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Chen SY, Wang L, Jia PF, Yang WC, Sze H, Li HJ. Osmoregulation determines sperm cell geometry and integrity for double fertilization in flowering plants. MOLECULAR PLANT 2022; 15:1488-1496. [PMID: 35918896 DOI: 10.1016/j.molp.2022.07.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 07/05/2022] [Accepted: 07/22/2022] [Indexed: 06/15/2023]
Abstract
Distinct from the motile flagellated sperm of animals and early land plants, the non-motile sperm cells of flowering plants are carried in the pollen grain to the female pistil. After pollination, a pair of sperm cells are delivered into the embryo sac by pollen tube growth and rupture. Unlike other walled plant cells with an equilibrium between internal turgor pressure and mechanical constraints of the cell walls, sperm cells wrapped inside the cytoplasm of a pollen vegetative cell have only thin and discontinuous cell walls. The sperm cells are uniquely ellipsoid in shape, although it is unclear how they maintain this shape within the pollen tubes and after release. In this study, we found that genetic disruption of three endomembrane-associated cation/H+ exchangers specifically causes sperm cells to become spheroidal in hydrated pollens of Arabidopsis. Moreover, the released mutant sperm cells are vulnerable and rupture before double fertilization, leading to failed seed set, which can be partially rescued by depletion of the sperm-expressed vacuolar water channel. These results suggest a critical role of cell-autonomous osmoregulation in adjusting the sperm cell shape for successful double fertilization in flowering plants.
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Affiliation(s)
- Shu-Yan Chen
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lan Wang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Peng-Fei Jia
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Wei-Cai Yang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Heven Sze
- Department of Cell Biology & Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Hong-Ju Li
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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2
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Ankit A, Kamali S, Singh A. Genomic & structural diversity and functional role of potassium (K +) transport proteins in plants. Int J Biol Macromol 2022; 208:844-857. [PMID: 35367275 DOI: 10.1016/j.ijbiomac.2022.03.179] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 03/11/2022] [Accepted: 03/25/2022] [Indexed: 01/03/2023]
Abstract
Potassium (K+) is an essential macronutrient for plant growth and productivity. It is the most abundant cation in plants and is involved in various cellular processes. Variable K+ availability is sensed by plant roots, consequently K+ transport proteins are activated to optimize K+ uptake. In addition to K+ uptake and translocation these proteins are involved in other important physiological processes like transmembrane voltage regulation, polar auxin transport, maintenance of Na+/K+ ratio and stomata movement during abiotic stress responses. K+ transport proteins display tremendous genomic and structural diversity in plants. Their key structural features, such as transmembrane domains, N-terminal domains, C-terminal domains and loops determine their ability of K+ uptake and transport and thus, provide functional diversity. Most K+ transporters are regulated at transcriptional and post-translational levels. Genetic manipulation of key K+ transporters/channels could be a prominent strategy for improving K+ utilization efficiency (KUE) in plants. This review discusses the genomic and structural diversity of various K+ transport proteins in plants. Also, an update on the function of K+ transport proteins and their regulatory mechanism in response to variable K+ availability, in improving KUE, biotic and abiotic stresses is provided.
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Affiliation(s)
- Ankit Ankit
- National Institute of Plant Genome Research, New Delhi 110067, India
| | | | - Amarjeet Singh
- National Institute of Plant Genome Research, New Delhi 110067, India.
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3
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Zhou JY, Hao DL, Yang GZ. Regulation of Cytosolic pH: The Contributions of Plant Plasma Membrane H +-ATPases and Multiple Transporters. Int J Mol Sci 2021; 22:12998. [PMID: 34884802 PMCID: PMC8657649 DOI: 10.3390/ijms222312998] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 11/24/2021] [Accepted: 11/25/2021] [Indexed: 11/17/2022] Open
Abstract
Cytosolic pH homeostasis is a precondition for the normal growth and stress responses in plants, and H+ flux across the plasma membrane is essential for cytoplasmic pH control. Hence, this review focuses on seven types of proteins that possess direct H+ transport activity, namely, H+-ATPase, NHX, CHX, AMT, NRT, PHT, and KT/HAK/KUP, to summarize their plasma-membrane-located family members, the effect of corresponding gene knockout and/or overexpression on cytosolic pH, the H+ transport pathway, and their functional regulation by the extracellular/cytosolic pH. In general, H+-ATPases mediate H+ extrusion, whereas most members of other six proteins mediate H+ influx, thus contributing to cytosolic pH homeostasis by directly modulating H+ flux across the plasma membrane. The fact that some AMTs/NRTs mediate H+-coupled substrate influx, whereas other intra-family members facilitate H+-uncoupled substrate transport, demonstrates that not all plasma membrane transporters possess H+-coupled substrate transport mechanisms, and using the transport mechanism of a protein to represent the case of the entire family is not suitable. The transport activity of these proteins is regulated by extracellular and/or cytosolic pH, with different structural bases for H+ transfer among these seven types of proteins. Notably, intra-family members possess distinct pH regulatory characterization and underlying residues for H+ transfer. This review is anticipated to facilitate the understanding of the molecular basis for cytosolic pH homeostasis. Despite this progress, the strategy of their cooperation for cytosolic pH homeostasis needs further investigation.
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Affiliation(s)
- Jin-Yan Zhou
- Jiangsu Vocational College of Agriculture and Forest, Jurong 212400, China;
| | - Dong-Li Hao
- The National Forestry and Grassland Administration Engineering Research Center for Germplasm Innovation and Utilization of Warm-Season Turfgrasses, Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing 210014, China
| | - Guang-Zhe Yang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning 530004, China;
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4
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Jia Q, Li MW, Zheng C, Xu Y, Sun S, Li Z, Wong FL, Song J, Lin WW, Li Q, Zhu Y, Liang K, Lin W, Lam HM. The soybean plasma membrane-localized cation/H + exchanger GmCHX20a plays a negative role under salt stress. PHYSIOLOGIA PLANTARUM 2021; 171:714-727. [PMID: 33094482 DOI: 10.1111/ppl.13250] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 10/01/2020] [Accepted: 10/20/2020] [Indexed: 06/11/2023]
Abstract
Cation/H+ -exchanger (CHX) perform diverse functions in plants, including being a part of the protective mechanisms to cope with salt stress. GmCHX1 has been previously identified as the causal gene in a major salt-tolerance quantitative trait locus (QTL) in soybean, but little is known about another close paralog, GmCHX20a, found in the same QTL. In this study, GmCHX20a was characterized along with GmCHX1. The expression patterns of the two genes and the direction of Na+ flux directed by overexpression of these two transporters are different, suggesting that they are functionally distinct. The ectopic expression of GmCHX20a led to an increase in salt sensitivity and osmotic tolerance, which was consistent with its role in increasing Na+ uptake into the root. Although this seems counter-intuitive, it may in fact be part of the mechanism by which soybean could counter act the effects of osmotic stress, which is commonly manifested in the initial stage of salinity stress. On the other hand, GmCHX1 from salt-tolerant soybean was shown to protect plants via Na+ exclusion under salt stress. Taken together these results suggest that GmCHX20a and GmCHX1 might work complementally through a concerted effort to address both osmotic stress and ionic stress as a result of elevated salinity.
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Affiliation(s)
- Qi Jia
- Key Laboratory for Genetics Breeding and Multiple Utilization of Crops, Ministry of Education, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
- School of Life Sciences and Center for Soybean Research of the State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, China
| | - Man-Wah Li
- School of Life Sciences and Center for Soybean Research of the State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, China
| | - Chengwen Zheng
- Key Laboratory for Genetics Breeding and Multiple Utilization of Crops, Ministry of Education, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yiyue Xu
- School of Life Sciences and Center for Soybean Research of the State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, China
| | - Song Sun
- Key Laboratory for Genetics Breeding and Multiple Utilization of Crops, Ministry of Education, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Zhong Li
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou, China
| | - Fuk-Ling Wong
- School of Life Sciences and Center for Soybean Research of the State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, China
| | - Junliang Song
- Key Laboratory for Genetics Breeding and Multiple Utilization of Crops, Ministry of Education, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Wei-Wei Lin
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou, China
| | - Qinghua Li
- Putian Institute of Agricultural Sciences, Putian, China
| | - Yebao Zhu
- Rice Research Institute, Fujian Academy of Agricultural Sciences, Fuzhou, China
| | - Kangjing Liang
- Key Laboratory for Genetics Breeding and Multiple Utilization of Crops, Ministry of Education, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Wenxiong Lin
- Key Laboratory for Genetics Breeding and Multiple Utilization of Crops, Ministry of Education, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou, China
| | - Hon-Ming Lam
- School of Life Sciences and Center for Soybean Research of the State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, China
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Nestrerenko EO, Krasnoperova OE, Isayenkov SV. Potassium Transport Systems and Their Role in Stress Response, Plant Growth, and Development. CYTOL GENET+ 2021. [DOI: 10.3103/s0095452721010126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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6
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Zhu YX, Jia JH, Yang L, Xia YC, Zhang HL, Jia JB, Zhou R, Nie PY, Yin JL, Ma DF, Liu LC. Identification of cucumber circular RNAs responsive to salt stress. BMC PLANT BIOLOGY 2019; 19:164. [PMID: 31029105 PMCID: PMC6486992 DOI: 10.1186/s12870-019-1712-3] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 03/11/2019] [Indexed: 05/05/2023]
Abstract
BACKGROUND Circular RNAs (circRNAs) are 3'-5' head-to-tail covalently closed non-coding RNA that have been proved to play essential roles in many cellular and developmental processes. However, no information relate to cucumber circRNAs is available currently, especially under salt stress condition. RESULTS In this study, we sequenced circRNAs in cucumber and a total of 2787 were identified, with 1934 in root and 44 in leaf being differentially regulated under salt stress. Characteristics analysis of these circRNAs revealed following features: most of them are exon circRNAs (79.51%) and they prefer to arise from middle exon(s) of parent genes (2035/2516); moreover, most of circularization events (88.3%) use non-canonical-GT/AG splicing signals; last but not least, pairing-driven circularization is not the major way to generate cucumber circRNAs since very few circRNAs (18) contain sufficient flanking complementary sequences. Annotation and enrichment analysis of both parental genes and target mRNAs were launched to uncover the functions of differentially expressed circRNAs induced by salt stress. The results showed that circRNAs may be paly roles in salt stress response by mediating transcription, signal transcription, cell cycle, metabolism adaptation, and ion homeostasis related pathways. Moreover, circRNAs may function to regulate proline metabolisms through regulating associated biosynthesis and degradation genes. CONCLUSIONS The present study identified large number of cucumber circRNAs and function annotation revealed their possible biological roles in response to salt stress. Our findings will lay a solid foundation for further structure and function studies of cucumber circRNAs.
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Affiliation(s)
- Yong-Xing Zhu
- Hubei Key Laboratory of Waterlogging Disaster and Agricultural Use of Wetland/College of Horticulture and Gardening/College of Agriculture, Yangtze University, Jingzhou, 434000 Hubei China
| | - Jian-Hua Jia
- College of Horticulture, Northwest A&F University, Yangling, 712100 Shaanxi China
| | - Lei Yang
- Hubei Key Laboratory of Waterlogging Disaster and Agricultural Use of Wetland/College of Horticulture and Gardening/College of Agriculture, Yangtze University, Jingzhou, 434000 Hubei China
| | - Yu-Chen Xia
- Hubei Key Laboratory of Waterlogging Disaster and Agricultural Use of Wetland/College of Horticulture and Gardening/College of Agriculture, Yangtze University, Jingzhou, 434000 Hubei China
| | - Hui-Li Zhang
- Hubei Key Laboratory of Waterlogging Disaster and Agricultural Use of Wetland/College of Horticulture and Gardening/College of Agriculture, Yangtze University, Jingzhou, 434000 Hubei China
| | - Jin-Bu Jia
- Department of Biology, Southern University of Science and Technology, Shenzhen, 518055 Guangdong China
| | - Ran Zhou
- Hubei Key Laboratory of Waterlogging Disaster and Agricultural Use of Wetland/College of Horticulture and Gardening/College of Agriculture, Yangtze University, Jingzhou, 434000 Hubei China
| | - Pei-Yao Nie
- Biomarker Technologies, Beijing, 101300 China
| | - Jun-Liang Yin
- Hubei Key Laboratory of Waterlogging Disaster and Agricultural Use of Wetland/College of Horticulture and Gardening/College of Agriculture, Yangtze University, Jingzhou, 434000 Hubei China
| | - Dong-Fang Ma
- Hubei Key Laboratory of Waterlogging Disaster and Agricultural Use of Wetland/College of Horticulture and Gardening/College of Agriculture, Yangtze University, Jingzhou, 434000 Hubei China
| | - Le-Cheng Liu
- Hubei Key Laboratory of Waterlogging Disaster and Agricultural Use of Wetland/College of Horticulture and Gardening/College of Agriculture, Yangtze University, Jingzhou, 434000 Hubei China
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7
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Ruiz-Lau N, Sáez Á, Lanza M, Benito B. Genomic and Transcriptomic Compilation of Chloroplast Ionic Transporters of Physcomitrella patens. Study of NHAD Transporters in Na+ and K+ Homeostasis. PLANT & CELL PHYSIOLOGY 2017; 58:2166-2178. [PMID: 29036645 DOI: 10.1093/pcp/pcx150] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 09/26/2017] [Indexed: 06/07/2023]
Abstract
K+ is widely used by plant cells, whereas Na+ can easily reach toxic levels during plant growth, which typically occurs in saline environments; however, the effects and functions in the chloroplast have been only roughly estimated. Traditionally, the occurrence of ionic fluxes across the chloroplast envelope or the thylakoid membranes has been mostly deduced from physiological measurements or from knowledge of chloroplast metabolism. However, many of the proteins involved in these fluxes have not yet been characterized. Based on genomic and RNA sequencing (RNA-seq) analyses, we present a comprehensive compilation of genes encoding putative ion transporters and channels expressed in the chloroplasts of the moss Physcomitrella patens, with a special emphasis on those related to Na+ and K+ fluxes. Based on the functional characterization of nhad mutants, we also discuss the putative role of NHAD transporters in Na+ homeostasis and osmoregulation of this organelle and the putative contribution of chloroplasts to salt tolerance in this moss. We demonstrate that NaCl does not affect the chloroplast functionality in Physcomitrella despite significantly modifying expression of ionic transporters and cellular morphology, specifically the chloroplast ultrastructure, revealing a high starch accumulation. Additionally, NHAD transporters apparently do not play any essential roles in salt tolerance.
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Affiliation(s)
- Nancy Ruiz-Lau
- CONACYT-Instituto Tecnológico de Tuxtla Gutiérrez, Carretera Panamericana Km 1080, Terán 29050, Tuxtla Gutiérrez, Chis, México
| | - Ángela Sáez
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo UPM, 28223-Pozuelo de Alarcón (Madrid), Spain
| | - Mónica Lanza
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo UPM, 28223-Pozuelo de Alarcón (Madrid), Spain
| | - Begoña Benito
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo UPM, 28223-Pozuelo de Alarcón (Madrid), Spain
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8
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Jia B, Sun M, DuanMu H, Ding X, Liu B, Zhu Y, Sun X. GsCHX19.3, a member of cation/H + exchanger superfamily from wild soybean contributes to high salinity and carbonate alkaline tolerance. Sci Rep 2017; 7:9423. [PMID: 28842677 PMCID: PMC5573395 DOI: 10.1038/s41598-017-09772-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 07/28/2017] [Indexed: 01/21/2023] Open
Abstract
Cation/H+ exchangers (CHX) are characterized to be involved in plant growth, development and stress responses. Although soybean genome sequencing has been completed, the CHX family hasn't yet been systematically analyzed, especially in wild soybean. Here, through Hidden Markov Model search against Glycine soja proteome, 34 GsCHXs were identified and phylogenetically clustered into five groups. Members within each group showed high conservation in motif architecture. Interestingly, according to our previous RNA-seq data, only Group IVa members exhibited highly induced expression under carbonate alkaline stress. Among them, GsCHX19.3 displayed the greatest up-regulation in response to carbonate alkaline stress, which was further confirmed by quantitative real-time PCR analysis. We also observed the ubiquitous expression of GsCHX19.3 in different tissues and its localization on plasma membrane. Moreover, we found that GsCHX19.3 expression in AXT4K, a yeast mutant lacking four ion transporters conferred resistance to low K+ at alkali pH, as well as carbonate stress. Consistently, in Arabidopsis, GsCHX19.3 overexpression increased plant tolerance both to high salt and carbonate alkaline stresses. Furthermore, we also confirmed that GsCHX19.3 transgenic lines showed lower Na+ concentration but higher K+/Na+ values under salt-alkaline stress. Taken together, our findings indicated that GsCHX19.3 contributed to high salinity and carbonate alkaline tolerance.
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Affiliation(s)
- Bowei Jia
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, P.R. China
- Crop Stress Molecular Biology Laboratory, Heilongjiang Bayi Agricultural University, Daqing, 163319, P.R. China
| | - Mingzhe Sun
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, P.R. China
- Crop Stress Molecular Biology Laboratory, Heilongjiang Bayi Agricultural University, Daqing, 163319, P.R. China
| | - Huizi DuanMu
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, P.R. China
| | - Xiaodong Ding
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, P.R. China
| | - Beidong Liu
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, Medicinaregatan, 9ES-413 90, Gothenburg, Sweden
| | - Yanming Zhu
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, P.R. China.
| | - Xiaoli Sun
- Crop Stress Molecular Biology Laboratory, Heilongjiang Bayi Agricultural University, Daqing, 163319, P.R. China.
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Padmanaban S, Czerny DD, Levin KA, Leydon AR, Su RT, Maugel TK, Zou Y, Chanroj S, Cheung AY, Johnson MA, Sze H. Transporters involved in pH and K+ homeostasis affect pollen wall formation, male fertility, and embryo development. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:3165-3178. [PMID: 28338823 PMCID: PMC5853877 DOI: 10.1093/jxb/erw483] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 12/01/2016] [Indexed: 05/20/2023]
Abstract
Flowering plant genomes encode multiple cation/H+ exchangers (CHXs) whose functions are largely unknown. AtCHX17, AtCHX18, and AtCHX19 are membrane transporters that modulate K+ and pH homeostasis and are localized in the dynamic endomembrane system. Loss of function reduced seed set, but the particular phase(s) of reproduction affected was not determined. Pollen tube growth and ovule targeting of chx17chx18chx19 mutant pollen appeared normal, but reciprocal cross experiments indicate a largely male defect. Although triple mutant pollen tubes reach ovules of a wild-type pistil and a synergid cell degenerated, half of those ovules were unfertilized or showed fertilization of the egg or central cell, but not both female gametes. Fertility could be partially compromised by impaired pollen tube and/or sperm function as CHX19 and CHX18 are expressed in the pollen tube and sperm cell, respectively. When fertilization was successful in self-pollinated mutants, early embryo formation was retarded compared with embryos from wild-type ovules receiving mutant pollen. Thus CHX17 and CHX18 proteins may promote embryo development possibly through the endosperm where these genes are expressed. The reticulate pattern of the pollen wall was disorganized in triple mutants, indicating perturbation of wall formation during male gametophyte development. As pH and cation homeostasis mediated by AtCHX17 affect membrane trafficking and cargo delivery, these results suggest that male fertility, sperm function, and embryo development are dependent on proper cargo sorting and secretion that remodel cell walls, plasma membranes, and extracellular factors.
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Affiliation(s)
- Senthilkumar Padmanaban
- Department of Cell Biology & Molecular Genetics, University of Maryland, College Park, MD, USA
| | - Daniel D Czerny
- Department of Cell Biology & Molecular Genetics, University of Maryland, College Park, MD, USA
| | - Kara A Levin
- Department of Cell Biology & Molecular Genetics, University of Maryland, College Park, MD, USA
| | - Alexander R Leydon
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, USA
| | - Robert T Su
- Department of Cell Biology & Molecular Genetics, University of Maryland, College Park, MD, USA
| | - Timothy K Maugel
- Laboratory for Biological Ultrastructure, University of Maryland, College Park, MD, USA
| | - Yanjiao Zou
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA, USA
| | - Salil Chanroj
- Department of Cell Biology & Molecular Genetics, University of Maryland, College Park, MD, USA
- Department of Biotechnology, Burapha University, Chon-Buri, Thailand
| | - Alice Y Cheung
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA, USA
| | - Mark A Johnson
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, USA
| | - Heven Sze
- Department of Cell Biology & Molecular Genetics, University of Maryland, College Park, MD, USA
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD, USA
- Maryland Agricultural Experiment Station, University of Maryland, College Park, MD, USA
- Correspondence:
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10
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Kumari PH, Kumar SA, Sivan P, Katam R, Suravajhala P, Rao KS, Varshney RK, Kishor PBK. Overexpression of a Plasma Membrane Bound Na +/H + Antiporter-Like Protein ( SbNHXLP) Confers Salt Tolerance and Improves Fruit Yield in Tomato by Maintaining Ion Homeostasis. FRONTIERS IN PLANT SCIENCE 2017; 7:2027. [PMID: 28111589 PMCID: PMC5216050 DOI: 10.3389/fpls.2016.02027] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 12/19/2016] [Indexed: 05/05/2023]
Abstract
A Na+/H+ antiporter-like protein (NHXLP) was isolated from Sorghum bicolor L. (SbNHXLP) and validated by overexpressing in tomato for salt tolerance. Homozygous T2 transgenic lines when evaluated for salt tolerance, accumulated low Na+ and displayed enhanced salt tolerance compared to wild-type plants (WT). This is consistent with the amiloride binding assay of the protein. Transgenics exhibited higher accumulation of proline, K+, Ca2+, improved cambial conductivity, higher PSII, and antioxidative enzyme activities than WT. Fluorescence imaging results revealed lower Na+ and higher Ca2+ levels in transgenic roots. Co-immunoprecipitation experiments demonstrate that SbNHXLP interacts with a Solanum lycopersicum cation proton antiporter protein2 (SlCHX2). qRT-PCR results showed upregulation of SbNHXLP and SlCHX2 upon treatment with 200 mM NaCl and 100 mM potassium nitrate. SlCHX2 is known to be involved in K+ acquisition, and the interaction between these two proteins might help to accumulate more K+ ions, and thus maintain ion homeostasis. These results strongly suggest that plasma membrane bound SbNHXLP involves in Na+ exclusion, maintains ion homeostasis in transgenics in comparison with WT and alleviates NaCl stress.
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Affiliation(s)
- P. Hima Kumari
- Department of Genetics, Osmania UniversityHyderabad, India
| | - S. Anil Kumar
- Department of Genetics, Osmania UniversityHyderabad, India
| | - Pramod Sivan
- Department of Biosciences, Sardar Patel UniversityAnand, India
| | - Ramesh Katam
- Department of Biological Sciences, College of Science and Technology, Florida A&M UniversityTallahassee, FL, USA
| | | | - K. S. Rao
- Department of Biosciences, Sardar Patel UniversityAnand, India
| | - Rajeev K. Varshney
- Center of Excellence in Genomics, International Crops Research Institute for the Semi-Arid TropicsHyderabad, India
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11
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Chen Y, Ma J, Miller AJ, Luo B, Wang M, Zhu Z, Ouwerkerk PBF. OsCHX14 is Involved in the K+ Homeostasis in Rice (Oryza sativa) Flowers. PLANT & CELL PHYSIOLOGY 2016; 57:1530-1543. [PMID: 27903806 DOI: 10.1093/pcp/pcw088] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Accepted: 04/26/2016] [Indexed: 05/22/2023]
Abstract
Previously we showed in the osjar1 mutants that the lodicule senescence which controls the closing of rice flowers was delayed. This resulted in florets staying open longer when compared with the wild type. The gene OsJAR1 is silenced in osjar1 mutants and is a key member of the jasmonic acid (JA) signaling pathway. We found that K concentrations in lodicules and flowers of osjar1-2 were significantly elevated compared with the wild type, indicating that K+ homeostasis may play a role in regulating the closure of rice flowers. The cation/H+ exchanger (CHX) family from rice was screened for potential K+ transporters involved as many members of this family in Arabidopsis were exclusively or preferentially expressed in flowers. Expression profiling confirmed that among 17 CHX genes in rice, OsCHX14 was the only member that showed an expression polymorphism, not only in osjar1 mutants but also in RNAi (RNA interference) lines of OsCOI1, another key member of the JA signaling pathway. This suggests that the expression of OsCHX14 is regulated by the JA signaling pathway. Green fluorescent protein (GFP)-tagged OsCHX14 protein was preferentially localized to the endoplasmic reticulum. Promoter-β-glucuronidase (GUS) analysis of transgenic rice revealed that OsCHX14 is mainly expressed in lodicules and the region close by throughout the flowering process. Characterization in yeast and Xenopus laevis oocytes verified that OsCHX14 is able to transport K+, Rb+ and Cs+ in vivo. Our data suggest that OsCHX14 may play an important role in K+ homeostasis during flowering in rice.
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Affiliation(s)
- Yi Chen
- Institute of Biology (IBL), Leiden University, Sylvius Laboratory, Sylviusweg 72, 2333 BE, PO Box 9505, 2300 RA Leiden, The Netherlands
- Department of Metabolic Biology, John Innes Centre, Norwich NR4 7UH, UK
- Department of Sustainable Soils and Grassland Systems, Rothamsted Research, Harpenden AL5 2JQ, UK
| | - Jingkun Ma
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, UK
| | - Anthony J Miller
- Department of Metabolic Biology, John Innes Centre, Norwich NR4 7UH, UK
| | - Bingbing Luo
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 219500, China
| | - Mei Wang
- Institute of Biology (IBL), Leiden University, Sylvius Laboratory, Sylviusweg 72, 2333 BE, PO Box 9505, 2300 RA Leiden, The Netherlands
- TNO Quality of Life, Zernikedreef 9, 2333 CK Leiden, PO Box 2215, 2301 CE Leiden, The Netherlands
| | - Zhen Zhu
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No. 1 West Beichen Road, Chaoyang District, Beijing, 100101 China
| | - Pieter B F Ouwerkerk
- Institute of Biology (IBL), Leiden University, Sylvius Laboratory, Sylviusweg 72, 2333 BE, PO Box 9505, 2300 RA Leiden, The Netherlands
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12
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Czerny DD, Padmanaban S, Anishkin A, Venema K, Riaz Z, Sze H. Protein architecture and core residues in unwound α-helices provide insights to the transport function of plant AtCHX17. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:1983-1998. [PMID: 27179641 DOI: 10.1016/j.bbamem.2016.05.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 04/13/2016] [Accepted: 05/08/2016] [Indexed: 01/27/2023]
Abstract
Using Arabidopsis thaliana AtCHX17 as an example, we combine structural modeling and mutagenesis to provide insights on its protein architecture and transport function which is poorly characterized. This approach is based on the observation that protein structures are significantly more conserved in evolution than linear sequences, and mechanistic similarities among diverse transporters are emerging. Two homology models of AtCHX17 were obtained that show a protein fold similar to known structures of bacterial Na(+)/H(+) antiporters, EcNhaA and TtNapA. The distinct secondary and tertiary structure models highlighted residues at positions potentially important for CHX17 activity. Mutagenesis showed that asparagine-N200 and aspartate-D201 inside transmembrane5 (TM5), and lysine-K355 inside TM10 are critical for AtCHX17 activity. We reveal previously unrecognized threonine-T170 and lysine-K383 as key residues at unwound regions in the middle of TM4 and TM11 α-helices, respectively. Mutation of glutamate-E111 located near the membrane surface inhibited AtCHX17 activity, suggesting a role in pH sensing. The long carboxylic tail of unknown purpose has an alternating β-sheet and α-helix secondary structure that is conserved in prokaryote universal stress proteins. These results support the overall architecture of AtCHX17 and identify D201, N200 and novel residues T170 and K383 at the functional core which likely participates in ion recognition, coordination and/or translocation, similar to characterized cation/H(+) exchangers. The core of AtCHX17 models according to EcNhaA and TtNapA templates faces inward and outward, respectively, which may reflect two conformational states of the alternating access transport mode for proteins belonging to the plant CHX family.
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Affiliation(s)
- Daniel D Czerny
- Department of Cell Biology and Molecular Genetics (DC, SP, ZR, HS), University of Maryland, College Park, MD 20742, USA
| | - Senthilkumar Padmanaban
- Department of Cell Biology and Molecular Genetics (DC, SP, ZR, HS), University of Maryland, College Park, MD 20742, USA
| | - Andriy Anishkin
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Kees Venema
- Dpto de Bioquímica, Biología Celular y Molecular de Plantas, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, c/. Profesor Albareda 1, 18008Granada, Spain
| | - Zoya Riaz
- Department of Cell Biology and Molecular Genetics (DC, SP, ZR, HS), University of Maryland, College Park, MD 20742, USA
| | - Heven Sze
- Department of Cell Biology and Molecular Genetics (DC, SP, ZR, HS), University of Maryland, College Park, MD 20742, USA; Maryland Agricultural Experiment Station, Department of Plant Science and Landscape Architecture (HS), University of Maryland, College Park, MD 20742, USA.
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13
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Abstract
Potassium is a macronutrient that is crucial for healthy plant growth. Potassium availability, however, is often limited in agricultural fields and thus crop yields and quality are reduced. Therefore, improving the efficiency of potassium uptake and transport, as well as its utilization, in plants is important for agricultural sustainability. This review summarizes the current knowledge on the molecular mechanisms involved in potassium uptake and transport in plants, and the molecular response of plants to different levels of potassium availability. Based on this information, four strategies for improving potassium use efficiency in plants are proposed; 1) increased root volume, 2) increasing efficiency of potassium uptake from the soil and translocation in planta, 3) increasing mobility of potassium in soil, and 4) molecular breeding new varieties with greater potassium efficiency through marker assisted selection which will require identification and utilization of potassium associated quantitative trait loci.
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Affiliation(s)
- Ryoung Shin
- RIKEN Center for Sustainable Resource Science, Yokohama 230-0045,
Japan
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14
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Ahmad I, Maathuis FJM. Cellular and tissue distribution of potassium: physiological relevance, mechanisms and regulation. JOURNAL OF PLANT PHYSIOLOGY 2014; 171:708-14. [PMID: 24810768 DOI: 10.1016/j.jplph.2013.10.016] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Revised: 10/27/2013] [Accepted: 10/28/2013] [Indexed: 05/25/2023]
Abstract
Potassium (K(+)) is the most important cationic nutrient for all living organisms. Its cellular levels are significant (typically around 100mM) and are highly regulated. In plants K(+) affects multiple aspects such as growth, tolerance to biotic and abiotic stress and movement of plant organs. These processes occur at the cell, organ and whole plant level and not surprisingly, plants have evolved sophisticated mechanisms for the uptake, efflux and distribution of K(+) both within cells and between organs. Great progress has been made in the last decades regarding the molecular mechanisms of K(+) uptake and efflux, particularly at the cellular level. For long distance K(+) transport our knowledge is less complete but the principles behind the overall processes are largely understood. In this chapter we will discuss how both long distance transport between different organs and intracellular transport between organelles works in general and in particular for K(+). Where possible, we will provide examples of specific genes and proteins that are responsible for these phenomena.
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Affiliation(s)
- Izhar Ahmad
- Department of Biology, University of York, York YO10 5DD, United Kingdom
| | - Frans J M Maathuis
- Department of Biology, University of York, York YO10 5DD, United Kingdom.
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15
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Adams E, Shin R. Transport, signaling, and homeostasis of potassium and sodium in plants. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2014; 56:231-49. [PMID: 24393374 DOI: 10.1111/jipb.12159] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 12/31/2013] [Indexed: 05/17/2023]
Abstract
Potassium (K⁺) is an essential macronutrient in plants and a lack of K⁺ significantly reduces the potential for plant growth and development. By contrast, sodium (Na⁺), while beneficial to some extent, at high concentrations it disturbs and inhibits various physiological processes and plant growth. Due to their chemical similarities, some functions of K⁺ can be undertaken by Na⁺ but K⁺ homeostasis is severely affected by salt stress, on the other hand. Recent advances have highlighted the fascinating regulatory mechanisms of K⁺ and Na⁺ transport and signaling in plants. This review summarizes three major topics: (i) the transport mechanisms of K⁺ and Na⁺ from the soil to the shoot and to the cellular compartments; (ii) the mechanisms through which plants sense and respond to K⁺ and Na⁺ availability; and (iii) the components involved in maintenance of K⁺/Na⁺ homeostasis in plants under salt stress.
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Affiliation(s)
- Eri Adams
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045, Japan
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16
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Haro R, Fraile-Escanciano A, González-Melendi P, Rodríguez-Navarro A. The potassium transporters HAK2 and HAK3 localize to endomembranes in Physcomitrella patens. HAK2 is required in some stress conditions. PLANT & CELL PHYSIOLOGY 2013; 54:1441-1454. [PMID: 23825217 DOI: 10.1093/pcp/pct097] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The function of HAK transporters in high-affinity K+ uptake in plants is well established; this study aims to demonstrate that some transporters of the same family play important roles in endomembranes. The PpHAK2-PpHAK4 genes of Physcomitrella patens encode three transporters of high sequence similarity. Quantitative PCR showed that PpHAK2 and PpHAK3 transcripts are expressed at approximately the same level as the PpACT5 gene, while the expression of PpHAK4 seems to be restricted to specific conditions that have not been determined. KHA1 is an endomembrane K+/H+ antiporter of Saccharomyces cerevisiae, and the expression of the PpHAK2 cDNA, but not that of PpHAK3, suppressed the defect of a kha1 mutant. Transient expression of the PpHAK2-green fluorescent protein (GFP) and PpHAK3-GFP fusion proteins in P. patens protoplasts localized to the endoplasmic reticulum and Golgi complex, respectively. To determine the function of PpHAK2 and PpHAK3 in planta, we constructed ΔPphak2 and ΔPphak2 ΔPphak3 plants. ΔPphak2 plants were normal under all of the conditions tested except under K+ starvation or at acidic pH in the presence of acetic acid, whereupon they die. The defect observed under K+ starvation was suppressed by the presence of Na+. We propose that PpHAK2 may encode either a K(+)-H(+) symporter or a K+/H+ antiporter that mediates the transfer of H+ from the endoplasmic reticulum lumen to the cytosol. PpHAK2 may be a model of the second function of HAK transporters in plant cells. The disruption of the PpHAK3 gene in ΔPphak2 plants showed no effect.
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Affiliation(s)
- Rosario Haro
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Campus de Montegancedo, Carretera M-40, km 38, 28223 Pozuelo de Alarcón, Madrid, Spain.
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