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Yuan G, Nong T, Hunpatin OS, Shi C, Su X, Xu F, Wang Y, Zhang Z, Ning Y, Liu H, Wang Q. Genome-wide identification of Shaker K + channel family in Nicotiana tabacum and functional analysis of NtSKOR1B in response to salt stress. FRONTIERS IN PLANT SCIENCE 2024; 15:1378738. [PMID: 38660442 PMCID: PMC11039879 DOI: 10.3389/fpls.2024.1378738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 03/26/2024] [Indexed: 04/26/2024]
Abstract
Soil salinization poses a mounting global ecological and environmental threat. The identification of genes responsible for negative regulation of salt tolerance and their utilization in crop improvement through gene editing technologies emerges as a swift strategy for the effective utilization of saline-alkali lands. One efficient mechanism of plant salt tolerance is maintaining the proper intracellular K+/Na+ ratio. The Shaker K+ channels play a crucial role in potassium absorption, transport, and intracellular potassium homeostasis in plant cells. Here, the study presents the first genome-wide identification of Shaker K+ channels in Nicotiana tabacum L., along with a detailed bioinformatic analysis of the 20 identified members. Transcriptome analysis revealed a significant up-regulation of NtSKOR1B, an outwardly-rectifying member predominantly expressed in the root tissue of tobacco seedlings, in response to salt stress. This finding was then confirmed by GUS staining of ProNtSKOR1B::GUS transgenic lines and RT-qPCR analysis. Subsequently, NtSKOR1B knockout mutants (ntskor1) were then generated and subjected to salt conditions. It was found that ntskor1 mutants exhibit enhanced salt tolerance, characterized by increased biomass, higher K+ content and elevated K+/Na+ ratios in both leaf and root tissues, compared to wild-type plants. These results indicate that NtSKOR1B knockout inhibits K+ efflux in root and leaf tissues of tobacco seedlings under salt stress, thereby maintaining higher K+/Na+ ratios within the cells. Thus, our study identifies NtSKOR1B as a negative regulator of salt tolerance in tobacco seedlings.
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Affiliation(s)
- Guang Yuan
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
- Graduate School of Chinese Academy of Agricultural Sciences, Beijing, China
| | - Tongjia Nong
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
- Graduate School of Chinese Academy of Agricultural Sciences, Beijing, China
| | - Oluwaseyi Setonji Hunpatin
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
- Graduate School of Chinese Academy of Agricultural Sciences, Beijing, China
| | - Chuhan Shi
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
- Graduate School of Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xiaoqing Su
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
- College of Agriculture, Qingdao Agricultural University, Qingdao, China
| | - Fangzheng Xu
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
| | - Yihui Wang
- China Tobacco Shandong Industrial Co., LTD Cigar Operation Center, Jinan, China
| | - Zhaoting Zhang
- Xuancheng City Xuanzhou District Tobacco Industry Development Center, Xuancheng, China
| | - Yang Ning
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
| | - Haobao Liu
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
| | - Qian Wang
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
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Han X, Zhou Y, Li Y, Ren W, Liu K, Zhang W, Zhang H, Tang M. LbKAT3 may assist in mycorrhizal potassium uptake, and overexpression of LbKAT3 may promote potassium, phosphorus, and water transport from arbuscular mycorrhizal fungi to the host plant. FRONTIERS IN PLANT SCIENCE 2023; 14:1161220. [PMID: 37409300 PMCID: PMC10319307 DOI: 10.3389/fpls.2023.1161220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 05/30/2023] [Indexed: 07/07/2023]
Abstract
Potassium plays important roles in most plant physiological processes. Arbuscular mycorrhizal (AM) fungi promote plant water and mineral nutrient acquisition to promote plant growth. However, few studies have focused on the effect of AM colonization on potassium uptake by the host plant. In this study, the effects of an AM fungus (Rhizophagus irregularis) and potassium concentration (0, 3, or 10 mM K+) on Lycium barbarum were evaluated. A split-root test with L. barbarum seedlings was conducted, and the potassium uptake capacity of LbKAT3 was verified in yeast. A tobacco line overexpressing LbKAT3 was generated and mycorrhizal functions under two potassium concentrations (0.2 and 2 mM K+) were studied. Inoculation of R. irregularis and application of potassium increased the dry weight, and potassium and phosphorus contents of L. barbarum, and increased the colonization rate and arbuscule abundance of R. irregularis. In addition, the expression of LbKAT3 and AQP genes in L. barbarum was upregulated. Inoculation of R. irregularis induced LbPT4, Rir-AQP1, and Rir-AQP2 expression, and application of potassium upregulated the expression of these genes. Inoculation with the AM fungus locally regulated the expression of LbKAT3. Inoculation of R. irregularis improved the growth, and potassium and phosphorus contents, and induced NtPT4, Rir-AQP1, and Rir-AQP2 expression in tobacco overexpressing LbKAT3 under both potassium concentrations. Overexpression of LbKAT3 in tobacco improved the growth, potassium accumulation, and AM colonization, and upregulated the expression of NtPT4 and Rir-AQP1 in mycorrhizal tobacco. The results suggest that LbKAT3 may assist in mycorrhizal potassium uptake, and overexpression of LbKAT3 may promote potassium, phosphorus, and water transport from the AM fungus to tobacco.
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Affiliation(s)
- Xia Han
- College of Forestry, Northwest A&F University, Yangling, Shaanxi, China
| | - Yuhao Zhou
- College of Forestry, Northwest A&F University, Yangling, Shaanxi, China
| | - Yanpeng Li
- College of Forestry, Northwest A&F University, Yangling, Shaanxi, China
| | - Wei Ren
- College of Forestry, Northwest A&F University, Yangling, Shaanxi, China
| | - Kunkun Liu
- College of Forestry, Northwest A&F University, Yangling, Shaanxi, China
| | - Wenrui Zhang
- College of Forestry, Northwest A&F University, Yangling, Shaanxi, China
| | - Haoqiang Zhang
- College of Forestry, Northwest A&F University, Yangling, Shaanxi, China
| | - Ming Tang
- College of Forestry, Northwest A&F University, Yangling, Shaanxi, China
- State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, Guangdong, China
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Hu W, Lu Z, Gu H, Ye X, Li X, Cong R, Ren T, Lu J. Potassium availability influences the mesophyll structure to coordinate the conductance of CO 2 and H 2 O during leaf expansion. PLANT, CELL & ENVIRONMENT 2022; 45:2987-3000. [PMID: 35864569 DOI: 10.1111/pce.14405] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 07/11/2022] [Accepted: 07/15/2022] [Indexed: 06/15/2023]
Abstract
Leaf growth relies on photosynthesis and hydraulics to provide carbohydrates and expansion power; in turn, leaves intercept light and construct organism systems for functioning. Under potassium (K) deficiency stress, leaf area, photosynthesis and hydraulics are all affected by alterations in leaf structure. However, the connection between changes in leaf growth and function caused by the structure under K regulation is unclear. Consequently, the leaf hydraulic conductance (Kleaf ) and photosynthetic rate (A) combined with leaf anatomical characteristics of Brassica napus were continuously observed during leaf growth under different K supply levels. The results showed that Kleaf and A decreased simultaneously after leaf area with the increasing K deficiency stress. K deficiency significantly increased longitudinal mesophyll cell investment, leading to a reduced volume fraction of intercellular air-space (fias ) and decreased leaf expansion rate. Furthermore, reduced fias decreased mesophyll and chloroplast surfaces exposed to intercellular airspace and gas phase H2 O transport, which induced coordinated changes in CO2 mesophyll conductance and hydraulic conductance in extra-xylem pathways. Adequate K supply facilitated higher fias through smaller palisade tissue cell density (loose mesophyll cell arrangement) and smaller spongy tissue cell size, which coordinated CO2 and H2 O conductance and promoted leaf area expansion.
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Affiliation(s)
- Wenshi Hu
- Microelement Research Center, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, China
| | - Zhifeng Lu
- Microelement Research Center, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, China
| | - Hehe Gu
- Microelement Research Center, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, China
| | - Xiaolei Ye
- Microelement Research Center, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, China
| | - Xiaokun Li
- Microelement Research Center, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, China
| | - Rihuan Cong
- Microelement Research Center, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, China
| | - Tao Ren
- Microelement Research Center, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, China
| | - Jianwei Lu
- Microelement Research Center, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Wuhan, China
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Yang ZX, Lin YC, Cao Y, Wang RG, Kong DJ, Hou Q, Gou JY, Kakar KU, Zhang JS, Wang ZH, Yu SZ. Potassium accumulation characteristics and expression of related genes involved in potassium metabolism in a high-potassium variety: tobacco ( Nicotiana tabacum) as a model. FUNCTIONAL PLANT BIOLOGY : FPB 2022; 49:887-897. [PMID: 35798353 DOI: 10.1071/fp22011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 06/12/2022] [Indexed: 06/15/2023]
Abstract
We investigated potassium (K) accumulation characteristics and expression of K metabolism related genes in one high-K variety (ND202) and a common variety (NC89) of tobacco (Nicotiana tabacum L.). Results showed that K accumulation and leaf K content in ND202 were higher than those in NC89. The distribution rate and K accumulation in the leaves of ND202 increased significantly, while the distribution rate in the roots and stems had lower values. In addition, the maximum K accumulation rate and high-speed K accumulation duration in ND202 were found to be better than those in NC89. The expression of NKT1 in the upper and middle leaves of ND202 had an advantage, and the relative expression of NtKC1 and NtTPK1 in both the upper and middle leaves, as well as the roots, was also significantly upregulated. Conversely, the expression of NTRK1 in the lower leaves and roots of ND202 was weaker. ND202 had significantly greater expression levels of NtHAK1 than NC89 in the upper and middle leaves and roots; moreover, the expression of NtKT12 in the upper leaves and roots of ND202 was also higher. In comparison with common varieties, high-K varieties had a stronger ability to absorb and accumulate K. They also possessed higher expression of K+ channel- and transporter-related genes and showed a superior K accumulation rate and longer duration of high-speed K accumulation. Furthermore, K accumulation rate at 40-60days can be suggested as an important reference for the selection of high-K tobacco varieties.
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Affiliation(s)
- Zhi-Xiao Yang
- Guizhou Academy of Tobacco Science, Guiyang 550081, China
| | - Ying-Chao Lin
- Guizhou Academy of Tobacco Science, Guiyang 550081, China
| | - Yi Cao
- Guizhou Academy of Tobacco Science, Guiyang 550081, China
| | - Ren-Gang Wang
- Guizhou Academy of Tobacco Science, Guiyang 550081, China
| | - De-Jun Kong
- Guizhou Academy of Tobacco Science, Guiyang 550081, China
| | - Qian Hou
- College of Agronomy, Northwest A&F University, Yangling 712100, China
| | - Jian-Yu Gou
- Zunyi Municipal Branch of Guizhou Tobacco Company, Zunyi 56300, China
| | - Kaleem U Kakar
- Department of Biotechnology, Faculty of Life Sciences, Balochistan University of Information Technology, Engineering, and Management Sciences (BUITEMS), Quetta 87300, Pakistan
| | - Ji-Shun Zhang
- Guizhou Academy of Tobacco Science, Guiyang 550081, China
| | - Zhi-Hong Wang
- Guizhou Academy of Tobacco Science, Guiyang 550081, China
| | - Shi-Zhou Yu
- Guizhou Academy of Tobacco Science, Guiyang 550081, China
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Huang YN, Yang SY, Li JL, Wang SF, Wang JJ, Hao DL, Su YH. The rectification control and physiological relevance of potassium channel OsAKT2. PLANT PHYSIOLOGY 2021; 187:2296-2310. [PMID: 34601582 PMCID: PMC8644434 DOI: 10.1093/plphys/kiab462] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 09/07/2021] [Indexed: 05/14/2023]
Abstract
AKT2 potassium (K+) channels are members of the plant Shaker family which mediate dual-directional K+ transport with weak voltage-dependency. Here we show that OsAKT2 of rice (Oryza sativa) functions mainly as an inward rectifier with strong voltage-dependency and acutely suppressed outward activity. This is attributed to the presence of a unique K191 residue in the S4 domain. The typical bi-directional leak-like property was restored by a single K191R mutation, indicating that this functional distinction is an intrinsic characteristic of OsAKT2. Furthermore, the opposite R195K mutation of AtAKT2 changed the channel to an inward-rectifier similar to OsAKT2. OsAKT2 was modulated by OsCBL1/OsCIPK23, evoking the outward activity and diminishing the inward current. The physiological relevance in relation to the rectification diversity of OsAKT2 was addressed by functional assembly in the Arabidopsis (Arabidopsis thaliana) akt2 mutant. Overexpression (OE) of OsAKT2 complemented the K+ deficiency in the phloem sap and leaves of the mutant plants but did not significantly contribute to the transport of sugars. However, the expression of OsAKT2-K191R overcame both the shortage of phloem K+ and sucrose of the akt2 mutant, which was comparable to the effects of the OE of AtAKT2, while the expression of the inward mutation AtAKT2-R195K resembled the effects of OsAKT2. Additionally, OE of OsAKT2 ameliorated the salt tolerance of Arabidopsis.
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Affiliation(s)
- Ya-Nan Huang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shun-Ying Yang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Jun-Lin Li
- Shandong Institute of Sericulture, Yantai 264002, China
| | - Shao-Fei Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Jia-Jin Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Dong-Li Hao
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Yan-Hua Su
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
- Author for communication:
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6
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Lhamo D, Wang C, Gao Q, Luan S. Recent Advances in Genome-wide Analyses of Plant Potassium Transporter Families. Curr Genomics 2021; 22:164-180. [PMID: 34975289 PMCID: PMC8640845 DOI: 10.2174/1389202922666210225083634] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 12/30/2020] [Accepted: 01/26/2021] [Indexed: 12/19/2022] Open
Abstract
Plants require potassium (K+) as a macronutrient to support numerous physiological processes. Understanding how this nutrient is transported, stored, and utilized within plants is crucial for breeding crops with high K+ use efficiency. As K+ is not metabolized, cross-membrane transport becomes a rate-limiting step for efficient distribution and utilization in plants. Several K+ transporter families, such as KUP/HAK/KT and KEA transporters and Shaker-like and TPK channels, play dominant roles in plant K+ transport processes. In this review, we provide a comprehensive contemporary overview of our knowledge about these K+ transporter families in angiosperms, with a major focus on the genome-wide identification of K+ transporter families, subcellular localization, spatial expression, function and regulation. We also expanded the genome-wide search for the K+ transporter genes and examined their tissue-specific expression in Camelina sativa, a polyploid oil-seed crop with a potential to adapt to marginal lands for biofuel purposes and contribution to sustainable agriculture. In addition, we present new insights and emphasis on the study of K+ transporters in polyploids in an effort to generate crops with high K+ Utilization Efficiency (KUE).
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Affiliation(s)
- Dhondup Lhamo
- 1Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA; 2School of Life Sciences, Northwest University, Xi'an 710069, China
| | - Chao Wang
- 1Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA; 2School of Life Sciences, Northwest University, Xi'an 710069, China
| | - Qifei Gao
- 1Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA; 2School of Life Sciences, Northwest University, Xi'an 710069, China
| | - Sheng Luan
- 1Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA; 2School of Life Sciences, Northwest University, Xi'an 710069, China
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Hu W, Lu Z, Meng F, Li X, Cong R, Ren T, Sharkey TD, Lu J. The reduction in leaf area precedes that in photosynthesis under potassium deficiency: the importance of leaf anatomy. THE NEW PHYTOLOGIST 2020; 227:1749-1763. [PMID: 32367581 DOI: 10.1111/nph.16644] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 04/26/2020] [Indexed: 06/11/2023]
Abstract
Synergistic improvement in leaf photosynthetic area and rate is essential for enhancing crop yield. However, reduction in leaf area occurs earlier than that in the photosynthetic rate under potassium (K) deficiency stress. The photosynthetic capacity and anatomical characteristics of oilseed rape (Brassica napus) leaves in different growth stages under different K levels were observed to clarify the mechanism regulating this process. Increased mesophyll cell size and palisade tissue thickness, in K-deficient leaves triggered significant enlargement of mesophyll cell area per transverse section width (S/W), in turn inhibiting leaf expansion. However, there was only a minor difference in chloroplast morphology, likely because of K redistribution from vacuole to chloroplast. As K stress increased, decreased mesophyll surface exposed to intercellular space and chloroplast density induced longer distances between neighbouring chloroplasts (Dchl-chl ) and decreased the chloroplast surface area exposed to intercellular space (Sc /S); conversely this induced a greater limitation imposed by the cytosol on CO2 transport, further reducing the photosynthetic rate. Changes in S/W associated with mesophyll cell morphology occurred earlier than changes in Sc /S and Dchl-chl , inducing a decrease in leaf area before photosynthetic rate reduction. Adequate K nutrition simultaneously increases photosynthetic area and rate, thus enhancing crop yield.
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Affiliation(s)
- Wenshi Hu
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River, Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Zhifeng Lu
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River, Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Fanjin Meng
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River, Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Xiaokun Li
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River, Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Rihuan Cong
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River, Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Tao Ren
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River, Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Thomas D Sharkey
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
| | - Jianwei Lu
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River, Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
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Hu W, Di Q, Zhang J, Liu J, Shi X. Response of grafting tobacco to low potassium stress. BMC PLANT BIOLOGY 2020; 20:286. [PMID: 32571243 PMCID: PMC7310080 DOI: 10.1186/s12870-020-02481-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 06/03/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND In the previous study, we investigated the alleviation effect of grafting on potassium uptake in roots and tobacco growth inhibition under low potassium stress. However, the effect of grafting on the low potassium stress perception and coping mechanism of tobacco at the whole plant level is not clear now. In order to clearly understand the impact of grafting on potassium deficit responding mechanism in tobacco, a mutual grafting experiment has been conducted in two varieties of tobacco ('Wufeng No.2' and 'Yunyan 87') in different K supply level (5 mmol L- 1 and 0.5 mmol L- 1 K). RESULTS The results show that compared with the self-rooted seedlings, grafting significantly increased the potassium content of the whole plant of Yunyan 87 (97.57 and 189.74% under normal potassium and low potassium conditions, respectively), and the increase in shoots was greater. The data of whole plant K content distribution and tobacco hypocotyls net K+ flux demonstrates that potassium stress makes plants more inclined to maintain K+ in the shoot rather than root. In addition, when K deficiency occurs, grafting could reduce the time required for downward net K+ flux in tobacco hypocotyl to decrease to stable levels. The results of net K+ flux in the roots indicated that K channel proteins and transporters play different roles in two rootstocks in terms of potassium tolerance. Transcription level analysis suggested that the increased circulating efficiency of K+ between the shoots and roots in tobacco constitutes one means to low potassium stress adaptation. CONCLUSIONS Grafting can activate more K+ channels in tobacco 'Yunyan 87', this means a more active K+ cycle, higher potassium content in shoot and faster response to low potassium stress signals in grafting tobacco. In addition, grafting can also change the K+ absorption mode of tobacco root from being dominated by HATS to being jointly responsible by HATS and LATS, greatly improving the ability of K+ transmembrane transportation on root surface under low potassium stress. These are undoubtedly the reasons why grafting tobacco performs better in coping with low potassium stress.
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Affiliation(s)
- Wei Hu
- College of Resources and Environment, Southwest University, Chongqing, 400716 China
- Vegetable and Flower Institute of Chongqing Academy of Agricultural Sciences, Chongqing, 401329 China
| | - Qing Di
- Vegetable and Flower Institute of Chongqing Academy of Agricultural Sciences, Chongqing, 401329 China
| | - Jie Zhang
- Nanchang Institute of Technology, Nanchang, 330099 China
| | - Jia Liu
- Soil and Fertilizer & Resources and Environment Institute, Jiangxi Academy of Agricultural Sciences, Nanchang, 330200 China
| | - Xiaojun Shi
- College of Resources and Environment, Southwest University, Chongqing, 400716 China
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Drain A, Thouin J, Wang L, Boeglin M, Pauly N, Nieves-Cordones M, Gaillard I, Véry AA, Sentenac H. Functional characterization and physiological roles of the single Shaker outward K + channel in Medicago truncatula. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 102:1249-1265. [PMID: 31958173 DOI: 10.1111/tpj.14697] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 11/29/2019] [Accepted: 12/13/2019] [Indexed: 06/10/2023]
Abstract
The model legume Medicago truncatula possesses a single outward Shaker K+ channel, whereas Arabidopsis thaliana possesses two channels of this type, named AtSKOR and AtGORK, with AtSKOR having been shown to play a major role in K+ secretion into the xylem sap in the root vasculature and with AtGORK being shown to mediate the efflux of K+ across the guard cell membrane, leading to stomatal closure. Here we show that the expression pattern of the single M. truncatula outward Shaker channel, which has been named MtGORK, includes the root vasculature, guard cells and root hairs. As shown by patch-clamp experiments on root hair protoplasts, besides the Shaker-type slowly activating outwardly rectifying K+ conductance encoded by MtGORK, a second K+ -permeable conductance, displaying fast activation and weak rectification, can be expressed by M. truncatula. A knock-out (KO) mutation resulting in an absence of MtGORK activity is shown to weakly reduce K+ translocation to shoots, and only in plants engaged in rhizobial symbiosis, but to strongly affect the control of stomatal aperture and transpirational water loss. In legumes, the early electrical signaling pathway triggered by Nod-factor perception is known to comprise a short transient depolarization of the root hair plasma membrane. In the absence of the functional expression of MtGORK, the rate of the membrane repolarization is found to be decreased by a factor of approximately two. This defect was without any consequence on infection thread development and nodule production in plants grown in vitro, but a decrease in nodule production was observed in plants grown in soil.
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Affiliation(s)
- Alice Drain
- Biochimie et Physiologie Moléculaire des Plantes, UMR BPMP, Univ Montpellier, CNRS, INRAE, Montpellier SupAgro, Montpellier, 34060, France
| | - Julien Thouin
- Biochimie et Physiologie Moléculaire des Plantes, UMR BPMP, Univ Montpellier, CNRS, INRAE, Montpellier SupAgro, Montpellier, 34060, France
| | - Limin Wang
- Biochimie et Physiologie Moléculaire des Plantes, UMR BPMP, Univ Montpellier, CNRS, INRAE, Montpellier SupAgro, Montpellier, 34060, France
| | - Martin Boeglin
- Biochimie et Physiologie Moléculaire des Plantes, UMR BPMP, Univ Montpellier, CNRS, INRAE, Montpellier SupAgro, Montpellier, 34060, France
| | - Nicolas Pauly
- Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, UMR 1355-7254 Institut Sophia Agrobiotech, Université Nice Sophia Antipolis, Sophia Antipolis, France
- Laboratoire des Interactions Plantes-Microorganismes, INRAE, CNRS, Université de Toulouse, Castanet-Tolosan, France
| | - Manuel Nieves-Cordones
- Biochimie et Physiologie Moléculaire des Plantes, UMR BPMP, Univ Montpellier, CNRS, INRAE, Montpellier SupAgro, Montpellier, 34060, France
- Departamento de Nutrición Vegetal, Centro de Edafología y Biología Aplicada del Segura-CSIC, Apartado de Correos 164, Murcia, 30100, Spain
| | - Isabelle Gaillard
- Biochimie et Physiologie Moléculaire des Plantes, UMR BPMP, Univ Montpellier, CNRS, INRAE, Montpellier SupAgro, Montpellier, 34060, France
| | - Anne-Aliénor Véry
- Biochimie et Physiologie Moléculaire des Plantes, UMR BPMP, Univ Montpellier, CNRS, INRAE, Montpellier SupAgro, Montpellier, 34060, France
| | - Hervé Sentenac
- Biochimie et Physiologie Moléculaire des Plantes, UMR BPMP, Univ Montpellier, CNRS, INRAE, Montpellier SupAgro, Montpellier, 34060, France
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10
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Chen L, Yang J, Li X, Liang T, Nie C, Xie F, Liu K, Peng X, Xie J. Carbon nanoparticles enhance potassium uptake via upregulating potassium channel expression and imitating biological ion channels in BY-2 cells. J Nanobiotechnology 2020; 18:21. [PMID: 31992314 PMCID: PMC6986061 DOI: 10.1186/s12951-020-0581-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 01/16/2020] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Carbon nanoparticles (CNPs) have been reported to boost plant growth, while the mechanism that CNPs enhanced potassium uptake for plant growth has not been reported so far. RESULTS In this study, the function that CNPs promoted potassium uptake in BY-2 cells was established and the potassium accumulated in cells had a significant correlation with the fresh biomass of BY-2 cells. The K+ accumulation in cells increased with the increasing concentration of CNPs. The K+ influx reached high level after treatment with CNPs and was significantly higher than that of the control group and the negative group treated with K+ channels blocker, tetraethylammonium chloride (TEA+). The K+ accumulation was not reduced in the presence of CNPs inhibitors. In the presence of potassium channel blocker TEA+ or CNPs inhibitors, the NKT1 gene expression was changed compared with the control group. The CNPs were found to preferentially transport K+ than other cations determined by rectification of ion current assay (RIC) in a conical nanocapillary. CONCLUSIONS These results indicated that CNPs upregulated potassium gene expression to enhance K+ accumulation in BY-2 cells. Moreover, it was speculated that the CNPs simulated protein of ion channels via bulk of carboxyl for K+ permeating. These findings will provide support for improving plant growth by carbon nanoparticles.
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Affiliation(s)
- Lijuan Chen
- Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, 116024, China
| | - Jinchu Yang
- Technology Center, China Tobacco Henan Industrial Co. Ltd, Zhengzhou, 450000, China
| | - Xiang Li
- Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou, 450001, China
| | - Taibo Liang
- Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou, 450001, China
| | - Cong Nie
- Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou, 450001, China
| | - Fuwei Xie
- Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou, 450001, China
| | - Kejian Liu
- Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou, 450001, China
| | - Xiaojun Peng
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, 116024, China
| | - Jianping Xie
- Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou, 450001, China.
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Villette J, Cuéllar T, Zimmermann SD, Verdeil JL, Gaillard I. Unique features of the grapevine VvK5.1 channel support novel functions for outward K+ channels in plants. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:6181-6193. [PMID: 31327013 PMCID: PMC6859719 DOI: 10.1093/jxb/erz341] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 07/15/2019] [Indexed: 05/04/2023]
Abstract
Grapevine (Vitis vinifera L.), one of the most important fruit crops, is a model plant for studying the physiology of fleshy fruits. Here, we report on the characterization of a new grapevine Shaker-type K+ channel, VvK5.1. Phylogenetic analysis revealed that VvK5.1 belongs to the SKOR-like subfamily. Our functional characterization of VvK5.1 in Xenopus oocytes confirms that it is an outwardly rectifying K+ channel that displays strict K+ selectivity. Gene expression level analyses by real-time quantitative PCR showed that VvK5.1 expression was detected in berries, roots, and flowers. In contrast to its Arabidopsis thaliana counterpart that is involved in K+ secretion in the root pericycle, allowing root to shoot K+ translocation, VvK5.1 expression territory is greatly enlarged. Using in situ hybridization we showed that VvK5.1 is expressed in the phloem and perivascular cells of berries and in flower pistil. In the root, in addition to being expressed in the root pericycle like AtSKOR, a strong expression of VvK5.1 is detected in small cells facing the xylem that are involved in lateral root formation. This fine and selective expression pattern of VvK5.1 at the early stage of lateral root primordia supports a role for outward channels to switch on cell division initiation.
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Affiliation(s)
- Jérémy Villette
- BPMP, Université Montpellier, CNRS, INRA, SupAgro, Montpellier, France
| | - Teresa Cuéllar
- CIRAD, UMR AGAP, F-34398 Montpellier, France
- Université Montpellier, CIRAD, INRA, Montpellier SupAgro, Montpellier, France
| | | | - Jean-Luc Verdeil
- CIRAD, UMR AGAP, F-34398 Montpellier, France
- Université Montpellier, CIRAD, INRA, Montpellier SupAgro, Montpellier, France
| | - Isabelle Gaillard
- BPMP, Université Montpellier, CNRS, INRA, SupAgro, Montpellier, France
- Correspondence:
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Hu W, Di Q, Wang Z, Zhang Y, Zhang J, Liu J, Shi X. Grafting alleviates potassium stress and improves growth in tobacco. BMC PLANT BIOLOGY 2019; 19:130. [PMID: 30961523 PMCID: PMC6454764 DOI: 10.1186/s12870-019-1706-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 03/11/2019] [Indexed: 05/26/2023]
Abstract
BACKGROUND Potassium is a nutrient element necessary for tobacco growth. Tobacco leaves with high potassium content are elastic and tough, rich in oil. And the same time, potassium can also improve the scent and aromatic value of flue-cured tobacco by regulating the synthesis of aromatic hydrocarbons in leaves.. It is an important quality indicator for flue-cured tobacco. However, the potassium concentration in tobacco leaves in most areas of China is generally lower than the global standard for high quality tobacco. Two tobacco genotypes were grafted to each other under different potassium levels to test whether potassium content and plant growth can be improved by grafting in tobacco. RESULTS The growth of tobacco in all treatments was inhibited under potassium starvation, and grafting significantly alleviated this potassium stress in 'Yunyan 87'. The trends in whole plant K+ uptake and K+ transfer efficiency to the leaves corresponded to the growth results of the different grafts. The nutrient depletion test results showed that the roots of 'Wufeng No.2' had higher K+ absorption potential, K+ affinity, and K+ inward flow rate. K+ enrichment circles appeared at the endoderm of the root section in the energy dispersive X-ray figure, indicating that the formation of Casparian strips may be partly responsible for the lower rate of lateral movement of K+ in the roots of 'Yunyan 87'. Gene expression analysis suggested that energy redistribution at the whole plant level might constitute one strategy for coping with potassium starvation. The feedback regulation effects between scion 'Wufeng No.2' and rootstock 'Yunyan 87' indicated that the transmission of certain signaling substances had occurred during grafting. CONCLUSIONS 'Wufeng No.2' tobacco rootstock grafting can increase the K+ uptake and transport efficiency of 'Yunyan 87' and enhance plant growth under potassium stress. The physiological mechanism of the improved performance of grafted tobacco is related to higher K+ uptake and utilization ability, improved xylem K+ loading capacity, and up-regulated expression of genes related to energy supply systems.
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Affiliation(s)
- Wei Hu
- College of Resources and Environment, Southwest University, Chongqing, 400716 China
| | - Qing Di
- Vegetable and Flower Institute of Chongqing Academy of Agricultural Sciences, Chongqing, 401329 China
| | - Zhijin Wang
- Vegetable and Flower Institute of Chongqing Academy of Agricultural Sciences, Chongqing, 401329 China
| | - Yimo Zhang
- Vegetable and Flower Institute of Chongqing Academy of Agricultural Sciences, Chongqing, 401329 China
| | - Jie Zhang
- Nanchang Institute of Technology, Nanchang, 330099 China
| | - Jia Liu
- Soil and Fertilizer & Resources and Environment Institute, Jiangxi Academy of Agricultural Sciences, Nanchang, 330200 China
| | - Xiaojun Shi
- College of Resources and Environment, Southwest University, Chongqing, 400716 China
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Chen G, Zhang Y, Ruan B, Guo L, Zeng D, Gao Z, Zhu L, Hu J, Ren D, Yu L, Xu G, Qian Q. OsHAK1 controls the vegetative growth and panicle fertility of rice by its effect on potassium-mediated sugar metabolism. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2018; 274:261-270. [PMID: 30080612 DOI: 10.1016/j.plantsci.2018.05.034] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 05/21/2018] [Accepted: 05/31/2018] [Indexed: 05/26/2023]
Abstract
Plant growth and reproduction are both energy-requiring processes; the necessary energy is supplied by the products of photosynthesis. Both the vegetative growth and reproductive success of rice are compromised by the absence of a functional copy of the gene OsHAK1. Here, a comparison between wild type rice and OsHAK1 knockout mutants not only confirmed the known detrimental effect of the absence of OsHAK1 on root growth, pollen viability and fertility, but also showed that sucrose phosphate synthase activity was lowered, and the sucrose content of the leaves was markedly increased, due to a partial block on the up-loading of sucrose into the phloem. The impaired allocation of sugar to the roots and spikelets caused by the knocking out of OsHAK1 was accompanied by a down-regulation in the leaf sheaths and panicle axes of genes encoding sucrose transporters (SUT genes), which are active in the phloem, as well as in the roots and spikelets of those encoding monosaccharide transporters (MST genes), which transport hexose sugars across the plant plasma membrane. The activity of sucrose synthase, acid invertase and neutral invertase in the roots of mutant plants assayed at the tillering stage, and in their spikelets, assayed during grain-filling, was significantly lower than in the equivalent organs of wild type plants. As a result, the supply of total soluble sugar, glucose and fructose to sink organs was reduced, consistent with the effect of the mutation on root growth and panicle fertility. Compared to wild type plants, the mutants accumulated less potassium (K) throughout the plant. The conclusion was that the failure to fully supply the demand of the mutant's sink organs for assimilate was responsible for its compromised phenotype, and that the deficiency in K uptake induced by the loss of OsHAK1 functionality was responsible for the disruption of sugar metabolism.
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Affiliation(s)
- Guang Chen
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, PR China; State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing 210095, PR China.
| | - Yu Zhang
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, PR China
| | - Banpu Ruan
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, PR China
| | - Longbiao Guo
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, PR China
| | - Dali Zeng
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, PR China
| | - Zhenyu Gao
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, PR China
| | - Li Zhu
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, PR China
| | - Jiang Hu
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, PR China
| | - Deyong Ren
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, PR China
| | - Ling Yu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Guohua Xu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing 210095, PR China.
| | - Qian Qian
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, PR China.
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15
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Jeong CY, Lee WJ, Truong HA, Trịnh CS, Jin JY, Kim S, Hwang KY, Kang CS, Moon JK, Hong SW, Lee H. Dual role of SND1 facilitates efficient communication between abiotic stress signalling and normal growth in Arabidopsis. Sci Rep 2018; 8:10114. [PMID: 29973639 PMCID: PMC6031621 DOI: 10.1038/s41598-018-28413-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 06/22/2018] [Indexed: 01/21/2023] Open
Abstract
Certain plant cells synthesize secondary cell walls besides primary cell walls. This biosynthesis is strictly controlled by an array of transcription factors. Here, we show that SND1, a regulator of cell-wall biosynthesis, regulates abscisic acid (ABA) biosynthesis to ensure optimal plant growth. In Arabidopsis, the lack of SND1 and its homolog NST1 leads to the deficiency of secondary cell walls, preventing snd1nst1 double mutant seedlings from growing upright. Compared to wild type seedlings, the snd1 knockout mutant seedlings accumulated less anthocyanin and exhibited low tolerance to salt stress. Compared to wild type seedlings, the snd1 knockout seedlings were more sensitive to salt stress. Although SND1 can bind to the promoter of Myb46, we observed that SND1 binds directly to the promoter of the ABI4 gene, thereby reducing ABA levels under normal growth conditions. Thus, plants adjust secondary cell wall thickening and growth via SND1. SND1 has a dual function: it activates the Myb46 pathway, fostering lignin biosynthesis to produce sufficient cell wall components for growth, while maintaining a low ABA concentration, as it inhibits growth. This dual function of SND1 may help plants modulate their growth efficiently.
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Affiliation(s)
- Chan Young Jeong
- Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Republic of Korea.,Institute of Life Science and Natural Resources, Korea University, Seoul, 136-713, Republic of Korea
| | - Won Je Lee
- Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Republic of Korea
| | - Hai An Truong
- Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Republic of Korea
| | - Cao Sơn Trịnh
- Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Republic of Korea
| | - Joo Yeon Jin
- Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Republic of Korea
| | - Sulhee Kim
- Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Republic of Korea
| | - Kwang Yeon Hwang
- Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Republic of Korea
| | - Chon-Sik Kang
- Crop Breeding Division, National Institute of Crop Science, RDA, 181 Hyeoksin-ro, Iseo-myeon, Wanju-gun, Jeollabuk-do, 54955, Republic of Korea
| | - Joon-Kwan Moon
- Department of Plant Life and Environmental Sciences, Hankyong National University, 327 Jungangro, Anseong, 17579, Republic of Korea
| | - Suk-Whan Hong
- Department of Molecular Biotechnology, College of Agriculture and Life Sciences, Bioenergy Research Center, Chonnam National University, Gwangju, Republic of Korea.
| | - Hojoung Lee
- Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Anam-dong 5-ga, Seongbuk-gu, Seoul, 136-713, Republic of Korea. .,Institute of Life Science and Natural Resources, Korea University, Seoul, 136-713, Republic of Korea.
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16
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Chen G, Liu C, Gao Z, Zhang Y, Jiang H, Zhu L, Ren D, Yu L, Xu G, Qian Q. OsHAK1, a High-Affinity Potassium Transporter, Positively Regulates Responses to Drought Stress in Rice. FRONTIERS IN PLANT SCIENCE 2017; 8:1885. [PMID: 29163608 PMCID: PMC5671996 DOI: 10.3389/fpls.2017.01885] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 10/17/2017] [Indexed: 05/04/2023]
Abstract
Drought is one of the environmental factors that severely restrict plant distribution and crop production. Recently, we reported that the high-affinity potassium transporter OsHAK1 plays important roles in K acquisition and translocation in rice over low and high K concentration ranges, however, knowledge on the regulatory roles of OsHAK1 in osmotic/drought stress is limited. Here, transcript levels of OsHAK1 were found transiently elevated by water deficit in roots and shoots, consistent with the enhanced GUS activity in transgenic plants under stress. Under drought conditions, OsHAK1 knockout mutants (KO) presented lower tolerance to the stress and displayed stunted growth at both the vegetative and reproductive stages. Phenotypic analysis of OsHAK1 overexpression seedlings (Ox) demonstrated that they present better tolerance to drought stress than wild-type (WT). Compared to WT seedlings, OsHAK1 overexpressors had lower level of lipid peroxidation, higher activities of antioxidant enzymes (POX and CAT) and higher proline accumulation. Furthermore, qPCR analysis revealed that OsHAK1 act as a positive regulator of the expression of stress-responsive genes as well as of two well-known rice channel genes (OsTPKb and OsAKT1) involved in K homeostasis and stress responses in transgenic plants under dehydration. Most important, OsHAK1-Ox plants displayed enhanced drought tolerance at the reproductive stage, resulting in 35% more grain yield than WT under drought conditions, and without exhibiting significant differences under normal growth conditions. Consequently, OsHAK1 can be considered to be used in molecular breeding for improvement of drought tolerance in rice.
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Affiliation(s)
- Guang Chen
- State Key Lab for Rice Biology, China National Rice Research Institute, Hangzhou, China
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing, China
| | - Chaolei Liu
- State Key Lab for Rice Biology, China National Rice Research Institute, Hangzhou, China
| | - Zhenyu Gao
- State Key Lab for Rice Biology, China National Rice Research Institute, Hangzhou, China
| | - Yu Zhang
- State Key Lab for Rice Biology, China National Rice Research Institute, Hangzhou, China
| | - Hongzhen Jiang
- State Key Lab for Rice Biology, China National Rice Research Institute, Hangzhou, China
| | - Li Zhu
- State Key Lab for Rice Biology, China National Rice Research Institute, Hangzhou, China
| | - Deyong Ren
- State Key Lab for Rice Biology, China National Rice Research Institute, Hangzhou, China
| | - Ling Yu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing, China
| | - Guohua Xu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing, China
| | - Qian Qian
- State Key Lab for Rice Biology, China National Rice Research Institute, Hangzhou, China
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17
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Ahanger MA, Tomar NS, Tittal M, Argal S, Agarwal RM. Plant growth under water/salt stress: ROS production; antioxidants and significance of added potassium under such conditions. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2017; 23:731-744. [PMID: 29158624 PMCID: PMC5671444 DOI: 10.1007/s12298-017-0462-7] [Citation(s) in RCA: 162] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Accepted: 07/31/2017] [Indexed: 05/18/2023]
Abstract
Plants are confronted with a variety of environmenmtal stresses resulting in enhanced production of ROS. Plants require a threshold level of ROS for vital functions and any change in their concentration alters the entire physiology of plant. Delicate balance of ROS is maintained by an efficient functioning of intriguing indigenous defence system called antioxidant system comprising enzymatic and non enzymatic components. Down regulation of antioxidant system leads to ROS induced oxidative stress causing damage to important cellular structures and hence anomalies in metabolism. Proper mineral nutrition, in addition to other agricultural practices, forms an important part for growth and hence the yield. Potassium (K) is a key macro-element regulating growth and development through alterations in physiological and biochemical attributes. K has been reported to result into accumulation of osmolytes and augmentation of antioxidant components in the plants exposed to water and salt stress. In the present review an effort has been made to revisit the old findings and the current advances in research regarding the role of optimal, suboptimal and deficient K soil status on growth under normal and stressful conditions. Effect of K deficiency and sufficiency is discussed and the information about the K mediated antioxidant regulation and plant response is highlighted.
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Affiliation(s)
| | - Nisha Singh Tomar
- School of Studies in Botany, Jiwaji University, Gwalior, MP 474011 India
| | - Megha Tittal
- School of Studies in Botany, Jiwaji University, Gwalior, MP 474011 India
| | - Surendra Argal
- School of Studies in Botany, Jiwaji University, Gwalior, MP 474011 India
| | - R. M. Agarwal
- School of Studies in Botany, Jiwaji University, Gwalior, MP 474011 India
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18
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Luo Q, Wei Q, Wang R, Zhang Y, Zhang F, He Y, Zhou S, Feng J, Yang G, He G. BdCIPK31, a Calcineurin B-Like Protein-Interacting Protein Kinase, Regulates Plant Response to Drought and Salt Stress. FRONTIERS IN PLANT SCIENCE 2017; 8:1184. [PMID: 28736568 PMCID: PMC5500663 DOI: 10.3389/fpls.2017.01184] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Accepted: 06/21/2017] [Indexed: 05/06/2023]
Abstract
Calcineurin B-like protein interacting protein kinases (CIPKs) are vital elements in plant abiotic stress signaling pathways. However, the functional mechanism of CIPKs has not been understood clearly, especially in Brachypodium distachyon, a new monocot model plant. In this study, BdCIPK31, a CIPK gene from B. distachyon was characterized. BdCIPK31 was downregulated by polyethylene glycol, NaCl, H2O2, and abscisic acid (ABA) treatments. Transgenic tobacco plants overexpressing BdCIPK31 presented improved drought and salt tolerance, and displayed hypersensitive response to exogenous ABA. Further investigations revealed that BdCIPK31 functioned positively in ABA-mediated stomatal closure, and transgenic tobacco exhibited reduced water loss under dehydration conditions compared with the controls. BdCIPK31 also affected Na+/K+ homeostasis and root K+ loss, which contributed to maintain intracellular ion homeostasis under salt conditions. Moreover, the reactive oxygen species scavenging system and osmolyte accumulation were enhanced by BdCIPK31 overexpression, which were conducive for alleviating oxidative and osmotic damages. Additionally, overexpression of BdCIPK31 could elevate several stress-associated gene expressions under stress conditions. In conclusion, BdCIPK31 functions positively to drought and salt stress through ABA signaling pathway. Overexpressing BdCIPK31 functions in stomatal closure, ion homeostasis, ROS scavenging, osmolyte biosynthesis, and transcriptional regulation of stress-related genes.
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Affiliation(s)
- Qingchen Luo
- The Genetic Engineering International Cooperation Base of Chinese Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Chinese Ministry of Education, College of Life Science and Technology, Huazhong University of Science and TechnologyWuhan, China
| | - Qiuhui Wei
- The Genetic Engineering International Cooperation Base of Chinese Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Chinese Ministry of Education, College of Life Science and Technology, Huazhong University of Science and TechnologyWuhan, China
| | - Ruibin Wang
- The Genetic Engineering International Cooperation Base of Chinese Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Chinese Ministry of Education, College of Life Science and Technology, Huazhong University of Science and TechnologyWuhan, China
| | - Yang Zhang
- The Genetic Engineering International Cooperation Base of Chinese Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Chinese Ministry of Education, College of Life Science and Technology, Huazhong University of Science and TechnologyWuhan, China
| | - Fan Zhang
- The Genetic Engineering International Cooperation Base of Chinese Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Chinese Ministry of Education, College of Life Science and Technology, Huazhong University of Science and TechnologyWuhan, China
| | - Yuan He
- The Genetic Engineering International Cooperation Base of Chinese Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Chinese Ministry of Education, College of Life Science and Technology, Huazhong University of Science and TechnologyWuhan, China
| | - Shiyi Zhou
- Hubei University of EducationWuhan, China
| | - Jialu Feng
- The Genetic Engineering International Cooperation Base of Chinese Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Chinese Ministry of Education, College of Life Science and Technology, Huazhong University of Science and TechnologyWuhan, China
| | - Guangxiao Yang
- The Genetic Engineering International Cooperation Base of Chinese Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Chinese Ministry of Education, College of Life Science and Technology, Huazhong University of Science and TechnologyWuhan, China
| | - Guangyuan He
- The Genetic Engineering International Cooperation Base of Chinese Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Chinese Ministry of Education, College of Life Science and Technology, Huazhong University of Science and TechnologyWuhan, China
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A rational approach for the improvement of biomass production and lipid profile in cacao cell suspensions. Bioprocess Biosyst Eng 2017. [PMID: 28646332 DOI: 10.1007/s00449-017-1805-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Cocoa butter (CB) is produced in the seeds of Theobroma cacao representing 50% of its dry weight. The lipid composition plays an important role in the physicochemical, rheological, and sensory properties of the CB, making this fat a valuable resource for the production of chocolates, cosmetics, and pharmaceuticals. In this paper, are described experimental strategies used for a rational improvement of biomass production and fatty acids in cacao cell suspension cultures. First, the lipid profile in four cacao varieties is characterized, and then, one variety is selected to induce cell suspensions using a direct method without previous establishment of a callus phase. To improve growth and total fat production in cell suspension cultures, modified DKW media and newly designed media culture, based on the mineral concentrations of cacao seeds (cacao biomass production, "CBP"), are analyzed and compared. In addition, the effect of acetate in the lipid profile of cell suspensions is evaluated. Ultrastructural histological analysis of lipid vesicles in cacao seeds and cell suspensions is also performed. The results will show that it is feasible to establish cacao suspensions without the calli step and increase the biomass production by selecting a suitable cacao variety and tissue and also applying a new culture media formulation. In addition, it is possible to synthesize fatty acids in cell cultures and modify the lipid profile adding a precursor of the novo biosynthesis of fatty acids such as the acetate. Transmission electronic microscopy examinations and differential interference contrast microscopy analysis will demonstrate that lipid vesicles are the main reserve substance in both cacao seeds and cell suspensions.
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Zhang H, Wei S, Hu W, Xiao L, Tang M. Arbuscular Mycorrhizal Fungus Rhizophagus irregularis Increased Potassium Content and Expression of Genes Encoding Potassium Channels in Lycium barbarum. FRONTIERS IN PLANT SCIENCE 2017; 8:440. [PMID: 28424720 PMCID: PMC5372814 DOI: 10.3389/fpls.2017.00440] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 03/14/2017] [Indexed: 05/29/2023]
Abstract
Potassium in plants accounts for up to 10% dry weight, and participates in different physiological processes. Under drought stress, plant requires more potassium but potassium availability in soil solutes is lowered by decreased soil water content. Forming symbiosis with arbuscular mycorrhizal (AM) fungi not only enlarges exploration range of plant for mineral nutrients and water in soil, but also improves plant drought tolerance. However, the regulation of AM fungi on plant root potassium uptake and translocation from root to shoot was less reported. In current study, the effect of an AM fungus (Rhizophagus irregularis), potassium application (0, 2, and 8 mM), and drought stress (30% field capacity) on Lycium barbarum growth and potassium status was analyzed. Ten weeks after inoculation, R. irregularis colonized more than 58% roots of L. barbarum seedlings, and increased plant growth as well as potassium content. Potassium application increased colonization rate of R. irregularis, plant growth, potassium content, and decreased root/shoot ratio. Drought stress increased colonization rate of R. irregularis and potassium content. Expression of two putative potassium channel genes in root, LbKT1 and LbSKOR, was positively correlated with potassium content in root and leaves, as well as the colonization rate of R. irregularis. The increased L. barbarum growth, potassium content and genes expression, especially under drought stress, suggested that R. irregularis could improve potassium uptake of L. barbarum root and translocation from root to shoot. Whether AM fungi could form a specific mycorrhizal pathway for plant potassium uptake deserves further studies.
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Affiliation(s)
- Haoqiang Zhang
- College of Forestry, Northwest A&F UniversityYangling, China
| | - Suzhen Wei
- College of Forestry, Northwest A&F UniversityYangling, China
- Weihai Ocean Vocational CollegeRongcheng, China
| | - Wentao Hu
- College of Forestry, Northwest A&F UniversityYangling, China
| | - Longmin Xiao
- College of Forestry, Northwest A&F UniversityYangling, China
| | - Ming Tang
- College of Forestry and Landscape Architecture, South China Agricultural UniversityGuangzhou, China
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21
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Abd-El-Haliem AM, Joosten MHAJ. Plant phosphatidylinositol-specific phospholipase C at the center of plant innate immunity. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2017; 59:164-179. [PMID: 28097830 DOI: 10.1111/jipb.12520] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 01/09/2017] [Indexed: 05/20/2023]
Abstract
Understanding plant resistance to pathogenic microbes requires detailed information on the molecular mechanisms controlling the execution of plant innate immune responses. A growing body of evidence places phosphoinositide-specific phospholipase C (PI-PLC) enzymes immediately downstream of activated immune receptors, well upstream of the initiation of early defense responses. An increase of the cytoplasmic levels of free Ca2+ , lowering of the intercellular pH and the oxidative burst are a few examples of such responses and these are regulated by PI-PLCs. Consequently, PI-PLC activation represents an early primary signaling switch between elicitation and response involving the controlled hydrolysis of essential signaling phospholipids, thereby simultaneously generating lipid and non-lipid second messenger molecules required for a swift cellular defense response. Here, we elaborate on the signals generated by PI-PLCs and their respective downstream effects, while providing an inventory of different types of evidence describing the involvement of PI-PLCs in various aspects of plant immunity. We project the discussed information into a model describing the cellular events occurring after the activation of plant immune receptors. With this review we aim to provide new insights supporting future research on plant PI-PLCs and the development of plants with improved resistance.
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Affiliation(s)
- Ahmed M Abd-El-Haliem
- Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Matthieu H A J Joosten
- Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
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Bojórquez-Quintal E, Ruiz-Lau N, Velarde-Buendía A, Echevarría-Machado I, Pottosin I, Martínez-Estévez M. Natural variation in primary root growth and K + retention in roots of habanero pepper (Capsicum chinense) under salt stress. FUNCTIONAL PLANT BIOLOGY : FPB 2016; 43:1114-1125. [PMID: 32480531 DOI: 10.1071/fp15391] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Accepted: 07/24/2016] [Indexed: 06/11/2023]
Abstract
In this work, we analysed the natural variation in mechanisms for protection against salt stress in pepper varieties (Capsicum chinense Jacq. cv. Rex, Chichen-Itza and Naranja and Capsicum annuum L. cv. Padron), considering primary root growth and viability of the post-stressed seedlings. NaCl-induced K+ and H+ efflux in roots was also studied by ion-selective microelectrodes under application of pharmacological agents. In these pepper varieties, the magnitude of the K+ leakage in the roots positively correlated with growth inhibition of the primary root in the presence of NaCl, with Rex variety showing a higher level of tolerance than Chichen-Itza. The K+ leakage and the activity of the H+ pump in the roots were dependent on the NaCl concentration. Pharmacological analysis indicated that the NaCl-induced K+ leakage was mediated by TEA+-sensitive KOR channels but not by NSCC channels. In addition, we present evidence for the possible participation of proline, and a Na+-insensitive HAK K+ transporter expressed in habanero pepper roots for maintaining K+ homeostasis under salt stress conditions.
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Affiliation(s)
- Emanuel Bojórquez-Quintal
- Unidad de Bioquímica y Biología Molecular de Plantas, Centro de Investigación Científica de Yucatán, Yucatán, México
| | - Nancy Ruiz-Lau
- Unidad de Bioquímica y Biología Molecular de Plantas, Centro de Investigación Científica de Yucatán, Yucatán, México
| | - Ana Velarde-Buendía
- Centro Universitario de Investigaciones Biomédicas, Universidad de Colima, Colima, México
| | - Ileana Echevarría-Machado
- Unidad de Bioquímica y Biología Molecular de Plantas, Centro de Investigación Científica de Yucatán, Yucatán, México
| | - Igor Pottosin
- Centro Universitario de Investigaciones Biomédicas, Universidad de Colima, Colima, México
| | - Manuel Martínez-Estévez
- Unidad de Bioquímica y Biología Molecular de Plantas, Centro de Investigación Científica de Yucatán, Yucatán, México
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23
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Silent S-Type Anion Channel Subunit SLAH1 Gates SLAH3 Open for Chloride Root-to-Shoot Translocation. Curr Biol 2016; 26:2213-20. [PMID: 27397895 DOI: 10.1016/j.cub.2016.06.045] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 06/05/2016] [Accepted: 06/21/2016] [Indexed: 01/26/2023]
Abstract
Higher plants take up nutrients via the roots and load them into xylem vessels for translocation to the shoot. After uptake, anions have to be channeled toward the root xylem vessels. Thereby, xylem parenchyma and pericycle cells control the anion composition of the root-shoot xylem sap [1-6]. The fact that salt-tolerant genotypes possess lower xylem-sap Cl(-) contents compared to salt-sensitive genotypes [7-10] indicates that membrane transport proteins at the sites of xylem loading contribute to plant salinity tolerance via selective chloride exclusion. However, the molecular mechanism of xylem loading that lies behind the balance between NO3(-) and Cl(-) loading remains largely unknown. Here we identify two root anion channels in Arabidopsis, SLAH1 and SLAH3, that control the shoot NO3(-)/Cl(-) ratio. The AtSLAH1 gene is expressed in the root xylem-pole pericycle, where it co-localizes with AtSLAH3. Under high soil salinity, AtSLAH1 expression markedly declined and the chloride content of the xylem sap in AtSLAH1 loss-of-function mutants was half of the wild-type level only. SLAH3 anion channels are not active per se but require extracellular nitrate and phosphorylation by calcium-dependent kinases (CPKs) [11-13]. When co-expressed in Xenopus oocytes, however, the electrically silent SLAH1 subunit gates SLAH3 open even in the absence of nitrate- and calcium-dependent kinases. Apparently, SLAH1/SLAH3 heteromerization facilitates SLAH3-mediated chloride efflux from pericycle cells into the root xylem vessels. Our results indicate that under salt stress, plants adjust the distribution of NO3(-) and Cl(-) between root and shoot via differential expression and assembly of SLAH1/SLAH3 anion channel subunits.
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Chen G, Hu Q, Luo L, Yang T, Zhang S, Hu Y, Yu L, Xu G. Rice potassium transporter OsHAK1 is essential for maintaining potassium-mediated growth and functions in salt tolerance over low and high potassium concentration ranges. PLANT, CELL & ENVIRONMENT 2015; 38:2747-65. [PMID: 26046301 DOI: 10.1111/pce.12585] [Citation(s) in RCA: 144] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Revised: 05/16/2015] [Accepted: 06/01/2015] [Indexed: 05/17/2023]
Abstract
Potassium (K) absorption and translocation in plants rely upon multiple K transporters for adapting varied K supply and saline conditions. Here, we report the expression patterns and physiological roles of OsHAK1, a member belonging to the KT/KUP/HAK gene family in rice (Oryza sativa L.). The expression of OsHAK1 is up-regulated by K deficiency or salt stress in various tissues, particularly in the root and shoot apical meristem, the epidermises and steles of root, and vascular bundles of shoot. Both oshak1 knockout mutants in comparison to their respective Dongjin or Manan wild types showed a dramatic reduction in K concentration and stunted root and shoot growth. Knockout of OsHAK1 reduced the K absorption rate of unit root surface area by ∼50-55 and ∼30%, and total K uptake by ∼80 and ∼65% at 0.05-0.1 and 1 mm K supply level, respectively. The root net high-affinity K uptake of oshak1 mutants was sensitive to salt stress but not to ammonium supply. Overexpression of OsHAK1 in rice increased K uptake and K/Na ratio. The positive relationship between K concentration and shoot biomass in the mutants suggests that OsHAK1 plays an essential role in K-mediated rice growth and salt tolerance over low and high K concentration ranges.
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Affiliation(s)
- Guang Chen
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Qingdi Hu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Le Luo
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Tianyuan Yang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Song Zhang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yibing Hu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Ling Yu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Guohua Xu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
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25
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Chen G, Feng H, Hu Q, Qu H, Chen A, Yu L, Xu G. Improving rice tolerance to potassium deficiency by enhancing OsHAK16p:WOX11-controlled root development. PLANT BIOTECHNOLOGY JOURNAL 2015; 13:833-48. [PMID: 25599895 DOI: 10.1111/pbi.12320] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 11/25/2014] [Accepted: 12/01/2014] [Indexed: 05/02/2023]
Abstract
Potassium (K) deficiency in plants confines root growth and decreases root-to-shoot ratio, thus limiting root K acquisition in culture medium. A WUSCHEL-related homeobox (WOX) gene, WOX11, has been reported as an integrator of auxin and cytokinin signalling that regulates root cell proliferation. Here, we report that ectopic expression of WOX11 gene driven by the promoter of OsHAK16 encoding a low-K-enhanced K transporter led to an extensive root system and adventitious roots and more effective tiller numbers in rice. The WOX11-regulated root and shoot phenotypes in the OsHAK16p:WOX11 transgenic lines were supported by K-deficiency-enhanced expression of several RR genes encoding type-A cytokinin-responsive regulators, PIN genes encoding auxin transporters and Aux/IAA genes. In comparison with WT, the transgenic lines showed increases in root biomass, root activity and K concentrations in the whole plants, and higher soluble sugar concentrations in roots particularly under low K supply condition. The improvement of sugar partitioning to the roots by the expression of OsHAK16p:WOX11 was further indicated by increasing the expression of OsSUT1 and OsSUT4 genes in leaf blades and several OsMSTs genes in roots. Expression of OsHAK16p:WOX11 in the rice grown in moderate K-deficient soil increased total K uptake by 72% and grain yield by 24%-32%. The results suggest that enlarging root growth and development by the expression of WOX11 in roots could provide a useful option for increasing K acquisition efficiency and cereal crop productivity in low K soil.
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Affiliation(s)
- Guang Chen
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing, China
| | - Huimin Feng
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing, China
| | - Qingdi Hu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing, China
| | - Hongye Qu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing, China
| | - Aiqun Chen
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing, China
| | - Ling Yu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing, China
| | - Guohua Xu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing, China
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26
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Planes MD, Niñoles R, Rubio L, Bissoli G, Bueso E, García-Sánchez MJ, Alejandro S, Gonzalez-Guzmán M, Hedrich R, Rodriguez PL, Fernández JA, Serrano R. A mechanism of growth inhibition by abscisic acid in germinating seeds of Arabidopsis thaliana based on inhibition of plasma membrane H+-ATPase and decreased cytosolic pH, K+, and anions. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:813-25. [PMID: 25371509 PMCID: PMC4321545 DOI: 10.1093/jxb/eru442] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The stress hormone abscisic acid (ABA) induces expression of defence genes in many organs, modulates ion homeostasis and metabolism in guard cells, and inhibits germination and seedling growth. Concerning the latter effect, several mutants of Arabidopsis thaliana with improved capability for H(+) efflux (wat1-1D, overexpression of AKT1 and ost2-1D) are less sensitive to inhibition by ABA than the wild type. This suggested that ABA could inhibit H(+) efflux (H(+)-ATPase) and induce cytosolic acidification as a mechanism of growth inhibition. Measurements to test this hypothesis could not be done in germinating seeds and we used roots as the most convenient system. ABA inhibited the root plasma-membrane H(+)-ATPase measured in vitro (ATP hydrolysis by isolated vesicles) and in vivo (H(+) efflux from seedling roots). This inhibition involved the core ABA signalling elements: PYR/PYL/RCAR ABA receptors, ABA-inhibited protein phosphatases (HAB1), and ABA-activated protein kinases (SnRK2.2 and SnRK2.3). Electrophysiological measurements in root epidermal cells indicated that ABA, acting through the PYR/PYL/RCAR receptors, induced membrane hyperpolarization (due to K(+) efflux through the GORK channel) and cytosolic acidification. This acidification was not observed in the wat1-1D mutant. The mechanism of inhibition of the H(+)-ATPase by ABA and its effects on cytosolic pH and membrane potential in roots were different from those in guard cells. ABA did not affect the in vivo phosphorylation level of the known activating site (penultimate threonine) of H(+)-ATPase in roots, and SnRK2.2 phosphorylated in vitro the C-terminal regulatory domain of H(+)-ATPase while the guard-cell kinase SnRK2.6/OST1 did not.
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Affiliation(s)
- María D Planes
- Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, Camino de Vera, 46022 Valencia, Spain
| | - Regina Niñoles
- Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, Camino de Vera, 46022 Valencia, Spain
| | - Lourdes Rubio
- Departamento de Biología Vegetal, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos, 29071 Málaga, Spain
| | - Gaetano Bissoli
- Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, Camino de Vera, 46022 Valencia, Spain
| | - Eduardo Bueso
- Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, Camino de Vera, 46022 Valencia, Spain
| | - María J García-Sánchez
- Departamento de Biología Vegetal, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos, 29071 Málaga, Spain
| | - Santiago Alejandro
- Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, Camino de Vera, 46022 Valencia, Spain
| | - Miguel Gonzalez-Guzmán
- Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, Camino de Vera, 46022 Valencia, Spain
| | - Rainer Hedrich
- Institute for Plant Physiology and Biophysics, University Würzburg, Julis-von-Sachs Platz 2, D-97082, Würzburg, Germany
| | - Pedro L Rodriguez
- Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, Camino de Vera, 46022 Valencia, Spain
| | - José A Fernández
- Departamento de Biología Vegetal, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos, 29071 Málaga, Spain
| | - Ramón Serrano
- Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, Camino de Vera, 46022 Valencia, Spain
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Specificity of Ion Uptake and Homeostasis Maintenance During Acid and Aluminium Stresses. ALUMINUM STRESS ADAPTATION IN PLANTS 2015. [DOI: 10.1007/978-3-319-19968-9_12] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Véry AA, Nieves-Cordones M, Daly M, Khan I, Fizames C, Sentenac H. Molecular biology of K+ transport across the plant cell membrane: what do we learn from comparison between plant species? JOURNAL OF PLANT PHYSIOLOGY 2014; 171:748-69. [PMID: 24666983 DOI: 10.1016/j.jplph.2014.01.011] [Citation(s) in RCA: 167] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Accepted: 01/30/2014] [Indexed: 05/20/2023]
Abstract
Cloning and characterizations of plant K(+) transport systems aside from Arabidopsis have been increasing over the past decade, favored by the availability of more and more plant genome sequences. Information now available enables the comparison of some of these systems between species. In this review, we focus on three families of plant K(+) transport systems that are active at the plasma membrane: the Shaker K(+) channel family, comprised of voltage-gated channels that dominate the plasma membrane conductance to K(+) in most environmental conditions, and two families of transporters, the HAK/KUP/KT K(+) transporter family, which includes some high-affinity transporters, and the HKT K(+) and/or Na(+) transporter family, in which K(+)-permeable members seem to be present in monocots only. The three families are briefly described, giving insights into the structure of their members and on functional properties and their roles in Arabidopsis or rice. The structure of the three families is then compared between plant species through phylogenic analyses. Within clusters of ortologues/paralogues, similarities and differences in terms of expression pattern, functional properties and, when known, regulatory interacting partners, are highlighted. The question of the physiological significance of highlighted differences is also addressed.
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Affiliation(s)
- Anne-Aliénor Véry
- Biochimie & Physiologie Moléculaire des Plantes, UMR 5004 CNRS/386 INRA/SupAgro Montpellier/Université Montpellier 2, Campus SupAgro-INRA, 34060 Montpellier Cedex 2, France.
| | - Manuel Nieves-Cordones
- Biochimie & Physiologie Moléculaire des Plantes, UMR 5004 CNRS/386 INRA/SupAgro Montpellier/Université Montpellier 2, Campus SupAgro-INRA, 34060 Montpellier Cedex 2, France
| | - Meriem Daly
- Biochimie & Physiologie Moléculaire des Plantes, UMR 5004 CNRS/386 INRA/SupAgro Montpellier/Université Montpellier 2, Campus SupAgro-INRA, 34060 Montpellier Cedex 2, France; Laboratoire d'Ecologie et d'Environnement, Faculté des Sciences Ben M'sik, Université Hassan II-Mohammedia, Avenue Cdt Driss El Harti, BP 7955, Sidi Othmane, Casablanca, Morocco
| | - Imran Khan
- Biochimie & Physiologie Moléculaire des Plantes, UMR 5004 CNRS/386 INRA/SupAgro Montpellier/Université Montpellier 2, Campus SupAgro-INRA, 34060 Montpellier Cedex 2, France; Department of Agronomy, University of Agriculture, Faisalabad, Pakistan
| | - Cécile Fizames
- Biochimie & Physiologie Moléculaire des Plantes, UMR 5004 CNRS/386 INRA/SupAgro Montpellier/Université Montpellier 2, Campus SupAgro-INRA, 34060 Montpellier Cedex 2, France
| | - Hervé Sentenac
- Biochimie & Physiologie Moléculaire des Plantes, UMR 5004 CNRS/386 INRA/SupAgro Montpellier/Université Montpellier 2, Campus SupAgro-INRA, 34060 Montpellier Cedex 2, France
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29
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Anschütz U, Becker D, Shabala S. Going beyond nutrition: regulation of potassium homoeostasis as a common denominator of plant adaptive responses to environment. JOURNAL OF PLANT PHYSIOLOGY 2014; 171:670-87. [PMID: 24635902 DOI: 10.1016/j.jplph.2014.01.009] [Citation(s) in RCA: 230] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 01/14/2014] [Accepted: 01/17/2014] [Indexed: 05/18/2023]
Abstract
Partially and fully completed plant genome sequencing projects in both lower and higher plants allow drawing a comprehensive picture of the molecular and structural diversities of plant potassium transporter genes and their encoded proteins. While the early focus of the research in this field was aimed on the structure-function studies and understanding of the molecular mechanisms underlying K(+) transport, availability of Arabidopsis thaliana mutant collections in combination with micro-array techniques have significantly advanced our understanding of K(+) channel physiology, providing novel insights into the transcriptional regulation of potassium homeostasis in plants. More recently, posttranslational regulation of potassium transport systems has moved into the center stage of potassium transport research. The current review is focused on the most exciting developments in this field. By summarizing recent work on potassium transporter regulation we show that potassium transport in general, and potassium channels in particular, represent important targets and are mediators of the cellular responses during different developmental stages in a plant's life cycle. We show that regulation of intracellular K(+) homeostasis is essential to mediate plant adaptive responses to a broad range of abiotic and biotic stresses including drought, salinity, and oxidative stress. We further link post-translational regulation of K(+) channels with programmed cell death and show that K(+) plays a critical role in controlling the latter process. Thus, is appears that K(+) is not just the essential nutrient required to support optimal plant growth and yield but is also an important signaling agent mediating a wide range of plant adaptive responses to environment.
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Affiliation(s)
- Uta Anschütz
- University of Wuerzburg, Plant Molecular Biology & Biophysics, Wuerzburg, Germany
| | - Dirk Becker
- University of Wuerzburg, Plant Molecular Biology & Biophysics, Wuerzburg, Germany.
| | - Sergey Shabala
- School of Agricultural Science, University of Tasmania, Hobart, Australia
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30
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Xu J, Tian X, Egrinya Eneji A, Li Z. Functional characterization of GhAKT1, a novel Shaker-like K⁺ channel gene involved in K⁺ uptake from cotton (Gossypium hirsutum). Gene 2014; 545:61-71. [PMID: 24802116 DOI: 10.1016/j.gene.2014.05.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Revised: 04/16/2014] [Accepted: 05/02/2014] [Indexed: 10/25/2022]
Abstract
Shaker-like potassium (K(+)) channels in plants play an important role in K(+) absorption and transport. In this study, we characterized a Shaker-like K(+) channel gene GhAKT1 from the roots of Gossypium hirsutum cv. Liaomian17. Phylogenetic analysis showed that the GhAKT1 belongs to the AKT1-subfamily in the Shaker-like K(+) channel family. Confocal imaging of a GhAKT1-green fluorescent fusion protein (GFP) in transgenic Arabidopsis plants indicated that GhAKT1 is localized in the plasma membrane. Transcript analysis located GhAKT1 predominantly in cotton leaves with low abundance in roots, stem and shoot apex. Similarly, β-glucuronidase (GUS) activity was detected in both leaves and roots of PGhAKT1::GUS transgenic Arabidopsis plants. In roots, the GUS signals appeared in the epidermis, cortex and endodermis and root hairs, suggesting the contribution of GhAKT1 to K(+) uptake. In leaves, GhAKT1 was expressed in differentiated leaf primordial as well as mesophyll cells and veins of expanded leaves, pointing to its involvement in cell elongation and K(+) transport and distribution in leaves. Severe K(+) deficiency did not affect the expression of GhAKT1 gene. GhAKT1-overexpression in either the Arabidopsis wild-type or akt1 mutant enhanced the growth of transgenic seedlings under low K(+) deficiency and raised the net K(+) influx in roots at 100μM external K(+) concentration, within the range of operation of the high-affinity K(+) uptake system. The application of 2mM BaCl2 resulted in net K(+) efflux in roots, and eliminated the differences between GhAKT1-overexpression lines and their acceptors indicating that the K(+) uptake mediated by GhAKT1 is also as Ba(2+)-sensitive as AtAKT1.
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Affiliation(s)
- Juan Xu
- State Key Laboratory of Plant Physiology and Biochemistry, Department of Agronomy, China Agricultural University, Beijing 100193, China
| | - Xiaoli Tian
- State Key Laboratory of Plant Physiology and Biochemistry, Department of Agronomy, China Agricultural University, Beijing 100193, China.
| | - A Egrinya Eneji
- Department of Soil Science, Faculty of Agriculture, Forestry and Wildlife Resources Management, University of Calabar, Nigeria
| | - Zhaohu Li
- State Key Laboratory of Plant Physiology and Biochemistry, Department of Agronomy, China Agricultural University, Beijing 100193, China
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Urrego D, Tomczak AP, Zahed F, Stühmer W, Pardo LA. Potassium channels in cell cycle and cell proliferation. Philos Trans R Soc Lond B Biol Sci 2014; 369:20130094. [PMID: 24493742 PMCID: PMC3917348 DOI: 10.1098/rstb.2013.0094] [Citation(s) in RCA: 269] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Normal cell-cycle progression is a crucial task for every multicellular organism, as it determines body size and shape, tissue renewal and senescence, and is also crucial for reproduction. On the other hand, dysregulation of the cell-cycle progression leading to uncontrolled cell proliferation is the hallmark of cancer. Therefore, it is not surprising that it is a tightly regulated process, with multifaceted and very complex control mechanisms. It is now well established that one of those mechanisms relies on ion channels, and in many cases specifically on potassium channels. Here, we summarize the possible mechanisms underlying the importance of potassium channels in cell-cycle control and briefly review some of the identified channels that illustrate the multiple ways in which this group of proteins can influence cell proliferation and modulate cell-cycle progression.
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Affiliation(s)
- Diana Urrego
- Oncophysiology Group, Max Planck Institute of Experimental Medicine, , Hermann-Rein-Strasse 3, Göttingen 37075, Germany
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Juraniec M, Lequeux H, Hermans C, Willems G, Nordborg M, Schneeberger K, Salis P, Vromant M, Lutts S, Verbruggen N. Towards the discovery of novel genetic component involved in stress resistance in Arabidopsis thaliana. THE NEW PHYTOLOGIST 2014; 201:810-824. [PMID: 24134393 DOI: 10.1111/nph.12554] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 09/16/2013] [Indexed: 05/23/2023]
Abstract
The exposure of plants to high concentrations of trace metallic elements such as copper involves a remodeling of the root system, characterized by a primary root growth inhibition and an increase in the lateral root density. These characteristics constitute easy and suitable markers for screening mutants altered in their response to copper excess. A forward genetic approach was undertaken in order to discover novel genetic factors involved in the response to copper excess. A Cu(2+) -sensitive mutant named copper modified resistance1 (cmr1) was isolated and a causative mutation in the CMR1 gene was identified by using positional cloning and next-generation sequencing. CMR1 encodes a plant-specific protein of unknown function. The analysis of the cmr1 mutant indicates that the CMR1 protein is required for optimal growth under normal conditions and has an essential role in the stress response. Impairment of the CMR1 activity alters root growth through aberrant activity of the root meristem, and modifies potassium concentration and hormonal balance (ethylene production and auxin accumulation). Our data support a putative role for CMR1 in cell division regulation and meristem maintenance. Research on the role of CMR1 will contribute to the understanding of the plasticity of plants in response to changing environments.
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Affiliation(s)
- Michal Juraniec
- Laboratory of Plant Physiology and Molecular Genetics, Université Libre de Bruxelles, 1050, Brussels, Belgium
| | - Hélène Lequeux
- Laboratory of Plant Physiology and Molecular Genetics, Université Libre de Bruxelles, 1050, Brussels, Belgium
- Groupe de Recherche en Physiologie Végétale, Earth and Life Institute, Université catholique de Louvain, 5 bte13, Croix du Sud, 1348, Louvain-La-Neuve, Belgium
| | - Christian Hermans
- Laboratory of Plant Physiology and Molecular Genetics, Université Libre de Bruxelles, 1050, Brussels, Belgium
| | - Glenda Willems
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Dr. Bohr-Gasse 3, 1030, Vienna, Austria
- Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829, Cologne, Germany
| | - Magnus Nordborg
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Dr. Bohr-Gasse 3, 1030, Vienna, Austria
| | - Korbinian Schneeberger
- Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829, Cologne, Germany
| | - Pietrino Salis
- Laboratory of Plant Physiology and Molecular Genetics, Université Libre de Bruxelles, 1050, Brussels, Belgium
| | - Maud Vromant
- Laboratory of Plant Physiology and Molecular Genetics, Université Libre de Bruxelles, 1050, Brussels, Belgium
| | - Stanley Lutts
- Groupe de Recherche en Physiologie Végétale, Earth and Life Institute, Université catholique de Louvain, 5 bte13, Croix du Sud, 1348, Louvain-La-Neuve, Belgium
| | - Nathalie Verbruggen
- Laboratory of Plant Physiology and Molecular Genetics, Université Libre de Bruxelles, 1050, Brussels, Belgium
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Dadacz-Narloch B, Kimura S, Kurusu T, Farmer EE, Becker D, Kuchitsu K, Hedrich R. On the cellular site of two-pore channel TPC1 action in the Poaceae. THE NEW PHYTOLOGIST 2013; 200:663-674. [PMID: 23845012 DOI: 10.1111/nph.12402] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 06/02/2013] [Indexed: 06/02/2023]
Abstract
The slow vacuolar (SV) channel has been characterized in different dicots by patch-clamp recordings. This channel represents the major cation conductance of the largest organelle in most plant cells. Studies with the tpc1-2 mutant of the model dicot plant Arabidopsis thaliana identified the SV channel as the product of the TPC1 gene. By contrast, research on rice and wheat TPC1 suggested that the monocot gene encodes a plasma membrane calcium-permeable channel. To explore the site of action of grass TPC1 channels, we expressed OsTPC1 from rice (Oryza sativa) and TaTPC1 from wheat (Triticum aestivum) in the background of the Arabidopsis tpc1-2 mutant. Cross-species tpc1 complementation and patch-clamping of vacuoles using Arabidopsis and rice tpc1 null mutants documented that both monocot TPC1 genes were capable of rescuing the SV channel deficit. Vacuoles from wild-type rice but not the tpc1 loss-of-function mutant harbor SV channels exhibiting the hallmark properties of dicot TPC1/SV channels. When expressed in human embryonic kidney (HEK293) cells OsTPC1 was targeted to Lysotracker-Red-positive organelles. The finding that the rice TPC1, just like those from the model plant Arabidopsis and even animal cells, is localized and active in lyso-vacuolar membranes associates this cation channel species with endomembrane function.
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Affiliation(s)
- Beata Dadacz-Narloch
- Institute for Molecular Plant Physiology and Biophysics, University of Wuerzburg, D-97082, Wuerzburg, Germany
| | - Sachie Kimura
- Department of Applied Biological Science, Tokyo University of Science, 2641 Yamazaki, Noda, 278-8510, Japan
| | - Takamitsu Kurusu
- Department of Applied Biological Science, Tokyo University of Science, 2641 Yamazaki, Noda, 278-8510, Japan
- School of Bioscience and Biotechnology, Tokyo University of Technology, Hachioji, Tokyo, 192-0982, Japan
| | - Edward E Farmer
- Department of Plant Molecular Biology, University of Lausanne, Biophore, 1015, Lausanne, Switzerland
| | - Dirk Becker
- Institute for Molecular Plant Physiology and Biophysics, University of Wuerzburg, D-97082, Wuerzburg, Germany
| | - Kazuyuki Kuchitsu
- Department of Applied Biological Science, Tokyo University of Science, 2641 Yamazaki, Noda, 278-8510, Japan
| | - Rainer Hedrich
- Institute for Molecular Plant Physiology and Biophysics, University of Wuerzburg, D-97082, Wuerzburg, Germany
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34
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Wegner LH. Cation selectivity of the plasma membrane of tobacco protoplasts in the electroporated state. BIOCHIMICA ET BIOPHYSICA ACTA 2013; 1828:1973-81. [PMID: 23603222 DOI: 10.1016/j.bbamem.2013.04.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Revised: 04/08/2013] [Accepted: 04/09/2013] [Indexed: 11/21/2022]
Abstract
Cation selectivity of the cellular membrane of tobacco culture cells (cell line 'bright yellow-2') exposed to pulsed electric fields in the millisecond range was investigated. The whole cell configuration of the patch clamp technique was established on protoplasts prepared from these cells. Ion selectivity of the electroporated membrane was investigated by measuring the reversal potential of currents passing through field-induced pores. To this end the membrane was hyper- or depolarized for 10ms (prepulse); subsequently the voltage was driven to opposite polarity at a constant rate (+40 or -40mV/ms, respectively). The experiment was started by polarizing the membrane to moderately negative or positive voltages (prepulse potential ±150mV) that would not induce pore formation. Subsequently, an extended voltage range was scanned in the porated state of the membrane (prepulse potential ±600mV). IV curves in the porated and the non-porated state (obtained at the same prepulse polarity) were superimposed to determine the voltage at which both curves intersected ('Intersection potential'). Using a modified version of the Goldmann-Hodgkin-Katz equation relative permeabilities to Ca(2+) and various monovalent alkali and organic cations were calculated. Pores were found to be fairly cation selective, with a selectivity sequence determined to be Ca(2+)>Li(+)>Rb(+)≈K(+)≈Na(+)>TEA(+)≈TBA(+)>Cl(-). Relative permeability to monovalent cations was inversely related to the ionic diameter. By fitting a formalism suggested by Dwyer at al. (J. Gen. Physiol. 75 (1980), 469-492) the effective average diameter of field induced pores was estimated to be about 1.8nm. Implications of these results for biotechnology and electroporation theory are discussed.
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Affiliation(s)
- Lars H Wegner
- Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany.
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35
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Asada T. Division of shape-standardized tobacco cells reveals a limit to the occurrence of single-criterion-based selection of the plane of symmetric division. PLANT & CELL PHYSIOLOGY 2013; 54:827-37. [PMID: 23531846 DOI: 10.1093/pcp/pct044] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
The plane of symmetric plant cell division tends to be selected so that the new cross-wall halving the cell volume has the least possible area, and several cases of such selection are best represented by a recently formulated model which promotes the view that the strength of the least area tendency is the only criterion for selecting the plane. To test this model, the present study examined the divisions of two types of shape-standardized tobacco BY-2 cell, oblate-spheroidal (os) cells prepared from protoplasts and spheri-cylindrical (sc) cells with unusual double-wall structures prepared from plasmolyzed cells. Measurements of cell shape parameters and division angles revealed that both cell types most frequently divide nearly along their short axes. While os cells did not exhibit any other division angle bias, sc cell division was characterized by another bias which made the frequency of longitudinal divisions secondarily high. The geometry of sc cells barely allows the longitudinal cross-walls to have locally minimum areas. Nevertheless, a comparison of detected and hypothetical standard divisions indicates that the frequency of longitudinal sc cell division can be significantly higher than that predicted when the longitudinal cross-walls are assumed to have locally minimum areas smaller than their original areas. These results suggest that, even in isolated plant cell types, the strength of the least area tendency is not the only criterion for selecting the division plane. The possibility that there is another basic, though often hidden, criterion is discussed.
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Affiliation(s)
- Tetsuhiro Asada
- Department of Biological Science, Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043 Japan.
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36
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Moriconi JI, Buet A, Simontacchi M, Santa-María GE. Near-isogenic wheat lines carrying altered function alleles of the Rht-1 genes exhibit differential responses to potassium deprivation. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2012; 185-186:199-207. [PMID: 22325882 DOI: 10.1016/j.plantsci.2011.10.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Revised: 10/12/2011] [Accepted: 10/13/2011] [Indexed: 05/05/2023]
Abstract
Most of the elements involved in the integration of signals of low external K(+)-supply into a physiological response pathway remain essentially unknown. The aim of this work was to study the influence exerted by DELLA proteins, which are known to be key components for the control of growth, on plant responses during K(+) deprivation in wheat (Triticum aestivum) by using two sets of near-isogenic lines (NILs) in the Maringa and April Bearded cultivars. After K(+) shortage, the NILs of both cultivars containing the Rht-B1b,Rht-D1b alleles, which encode altered function DELLA proteins, displayed either a slight or no decrease in chlorophyll content, in contrast to the sharp decrease observed in the NILs having the wild type alleles (Rht-B1a,Rht-D1a). That difference was accompanied by a lower relative decrease of biomass accumulation only in the Maringa cultivar. In both cultivars, high chlorophyll retention was coupled with K(+) starvation-induced differences in superoxide dismutase and ascorbate peroxidase activities, which were enhanced in K(+)-starved Rht-B1b,Rht-D1b NILs. In addition, Rht-B1b,Rht-D1b and Rht-B1a,Rht-D1a NILs markedly differed in the accumulation of the major cations Ca(2+), Na(+) and K(+). These results suggest a major role of the Rht-1 genes in the control of physiological responses during K(+) deprivation.
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Affiliation(s)
- Jorge I Moriconi
- Instituto Tecnológico Chascomús, Consejo Nacional de Investigaciones Científicas y Técnicas, Camino Circunvalación Laguna Km 8.5, Chascomús, Buenos Aires 7130, Argentina
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37
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Undurraga SF, Santos MP, Paez-Valencia J, Yang H, Hepler PK, Facanha AR, Hirschi KD, Gaxiola RA. Arabidopsis sodium dependent and independent phenotypes triggered by H⁺-PPase up-regulation are SOS1 dependent. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2012; 183:96-105. [PMID: 22195582 DOI: 10.1016/j.plantsci.2011.11.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Revised: 11/11/2011] [Accepted: 11/15/2011] [Indexed: 05/31/2023]
Abstract
Coordinate regulation of transporters at both the plasma membrane and vacuole contribute to plant cell's ability to adapt to a changing environment and play a key role in the maintenance of the chemiosmotic circuits required for cellular growth. The plasma membrane (PM) Na⁺/H⁺ antiporter (SOS1) is involved in salt tolerance, presumably in sodium extrusion; the vacuolar type I H⁺-PPase AVP1 is involved in vacuolar sodium sequestration, but its overexpression has also been shown to alter the abundance and activity of the PM H⁺-ATPase. Here we investigate the relationship between these transporters utilizing loss-of-function mutants of SOS1 (sos1) and increased expression of AVP1 (AVP1OX). Heightened expression of AVP1 enhances pyrophosphate-dependent proton pump activity, salt tolerance, ion vacuolar sequestration, K⁺ uptake capacity, root hair development, osmotic responses, and PM ATPase hydrolytic and proton pumping activities. In sos1 lines overexpressing AVP1, these phenotypes are negatively affected demonstrating that sos1 is epistatic to AVP1. Enhanced AVP1 protein levels require SOS1 and this regulation appears to be post-translational.
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Affiliation(s)
- Soledad F Undurraga
- Department of Genome Sciences, University of Washington, S410 Foege Building South, 1705 NE Pacific Street, Seattle, WA 98195, USA
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38
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Wegner LH, Flickinger B, Eing C, Berghöfer T, Hohenberger P, Frey W, Nick P. A patch clamp study on the electro-permeabilization of higher plant cells: Supra-physiological voltages induce a high-conductance, K+ selective state of the plasma membrane. BIOCHIMICA ET BIOPHYSICA ACTA 2011; 1808:1728-36. [PMID: 21296050 DOI: 10.1016/j.bbamem.2011.01.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2010] [Revised: 01/26/2011] [Accepted: 01/28/2011] [Indexed: 11/30/2022]
Abstract
Permeabilization of biological membranes by pulsed electric fields ("electroporation") is frequently used as a tool in biotechnology. However, the electrical properties of cellular membranes at supra-physiological voltages are still a topic of intensive research efforts. Here, the patch clamp technique in the whole cell and the outside out configuration was employed to monitor current-voltage relations of protoplasts derived from the tobacco culture cell line "Bright yellow-2". Cells were exposed to a sequence of voltage pulses including supra-physiological voltages. A transition from a low-conductance (~0.1 nS/pF) to a high-conductance state (~5 nS/pF) was observed when the membrane was either hyperpolarized or depolarized beyond threshold values of around -250 to -300 mV and +200 to +250 mV, respectively. Current-voltage curves obtained with ramp protocols revealed that the electro-permeabilized membrane was 5-10 times more permeable to K+ than to gluconate. The K+ channel blocker tetraethylammonium (25 mM) did not affect currents elicited by 10 ms-pulses, suggesting that the electro-permeabilization was not caused by a non-physiological activation of K+ channels. Supra-physiological voltage pulses even reduced "regular" K+ channel activity, probably due to an increase of cytosolic Ca2+ that is known to inhibit outward-rectifying K+ channels in Bright yellow-2 cells. Our data are consistent with a reversible formation of aqueous membrane pores at supra-physiological voltages.
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Affiliation(s)
- Lars H Wegner
- Karlsruhe Institute of Technology, Institute for Pulsed Power and Microwave Technology (IHM), Campus North, 76344 Eggenstein-Leopoldshafen, Germany; Karlsruhe Institute of Technology, Botanical Institute I-Molecular Cell Biology, Campus South, 76131 Karlsruhe, Germany.
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Potassium (K+) gradients serve as a mobile energy source in plant vascular tissues. Proc Natl Acad Sci U S A 2010; 108:864-9. [PMID: 21187374 DOI: 10.1073/pnas.1009777108] [Citation(s) in RCA: 136] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The essential mineral nutrient potassium (K(+)) is the most important inorganic cation for plants and is recognized as a limiting factor for crop yield and quality. Nonetheless, it is only partially understood how K(+) contributes to plant productivity. K(+) is used as a major active solute to maintain turgor and to drive irreversible and reversible changes in cell volume. K(+) also plays an important role in numerous metabolic processes, for example, by serving as an essential cofactor of enzymes. Here, we provide evidence for an additional, previously unrecognized role of K(+) in plant growth. By combining diverse experimental approaches with computational cell simulation, we show that K(+) circulating in the phloem serves as a decentralized energy storage that can be used to overcome local energy limitations. Posttranslational modification of the phloem-expressed Arabidopsis K(+) channel AKT2 taps this "potassium battery," which then efficiently assists the plasma membrane H(+)-ATPase in energizing the transmembrane phloem (re)loading processes.
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40
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Prinzenberg AE, Barbier H, Salt DE, Stich B, Reymond M. Relationships between growth, growth response to nutrient supply, and ion content using a recombinant inbred line population in Arabidopsis. PLANT PHYSIOLOGY 2010; 154:1361-71. [PMID: 20826703 PMCID: PMC2971612 DOI: 10.1104/pp.110.161398] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2010] [Accepted: 09/05/2010] [Indexed: 05/18/2023]
Abstract
Growth is an integrative trait that responds to environmental factors and is crucial for plant fitness. A major environmental factor influencing plant growth is nutrient supply. In order to explore this relationship further, we quantified growth-related traits, ion content, and other biochemical traits (protein, hexose, and chlorophyll contents) of a recombinant inbred line population of Arabidopsis (Arabidopsis thaliana) grown on different levels of potassium and phosphate. Performing an all subsets multiple regression analyses revealed a link between growth-related traits and mineral nutrient content. Based on our results, up to 85% of growth variation can be explained by variation in ion content, highlighting the importance of ionomics for a broader understanding of plant growth. In addition, quantitative trait loci (QTLs) were detected for growth-related traits, ion content, further biochemical traits, and their responses to reduced supplies of potassium or phosphate. Colocalization of these QTLs is explored, and candidate genes are discussed. A QTL for rosette weight response to reduced potassium supply was identified on the bottom of chromosome 5, and its effects were validated using selected near isogenic lines. These lines retained over 20% more rosette weight in reduced potassium supply, accompanied by an increase in potassium content in their leaves.
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Affiliation(s)
| | | | | | | | - Matthieu Reymond
- Department of Plant Breeding and Genetics, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany (A.E.P., B.S., M.R.); Institut de Biologie Moléculaire des Plantes du CNRS, Institut de Biologie Moléculaire des Plantes-CNRS-UPR2357, 67084 Strasbourg, France (H.B.); Center for Plant Environmental Stress Physiology, Horticulture and Landscape Architecture Department, Purdue University, West Lafayette, Indiana 47907 (D.E.S.); Institut Jean-Pierre Bourgin, UMR1318 INRA-AgroParisTech, INRA Centre de Versailles-Grignon, 78026 Versailles cedex, France (M.R.)
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Wang Y, He L, Li HD, Xu J, Wu WH. Potassium channel α-subunit AtKC1 negatively regulates AKT1-mediated K+ uptake in Arabidopsis roots under low-K+ stress. Cell Res 2010; 20:826-37. [DOI: 10.1038/cr.2010.74] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Volkov V, Boscari A, Clément M, Miller AJ, Amtmann A, Fricke W. Electrophysiological characterization of pathways for K(+) uptake into growing and non-growing leaf cells of barley. PLANT, CELL & ENVIRONMENT 2009; 32:1778-90. [PMID: 19682290 DOI: 10.1111/j.1365-3040.2009.02034.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Potassium is a major osmolyte used by plant cells. The accumulation rates of K(+) in cells may limit the rate of expansion. In the present study, we investigated the involvement of ion channels in K(+) uptake using patch clamp technique. Ion currents were quantified in protoplasts of the elongation and emerged blade zone of the developing leaf 3 of barley (Hordeum vulgare L.). A time-dependent inward-rectifying K(+)-selective current was observed almost exclusively in elongation zone protoplasts. The current showed characteristics typical of Shaker-type channels. Instantaneous inward current was highest in the epidermis of the emerged blade and selective for Na(+) over K(+). Selectivity disappeared, and currents decreased or remained the same, depending on tissue, in response to salt treatment. Net accumulation rates of K(+) in cells calculated from patch clamp current-voltage curves exceeded rates calculated from membrane potential and K(+) concentrations of cells measured in planta by factor 2.5-2.7 at physiological apoplastic K(+) concentrations (10-100 mm). It is concluded that under these conditions, K(+) accumulation in growing barley leaf cells is not limited by transport properties of cells. Under saline conditions, down-regulation of voltage-independent channels may reduce the capacity for growth-related K(+) accumulation.
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Affiliation(s)
- Vadim Volkov
- Division of Biological Sciences, University of Paisley, Paisley PA1 2BE, UK
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Ma X, Shor O, Diminshtein S, Yu L, Im YJ, Perera I, Lomax A, Boss WF, Moran N. Phosphatidylinositol (4,5)bisphosphate inhibits K+-efflux channel activity in NT1 tobacco cultured cells. PLANT PHYSIOLOGY 2009; 149:1127-40. [PMID: 19052153 PMCID: PMC2633837 DOI: 10.1104/pp.108.129007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2008] [Accepted: 11/24/2008] [Indexed: 05/18/2023]
Abstract
In the animal world, the regulation of ion channels by phosphoinositides (PIs) has been investigated extensively, demonstrating a wide range of channels controlled by phosphatidylinositol (4,5)bisphosphate (PtdInsP2). To understand PI regulation of plant ion channels, we examined the in planta effect of PtdInsP2 on the K+-efflux channel of tobacco (Nicotiana tabacum), NtORK (outward-rectifying K channel). We applied a patch clamp in the whole-cell configuration (with fixed "cytosolic" Ca2+ concentration and pH) to protoplasts isolated from cultured tobacco cells with genetically manipulated plasma membrane levels of PtdInsP2 and cellular inositol (1,4,5)trisphosphate: "Low PIs" had depressed levels of these PIs, and "High PIs" had elevated levels relative to controls. In all of these cells, K channel activity, reflected in the net, steady-state outward K+ currents (IK), was inversely related to the plasma membrane PtdInsP2 level. Consistent with this, short-term manipulations decreasing PtdInsP2 levels in the High PIs, such as pretreatment with the phytohormone abscisic acid (25 microM) or neutralizing the bath solution from pH 5.6 to pH 7, increased IK (i.e. NtORK activity). Moreover, increasing PtdInsP2 levels in controls or in abscisic acid-treated high-PI cells, using the specific PI-phospholipase C inhibitor U73122 (2.5-4 microM), decreased NtORK activity. In all cases, IK decreases stemmed largely from decreased maximum attainable NtORK channel conductance and partly from shifted voltage dependence of channel gating to more positive potentials, making it more difficult to activate the channels. These results are consistent with NtORK inhibition by the negatively charged PtdInsP2 in the internal plasma membrane leaflet. Such effects are likely to underlie PI signaling in intact plant cells.
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Affiliation(s)
- Xiaohong Ma
- Robert H. Smith Institute for Plant Sciences and Genetics in Agriculture, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot 76100, Israel
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Sano T, Kutsuna N, Becker D, Hedrich R, Hasezawa S. Outward-rectifying K+ channel activities regulate cell elongation and cell division of tobacco BY-2 cells. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2009; 57:55-64. [PMID: 18778403 DOI: 10.1111/j.1365-313x.2008.03672.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Potassium ions (K+) are required for plant growth and development, including cell division and cell elongation/expansion, which are mediated by the K+ transport system. In this study, we investigated the role of K+ in cell division using tobacco BY-2 protoplast cultures. Gene expression analysis revealed induction of the Shaker-like outward K+ channel gene, NTORK1, under cell-division conditions, whereas the inward K+ channel genes NKT1 and NtKC1 were induced under both cell-elongation and cell-division conditions. Repression of NTORK1 gene expression by expression of its antisense construct repressed cell division but accelerated cell elongation even under conditions promoting cell division. A decrease in the K+ content of cells and cellular osmotic pressure in dividing cells suggested that an increase in cell osmotic pressure by K+ uptake is not required for cell division. In contrast, K+ depletion, which reduced cell-division activity, decreased cytoplasmic pH as monitored using a fluorescent pH indicator, SNARF-1. Application of K+ or the cytoplasmic alkalizing reagent (NH(4))(2)SO(4) increased cytoplasmic pH and suppressed the reduction in cell-division activity. These results suggest that the K+ taken up into cells is used to regulate cytoplasmic pH during cell division.
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Affiliation(s)
- Toshio Sano
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan
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Dai XY, Su YR, Wei WX, Wu JS, Fan YK. Effects of top excision on the potassium accumulation and expression of potassium channel genes in tobacco. JOURNAL OF EXPERIMENTAL BOTANY 2008; 60:279-89. [PMID: 19112172 DOI: 10.1093/jxb/ern285] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The effects of the removal of the shoot apex of tobacco on the relative transcript levels of potassium channel genes, determined by real-time PCR, and on the relationship between the expression of genes encoding potassium channels and potassium concentration, were studied. The results from the study indicated that comparatively more assimilates of photosynthesis were allocated to the apex in control plants than in both decapitated and IAA-treated decapitated plants. By contrast, dry matter in the upper leaves, roots, and stems in both decapitated and IAA-treated plants was significantly increased relative to control plants. The potassium level in whole plants decreased post-decapitation compared with control plants, and so did the potassium concentration in middle and upper leaves, stem, and roots. Expression of NKT1, NtKC1, NTORK1, and NKT2 was inhibited by decapitation in tobacco leaves with a gradual reduction after decapitation, but was induced in roots. The relative expression of NKT1, NTORK1, and NKT2 in tobacco leaves was higher than that in roots, whereas the expression of NtKC1 was higher in roots. The levels of inhibition and induction of NKT1, NtKC1, NTORK1, and NKT2 in leaves and roots, respectively, associated with decapitation were reduced by the application of IAA on the cut surface of the decapitated stem. Further results showed that the level of endogenous auxin IAA in decapitated plants, which dropped in leaves and increased in roots by 140.7% at 14 d compared with the control plant, might be attributed to the change in the expression of potassium channel genes. The results suggest that there is a reciprocal relationship among endogenous auxin IAA, expression of potassium channel genes and potassium accumulation. They further imply that the endogenous IAA probably plays a role in regulating the expression of potassium channel genes, and that variations in expression of these genes affected the accumulation and distribution of potassium in tobacco.
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Affiliation(s)
- Xiao Yan Dai
- College of Resource and Enviroment, Huazhong Agriculture University, Wuhan 430070, PR China
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47
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Britto DT, Kronzucker HJ. Cellular mechanisms of potassium transport in plants. PHYSIOLOGIA PLANTARUM 2008; 133:637-50. [PMID: 18312500 DOI: 10.1111/j.1399-3054.2008.01067.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Potassium (K(+)) is the most abundant ion in the plant cell and is required for a wide array of functions, ranging from the maintenance of electrical potential gradients across cell membranes, to the generation of turgor, to the activation of numerous enzymes. The majority of these functions depend more or less directly upon the activities and regulation of membrane-bound K(+) transport proteins, operating over a wide range of K(+) concentrations. Here, we review the physiological aspects of potassium transport systems in the plasma membrane, re-examining fundamental problems in the field such as the distinctions between high- and low-affinity transport systems, the interactions between K(+) and other ions such as NH(4)(+) and Na(+), the regulation of cellular K(+) pools, the generation of electrical potentials and the problems involved in measurement of unidirectional K(+) fluxes. We place these discussions in the context of recent discoveries in the molecular biology of K(+) acquisition and produce an overview of gene families encoding K(+) transporters.
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Affiliation(s)
- Dev T Britto
- Department of Biological Sciences, University of Toronto, 1265 Military Trail, Toronto, Ontario, Canada
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Bregante M, Yang Y, Formentin E, Carpaneto A, Schroeder JI, Gambale F, Lo Schiavo F, Costa A. KDC1, a carrot Shaker-like potassium channel, reveals its role as a silent regulatory subunit when expressed in plant cells. PLANT MOLECULAR BIOLOGY 2008; 66:61-72. [PMID: 17955184 DOI: 10.1007/s11103-007-9252-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2007] [Accepted: 10/06/2007] [Indexed: 05/13/2023]
Abstract
The Shaker potassium channels are tetrameric proteins formed by the assembly of four alpha-subunits. The oligomerization can occur among both homo- and hetero-alpha-subunits. KDC1 is a carrot Shaker-like potassium channel expressed in the epidermis of plantlet roots and the protoderm of somatic embryos. KDC1 was previously characterised electrophysiologically in CHO and Xenopus oocytes cells, but the experiments performed in these systems did not provide conclusive evidence that KDC1 forms a functional homomeric channel in plant cells. In this report, we show that KDC1 localizes to the plasma membrane of root cells in transgenic tobacco plants transformed with a KDC1::GFP fusion construct. In tobacco mesophyll protoplasts, transiently transformed with KDC1::GFP, KDC1 was present on the endomembrane and the protoplasts did not show any inward potassium current, as demonstrated by patch-clamp experiments. The co-expression of KDC1::GFP with the Arabidopsis thaliana potassium channel AKT1 in tobacco mesophyll protoplasts has the effect of shifting KDC1 localization from endomembranes to the plasma membrane. Patch-clamp experiments performed on tobacco mesophyll protoplasts expressing AKT1 alone or in combination with KDC1::GFP showed voltage-activated inward potassium currents with different properties. In particular, the addition of Zn2+ to the bath solution induced a clear decrease of the potassium currents in protoplasts transformed with AKT1 alone, whereas a current potentiation (indicative of KDC1 presence) was observed in protoplasts co-transformed with AKT1 + KDC1::GFP. Split-Ubiquitin assay experiments performed in yeast cells confirmed the interaction between AKT1 and KDC1.
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Affiliation(s)
- Monica Bregante
- Istituto di Biofisica-CNR, Via De Marini 6, Genova 16149, Italy
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Sukhorukov VL, Endter JM, Zimmermann D, Shirakashi R, Fehrmann S, Kiesel M, Reuss R, Becker D, Hedrich R, Bamberg E, Roitsch T, Zimmermann U. Mechanisms of electrically mediated cytosolic Ca2+ transients in aequorin-transformed tobacco cells. Biophys J 2007; 93:3324-37. [PMID: 17675352 PMCID: PMC2025648 DOI: 10.1529/biophysj.107.110783] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2007] [Accepted: 07/10/2007] [Indexed: 11/18/2022] Open
Abstract
Cytosolic Ca(2+) changes induced by electric field pulses of 50-micros duration and 200-800 V/cm strength were monitored by measuring chemiluminescence in aequorin-transformed BY-2 tobacco cells. In Ca(2+)-substituted media, electropulsing led to a very fast initial increase of the cytosolic Ca(2+) concentration reaching a peak value within <100-200 ms. Peaking of [Ca(2+)](cyt) was followed by a biphasic decay due to removal of Ca(2+) (e.g., by binding and/or sequestration in the cytosol). The decay had fast and slow components, characterized by time constants of approximately 0.5 and 3-5 s, respectively. Experiments with various external Ca(2+) concentrations and conductivities showed that the fast decay arises from Ca(2+) fluxes through the plasmalemma, whereas the slow decay must be assigned to Ca(2+) fluxes through the tonoplast. The amplitude of the [Ca(2+)](cyt) transients increased with increasing field strength, whereas the time constants of the decay kinetics remained invariant. Breakdown of the plasmalemma was achieved at a critical field strength of approximately 450 V/cm, whereas breakdown of the tonoplast required approximately 580 V/cm. The above findings could be explained by the transient potential profiles generated across the two membranes in response to an exponentially decaying field pulse. The dielectric data required for calculation of the tonoplast and plasmalemma potentials were derived from electrorotation experiments on isolated vacuolated and evacuolated BY-2 protoplasts. The electrorotation response of vacuolated protoplasts could be described in terms of a three-shell model (i.e., by assuming that the capacitances of tonoplast and plasmalemma are arranged in series). Among other things, the theoretical analysis together with the experimental data show that genetic manipulations of plant cells by electrotransfection or electrofusion must be performed in low-conductivity media to minimize release of vacuolar Ca(2+) and presumably other vacuolar ingredients.
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Affiliation(s)
- V L Sukhorukov
- Lehrstuhl für Biotechnologie, Julius-von-Sachs-Institut für Biowissenschaften, Universität Würzburg, Würzburg, Germany
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