作者：
Xu, Xun;Pan, Shengkai;Cheng, Shifeng;Zhang, Bo;Mu, Desheng;Ni, Peixiang;Zhang, Gengyun;Yang, Shuang;Li, Ruiqiang;Wang, Jun;Orjeda, Gisella;Guzman, Frank;Torres, Michael;Lozano, Roberto;Ponce, Olga;Martinez, Diana;De la Cruz, German;Chakrabarti, S K;Patil, Virupaksh U;Skryabin, Konstantin G
期刊：
Nature,2011年475(7355):189-U94 ISSN：0028-0836
通讯作者：
Huang, Sanwen
作者机构：
[Yang, Shuang; Cheng, Shifeng; Zhang, Bo; Ni, Peixiang; Xu, Xun; Li, Ruiqiang; Pan, Shengkai; Zhang, Gengyun; Mu, Desheng; Wang, Jun] Chinese Minist Agr, Key Lab Genom, BGI Shenzhen, Shenzhen 518083, Peoples R China.;[He, Ying; Xu, Jianfei; Du, Yongchen; Qu, Dongyu; Zhang, Youjun; Huang, Sanwen; Xie, Binyan; Zhang, Zhonghua; He, Jun; Li, Ying; Liang, Chunbo] Chinese Acad Agr Sci, Key Lab Hort Crops Genet Improvement, Sino Dutch Joint Lab Hort Genom, Inst Vegetables & Flowers,Minist Agr, Beijing 100081, Peoples R China.;[Ponce, Olga; Orjeda, Gisella; Guzman, Frank; Martinez, Diana; De la Cruz, German; Torres, Michael; Lozano, Roberto] Cayetano Heredia Univ, Genom Res Unit, Lima 13, Peru.;[Ponce, Olga; Orjeda, Gisella; Guzman, Frank; Martinez, Diana; De la Cruz, German; Torres, Michael; Lozano, Roberto] San Cristobal Huamanga Univ, Biotechnol & Plant Genet Lab, Ayacucho, Peru.;[Chakrabarti, S K; Patil, Virupaksh U] Cent Potato Res Inst, Shimla 171001, Himachal Prades, India.
通讯机构：
[Huang, Sanwen] Chinese Acad Agr Sci, Key Lab Hort Crops Genet Improvement, Sino Dutch Joint Lab Hort Genom, Inst Vegetables & Flowers,Minist Agr, Beijing 100081, Peoples R China.
摘要：
Potato (Solanum tuberosum L.) is the world's most important non-grain food crop and is central to global food security. It is clonally propagated, highly heterozygous, autotetraploid, and suffers acute inbreeding depression. Here we use a homozygous doubled-monoploid potato clone to sequence and assemble 86% of the 844-megabase genome. We predict 39,031 protein-coding genes and present evidence for at least two genome duplication events indicative of a palaeopolyploid origin. As the first genome sequence of an asterid, the potato genome reveals 2,642 genes specific to this large angiosperm clade. We also sequenced a heterozygous diploid clone and show that gene presence/absence variants and other potentially deleterious mutations occur frequently and are a likely cause of inbreeding depression. Gene family expansion, tissue-specific expression and recruitment of genes to new pathways contributed to the evolution of tuber development. The potato genome sequence provides a platform for genetic improvement of this vital crop.
作者机构：
[Thi, Vinh Ha Dinh; Mestiri, Imen; Chalabi, Smahane; Jabbari, Kamel; Just, Jeremy; Lu, Yunhai; Arnaud, Dominique; Canaguier, Aurelie; Le Clainche, Isabelle; Chalhoub, Boulos; Chelaifa, Houda; Belcram, Harry] Univ Evry Val dEssone, Inst Natl Rech Agron INRA, Unite Rech Genom Vegetale, UMR1165, F-91057 Evry, France.;[Da Silva, Corinne; Denoeud, France; Bento, Pascal; Wincker, Patrick; Labadie, Karine; Alberti, Adriana; Correa, Margot; Noel, Benjamin; Bernard, Maria; Aury, Jean-Marc; Battail, Christophe] Commissariat Energie Atom CEA, Inst Genom IG, F-91057 Evry, France.;[Denoeud, France; Wincker, Patrick] Univ Evry Val dEssone, UMR 8030, F-91057 Evry, France.;[Denoeud, France; Wincker, Patrick] Ctr Natl Rech Sci CNRS, UMR 8030, Evry, France.;[Hu, Qiong; Wang, Xinfa; Tong, Chaobo; Liu, Shengyi; Hua, Wei] Chinese Acad Agr Sci, Key Lab Biol & Genet Improvement Oil Crops, Minist Agr Peoples Republ China, Oil Crops Res Inst, Wuhan 430062, Peoples R China.
通讯机构：
[Chalhoub, Boulos] Univ Evry Val dEssone, Inst Natl Rech Agron INRA, Unite Rech Genom Vegetale, UMR1165, 2 Rue Gaston Cremieux, F-91057 Evry, France.
摘要：
↵* These authors contributed equally to this work.
通讯机构：
[Liu, Shengyi] 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.
作者机构：
[An, Ning; Ma, Lin; Fan, Mingsheng; Wu, Liangquan; Zhang, Fusuo; Wu, Liang; Wang, Guiliang; Chen, Xinping; Cui, Zhenling; Zhang, Weifeng] China Agr Univ, Coll Resources & Environm Sci, Beijing 100193, Peoples R China.;[Vitousek, Peter] Stanford Univ, Dept Biol, Stanford, CA 94305 USA.;[Zhao, Ming; Zhang, Weijian] Chinese Acad Agr Sci, Inst Crop Sci, Beijing 100081, Peoples R China.;[Ma, Wenqi] Agr Univ Hebei, Coll Resources & Environm Sci, Baoding 071001, Peoples R China.;[Zhang, Jiwang; He, Mingrong; Wang, Zhenlin] Shandong Agr Univ, Coll Agron, Tai An 271000, Shandong, Peoples R China.
通讯机构：
[Zhang, Fusuo] 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.
通讯机构：
[Xie, Daoxin] Tsinghua Univ, Sch Life Sci, Beijing 100084, Peoples R China.
摘要：
Jasmonates (JAs) mediate plant responses to insect attack, wounding, pathogen infection, stress, and UV damage and regulate plant fertility, anthocyanin accumulation, trichome formation, and many other plant developmental processes. Arabidopsis thaliana Jasmonate ZIM-domain (JAZ) proteins, substrates of the CORONATINE INSENSITIVE1 (COI1)-based SCF(COI1) complex, negatively regulate these plant responses. Little is known about the molecular mechanism for JA regulation of anthocyanin accumulation and trichome initiation. In this study, we revealed that JAZ proteins interact with bHLH (Transparent Testa8, Glabra3 [GL3], and Enhancer of Glabra3 [EGL3]) and R2R3 MYB transcription factors (MYB75 and Glabra1), essential components of WD-repeat/bHLH/MYB transcriptional complexes, to repress JA-regulated anthocyanin accumulation and trichome initiation. Genetic and physiological evidence showed that JA regulates WD-repeat/bHLH/MYB complex-mediated anthocyanin accumulation and trichome initiation in a COI1-dependent manner. Overexpression of the MYB transcription factor MYB75 and bHLH factors (GL3 and EGL3) restored anthocyanin accumulation and trichome initiation in the coi1 mutant, respectively. We speculate that the JA-induced degradation of JAZ proteins abolishes the interactions of JAZ proteins with bHLH and MYB factors, allowing the transcriptional function of WD-repeat/bHLH/MYB complexes, which subsequently activate respective downstream signal cascades to modulate anthocyanin accumulation and trichome initiation.
作者：
Dong-Lei Yang;Jian Yao;Chuan-Sheng Mei;Xiao-Hong Tong;Long-Jun Zeng;Qun Li;Lang-Tao Xiao;Tai-ping Sun;Jigang Li;Xing-Wang Deng;Chin Mei Lee;Michael F. Thomashow;Yinong Yang;Zuhua He;Sheng Yang He
期刊：
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA,2012年109(19):E1192-E1200 ISSN：0027-8424
通讯作者：
Yang, Yinong
作者机构：
[Zuhua He; Xiao-Hong Tong; Long-Jun Zeng; Qun Li; Dong-Lei Yang] Chinese Acad Sci, Natl Key Lab Plant Mol Genet, Inst Plant Physiol & Ecol, Shanghai Inst Biol Sci, Shanghai 200032, Peoples R China.;[Yinong Yang; Chuan-Sheng Mei] Univ Arkansas, Dept Plant Pathol, Fayetteville, AR 72701 USA.;[Sheng Yang He; Jian Yao; Michael F. Thomashow; Chin Mei Lee] Michigan State Univ, Dept Energy Plant Res Lab, E Lansing, MI 48824 USA.;[Sheng Yang He; Jian Yao] Howard Hughes Med Inst, Chevy Chase, MD 20815 USA.;[Lang-Tao Xiao] Hunan Agr Univ, Hunan Prov Key Lab Phytohormones, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Yang, Yinong] Univ Arkansas, Dept Plant Pathol, Fayetteville, AR 72701 USA.
摘要：
<p>Plants must effectively defend against biotic and abiotic stresses to survive in nature. However, this defense is costly and is often accompanied by significant growth inhibition. How plants coordinate the fluctuating growth-defense dynamics is not well understood and remains a fundamental question. Jasmonate (JA) and gibberellic acid (GA) are important plant hormones that mediate defense and growth, respectively. Binding of bioactive JA or GA ligands to cognate receptors leads to proteasome-dependent degradation of specific transcriptional repressors (the JAZ or DELLA family of proteins), which, at the resting state, represses cognate transcription factors involved in defense (e.g., MYCs) or growth [e.g. phytochrome interacting factors (PIFs)]. In this study, we found that the <i>coi1</i> JA receptor mutants of rice (a domesticated monocot crop) and <i>Arabidopsis</i> (a model dicot plant) both exhibit hallmark phenotypes of GA-hypersensitive mutants. JA delays GA-mediated DELLA protein degradation, and the <i>della</i> mutant is less sensitive to JA for growth inhibition. Overexpression of a selected group of JAZ repressors in <i>Arabidopsis</i> plants partially phenocopies GA-associated phenotypes of the <i>coi1</i> mutant, and JAZ9 inhibits RGA (a DELLA protein) interaction with transcription factor PIF3. Importantly, the <i>pif</i> quadruple (<i>pifq</i>) mutant no longer responds to JA-induced growth inhibition, and overexpression of PIF3 could partially overcome JA-induced growth inhibition. Thus, a molecular cascade involving the COI1–JAZ–DELLA–PIF signaling module, by which angiosperm plants prioritize JA-mediated defense over growth, has been elucidated.</p>
摘要：
Applying biochar to soils may cause a win-win situation resulting in C sequestration and soil fertility improvement. The effect may be more evident in highly weathered and infertile tropical soils, but will be dependent on biochar quality. An Ultisol, typical to southern China, was used to evaluate amendment with biochars produced by a range of temperatures and durations, to investigate its effects on soil properties and plant growth. Rice straw-derived biochars were charred at temperatures from 250 to 450 degrees C for between 2 and 8 h. The increase of temperature caused smaller less structured (as viewed by SEM) fragments to form with less 0, H and aliphatic C functional groups, but more aromatic C as indicated by infrared spectroscopy. The mean residence time of biochars under controlled conditions (25 degrees C, 40% field capacity) was estimated from 244 to 1700 years, generally increasing with charring temperature and duration. Amendment of 1% biochar increased pH by 0.1-0.46 (P < 0.01) and CEC by 3.9-17.3% (P < 0.05), but had no effect on aggregate stability. In pot trials maize biomass was increased by 64% (without NPK) to 146% (with NPK) after biochar amendment. The study emphasizes that amendment with biochar can improve soil fertility at least in the short term. Future studies focusing on the persistence of biochar fertility in the field must explicitly take into account additional factors to transfer this technology. (C) 2011 Elsevier B.V. All rights reserved.
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 to 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 its 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 consumer 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 can drive increased rice production in China. These include the development of 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.
通讯机构：
[Wang, Guo-Liang] Ohio State Univ, Dept Plant Pathol, Columbus, OH 43210 USA.
摘要：
With the recent availability of complete genomic sequences of many organisms, high-throughput and cost-efficient systems for gene cloning and functional analysis are in great demand. Although site-specific recombination-based cloning systems, such as Gateway cloning technology, are extremely useful for efficient transfer of DNA fragments into multiple destination vectors, the two-step cloning process is time consuming and expensive. Here, we report a zero background TA cloning system that provides simple and high-efficiency direct cloning of PCR-amplified DNA fragments with almost no self-ligation. The improved T-vector system takes advantage of the restriction enzyme XcmI to generate a T-overhang after digestion and the negative selection marker gene ccdB to eliminate the self-ligation background after transformation. We demonstrate the feasibility and flexibility of the technology by developing a set of transient and stable transformation vectors for constitutive gene expression, gene silencing, protein tagging, protein subcellular localization detection, and promoter fragment activity analysis in plants. Because the system can be easily adapted for developing specialized expression vectors for other organisms, zero background TA provides a general, cost-efficient, and high-throughput platform that complements the Gateway cloning system for gene cloning and functional genomics.
摘要：
Increasing soil pollution problems have caused world-wide concerns. Large numbers of contaminants such as polycyclic aromatic hydrocarbons (PAHs), petroleum and related products, pesticides, chlorophenols and heavy metals enter the soil, posing a huge threat to human health and natural ecosystem. Chemical and physical technologies for soil remediation are either incompetent or too costly. Composting or compost addition can simultaneously increase soil organic matter content and soil fertility besides bioremediation, and thus is believed to be one of the most cost-effective methods for soil remediation. This paper reviews the application of composting/compost for soil bioremediation, and further provides a critical view on the effects of this technology on microbial aspects in contaminated soils. This review also discusses the future research needs for contaminated soils.
摘要：
Precise coordination between stamen and pistil development is essential to make a fertile flower. Mutations impairing stamen filament elongation, pollen maturation, or anther dehiscence will cause male sterility. Deficiency in plant hormone gibberellin (GA) causes male sterility due to accumulation of DELLA proteins, and GA triggers DELLA degradation to promote stamen development. Deficiency in plant hormone jasmonate (JA) also causes male sterility. However, little is known about the relationship between GA and JA in controlling stamen development. Here, we show that MYB21, MYB24, and MYB57 are GA-dependent stamen-enriched genes. Loss-of-function of two DELLAs RGA and RGL2 restores the expression of these three MYB genes together with restoration of stamen filament growth in GA-deficient plants. Genetic analysis showed that the myb21-t1 myb24-t1 myb57-t1 triple mutant confers a short stamen phenotype leading to male sterility. Further genetic and molecular studies demonstrate that GA suppresses DELLAs to mobilize the expression of the key JA biosynthesis gene DAD1, and this is consistent with the observation that the JA content in the young flower buds of the GA-deficient quadruple mutant ga1-3 gai-t6 rga-t2 rgl1-1 is much lower than that in the WT. We conclude that GA promotes JA biosynthesis to control the expression of MYB21, MYB24, and MYB57. Therefore, we have established a hierarchical relationship between GA and JA in that modulation of JA pathway by GA is one of the prerequisites for GA to regulate the normal stamen development in Arabidopsis.
通讯机构：
[Peng, Shaobing] 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：
Notably, many significant breakthroughs for a new generation of supercapacitors have been reported in recent years, related to theoretical understanding, material synthesis and device designs. Herein, we summarize the state-of-the-art progress toward mechanisms, new materials, and novel device designs for supercapacitors. Firstly, fundamental understanding of the mechanism is mainly focused on the relationship between the structural properties of electrode materials and their electrochemical performances based on some in situ characterization techniques and simulations. Secondly, some emerging electrode materials are discussed, including metal-organic frameworks (MOFs), covalent organic frameworks (COFs), MXenes, metal nitrides, black phosphorus, LaMnO3, and RbAg4I5/graphite. Thirdly, the device innovations for the next generation of supercapacitors are provided successively, mainly emphasizing flow supercapacitors, alternating current (AC) line-filtering supercapacitors, redox electrolyte enhanced supercapacitors, metal ion hybrid supercapacitors, micro-supercapacitors (fiber, plane and three-dimensional) and multifunctional supercapacitors including electrochromic supercapacitors, self-healing supercapacitors, piezoelectric supercapacitors, shape-memory supercapacitors, thermal self-protective supercapacitors, thermal self-charging supercapacitors, and photo self-charging supercapacitors. Finally, the future developments and key technical challenges are highlighted regarding further research in this thriving field.
摘要：
Most fruits in our daily diet are the products of domestication and breeding. Here we report a map of genome variation for a major fruit that encompasses similar to 3.6 million variants, generated by deep resequencing of 115 cucumber lines sampled from 3,342 accessions worldwide. Comparative analysis suggests that fruit crops underwent narrower bottlenecks during domestication than grain crops. We identified 112 putative domestication sweeps; 1 of these regions contains a gene involved in the loss of bitterness in fruits, an essential domestication trait of cucumber. We also investigated the genomic basis of divergence among the cultivated populations and discovered a natural genetic variant in a beta-carotene hydroxylase gene that could be used to breed cucumbers with enhanced nutritional value. The genomic history of cucumber evolution uncovered here provides the basis for future genomics-enabled breeding.
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.
摘要：
Lignocellulose is the most abundant biomass on earth. However, biomass recalcitrance has become a major factor affecting biofuel production. Although cellulose crystallinity significantly influences biomass saccharification, little is known about the impact of three major wall polymers on cellulose crystallization. In this study, we selected six typical pairs of Miscanthus samples that presented different cell wall compositions, and then compared their cellulose crystallinity and biomass digestibility after various chemical pretreatments. A Miscanthus sample with a high hemicelluloses level was determined to have a relatively low cellulose crystallinity index (CrI) and enhanced biomass digestibility at similar rates after pretreatments of NaOH and H2SO4 with three concentrations. By contrast, a Miscanthus sample with a high cellulose or lignin level showed increased CrI and low biomass saccharification, particularly after H2SO4 pretreatment. Correlation analysis revealed that the cellulose CrI negatively affected biomass digestion. Increased hemicelluloses level by 25% or decreased cellulose and lignin contents by 31% and 37% were also found to result in increased hexose yields by 1.3-times to 2.2-times released from enzymatic hydrolysis after NaOH or H2SO4 pretreatments. The findings indicated that hemicelluloses were the dominant and positive factor, whereas cellulose and lignin had synergistic and negative effects on biomass digestibility. Using six pairs of Miscanthus samples with different cell wall compositions, hemicelluloses were revealed to be the dominant factor that positively determined biomass digestibility after pretreatments with NaOH or H2SO4 by negatively affecting cellulose crystallinity. The results suggested potential approaches to the genetic modifications of bioenergy crops.
摘要：
AP2/ERF proteins play crucial roles in various biological processes. RAP2.6, an Arabidopsis AP2/ERF family member, has been reported to function in plant response to biotic stress, but whether it also functions in plant response to abiotic stress is not known. In this work, we demonstrate that in wild-type Arabidopsis, the expression of RAP2.6 is responsive to abscisic acid (ABA) and different stress conditions such as high salt, osmotic stress, and cold. Trans-activating ability tests in yeast demonstrate that RAP2.6 could act as a transactivator. RAP2.6 is able to bind to the GCC and CE1 cis-elements, as confirmed by both electrophoretic mobility shift assay (EMSA) and yeast one-hybrid assay. Experiments with RAP2.6-YFP fusion protein indicated that RAP2.6 is nuclear localized. Overexpression of RAP2.6 conferred hypersensitivity to exogenous ABA and abiotic stresses during seed germination and early seedling growth in Arabidopsis. The ABA content in RAP2.6 overexpressor lines decreased after being treated with salt. Furthermore, transcripts of AtABl4 and some stress inducible genes increased, and loss of ABl4 function rescues the hypersensitive phenotype of RAP2.6 overexpression lines under ABA and stress treatment. These results suggest that RAP2.6 participates in abiotic stress, possibly through the ABA-dependent pathway. (C) 2010 Elsevier B.V. All rights reserved.
