins and efficient protein modification and repair mechanisms (particularly at the early grain-filling stage) enhanced N22 tolerance for HNT. The increased rate of grain filling and efficient proteomic protection, fueled by better assimilate translocation, overcome HNT tolerance in rice. Temporal and spatial proteome programming alters dynamically between key developmental stages and guides future transgenic and molecular analysis targeted towards crop improvement.
作者机构：
[Nejsum, Peter] Univ Copenhagen, Dept Vet Dis Biol, Frederiksberg, Denmark.;[Nejsum, Peter] Univ Copenhagen, Dept Basic Anim & Vet Sci, Frederiksberg, Denmark.;[Zhu, Xing-Quan; Liu, Guo-Hua; Su, Ang; Xu, Min-Jun] Chinese Acad Agr Sci, State Key Lab Vet Etiol Biol, Key Lab Vet Parasitol Gansu Prov, Lanzhou Vet Res Inst, Lanzhou, Gansu, Peoples R China.;[Zhu, Xing-Quan; Liu, Guo-Hua] Hunan Agr Univ, Coll Vet Med, Changsha, Hunan, Peoples R China.;[Zhu, Xing-Quan] Heilongjiang Bayi Agr Univ, Coll Anim Sci & Vet Med, Daqing, Heilongjiang Pr, Peoples R China.
通讯机构：
[Liu, GH] Chinese Acad Agr Sci, State Key Lab Vet Etiol Biol, Key Lab Vet Parasitol Gansu Prov, Lanzhou Vet Res Inst, Lanzhou, Gansu, Peoples R China.
摘要：
The whipworm, Trichuris trichiura, causes trichuriasis in approximately 600 million people worldwide, mainly in developing countries. Whipworms also infect other animal hosts, including pigs (T. suis), dogs (T. vulpis) and non-human primates, and cause disease in these hosts, which is similar to trichuriasis of humans. Although Trichuris species are considered to be host specific, there has been considerable controversy, over the years, as to whether T. trichiura and T. suis are the same or distinct species. Here, we characterised the entire mitochondrial genomes of human-derived Trichuris and pig-derived Trichuris, compared them and then tested the hypothesis that the parasites from these two host species are genetically distinct in a phylogenetic analysis of the sequence data. Taken together, the findings support the proposal that T. trichiura and T. suis are separate species, consistent with previous data for nuclear ribosomal DNA. Using molecular analytical tools, employing genetic markers defined herein, future work should conduct large-scale studies to establish whether T. trichiura is found in pigs and T. suis in humans in endemic regions.
摘要：
Rice blast, caused by the fungal pathogen Magnaporthe oryzae, is one of the most destructive diseases of rice worldwide. The rice-M. oryzae pathosystem has become a model in the study of plant-fungal interactions because of its scientific advancement and economic importance. Recent studies have identified a number of new pathogen-associated molecular patterns (PAMPs) and effectors from the blast fungus that trigger rice immune responses upon perception. Interaction analyses between avirulence effectors and their cognate resistance proteins have provided new insights into the molecular basis of plant-fungal interactions. In this review, we summarize the recent research on the characterization of those genes in both M. oryzae and rice that are important for the PAMP- and effector-triggered immunity recognition and signaling processes. We also discuss future directions for research that will further our understanding of this pathosystem.
作者：
Xu, W.;Luo, X. S.;Pan, Y. P.;Zhang, L.;Tang, A. H.;Shen, J. L.;Zhang, Y.;Li, K. H.;Wu, Q. H.;Yang, D. W.;Zhang, Y. Y.;Xue, J.;Li, W. Q.;Li, Q. Q.;Tang, L.;Lu, S. H.;Liang, T.;Tong, Y. A.;Liu, P.;Zhang, Q.
期刊：
ATMOSPHERIC CHEMISTRY AND PHYSICS,2015年15(21):12345-12360 ISSN：1680-7316
通讯作者：
Liu, XJ
作者机构：
[Li, K. H.] Chinese Acad Sci, Xinjiang Inst Ecol & Geog, Urumqi 830011, Peoples R China.;[Zhang, F. S.; Luo, X. S.; Xue, J.; Yang, D. W.; Li, Q. Q.; Tang, A. H.; Xu, W.; Liu, X. J.; Zhang, Y. Y.; Wu, Q. H.] China Agr Univ, Coll Resources & Environm Sci, Beijing 100193, Peoples R China.;[Dore, A. J.; Tang, S.] Ctr Ecol & Hydrol Edinburgh, Penicuik EH26 0QB, Midlothian, Scotland.;[Shi, W. Q.] Chinese Acad Trop Agr Sci, South Subtrop Crops Res Inst, Zhanjiang 524091, Peoples R China.;[Luo, X. S.] Henan Acad Agr Sci, Inst Plant Nutr Resources & Environm Sci, Zhengzhou 450002, Peoples R China.
通讯机构：
[Liu, XJ] China Agr Univ, Coll Resources & Environm Sci, Beijing 100193, Peoples R China.
摘要：
A Nationwide Nitrogen Deposition Monitoring Network (NNDMN) containing 43 monitoring sites was established in China to measure gaseous NH3, NO2, and HNO3 and particulate NH4+ and NO3- in air and/or precipitation from 2010 to 2014. Wet/bulk deposition fluxes of N-r species were collected by precipitation gauge method and measured by continuous-flow analyzer; dry deposition fluxes were estimated using airborne concentration measurements and inferential models. Our observations reveal large spatial variations of atmospheric N-r concentrations and dry and wet/bulk N-r deposition. On a national basis, the annual average concentrations (1.3-47.0 mu g N m(-3)) and dry plus wet/bulk deposition fluxes (2.9-83.3 kg N ha(-1) yr(-1)) of inorganic Nr species are ranked by land use as urban > rural > background sites and by regions as north China > southeast China > southwest China > northeast China > northwest China > Tibetan Plateau, reflecting the impact of anthropogenic N-r emission. Average dry and wet/bulk N deposition fluxes were 20.6 +/- 11.2 (mean +/- standard deviation) and 19.3 +/- 9.2 kg N ha(-1) yr(-1) across China, with reduced N deposition dominating both dry and wet/bulk deposition. Our results suggest atmospheric dry N deposition is equally important to wet/bulk N deposition at the national scale. Therefore, both deposition forms should be included when considering the impacts of N deposition on environment and ecosystem health.
摘要：
To reduce the influx of cadmium (Cd), a toxic heavy metal, into the human food chain through vegetable intake, a pot experiment for the selection of a pollution-safe cultivar (PSC) of water spinach (Ipomoea aquatica Forsk.) was carried out. The experiment with 30 tested cultivars revealed that the maximum differences in Cd concentration between the cultivars containing the highest and the lowest Cd were 3.0-3.9-fold under low-Cd treatment (soil Cd = 0.593 mg kg(-1)), 2.7-3.5-fold under middle-Cd treatment (soil Cd = 1.091 mg kg(-1)), and 2.6-2.7-fold under high-Cd treatment (soil Cd = 1.824 mg kg(-1)), large enough to define the Cd-PSCs. Concentrations of Cd in edible parts of six cultivars, cv. Daxingbaigu, Huifengqing, Qiangkunbaigu, Qiangkunqinggu, Shenniuliuye, and Xingtianqinggu, were lower than 0.2 mg kg(-1), the maximum level (ML) of Cd allowed by the Codex Alimentarius Commission (CAC) standard, even under middle-Cd treatment. Accordingly, these cultivars were treated as typical Cd-PSCs. Four cultivars, cv. Jieyangbaigeng, Xianggangdaye, Sannongbaigeng, and Taiwan 308, contained Cd in edible parts exceeding the ML even under low-Cd treatment, and they were defined as typical non-Cd-PSCs. The correlations of the Cd concentrations among the tested cultivars between the three treatments were significant at the p < 0.05 level. A conspicuous difference in Cd subcellular distribution in hydroponic plant tissues between cv. Qiangkunqinggu (a typical Cd-PSC) and cv. Taiwan 308 (a typical non-Cd-PSC) were observed. Cd absorbed by cv. Qiangkunqinggu seemed to be well-compartmentalized in root and in cell wall fragment, which may be one of the mechanisms leading to its low Cd accumulating property. The results indicated that water spinach, a leafy vegetable, could be easily polluted by soils contaminated with Cd, as 80% of the tested cultivars had exceeded the ML of Cd according to the CAC standard even under the middle-Cd treatment. Much of the evidence obtained from the present study proved that the high Cd-accumulating ability of water spinach is a stable biological property at cultivar level and, thus, is genotype dependent. Therefore, application of the PSC strategy to produce water spinach that is safer to consume is feasible and necessary.
通讯机构：
[Wang, GL] Ohio State Univ, Dept Plant Pathol, Plant Mol Biol & Biotechnol Program, Columbus, OH 43210 USA.
摘要：
The rice (Oryza sativa) E3 ligase SPOTTED LEAF11 (SPL11) negatively regulates programmed cell death and disease resistance. We demonstrate here that SPL11 also regulates flowering via interaction with SPIN1 (for SPL11-interacting protein1), a Signal Transduction and Activation of RNA family member. SPIN1 binds RNA and DNA in vitro and interacts with SPL11 in the nucleus. Spl11 mutants have delayed flowering under long-day conditions. Spin1 overexpression causes late flowering independently of daylength; expression analyses of flowering marker genes in these lines suggested that SPIN1 represses flowering by downregulating the flowering promoter gene Heading date3a (Hd3a) via Hd1-dependent mechanisms in short days and by targeting Hd1-independent factors in long days. Both Spin1 and Spl11 are regulated diurnally in opposing phases. SPL11 negatively regulates Spin1 transcript levels, while SPIN1 also affects Spl11 expression. Moreover, we show that coincidence of high accumulation of Spin1 mRNA with the light in the morning and early evening is needed to repress flowering. SPIN1 is monoubiquitinated by SPL11, suggesting that it is not targeted for degradation. Our data are consistent with a model in which SPIN1 acts as a negative regulator of flowering that itself is negatively regulated by SPL11, possibly via ubiquitination.
通讯机构：
[Sun, WX] China Agr Univ, Key Lab Plant Pathol, Minist Agr, Dept Plant Pathol, Beijing 100193, Peoples R China.
摘要：
Ustilaginoidea virens (Cooke) Takah is an ascomycetous fungus that causes rice false smut, a devastating emerging disease worldwide. Here we report a 39.4 Mb draft genome sequence of U. virens that encodes 8,426 predicted genes. The genome has similar to 25% repetitive sequences that have been affected by repeat-induced point mutations. Evolutionarily, U. virens is close to the entomopathogenic Metarhizium spp., suggesting potential host jumping across kingdoms. U. virens possesses reduced gene inventories for polysaccharide degradation, nutrient uptake and secondary metabolism, which may result from adaptations to the specific floret infection and biotrophic lifestyles. Consistent with their potential roles in pathogenicity, genes for secreted proteins and secondary metabolism and the pathogen-host interaction database genes are highly enriched in the transcriptome during early infection. We further show that 18 candidate effectors can suppress plant hypersensitive responses. Together, our analyses offer new insights into molecular mechanisms of evolution, biotrophy and pathogenesis of U. virens.
