101
|
Mangano S, Martínez Pacheco J, Marino-Buslje C, Estevez JM. How Does pH Fit in with Oscillating Polar Growth? TRENDS IN PLANT SCIENCE 2018; 23:479-489. [PMID: 29605100 DOI: 10.1016/j.tplants.2018.02.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 02/08/2018] [Accepted: 02/23/2018] [Indexed: 05/22/2023]
Abstract
Polar growth in root hairs and pollen tubes is an excellent model for investigating plant cell size regulation. While linear plant growth is historically explained by the acid growth theory, which considers that auxin triggers apoplastic acidification by activating plasma membrane P-type H+-ATPases (AHAs) along with cell wall relaxation over long periods, the apoplastic pH (apopH) regulatory mechanisms are unknown for polar growth. Polar growth is a fast process mediated by rapid oscillations that repeat every ∼20-40s. In this review, we explore a reactive oxygen species (ROS)-dependent mechanism that could generate oscillating apopH gradients in a coordinated manner with growth and Ca2+ oscillations. We propose possible mechanisms by which apopH oscillations are coordinated with polar growth together with ROS and Ca2+ waves.
Collapse
Affiliation(s)
- Silvina Mangano
- Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA-CONICET), Av. Patricias Argentinas 435, Buenos Aires CP C1405BWE, Argentina; These authors contributed equally to this work
| | - Javier Martínez Pacheco
- Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA-CONICET), Av. Patricias Argentinas 435, Buenos Aires CP C1405BWE, Argentina; Department of Genetics and Phytopathology, Biological Research Division, Tobacco Research Institute, Carretera Tumbadero, 8 1/2 km, San Antonio de los Baños, Artemisa, Cuba; These authors contributed equally to this work
| | - Cristina Marino-Buslje
- Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA-CONICET), Av. Patricias Argentinas 435, Buenos Aires CP C1405BWE, Argentina
| | - José M Estevez
- Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA-CONICET), Av. Patricias Argentinas 435, Buenos Aires CP C1405BWE, Argentina.
| |
Collapse
|
102
|
Hima Kumari P, Anil Kumar S, Ramesh K, Sudhakar Reddy P, Nagaraju M, Bhanu Prakash A, Shah T, Henderson A, Srivastava RK, Rajasheker G, Chitikineni A, Varshney RK, Rathnagiri P, Lakshmi Narasu M, Kavi Kishor PB. Genome-Wide Identification and Analysis of Arabidopsis Sodium Proton Antiporter (NHX) and Human Sodium Proton Exchanger (NHE) Homologs in Sorghum bicolor. Genes (Basel) 2018; 9:genes9050236. [PMID: 29751546 PMCID: PMC5977176 DOI: 10.3390/genes9050236] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 04/24/2018] [Accepted: 04/24/2018] [Indexed: 11/16/2022] Open
Abstract
Na⁺ transporters play an important role during salt stress and development. The present study is aimed at genome-wide identification, in silico analysis of sodium-proton antiporter (NHX) and sodium-proton exchanger (NHE)-type transporters in Sorghum bicolor and their expression patterns under varied abiotic stress conditions. In Sorghum, seven NHX and nine NHE homologs were identified. Amiloride (a known inhibitor of Na⁺/H⁺ exchanger activity) binding motif was noticed in both types of the transporters. Chromosome 2 was found to be a hotspot region with five sodium transporters. Phylogenetic analysis inferred six ortholog and three paralog groups. To gain an insight into functional divergence of SbNHX/NHE transporters, real-time gene expression was performed under salt, drought, heat, and cold stresses in embryo, root, stem, and leaf tissues. Expression patterns revealed that both SbNHXs and SbNHEs are responsive either to single or multiple abiotic stresses. The predicted protein⁻protein interaction networks revealed that only SbNHX7 is involved in the calcineurin B-like proteins (CBL)- CBL interacting protein kinases (CIPK) pathway. The study provides insights into the functional divergence of SbNHX/NHE transporter genes with tissue specific expressions in Sorghum under different abiotic stress conditions.
Collapse
Affiliation(s)
- P Hima Kumari
- Department of Genetics, Osmania University, Hyderabad 500 007, India.
- Centre for Biotechnology, Institute of Science & Technology, JNT University, Hyderabad 500 085, India.
| | - S Anil Kumar
- Department of Genetics, Osmania University, Hyderabad 500 007, India.
- Centre for Biotechnology, Institute of Science & Technology, JNT University, Hyderabad 500 085, India.
| | - Katam Ramesh
- Department of Biological Sciences, Florida A&M University, Tallahassee, FL 32307, USA.
| | - Palakolanu Sudhakar Reddy
- Center of Excellence in Genomics & Systems Biology, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Hyderabad 502 324, India.
| | - M Nagaraju
- Department of Genetics, Osmania University, Hyderabad 500 007, India.
| | - A Bhanu Prakash
- Center of Excellence in Genomics & Systems Biology, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Hyderabad 502 324, India.
| | - Trushar Shah
- IITA-Kenya c/o International Livestock Research Institute (ILRI), PO Box 30709, Nairobi 00100, Kenya.
| | - Ashley Henderson
- Department of Biological Sciences, Florida A&M University, Tallahassee, FL 32307, USA.
- Ottawa University, Ottawa, KS 66067, USA.
| | - Rakesh K Srivastava
- Center of Excellence in Genomics & Systems Biology, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Hyderabad 502 324, India.
| | - G Rajasheker
- Department of Genetics, Osmania University, Hyderabad 500 007, India.
| | - A Chitikineni
- Center of Excellence in Genomics & Systems Biology, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Hyderabad 502 324, India.
| | - Rajeev K Varshney
- Center of Excellence in Genomics & Systems Biology, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Hyderabad 502 324, India.
| | - P Rathnagiri
- Genomix CARL Pvt. Ltd. Rayalapuram Road, Pulivendula, 516 390, Kadapa, Andhra Pradesh, India.
| | - M Lakshmi Narasu
- Centre for Biotechnology, Institute of Science & Technology, JNT University, Hyderabad 500 085, India.
| | - P B Kavi Kishor
- Department of Genetics, Osmania University, Hyderabad 500 007, India.
| |
Collapse
|
103
|
Huang Y, Cui X, Cen H, Wang K, Zhang Y. Transcriptomic analysis reveals vacuolar Na + (K +)/H + antiporter gene contributing to growth, development, and defense in switchgrass (Panicum virgatum L.). BMC PLANT BIOLOGY 2018; 18:57. [PMID: 29631566 PMCID: PMC5892015 DOI: 10.1186/s12870-018-1278-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Accepted: 03/29/2018] [Indexed: 05/19/2023]
Abstract
BACKGROUND Intracellular Na+ (K+)/H+ antiporters (NHXs) have pivotal functions in regulating plant growth, development, and resistance to a range of stresses. To gain insight into the molecular events underlying their actions in switchgrass (Panicum virgatum L.), we analyzed transcriptomic changes between PvNHX1-overexpression transgenic lines and wild-type (WT) plants using RNA sequencing (RNA-seq) technology. RESULTS The comparison of transcriptomic data from the WT and transgenic plants revealed a large number of differentially expressed genes (DEGs) in the latter. Gene ontology (GO) and KEGG pathway analyses showed that these DEGs were associated with a wide range of functions, and participated in many biological processes. For example, we found that PvNHX1 had an important role in plant growth through its regulation of photosynthetic activity and cell expansion. In addition, PvNHX1 regulated K+ homeostasis, cell expansion and pollen development, indicating that it has unique and specific roles in flower development. We also found that transgenic switchgrass exhibited a higher level of transcription of defense-related genes, especially those involved in disease resistance. CONCLUSION We showed that PvNHX1 had an important role in plant growth and development through its regulation of photosynthetic activity, cell expansion, K+ homeostasis, and pollen development. Additionally, PvNHX1 overexpression activated a complex signal transduction network in response to various biotic and abiotic stresses. In relation to plant growth, development, and defense responses, PvNHX1 also had a vital regulatory role in the formation of a series of plant hormones and transcription factors (TFs). The reliability of the RNA-seq data was confirmed by quantitative real-time PCR. Our data provide a valuable foundation for further research into the molecular mechanisms and physiological roles of NHXs in plants.
Collapse
Affiliation(s)
- Yanhua Huang
- College of Agriculture, China Agricultural University, Beijing, People’s Republic of China
- College of Animal Science and Technology, China Agricultural University, Beijing, People’s Republic of China
| | - Xin Cui
- College of Animal Science and Technology, China Agricultural University, Beijing, People’s Republic of China
| | - Huifang Cen
- College of Animal Science and Technology, China Agricultural University, Beijing, People’s Republic of China
| | - Kehua Wang
- College of Animal Science and Technology, China Agricultural University, Beijing, People’s Republic of China
| | - Yunwei Zhang
- College of Animal Science and Technology, China Agricultural University, Beijing, People’s Republic of China
- National Energy R&D Center for Biomass (NECB), Beijing Sure Academy of Biosciences, Beijing, People’s Republic of China
| |
Collapse
|
104
|
Fan L, Zhao L, Hu W, Li W, Novák O, Strnad M, Simon S, Friml J, Shen J, Jiang L, Qiu QS. Na + ,K + /H + antiporters regulate the pH of endoplasmic reticulum and auxin-mediated development. PLANT, CELL & ENVIRONMENT 2018; 41:850-864. [PMID: 29360148 DOI: 10.1111/pce.13153] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 11/30/2017] [Accepted: 01/17/2018] [Indexed: 06/07/2023]
Abstract
AtNHX5 and AtNHX6 are endosomal Na+ ,K+ /H+ antiporters that are critical for growth and development in Arabidopsis, but the mechanism behind their action remains unknown. Here, we report that AtNHX5 and AtNHX6, functioning as H+ leak, control auxin homeostasis and auxin-mediated development. We found that nhx5 nhx6 exhibited growth variations of auxin-related defects. We further showed that nhx5 nhx6 was affected in auxin homeostasis. Genetic analysis showed that AtNHX5 and AtNHX6 were required for the function of the endoplasmic reticulum (ER)-localized auxin transporter PIN5. Although AtNHX5 and AtNHX6 were colocalized with PIN5 at ER, they did not interact directly. Instead, the conserved acidic residues in AtNHX5 and AtNHX6, which are essential for exchange activity, were required for PIN5 function. AtNHX5 and AtNHX6 regulated the pH in ER. Overall, AtNHX5 and AtNHX6 may regulate auxin transport across the ER via the pH gradient created by their transport activity. H+ -leak pathway provides a fine-tuning mechanism that controls cellular auxin fluxes.
Collapse
Affiliation(s)
- Ligang Fan
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, China
| | - Lei Zhao
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, China
| | - Wei Hu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, China
| | - Weina Li
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, China
| | - Ondřej Novák
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany AS CR and Palacký University, Šlechtitelů 27, CZ-78371, Olomouc, Czech Republic
| | - Miroslav Strnad
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany AS CR and Palacký University, Šlechtitelů 27, CZ-78371, Olomouc, Czech Republic
| | - Sibu Simon
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, CZ-625 00, Brno, Czech Republic
| | - Jiří Friml
- Institute of Science and Technology (IST) Austria, Am Campus 1, 3400, Klosterneuburg, Austria
| | - Jinbo Shen
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - Liwen Jiang
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - Quan-Sheng Qiu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, China
| |
Collapse
|
105
|
Shen Q, Yu J, Fu L, Wu L, Dai F, Jiang L, Wu D, Zhang G. Ionomic, metabolomic and proteomic analyses reveal molecular mechanisms of root adaption to salt stress in Tibetan wild barley. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2018; 123:319-330. [PMID: 29289898 DOI: 10.1016/j.plaphy.2017.12.032] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 12/14/2017] [Accepted: 12/20/2017] [Indexed: 05/18/2023]
Abstract
In our previous study, Tibetan wild barley (Hordeum spontaneum L.) has been found to be rich in the elite accessions with strong abiotic stress tolerance, including salt stress tolerance. However, the molecular mechanism of salt tolerance underlying the wild barley remains to be elucidated. In this study, two Tibetan wild barley accessions, XZ26 (salt-tolerant) and XZ169 (salt-sensitive), were used to investigate ionomic, metabolomic and proteomic responses in roots when exposed to 0, 200 (moderate) and 400 mM (high) salinity. XZ26 showed stronger root growth and maintained higher K concentrations when compared with XZ169 under moderate salinity, while no significant difference was found between the two accessions under high salinity. A total of 574 salt-regulated proteins and 153 salt-regulated metabolites were identified in the roots of both accessions based on quantitative proteomic (iTRAQ methods) and metabolomic (GC-TOF/MS) analysis. XZ26 developed its root adaptive strategies mainly by accumulating more compatible solutes such as proline and inositol, acquiring greater antioxidant ability to cope with ROS, and consuming less energy under salt stress for producing biomass. These findings provide a better understanding of molecular responses of root adaptive strategies to salt stress in the wild barley.
Collapse
Affiliation(s)
- Qiufang Shen
- Department of Agronomy, Key Laboratory of Crop Germplasm Resource of Zhejiang Province, Zhejiang University, Hangzhou 310058, China
| | - Jiahua Yu
- Department of Agronomy, Key Laboratory of Crop Germplasm Resource of Zhejiang Province, Zhejiang University, Hangzhou 310058, China
| | - Liangbo Fu
- Department of Agronomy, Key Laboratory of Crop Germplasm Resource of Zhejiang Province, Zhejiang University, Hangzhou 310058, China
| | - Liyuan Wu
- Department of Agronomy, Key Laboratory of Crop Germplasm Resource of Zhejiang Province, Zhejiang University, Hangzhou 310058, China
| | - Fei Dai
- Department of Agronomy, Key Laboratory of Crop Germplasm Resource of Zhejiang Province, Zhejiang University, Hangzhou 310058, China
| | - Lixi Jiang
- Department of Agronomy, Key Laboratory of Crop Germplasm Resource of Zhejiang Province, Zhejiang University, Hangzhou 310058, China
| | - Dezhi Wu
- Department of Agronomy, Key Laboratory of Crop Germplasm Resource of Zhejiang Province, Zhejiang University, Hangzhou 310058, China.
| | - Guoping Zhang
- Department of Agronomy, Key Laboratory of Crop Germplasm Resource of Zhejiang Province, Zhejiang University, Hangzhou 310058, China
| |
Collapse
|
106
|
Zeng Y, Li Q, Wang H, Zhang J, Du J, Feng H, Blumwald E, Yu L, Xu G. Two NHX-type transporters from Helianthus tuberosus improve the tolerance of rice to salinity and nutrient deficiency stress. PLANT BIOTECHNOLOGY JOURNAL 2018; 16:310-321. [PMID: 28627026 PMCID: PMC5785360 DOI: 10.1111/pbi.12773] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2017] [Revised: 05/30/2017] [Accepted: 06/08/2017] [Indexed: 05/18/2023]
Abstract
The NHX-type cation/H+ transporters in plants have been shown to mediate Na+ (K+ )/H+ exchange for salinity tolerance and K+ homoeostasis. In this study, we identified and characterized two NHX homologues, HtNHX1 and HtNHX2 from an infertile and salinity tolerant species Helianthus tuberosus (cv. Nanyu No. 1). HtNHX1 and HtNHX2 share identical 5'- and 3'-UTR and coding regions, except for a 342-bp segment encoding 114 amino acids (L272 to Q385 ) which is absent in HtNHX2. Both hydroponics and soil culture experiments showed that the expression of HtNHX1 or HtNHX2 improved the rice tolerance to salinity. Expression of HtNHX2, but not HtNHX1, increased rice grain yield, harvest index, total nutrient uptake under K+ -limited salt-stress or general nutrient deficiency conditions. The results provide a novel insight into NHX function in plant mineral nutrition.
Collapse
Affiliation(s)
- Yang Zeng
- State Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjingChina
- Key Laboratory of Plant Nutrition and Fertilization in Low‐Middle Reaches of the Yangtze RiverMinistry of AgricultureNanjing Agricultural UniversityNanjingChina
| | - Qing Li
- Key Laboratory of Plant Nutrition and Fertilization in Low‐Middle Reaches of the Yangtze RiverMinistry of AgricultureNanjing Agricultural UniversityNanjingChina
| | - Haiya Wang
- State Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjingChina
- Key Laboratory of Plant Nutrition and Fertilization in Low‐Middle Reaches of the Yangtze RiverMinistry of AgricultureNanjing Agricultural UniversityNanjingChina
| | - Jianliang Zhang
- State Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjingChina
- Key Laboratory of Plant Nutrition and Fertilization in Low‐Middle Reaches of the Yangtze RiverMinistry of AgricultureNanjing Agricultural UniversityNanjingChina
| | - Jia Du
- State Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjingChina
- Key Laboratory of Plant Nutrition and Fertilization in Low‐Middle Reaches of the Yangtze RiverMinistry of AgricultureNanjing Agricultural UniversityNanjingChina
| | - Huimin Feng
- State Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjingChina
- Key Laboratory of Plant Nutrition and Fertilization in Low‐Middle Reaches of the Yangtze RiverMinistry of AgricultureNanjing Agricultural UniversityNanjingChina
| | | | - Ling Yu
- State Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjingChina
- Key Laboratory of Plant Nutrition and Fertilization in Low‐Middle Reaches of the Yangtze RiverMinistry of AgricultureNanjing Agricultural UniversityNanjingChina
| | - Guohua Xu
- State Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjingChina
- Key Laboratory of Plant Nutrition and Fertilization in Low‐Middle Reaches of the Yangtze RiverMinistry of AgricultureNanjing Agricultural UniversityNanjingChina
| |
Collapse
|
107
|
Pan T, Liu Y, Su X, An L, Qiu QS. Domain-switch analysis of PeNHX3 from Populus euphratica reveals the critical role of the transmembrane domain 11 in Na + and Li + transport. JOURNAL OF PLANT PHYSIOLOGY 2017; 219:1-11. [PMID: 28946051 DOI: 10.1016/j.jplph.2017.09.003] [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: 05/30/2017] [Revised: 09/12/2017] [Accepted: 09/13/2017] [Indexed: 06/07/2023]
Abstract
Populus euphratica, the well-known tree halophyte, tolerates the stress of high levels of salt. We previously showed that the transmembrane domain 11 (TM11) of PeNHX3, a Na+,K+/H+ antiporter from P. euphratica, was crucial for Na+ and Li+ transport in a yeast growth assay. Here, we examined the role of TM11 in catalyzing Na+ and Li+ transport in transgenic Arabidopsis. We found that PeNHX3 localized to the tonoplasts in Arabidopsis. Overexpression of PeNHX3 in Arabidopsis improved seedling growth and enhanced salt tolerance and Li+ detoxification. However, overexpression of PeNHX3 did not improve Arabidopsis growth at KCl concentrations higher than 0.1mM, suggesting a low K+ transport activity for PeNHX3 in plants. We performed in planta domain-switch analysis by replacing the C-terminal domain of AtNHX1 with a C-terminal segment of PeNHX3 containing the TM11 domain. We demonstrated that TM11 was critical for the Na+ and Li+ transport activities by PeNHX3. Taken together, PeNHX3 plays an important role in salt tolerance and Li+ detoxification in plants. TM11 controls the Na+ and Li+ transport activities of PeNHX3 in Arabidopsis.
Collapse
Affiliation(s)
- Ting Pan
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 73000, China
| | - Yafen Liu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 73000, China
| | - Xiaomeng Su
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 73000, China
| | - Lizhe An
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 73000, China
| | - Quan-Sheng Qiu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 73000, China.
| |
Collapse
|
108
|
Brillada C, Rojas-Pierce M. Vacuolar trafficking and biogenesis: a maturation in the field. CURRENT OPINION IN PLANT BIOLOGY 2017; 40:77-81. [PMID: 28865974 DOI: 10.1016/j.pbi.2017.08.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 07/20/2017] [Accepted: 08/15/2017] [Indexed: 05/24/2023]
Abstract
The vacuole is a prominent organelle that is essential for plant viability. The vacuole size, and its role in ion homeostasis, protein degradation and storage, place significant demands for trafficking of vacuolar cargo along the endomembrane system. Recent studies indicate that sorting of vacuolar cargo initiates at the ER and Golgi, but not the trans-Golgi network/early endosome, as previously thought. Furthermore, maturation of the trans-Golgi network into pre-vacuolar compartments seems to contribute to a major route for plant vacuolar traffic that works by bulk flow and ends with membrane fusion between the pre-vacuolar compartment and the tonoplast. Here we summarize recent evidence that indicates conserved and plant-specific mechanisms involved in sorting and trafficking of proteins to this major organelle.
Collapse
Affiliation(s)
- Carla Brillada
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, United States
| | - Marcela Rojas-Pierce
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, United States.
| |
Collapse
|
109
|
Abdelaziz ME, Kim D, Ali S, Fedoroff NV, Al-Babili S. The endophytic fungus Piriformospora indica enhances Arabidopsis thaliana growth and modulates Na +/K + homeostasis under salt stress conditions. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2017; 263:107-115. [PMID: 28818365 DOI: 10.1016/j.plantsci.2017.07.006] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 07/05/2017] [Accepted: 07/08/2017] [Indexed: 05/08/2023]
Abstract
The mutualistic, endophytic fungus Piriformospora indica has been shown to confer biotic and abiotic stress tolerance to host plants. In this study, we investigated the impact of P. indica on the growth of Arabidopsis plants under normal and salt stress conditions. Our results demonstrate that P. indica colonization increases plant biomass, lateral roots density, and chlorophyll content under both conditions. Colonization with P. indica under salt stress was accompanied by a lower Na+/K+ ratio and less pronounced accumulation of anthocyanin, compared to control plants. Moreover, P. indica colonized roots under salt stress showed enhanced transcript levels of the genes encoding the high Affinity Potassium Transporter 1 (HKT1) and the inward-rectifying K+ channels KAT1 and KAT2, which play key roles in regulating Na+ and K+ homeostasis. The effect of P. indica colonization on AtHKT1;1 expression was also confirmed in the Arabidopsis line gl1-HKT:AtHKT1;1 that expresses an additional AtHKT1;1 copy driven by the native promoter. Colonization of the gl1-HKT:AtHKT1;1 by P. indica also increased lateral roots density and led to a better Na+/K+ ratio, which may be attributed to the observed increase in KAT1 and KAT2 transcript levels. Our findings demonstrate that P. indica colonization promotes Arabidopsis growth under salt stress conditions and that this effect is likely caused by modulation of the expression levels of the major Na+ and K+ ion channels, which allows establishing a balanced ion homeostasis of Na+/K+ under salt stress conditions.
Collapse
Affiliation(s)
- Mohamed E Abdelaziz
- King Abdullah University of Science and Technology (KAUST), BESE Division, 23955-6900 Thuwal, Saudi Arabia; Faculty of Agriculture, Cairo University, 12613, Giza, Egypt
| | - Dongjin Kim
- King Abdullah University of Science and Technology (KAUST), BESE Division, 23955-6900 Thuwal, Saudi Arabia; Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT 59717, USA
| | - Shawkat Ali
- King Abdullah University of Science and Technology (KAUST), BESE Division, 23955-6900 Thuwal, Saudi Arabia
| | - Nina V Fedoroff
- King Abdullah University of Science and Technology (KAUST), BESE Division, 23955-6900 Thuwal, Saudi Arabia
| | - Salim Al-Babili
- King Abdullah University of Science and Technology (KAUST), BESE Division, 23955-6900 Thuwal, Saudi Arabia.
| |
Collapse
|
110
|
Gong X, Shi S, Dou F, Song Y, Ma F. Exogenous Melatonin Alleviates Alkaline Stress in Malus hupehensis Rehd. by Regulating the Biosynthesis of Polyamines. Molecules 2017; 22:molecules22091542. [PMID: 28902159 PMCID: PMC6151414 DOI: 10.3390/molecules22091542] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Revised: 09/07/2017] [Accepted: 09/11/2017] [Indexed: 12/25/2022] Open
Abstract
Since melatonin was identified in plants decades ago, much attention has been devoted to discovering its role in plant science. There is still a great deal to learn about the functional importance of melatonin, as well as its functional mode. In this paper, we examine the role of melatonin treatment in the response of Malus hupehensis Rehd. to alkaline conditions. Stressed seedlings showed chlorosis and suppressed growth. However, this phenotype was ameliorated when 5 µM melatonin was added to the irrigation solution. This supplementation was also associated with a reduction in cell membrane damage and maintenance of a normal root system architecture. Fewer reactive oxygen species (ROS) were accumulated due to the enhanced scavenging activity of antioxidant enzymes superoxide dismutase, peroxidase, and catalase. In addition, alkaline-stressed seedlings that received the melatonin supplement accumulated more polyamines compared with untreated seedlings. Transcript levels of six genes involved in polyamine synthesis, including SAMDC1, -3, and -4, and SPDS1, -3, and -5, -6, were upregulated in response to melatonin application. All of these results demonstrate that melatonin has a positive function in plant tolerance to alkaline stress because it regulates enzyme activity and the biosynthesis of polyamines.
Collapse
Affiliation(s)
- Xiaoqing Gong
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A & F University, Yangling 712100, Shaanxi, China.
| | - Shuting Shi
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A & F University, Yangling 712100, Shaanxi, China.
| | - Fangfang Dou
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A & F University, Yangling 712100, Shaanxi, China.
| | - Yi Song
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A & F University, Yangling 712100, Shaanxi, China.
| | - Fengwang Ma
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A & F University, Yangling 712100, Shaanxi, China.
| |
Collapse
|
111
|
Assaha DVM, Ueda A, Saneoka H, Al-Yahyai R, Yaish MW. The Role of Na + and K + Transporters in Salt Stress Adaptation in Glycophytes. Front Physiol 2017; 8:509. [PMID: 28769821 PMCID: PMC5513949 DOI: 10.3389/fphys.2017.00509] [Citation(s) in RCA: 335] [Impact Index Per Article: 47.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 07/03/2017] [Indexed: 12/30/2022] Open
Abstract
Ionic stress is one of the most important components of salinity and is brought about by excess Na+ accumulation, especially in the aerial parts of plants. Since Na+ interferes with K+ homeostasis, and especially given its involvement in numerous metabolic processes, maintaining a balanced cytosolic Na+/K+ ratio has become a key salinity tolerance mechanism. Achieving this homeostatic balance requires the activity of Na+ and K+ transporters and/or channels. The mechanism of Na+ and K+ uptake and translocation in glycophytes and halophytes is essentially the same, but glycophytes are more susceptible to ionic stress than halophytes. The transport mechanisms involve Na+ and/or K+ transporters and channels as well as non-selective cation channels. Thus, the question arises of whether the difference in salt tolerance between glycophytes and halophytes could be the result of differences in the proteins or in the expression of genes coding the transporters. The aim of this review is to seek answers to this question by examining the role of major Na+ and K+ transporters and channels in Na+ and K+ uptake, translocation and intracellular homeostasis in glycophytes. It turns out that these transporters and channels are equally important for the adaptation of glycophytes as they are for halophytes, but differential gene expression, structural differences in the proteins (single nucleotide substitutions, impacting affinity) and post-translational modifications (phosphorylation) account for the differences in their activity and hence the differences in tolerance between the two groups. Furthermore, lack of the ability to maintain stable plasma membrane (PM) potentials following Na+-induced depolarization is also crucial for salt stress tolerance. This stable membrane potential is sustained by the activity of Na+/H+ antiporters such as SOS1 at the PM. Moreover, novel regulators of Na+ and K+ transport pathways including the Nax1 and Nax2 loci regulation of SOS1 expression and activity in the stele, and haem oxygenase involvement in stabilizing membrane potential by activating H+-ATPase activity, favorable for K+ uptake through HAK/AKT1, have been shown and are discussed.
Collapse
Affiliation(s)
- Dekoum V. M. Assaha
- Department of Biology, College of Science, Sultan Qaboos UniversityMuscat, Oman
| | - Akihiro Ueda
- Graduate School of Biosphere Science, Hiroshima UniversityHiroshima, Japan
| | - Hirofumi Saneoka
- Graduate School of Biosphere Science, Hiroshima UniversityHiroshima, Japan
| | - Rashid Al-Yahyai
- Department of Crop Sciences, College of Agricultural and Marine Sciences, Sultan Qaboos UniversityMuscat, Oman
| | - Mahmoud W. Yaish
- Department of Biology, College of Science, Sultan Qaboos UniversityMuscat, Oman
| |
Collapse
|
112
|
Olmos E, García De La Garma J, Gomez-Jimenez MC, Fernandez-Garcia N. Arabinogalactan Proteins Are Involved in Salt-Adaptation and Vesicle Trafficking in Tobacco by-2 Cell Cultures. FRONTIERS IN PLANT SCIENCE 2017; 8:1092. [PMID: 28676820 PMCID: PMC5476920 DOI: 10.3389/fpls.2017.01092] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 06/06/2017] [Indexed: 05/21/2023]
Abstract
Arabinogalactan proteins (AGPs) are a highly diverse family of glycoproteins that are commonly found in most plant species. However, little is known about the physiological and molecular mechanisms of their function. AGPs are involved in different biological processes such as cell differentiation, cell expansion, tissue development and somatic embryogenesis. AGPs are also involved in abiotic stress response such as salinity modulating cell wall expansion. In this study, we describe how salt-adaptation in tobacco BY-2 cell cultures induces important changes in arabinogalactan proteins distribution and contents. Using the immuno-dot blot technique with different anti-AGP antibodies (JIM13, JIM15, and others), we observed that AGPs were highly accumulated in the culture medium of salt-adapted tobacco cells, probably due to the action of phospholipases. We located these AGP epitopes using immunogold labeling in the cytoplasm associated to the endoplasmic reticulum, the golgi apparatus, and vesicles, plasma membrane and tonoplast. Our results show that salt-adaptation induced a significant reduction of the cytoplasm, plasma membrane and tonoplast content of these epitopes. Yariv reagent was added to the control and salt-adapted tobacco cell cultures, leading to cell death induction in control cells but not in salt-adapted cells. Ultrastructural and immunogold labeling revealed that cell death induced by Yariv reagent in control cells was due to the interaction of Yariv reagent with the AGPs linked to the plasma membranes. Finally, we propose a new function of AGPs as a possible sodium carrier through the mechanism of vesicle trafficking from the apoplast to the vacuoles in salt-adapted tobacco BY-2 cells. This mechanism may contribute to sodium homeostasis during salt-adaptation to high saline concentrations.
Collapse
Affiliation(s)
- Enrique Olmos
- Department of Abiotic Stress and Plant Pathology, Centro de Edafología y Biología Aplicada del Segura (CSIC)Murcia, Spain
| | - Jesús García De La Garma
- Department of Abiotic Stress and Plant Pathology, Centro de Edafología y Biología Aplicada del Segura (CSIC)Murcia, Spain
| | - Maria C. Gomez-Jimenez
- Department of Plant Physiology, Faculty of Science, University of ExtremaduraBadajoz, Spain
| | - Nieves Fernandez-Garcia
- Department of Abiotic Stress and Plant Pathology, Centro de Edafología y Biología Aplicada del Segura (CSIC)Murcia, Spain
| |
Collapse
|
113
|
Konopka-Postupolska D, Clark G. Annexins as Overlooked Regulators of Membrane Trafficking in Plant Cells. Int J Mol Sci 2017; 18:E863. [PMID: 28422051 PMCID: PMC5412444 DOI: 10.3390/ijms18040863] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Revised: 04/03/2017] [Accepted: 04/06/2017] [Indexed: 12/11/2022] Open
Abstract
Annexins are an evolutionary conserved superfamily of proteins able to bind membrane phospholipids in a calcium-dependent manner. Their physiological roles are still being intensively examined and it seems that, despite their general structural similarity, individual proteins are specialized toward specific functions. However, due to their general ability to coordinate membranes in a calcium-sensitive fashion they are thought to participate in membrane flow. In this review, we present a summary of the current understanding of cellular transport in plant cells and consider the possible roles of annexins in different stages of vesicular transport.
Collapse
Affiliation(s)
- Dorota Konopka-Postupolska
- Plant Biochemistry Department, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw 02-106, Poland.
| | - Greg Clark
- Molecular, Cell, and Developmental Biology, University of Texas, Austin, TX 78712, USA.
| |
Collapse
|
114
|
Almeida DM, Oliveira MM, Saibo NJM. Regulation of Na+ and K+ homeostasis in plants: towards improved salt stress tolerance in crop plants. Genet Mol Biol 2017; 40:326-345. [PMID: 28350038 PMCID: PMC5452131 DOI: 10.1590/1678-4685-gmb-2016-0106] [Citation(s) in RCA: 226] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 08/18/2016] [Indexed: 01/17/2023] Open
Abstract
Soil salinity is a major abiotic stress that results in considerable crop yield losses worldwide. However, some plant genotypes show a high tolerance to soil salinity, as they manage to maintain a high K+/Na+ ratio in the cytosol, in contrast to salt stress susceptible genotypes. Although, different plant genotypes show different salt tolerance mechanisms, they all rely on the regulation and function of K+ and Na+ transporters and H+ pumps, which generate the driving force for K+ and Na+ transport. In this review we will introduce salt stress responses in plants and summarize the current knowledge about the most important ion transporters that facilitate intra- and intercellular K+ and Na+ homeostasis in these organisms. We will describe and discuss the regulation and function of the H+-ATPases, H+-PPases, SOS1, HKTs, and NHXs, including the specific tissues where they work and their response to salt stress.
Collapse
Affiliation(s)
- Diego M Almeida
- Genomics of Plant Stress Unit, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa and Instituto de Biologia Experimental e Tecnológica, Oeiras, Portugal
| | - M Margarida Oliveira
- Genomics of Plant Stress Unit, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa and Instituto de Biologia Experimental e Tecnológica, Oeiras, Portugal
| | - Nelson J M Saibo
- Genomics of Plant Stress Unit, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa and Instituto de Biologia Experimental e Tecnológica, Oeiras, Portugal
| |
Collapse
|
115
|
Ben Romdhane W, Ben-Saad R, Meynard D, Verdeil JL, Azaza J, Zouari N, Fki L, Guiderdoni E, Al-Doss A, Hassairi A. Ectopic Expression of Aeluropus littoralis Plasma Membrane Protein Gene AlTMP1 Confers Abiotic Stress Tolerance in Transgenic Tobacco by Improving Water Status and Cation Homeostasis. Int J Mol Sci 2017; 18:E692. [PMID: 28338609 PMCID: PMC5412278 DOI: 10.3390/ijms18040692] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 03/12/2017] [Accepted: 03/20/2017] [Indexed: 01/15/2023] Open
Abstract
We report here the isolation and functional analysis of AlTMP1 gene encoding a member of the PMP3 protein family. In Aeluropus littoralis, AlTMP1 is highly induced by abscisic acid (ABA), cold, salt, and osmotic stresses. Transgenic tobacco expressing AlTMP1 exhibited enhanced tolerance to salt, osmotic, H₂O₂, heat and freezing stresses at the seedling stage. Under greenhouse conditions, the transgenic plants showed a higher level of tolerance to drought than to salinity. Noteworthy, AlTMP1 plants yielded two- and five-fold more seeds than non-transgenic plants (NT) under salt and drought stresses, respectively. The leaves of AlTMP1 plants accumulated lower Na⁺ but higher K⁺ and Ca2+ than those of NT plants. Tolerance to osmotic and salt stresses was associated with higher membrane stability, low electrolyte leakage, and improved water status. Finally, accumulation of AlTMP1 in tobacco altered the regulation of some stress-related genes in either a positive (NHX1, CAT1, APX1, and DREB1A) or negative (HKT1 and KT1) manner that could be related to the observed tolerance. These results suggest that AlTMP1 confers stress tolerance in tobacco through maintenance of ion homeostasis, increased membrane integrity, and water status. The observed tolerance may be due to a direct or indirect effect of AlTMP1 on the expression of stress-related genes which could stimulate an adaptive potential not present in NT plants.
Collapse
Affiliation(s)
- Walid Ben Romdhane
- Plant Production Department, College of Food and Agricultural Sciences, King Saud University, P.O. Box 2460, 11451 Riyadh, Saudi Arabia.
- Biotechnology and Plant Improvement Laboratory, Centre of Biotechnology of Sfax, University of Sfax, B.P 1177, 3018 Sfax, Tunisia.
- Current Address: Plant Production Department, College of Food and Agricultural Sciences, King Saud University, P.O. Box 2460, 11451 Riyadh, Saudi Arabia..
| | - Rania Ben-Saad
- Biotechnology and Plant Improvement Laboratory, Centre of Biotechnology of Sfax, University of Sfax, B.P 1177, 3018 Sfax, Tunisia.
| | - Donaldo Meynard
- CIRAD-UMR AGAP (Centre de Cooperation Internationale en Recherche Agronomique pour le Developpement), Avenue Agropolis, 34398 Montpellier CEDEX 5, France.
| | - Jean-Luc Verdeil
- CIRAD-UMR AGAP (Centre de Cooperation Internationale en Recherche Agronomique pour le Developpement), Avenue Agropolis, 34398 Montpellier CEDEX 5, France.
| | - Jalel Azaza
- Biotechnology and Plant Improvement Laboratory, Centre of Biotechnology of Sfax, University of Sfax, B.P 1177, 3018 Sfax, Tunisia.
| | - Nabil Zouari
- Biotechnology and Plant Improvement Laboratory, Centre of Biotechnology of Sfax, University of Sfax, B.P 1177, 3018 Sfax, Tunisia.
| | - Lotfi Fki
- Laboratory of Plant Biotechnology Applied to Crop Improvement, Faculty of Sciences of Sfax, University of Sfax, B.P 802, 3038 Sfax, Tunisia.
| | - Emmanuel Guiderdoni
- CIRAD-UMR AGAP (Centre de Cooperation Internationale en Recherche Agronomique pour le Developpement), Avenue Agropolis, 34398 Montpellier CEDEX 5, France.
| | - Abdullah Al-Doss
- Plant Production Department, College of Food and Agricultural Sciences, King Saud University, P.O. Box 2460, 11451 Riyadh, Saudi Arabia.
| | - Afif Hassairi
- Plant Production Department, College of Food and Agricultural Sciences, King Saud University, P.O. Box 2460, 11451 Riyadh, Saudi Arabia.
- Biotechnology and Plant Improvement Laboratory, Centre of Biotechnology of Sfax, University of Sfax, B.P 1177, 3018 Sfax, Tunisia.
- Current Address: Plant Production Department, College of Food and Agricultural Sciences, King Saud University, P.O. Box 2460, 11451 Riyadh, Saudi Arabia..
| |
Collapse
|
116
|
Chen CL, van der Schoot H, Dehghan S, Alvim Kamei CL, Schwarz KU, Meyer H, Visser RGF, van der Linden CG. Genetic Diversity of Salt Tolerance in Miscanthus. FRONTIERS IN PLANT SCIENCE 2017; 8:187. [PMID: 28261243 PMCID: PMC5306379 DOI: 10.3389/fpls.2017.00187] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 01/30/2017] [Indexed: 05/08/2023]
Abstract
Miscanthus is a woody rhizomatous C4 grass that can be used as a CO2 neutral biofuel resource. It has potential to grow in marginal areas such as saline soils, avoiding competition for arable lands with food crops. This study explored genetic diversity for salt tolerance in Miscanthus and discovered mechanisms and traits that can be used to improve the yield under salt stress. Seventy genotypes of Miscanthus (including 57 M. sinensis, 5 M. sacchariflorus, and 8 hybrids) were evaluated for salt tolerance under saline (150 mM NaCl) and normal growing conditions using a hydroponic system. Analyses of shoot growth traits and ion concentrations revealed the existence of large variation for salt tolerance in the genotypes. We identified genotypes with potential for high biomass production both under control and saline conditions that may be utilized for growth under marginal, saline conditions. Several relatively salt tolerant genotypes had clearly lower Na+ concentrations and showed relatively high K+/Na+ ratios in the shoots under salt stress, indicating that a Na+ exclusion mechanism was utilized to prevent Na+ accumulation in the leaves. Other genotypes showed limited reduction in leaf expansion and growth rate under saline conditions, which may be indicative of osmotic stress tolerance. The genotypes demonstrating potentially different salt tolerance mechanisms can serve as starting material for breeding programs aimed at improving salinity tolerance of Miscanthus.
Collapse
Affiliation(s)
- Chang-Lin Chen
- Plant Breeding, Wageningen University and ResearchWageningen, Netherlands
- Graduate School Experimental Plant Science, Wageningen University and ResearchWageningen, Netherlands
| | | | - Shiva Dehghan
- Plant Breeding, Wageningen University and ResearchWageningen, Netherlands
| | - Claire L. Alvim Kamei
- Plant Breeding, Wageningen University and ResearchWageningen, Netherlands
- Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding ResearchCologne, Germany
| | - Kai-Uwe Schwarz
- Julius Kühn-Institute, Institute for Crop and Soil ScienceBraunschweig, Germany
| | - Heike Meyer
- Julius Kühn-Institute, Institute for Crop and Soil ScienceBraunschweig, Germany
| | | | | |
Collapse
|
117
|
Ma Y, Augé RM, Dong C, Cheng Z(M. Increased salt tolerance with overexpression of cation/proton antiporter 1 genes: a meta-analysis. PLANT BIOTECHNOLOGY JOURNAL 2017; 15:162-173. [PMID: 27383431 PMCID: PMC5258863 DOI: 10.1111/pbi.12599] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 06/21/2016] [Accepted: 06/23/2016] [Indexed: 05/05/2023]
Abstract
Cation/proton antiporter 1 (CPA1) genes encode cellular Na+ /H+ exchanger proteins, which act to adjust ionic balance. Overexpression of CPA1s can improve plant performance under salt stress. However, the diversified roles of the CPA1 family and the various parameters used in evaluating transgenic plants over-expressing CPA1s make it challenging to assess the complex functions of CPA1s and their physiological mechanisms in salt tolerance. Using meta-analysis, we determined how overexpression of CPA1s has influenced several plant characteristics involved in response and resilience to NaCl stress. We also evaluated experimental variables that favour or reduce CPA1 effects in transgenic plants. Viewed across studies, overexpression of CPA1s has increased the magnitude of 10 of the 19 plant characteristics examined, by 25% or more. Among the ten moderating variables, several had substantial impacts on the extent of CPA1 influence: type of culture media, donor and recipient type and genus, and gene family. Genes from monocotyledonous plants stimulated root K+ , root K+ /Na+ , total chlorophyll, total dry weight and root length much more than genes from dicotyledonous species. Genes transformed to or from Arabidopsis have led to smaller CPA1-induced increases in plant characteristics than genes transferred to or from other genera. Heterogeneous expression of CPA1s led to greater increases in leaf chlorophyll and root length than homologous expression. These findings should help guide future investigations into the function of CPA1s in plant salt tolerance and the use of genetic engineering for breeding of resistance.
Collapse
Affiliation(s)
- Yuan‐Chun Ma
- Institute of HorticultureJiangsu Academy of Agricultural Sciences/Jiangsu Key Laboratory for Horticultural Crop Genetic ImprovementNanjingJiangsuChina
- College of HorticultureNanjing Agricultural UniversityNanjingJiangsuChina
- Department of Plant SciencesUniversity of TennesseeKnoxvilleTNUSA
| | - Robert M. Augé
- Department of Plant SciencesUniversity of TennesseeKnoxvilleTNUSA
| | - Chao Dong
- College of HorticultureNanjing Agricultural UniversityNanjingJiangsuChina
| | - Zong‐Ming (Max) Cheng
- College of HorticultureNanjing Agricultural UniversityNanjingJiangsuChina
- Department of Plant SciencesUniversity of TennesseeKnoxvilleTNUSA
| |
Collapse
|
118
|
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.
Collapse
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
| | | |
Collapse
|
119
|
Tardi-Ovadia R, Linker R, Tsror Lahkim L. Direct Estimation of Local pH Change at Infection Sites of Fungi in Potato Tubers. PHYTOPATHOLOGY 2017; 107:132-137. [PMID: 27819539 DOI: 10.1094/phyto-07-16-0262-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Fungi can modify the pH in or around the infected site via alkalization or acidification, and pH monitoring may provide valuable information on host-fungus interactions. The objective of the present study was to examine the ability of two fungi, Colletotrichum coccodes and Helminthosporium solani, to modify the pH of potato tubers during artificial inoculation in situ. Both fungi cause blemishes on potato tubers, which downgrades tuber quality and yield. Direct visualization and estimation of pH changes near the inoculation area were achieved using pH indicators and image analysis. The results showed that the pH of the area infected by either fungus increased from potato native pH of approximately 6.0 to 7.4 to 8.0. By performing simple analysis of the images, it was also possible to derive the growth curve of each fungus and estimate the lag phase of the radial growth: 10 days for C. coccodes and 17 days H. solani. In addition, a distinctive halo (an edge area with increased pH) was observed only during the lag phase of H. solani infection. pH modulation is a major factor in pathogen-host interaction and the proposed method offers a simple and rapid way to monitor these changes.
Collapse
Affiliation(s)
- R Tardi-Ovadia
- First and second authors: Faculty of Civil and Environmental Engineering, Technion-Israel Institute of Technology. Haifa 32000, Israel; and third author: Department of Plant Pathology & Weed Research, Institute of Plant Protection, Agricultural Research Organization, Gilat Research Center, M.P. Negev 85280, Israel
| | - R Linker
- First and second authors: Faculty of Civil and Environmental Engineering, Technion-Israel Institute of Technology. Haifa 32000, Israel; and third author: Department of Plant Pathology & Weed Research, Institute of Plant Protection, Agricultural Research Organization, Gilat Research Center, M.P. Negev 85280, Israel
| | - L Tsror Lahkim
- First and second authors: Faculty of Civil and Environmental Engineering, Technion-Israel Institute of Technology. Haifa 32000, Israel; and third author: Department of Plant Pathology & Weed Research, Institute of Plant Protection, Agricultural Research Organization, Gilat Research Center, M.P. Negev 85280, Israel
| |
Collapse
|
120
|
Tripathy MK, Tiwari BS, Reddy MK, Deswal R, Sopory SK. Ectopic expression of PgRab7 in rice plants (Oryza sativa L.) results in differential tolerance at the vegetative and seed setting stage during salinity and drought stress. PROTOPLASMA 2017; 254:109-124. [PMID: 26666551 DOI: 10.1007/s00709-015-0914-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 11/19/2015] [Indexed: 05/23/2023]
Abstract
In this work, we have overexpressed a vesicle trafficking protein, Rab7, from a stress-tolerant plant, Pennisetum glaucum, in a high-yielding but stress-sensitive rice variety Pusa Basmati-1 (PB-1). The transgenic rice plants were tested for tolerance against salinity and drought stress. The transgenic plants showed considerable tolerance at the vegetative stage against both salinity (200 mM NaCl) and drought stress (up to 12 days after withdrawing water). The protection against salt and drought stress may be by regulating Na+ ion homeostasis, as the transgenic plants showed altered expression of multiple transporter genes, including OsNHX1, OsNHX2, OsSOS1, OsVHA, and OsGLRs. In addition, decreased generation and maintenance of lesser reactive oxygen species (ROS), with maintenance of chloroplast grana and photosynthetic machinery was observed. When evaluated for reproductive growth, 89-96 % of seed setting was maintained in transgenic plants during drought stress; however, under salt stress, a 33-53 % decrease in seed setting was observed. These results indicate that PgRab7 overexpression in rice confers differential tolerance at the seed setting stage during salinity and drought stress and could be a favored target for raising drought-tolerant crops.
Collapse
Affiliation(s)
- Manas Kumar Tripathy
- Plant Molecular Biology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, 78712, USA.
| | - Budhi Sagar Tiwari
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Malireddy K Reddy
- Plant Molecular Biology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Renu Deswal
- Department of Botany, University of Delhi, Delhi, 110007, India
| | - Sudhir K Sopory
- Plant Molecular Biology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
- Jawaharlal Nehru University, New Delhi, 110067, India.
| |
Collapse
|
121
|
Almeida DM, Gregorio GB, Oliveira MM, Saibo NJM. Five novel transcription factors as potential regulators of OsNHX1 gene expression in a salt tolerant rice genotype. PLANT MOLECULAR BIOLOGY 2017; 93:61-77. [PMID: 27766460 DOI: 10.1007/s11103-016-0547-7] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Accepted: 09/24/2016] [Indexed: 05/03/2023]
Abstract
This manuscript reports the identification and characterization of five transcription factors binding to the promoter of OsNHX1 in a salt stress tolerant rice genotype (Hasawi). Although NHX1 encoding genes are known to be highly regulated at the transcription level by different abiotic stresses, namely salt and drought stress, until now only one transcription factor (TF) binding to its promoter has been reported. In order to unveil the TFs regulating NHX1 gene expression, which is known to be highly induced under salt stress, we have used a Y1H system to screen a salt induced rice cDNA expression library from Hasawi. This approach allowed us to identify five TFs belonging to three distinct TF families: one TCP (OsPCF2), one CPP (OsCPP5) and three NIN-like (OsNIN-like2, OsNIN-like3 and OsNIN-like4) binding to the OsNHX1 gene promoter. We have also shown that these TFs act either as transcriptional activators (OsPCF2, OsNIN-like4) or repressors (OsCPP5, OsNIN-like2) and their encoding genes are differentially regulated by salt and PEG-induced drought stress in two rice genotypes, Nipponbare (salt-sensitive) and Hasawi (salt-tolerant). The transactivation activity of OsNIN-like3 was not possible to determine. Increased soil salinity has a direct impact on the reduction of plant growth and crop yield and it is therefore fundamental to understand the molecular mechanisms underlying gene expression regulation under adverse environmental conditions. OsNHX1 is the most abundant K+-Na+/H+ antiporter localized in the tonoplast and its gene expression is induced by salt, drought and ABA. To investigate how OsNHX1 is transcriptionally regulated in response to salt stress in a salt-tolerant rice genotype (Hasawi), a salt-stress-induced cDNA expression library was constructed and subsequently screened using the yeast one-hybrid system and the OsNHX1 promoter as bait. Five transcription factors (TFs) belonging to three distinct TF families: one TCP (OsPCF2), one CPP (OsCPP5) and three NIN-like (OsNIN-like2, OsNIN-like3 and OsNIN-like4) were identified as binding to OsNHX1 promoter. Transactivation activity assays performed in Arabidopsis and rice protoplasts showed that OsPCF2 and OsNIN-like4 are activators of the OsNHX1 gene expression, while OsCPP5 and OsNIN-like2 act as repressors. The transactivation activity of OsNIN-like3 needs to be further investigated. Gene expression studies showed that OsNHX1 transcript level is highly induced by salt and PEG-induced drought stress in both shoots and roots in both Nipponbare and Hasawi rice genotypes. Nevertheless, OsNHX1 seems to play a particular role in shoots in response to drought. Most of the TFs binding to OsNHX1 promoter showed a modest transcriptional regulation under stress conditions, however, in response to most of the conditions studied, the OsPCF2 was induced earlier than OsNHX1, indicating that OsPCF2 may activate OsNHX1 gene expression. In addition, although the OsNHX1 response to salt and PEG-induced drought stress in either shoots or roots was quite similar in both rice genotypes, the expression of OsPCF2 in roots under salt stress and the OsNIN-like4 in roots subjected to PEG was mainly up-regulated in Hasawi, indicating that these TFs may be associated with the salt and drought stress tolerance observed for this genotype.
Collapse
Affiliation(s)
- Diego M Almeida
- Genomics of Plant Stress Unit, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa and Instituto de Biologia Experimental e Tecnológica, Av. da República, 2780-157, Oeiras, Portugal
| | - Glenn B Gregorio
- International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines
- East-West Seed Company (EWS), Km. 54 Cagayan Valley Road, San Rafael, 3008, Bulacan, Philippines
| | - M Margarida Oliveira
- Genomics of Plant Stress Unit, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa and Instituto de Biologia Experimental e Tecnológica, Av. da República, 2780-157, Oeiras, Portugal
| | - Nelson J M Saibo
- Genomics of Plant Stress Unit, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa and Instituto de Biologia Experimental e Tecnológica, Av. da República, 2780-157, Oeiras, Portugal.
| |
Collapse
|
122
|
Porcel R, Aroca R, Azcon R, Ruiz-Lozano JM. Regulation of cation transporter genes by the arbuscular mycorrhizal symbiosis in rice plants subjected to salinity suggests improved salt tolerance due to reduced Na(+) root-to-shoot distribution. MYCORRHIZA 2016; 26:673-84. [PMID: 27113587 DOI: 10.1007/s00572-016-0704-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 04/18/2016] [Indexed: 05/18/2023]
Abstract
Rice is a salt-sensitive crop whose productivity is strongly reduced by salinity around the world. Plants growing in saline soils are subjected to the toxicity of specific ions such as sodium, which damage cell organelles and disrupt metabolism. Plants have evolved biochemical and molecular mechanisms to cope with the negative effects of salinity. These include the regulation of genes with a role in the uptake, transport or compartmentation of Na(+) and/or K(+). Studies have shown that the arbuscular mycorrhizal (AM) symbiosis alleviates salt stress in several host plant species. However, despite the abundant literature showing mitigation of ionic imbalance by the AM symbiosis, the molecular mechanisms involved are barely explored. The objective of this study was to elucidate the effects of the AM symbiosis on the expression of several well-known rice transporters involved in Na(+)/K(+) homeostasis and measure Na(+) and K(+) contents and their ratios in different plant tissues. Results showed that OsNHX3, OsSOS1, OsHKT2;1 and OsHKT1;5 genes were considerably upregulated in AM plants under saline conditions as compared to non-AM plants. Results suggest that the AM symbiosis favours Na(+) extrusion from the cytoplasm, its sequestration into the vacuole, the unloading of Na(+) from the xylem and its recirculation from photosynthetic organs to roots. As a result, there is a decrease of Na(+) root-to-shoot distribution and an increase of Na(+) accumulation in rice roots which seems to enhance the plant tolerance to salinity and allows AM rice plants to maintain their growing processes under salt conditions.
Collapse
Affiliation(s)
- Rosa Porcel
- Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín (CSIC), Profesor Albareda n° 1, 18008, Granada, Spain
| | - Ricardo Aroca
- Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín (CSIC), Profesor Albareda n° 1, 18008, Granada, Spain
| | - Rosario Azcon
- Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín (CSIC), Profesor Albareda n° 1, 18008, Granada, Spain
| | - Juan Manuel Ruiz-Lozano
- Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín (CSIC), Profesor Albareda n° 1, 18008, Granada, Spain.
| |
Collapse
|
123
|
Qiu QS. AtNHX5 and AtNHX6: Roles in protein transport. PLANT SIGNALING & BEHAVIOR 2016; 11:e1184810. [PMID: 27175802 PMCID: PMC4973783 DOI: 10.1080/15592324.2016.1184810] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 04/27/2016] [Accepted: 04/27/2016] [Indexed: 05/24/2023]
Abstract
AtNHX5 and AtNHX6, endosomal Na(+),K(+)/H(+) antiporters in Arabidopsis, are localized in the Golgi, trans-Golgi network, and prevacuolear compartment. It becomes evident that AtNHX5 and AtNHX6 play an important role in protein transport toward the vacuole. Studies have shown that AtNHX5 and AtNHX6 regulate the transport of seed storage proteins as well as the biogenesis of the protein storage vacuoles. Three distinct mechanisms have been revealed for the roles of AtNHX5 and AtNHX6 in protein transport. AtNHX5 and AtNHX6 control: (i) the binding of VSR to its cargoes; (ii) the recycling of VSRs; and (iii) subcellular localization of the SNARE complex. Moreover, it has been found that the endosomal pH homeostasis maintained by AtNHX5 and AtNHX6 is critical for the transport of seed storage proteins. Taken together, AtNHX5 and AtNHX6 regulate the trafficking of seed storage proteins into the vacuole; the H(+) leak pathway conducted by AtNHX5 and AtNHX6 is critical for protein transport.
Collapse
Affiliation(s)
- Quan-Sheng Qiu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, China
| |
Collapse
|
124
|
Zhou H, Qi K, Liu X, Yin H, Wang P, Chen J, Wu J, Zhang S. Genome-wide identification and comparative analysis of the cation proton antiporters family in pear and four other Rosaceae species. Mol Genet Genomics 2016; 291:1727-42. [DOI: 10.1007/s00438-016-1215-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2015] [Accepted: 05/06/2016] [Indexed: 11/28/2022]
|
125
|
Cai X, Zhang C, Shu W, Ye Z, Li H, Zhang Y. The transcription factor SlDof22 involved in ascorbate accumulation and salinity stress in tomato. Biochem Biophys Res Commun 2016; 474:736-741. [PMID: 27157141 DOI: 10.1016/j.bbrc.2016.04.148] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2016] [Accepted: 04/28/2016] [Indexed: 11/18/2022]
Abstract
Ascorbic acid (AsA) is an important antioxidant and its biosynthesis in plants has extensively been investigated. However, the key regulatory factors controlling the accumulation of AsA remain elusive. Here we report that tomato SlDof22, a member of the Dof family, negatively regulated AsA accumulation in tomato. RNA interference (RNAi) of SlDof22 in transgenic lines induced AsA levels, and affected the expression of genes in the D-mannose/L-galactose pathway and AsA recycling. In addition, SlSOS1 was significantly down-regulated in SlDof22 RNAi plants which resulted in reduced tolerance to salt stress. We further found that SlDof22 could bind to the promoter sequence of SlSOS1 gene by yeast one-hybrid analysis. Taken together, our data suggested that the Dof transcription factor SIDof22 involved in ascorbate accumulation and salt stress response in tomato.
Collapse
Affiliation(s)
- Xiaofeng Cai
- Development and Collaborative Innovation Center of Plant Germplasm Resources, College of Life and Environment Science, Shanghai Normal University, Shanghai, 200234, China
| | - Chanjuan Zhang
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | - Wenbo Shu
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | - Zhibiao Ye
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | - Hanxia Li
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yuyang Zhang
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China.
| |
Collapse
|
126
|
Qiu QS. Plant endosomal NHX antiporters: Activity and function. PLANT SIGNALING & BEHAVIOR 2016; 11:e1147643. [PMID: 26890367 PMCID: PMC4973769 DOI: 10.1080/15592324.2016.1147643] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 01/25/2016] [Accepted: 01/25/2016] [Indexed: 05/28/2023]
Abstract
The Arabidopsis NHX antiporter family contains eight members that are divided into three subclasses: vacuolar, endosomal, and plasma membrane. While the plasma membrane and vacuolar NHXs have been studied extensively, the activity and function of the endosomal NHXs are beginning to be discovered. AtNHX5 and AtNHX6 are endosomal Na(+),K(+)/H(+) antiporters that share high sequence similarity. They are localized in the Golgi, trans-Golgi network (TGN), and prevacuolear compartment (PVC). Studies have shown that AtNHX5 and AtNHX6 mediate K(+) and Na(+) transport, and regulate cellular pH homeostasis. Sequence alignment has found that AtNHX5 and AtNHX6 contain four conserved acidic amino acid residues in transmembrane domains that align with yeast and human NHXs. Three of these conserved acidic residues are critical for K(+) transport and seedling growth in Arabidopsis. Moreover, studies have shown that the precursors of the seed storage proteins are missorted to the apoplast in the nhx5 nhx6 knockout mutant, suggesting that AtNHX5 and AtNHX6 regulate protein transport into the vacuole. Further analysis found that AtNHX5 and AtNHX6 regulated the binding of VSR to its cargoes. Taken together, AtNHX5 and AtNHX6 play an important role in cellular ion and pH homeostasis, and are essential for protein transport into the vacuole.
Collapse
Affiliation(s)
- Quan-Sheng Qiu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, China
| |
Collapse
|
127
|
AtNHX5 and AtNHX6 Are Required for the Subcellular Localization of the SNARE Complex That Mediates the Trafficking of Seed Storage Proteins in Arabidopsis. PLoS One 2016; 11:e0151658. [PMID: 26986836 PMCID: PMC4795774 DOI: 10.1371/journal.pone.0151658] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 03/02/2016] [Indexed: 12/02/2022] Open
Abstract
The SNARE complex composed of VAMP727, SYP22, VTI11 and SYP51 is critical for protein trafficking and PSV biogenesis in Arabidopsis. This SNARE complex directs the fusion between the prevacuolar compartment (PVC) and the vacuole, and thus mediates protein trafficking to the vacuole. In this study, we examined the role of AtNHX5 and AtNHX6 in regulating this SNARE complex and its function in protein trafficking. We found that AtNHX5 and AtNHX6 were required for seed production, protein trafficking and PSV biogenesis. We further found that the nhx5 nhx6 syp22 triple mutant showed severe defects in seedling growth and seed development. The triple mutant had short siliques and reduced seed sets, but larger seeds. In addition, the triple mutant had numerous smaller protein storage vacuoles (PSVs) and accumulated precursors of the seed storage proteins in seeds. The PVC localization of SYP22 and VAMP727 was repressed in nhx5 nhx6, while a significant amount of SYP22 and VAMP727 was trapped in the Golgi or TGN in nhx5 nhx6. AtNHX5 and AtNHX6 were co-localized with SYP22 and VAMP727. Three conserved acidic residues, D164, E188, and D193 in AtNHX5 and D165, E189, and D194 in AtNHX6, were essential for the transport of the storage proteins, indicating the importance of exchange activity in protein transport. AtNHX5 or AtNHX6 did not interact physically with the SNARE complex. Taken together, AtNHX5 and AtNHX6 are required for the PVC localization of the SNARE complex and hence its function in protein transport. AtNHX5 and AtNHX6 may regulate the subcellular localization of the SNARE complex by their transport activity.
Collapse
|
128
|
Solis J, Baisakh N, Brandt SR, Villordon A, La Bonte D. Transcriptome Profiling of Beach Morning Glory (Ipomoea imperati) under Salinity and Its Comparative Analysis with Sweetpotato. PLoS One 2016; 11:e0147398. [PMID: 26848754 PMCID: PMC4743971 DOI: 10.1371/journal.pone.0147398] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 01/04/2016] [Indexed: 01/23/2023] Open
Abstract
The response and adaption to salt remains poorly understood for beach morning glory [Ipomoea imperati (Vahl) Griseb], one of a few relatives of sweetpotato, known to thrive under salty and extreme drought conditions. In order to understand the genetic mechanisms underlying salt tolerance of a Convolvulaceae member, a genome-wide transcriptome study was carried out in beach morning glory by 454 pyrosequencing. A total of 286,584 filtered reads from both salt stressed and unstressed (control) root and shoot tissues were assembled into 95,790 unigenes with an average length of 667 base pairs (bp) and N50 of 706 bp. Putative differentially expressed genes (DEGs) were identified as transcripts overrepresented under salt stressed tissues compared to the control, and were placed into metabolic pathways. Most of these DEGs were involved in stress response, membrane transport, signal transduction, transcription activity and other cellular and molecular processes. We further analyzed the gene expression of 14 candidate genes of interest for salt tolerance through quantitative reverse transcription PCR (qRT-PCR) and confirmed their differential expression under salt stress in both beach morning glory and sweetpotato. The results comparing transcripts of I. imperati against the transcriptome of other Ipomoea species, including sweetpotato are also presented in this study. In addition, 6,233 SSR markers were identified, and an in silico analysis predicted that 434 primer pairs out of 4,897 target an identifiable homologous sequence in other Ipomoea transcriptomes, including sweetpotato. The data generated in this study will help in understanding the basics of salt tolerance of beach morning glory and the SSR resources generated will be useful for comparative genomics studies and further enhance the path to the marker-assisted breeding of sweetpotato for salt tolerance.
Collapse
Affiliation(s)
- Julio Solis
- School of Plant, Environmental, and Soil Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, United States of America
| | - Niranjan Baisakh
- School of Plant, Environmental, and Soil Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, United States of America
- * E-mail: (NB); (DL)
| | - Steven R. Brandt
- Louisiana Digital Media Center, Louisiana State University, Baton Rouge, LA, United States of America
| | - Arthur Villordon
- Sweet Potato Research Station, Louisiana State University Agricultural Center, Chase, LA, United States of America
| | - Don La Bonte
- School of Plant, Environmental, and Soil Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, United States of America
- * E-mail: (NB); (DL)
| |
Collapse
|
129
|
Cao B, Long D, Zhang M, Liu C, Xiang Z, Zhao A. Molecular characterization and expression analysis of the mulberry Na(+)/H(+) exchanger gene family. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2016; 99:49-58. [PMID: 26730882 DOI: 10.1016/j.plaphy.2015.12.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 12/16/2015] [Accepted: 12/16/2015] [Indexed: 06/05/2023]
Abstract
Na(+)/H(+) exchangers (NHXs) have important roles in cellular pH, and Na(+) and K(+) homeostasis in plants. Mulberry is not only an important traditional economic woody plant known for its leaves, which are the exclusive food source of the silkworm Bombyx mori, but it can also adapt to many different adverse conditions, including saline environments. However, little is known about the NHXs in this important perennial tree. In this study, we identified and cloned seven putative NHX gene family members from Morus atropurpurea based on a genome-wide analysis of the Morus genome database. A phylogenetic analysis and genomic organization of mulberry NHXs suggested that the mulberry NHX family forms three distinct subgroups. Transcriptome data and real-time PCR of different mulberry varieties under normal culture conditions revealed that the mulberry NHX family has a different tissue-specific pattern in the two mulberry species. The MaNHX genes' expression analyses under different stresses (salt and drought) and signal molecules (abscisic acid, salicylic acid, hydrogen peroxide and methyl jasmonate) revealed that MaNHXs not only could be induced by salt, drought and abscisic acid as describe in the literature, but were also induced by other signal molecules, which indicated that MaNHX members exhibited diverse and complicated expression patterns in different mulberry tissues under various abiotic stresses, phytohormones and plant signaling molecules. Our results provide some insights into new and emerging cellular and physiological functions of this group of H(+)-coupled cation exchangers, beyond their function in salt tolerance, and also provide the basis for further characterizations of MaNHXs' physiological functions.
Collapse
Affiliation(s)
- Boning Cao
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing 400716, China
| | - Dingpei Long
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing 400716, China
| | - Meng Zhang
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing 400716, China
| | - Changying Liu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing 400716, China
| | - Zhonghuai Xiang
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing 400716, China
| | - Aichun Zhao
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing 400716, China.
| |
Collapse
|
130
|
Uslu VV, Grossmann G. The biosensor toolbox for plant developmental biology. CURRENT OPINION IN PLANT BIOLOGY 2016; 29:138-47. [PMID: 26802805 DOI: 10.1016/j.pbi.2015.12.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 12/01/2015] [Accepted: 12/02/2015] [Indexed: 05/14/2023]
Abstract
Plant development is highly interconnected with the metabolic state of tissues and cells. Current research efforts focus on the identification of the links and mechanisms that govern the interplay between metabolic and gene-regulatory networks. Genetically encoded sensors that allow detection of small molecules in vivo and at high spatio-temporal resolution promise to be the tools of choice for quantifying and visualizing the dynamics of metabolite flux in plants. We provide an overview about current approaches to measure signaling molecules, such as hormones, calcium and sugars, as well as for monitoring the metabolic state via energy equivalents and pH. Biosensors show great potential to address questions of plant development but there are also limitations where alternative approaches are needed.
Collapse
Affiliation(s)
- Veli V Uslu
- Ruprecht-Karls-Universität Heidelberg, Department of Plant Molecular Biology, Centre for Organismal Studies, Im Neuenheimer Feld 360, 69120 Heidelberg, Germany
| | - Guido Grossmann
- Ruprecht-Karls-Universität Heidelberg, CellNetworks Excellence Cluster and Centre for Organismal Studies, Im Neuenheimer Feld 329, 69120 Heidelberg, Germany.
| |
Collapse
|
131
|
Amin USM, Biswas S, Elias SM, Razzaque S, Haque T, Malo R, Seraj ZI. Enhanced Salt Tolerance Conferred by the Complete 2.3 kb cDNA of the Rice Vacuolar Na(+)/H(+) Antiporter Gene Compared to 1.9 kb Coding Region with 5' UTR in Transgenic Lines of Rice. FRONTIERS IN PLANT SCIENCE 2016; 7:14. [PMID: 26834778 PMCID: PMC4724728 DOI: 10.3389/fpls.2016.00014] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2015] [Accepted: 01/07/2016] [Indexed: 05/23/2023]
Abstract
Soil salinity is one of the most challenging problems that restricts the normal growth and production of rice worldwide. It has therefore become very important to produce more saline tolerant rice varieties. This study shows constitutive over-expression of the vacuolar Na(+)/H(+) antiporter gene (OsNHX1) from the rice landrace (Pokkali) and attainment of enhanced level of salinity tolerance in transgenic rice plants. It also shows that inclusion of the complete un-translated regions (UTRs) of the alternatively spliced OsNHX1 gene provides a higher level of tolerance to the transgenic rice. Two separate transformation events of the OsNHX1 gene, one with 1.9 kb region containing the 5' UTR with CDS and the other of 2.3 kb, including 5' UTR, CDS, and the 3' UTR regions were performed. The transgenic plants with these two different constructs were advanced to the T3 generation and physiological and molecular screening of homozygous plants was conducted at seedling and reproductive stages under salinity (NaCl) stress. Both transgenic lines were observed to be tolerant compared to WT plants at both physiological stages. However, the transgenic lines containing the CDS with both the 5' and 3' UTR were significantly more tolerant compared to the transgenic lines containing OsNHX1 gene without the 3' UTR. At the seedling stage at 12 dS/m stress, the chlorophyll content was significantly higher (P < 0.05) and the electrolyte leakage significantly lower (P < 0.05) in the order 2.3 kb > 1.9 kb > and WT lines. Yield in g/plant in the best line from the 2.3 kb plants was significantly more (P < 0.01) compared, respectively, to the best 1.9 kb line and WT plants at stress of 6 dS/m. Transformation with the complete transcripts rather than the CDS may therefore provide more durable level of tolerance.
Collapse
|
132
|
Gharsallah C, Fakhfakh H, Grubb D, Gorsane F. Effect of salt stress on ion concentration, proline content, antioxidant enzyme activities and gene expression in tomato cultivars. AOB PLANTS 2016; 8:plw055. [PMID: 27543452 PMCID: PMC5091694 DOI: 10.1093/aobpla/plw055] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Accepted: 07/29/2016] [Indexed: 05/20/2023]
Abstract
Salinity is a constraint limiting plant growth and productivity of crops throughout the world. Understanding the mechanism underlying plant response to salinity provides new insights into the improvement of salt tolerance-crops of importance. In the present study, we report on the responses of twenty cultivars of tomato. We have clustered genotypes into scale classes according to their response to increased NaCl levels. Three local tomato genotypes, representative of different saline scale classes, were selected for further investigation. During early (0 h, 6 h and 12 h) and later (7 days) stages of the response to salt treatment, ion concentrations (Na+, K+ and Ca2+), proline content, enzyme activities (catalase, ascorbate peroxidase and guiacol peroxidase) were recorded. qPCR analysis of candidate genes WRKY (8, 31and 39), ERF (9, 16 and 80), LeNHX (1, 3 and 4) and HKT (class I) were performed. A high K+, Ca2 +and proline accumulation as well as a decrease of Na+ concentration-mediated salt tolerance. Concomitant with a pattern of high-antioxidant enzyme activities, tolerant genotypes also displayed differential patterns of gene expression during the response to salt stress.
Collapse
Affiliation(s)
- Charfeddine Gharsallah
- Laboratory of Molecular Genetics, Immunology and Biotechnology, Faculty of Sciences of Tunis, University of Tunis ElManar, Tunis 2092, Tunisia
| | - Hatem Fakhfakh
- Laboratory of Molecular Genetics, Immunology and Biotechnology, Faculty of Sciences of Tunis, University of Tunis ElManar, Tunis 2092, Tunisia Faculty of Sciences of Bizerte, University of Carthage, Zarzouna 7021, Tunisia
| | - Douglas Grubb
- Department of Molecular Signal Processing, Leibniz Institute of Plant Biochemistry, Weinberg 3, Halle, 06120 Saale, Germany
| | - Faten Gorsane
- Laboratory of Molecular Genetics, Immunology and Biotechnology, Faculty of Sciences of Tunis, University of Tunis ElManar, Tunis 2092, Tunisia Faculty of Sciences of Bizerte, University of Carthage, Zarzouna 7021, Tunisia
| |
Collapse
|
133
|
Gürel F, Öztürk ZN, Uçarlı C, Rosellini D. Barley Genes as Tools to Confer Abiotic Stress Tolerance in Crops. FRONTIERS IN PLANT SCIENCE 2016; 7:1137. [PMID: 27536305 PMCID: PMC4971604 DOI: 10.3389/fpls.2016.01137] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 07/18/2016] [Indexed: 05/19/2023]
Abstract
Barley is one of the oldest cultivated crops in the world with a high adaptive capacity. The natural tolerance of barley to stress has led to increasing interest in identification of stress responsive genes through small/large-scale omics studies, comparative genomics, and overexpression of some of these genes by genetic transformation. Two major categories of proteins involved in stress tolerance are transcription factors (TFs) responsible from the re-programming of the metabolism in stress environment, and genes encoding Late Embryogenesis Abundant (LEA) proteins, antioxidant enzymes, osmolytes, and transporters. Constitutive overexpression of several barley TFs, such as C-repeat binding factors (HvCBF4), dehydration-responsive element-binding factors (HvDREB1), and WRKYs (HvWRKY38), in transgenic plants resulted in higher tolerance to drought and salinity, possibly by effectively altering the expression levels of stress tolerance genes due to their higher DNA binding affinity. Na(+)/H(+) antiporters, channel proteins, and lipid transporters can also be the strong candidates for engineering plants for tolerance to salinity and low temperatures.
Collapse
Affiliation(s)
- Filiz Gürel
- Department of Molecular Biology and Genetics, Faculty of Science, Istanbul UniversityIstanbul, Turkey
- *Correspondence: Filiz Gürel
| | - Zahide N. Öztürk
- Department of Agricultural Genetic Engineering, Ayhan Şahenk Faculty of Agricultural Sciences and Technologies, Niğde UniversityNiğde, Turkey
| | - Cüneyt Uçarlı
- Department of Molecular Biology and Genetics, Faculty of Science, Istanbul UniversityIstanbul, Turkey
| | - Daniele Rosellini
- Department of Agricultural, Food, and Environmental Sciences, University of PerugiaPerugia, Italy
| |
Collapse
|
134
|
Alkanaimsh S, Karuppanan K, Guerrero A, Tu AM, Hashimoto B, Hwang MS, Phu ML, Arzola L, Lebrilla CB, Dandekar AM, Falk BW, Nandi S, Rodriguez RL, McDonald KA. Transient Expression of Tetrameric Recombinant Human Butyrylcholinesterase in Nicotiana benthamiana. FRONTIERS IN PLANT SCIENCE 2016; 7:743. [PMID: 27379103 PMCID: PMC4909763 DOI: 10.3389/fpls.2016.00743] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 05/17/2016] [Indexed: 05/08/2023]
Abstract
To optimize the expression, extraction and purification of plant-derived tetrameric recombinant human butyrylcholinesterase (prBChE), we describe the development and use of plant viral amplicon-based gene expression system; Tobacco Mosaic Virus (TMV) RNA-based overexpression vector (TRBO) to express enzymatically active FLAG-tagged plant made recombinant butyrylcholinesterase (rBChE) in Nicotiana benthamiana leaves using transient agroinfiltration. Two gene expression cassettes were designed to express the recombinant protein in either the ER or to the apoplastic compartment. Leaf homogenization was used to isolate ER-retained recombinant butyrylcholinesterase (prBChE-ER) while apoplast-targeted rBChE was isolated by either leaf homogenization (prBChE) or vacuum-extraction of apoplastic wash fluid (prBChE-AWF). rBChE from apoplast wash fluid had a higher specific activity but lower enzyme yield than leaf homogenate. To optimize the isolation and purification of total recombinant protein from leaf homogenates, an acidic extraction buffer was used. The acidic extraction buffer yielded >95% enzymatically active tetrameric rBChE as verified by Coomassie stained and native gel electrophoresis. Furthermore, when compared to human butyrylcholinesterase, the prBChE was found to be similar in terms of tetramerization and enzyme kinetics. The N-linked glycan profile of purified prBChE-ER was found to be mostly high mannose structures while the N-linked glycans on prBChE-AWF were primarily complex. The glycan profile of the prBChE leaf homogenates showed a mixture of high mannose, complex and paucimannose type N-glycans. These findings demonstrate the ability of plants to produce rBChE that is enzymatically active and whose oligomeric state is comparable to mammalian butyrylcholinesterase. The process of plant made rBChE tetramerization and strategies for improving its pharmacokinetics properties are also discussed.
Collapse
Affiliation(s)
- Salem Alkanaimsh
- Department of Chemical Engineering, University of California, DavisDavis, CA, USA
| | - Kalimuthu Karuppanan
- Department of Chemical Engineering, University of California, DavisDavis, CA, USA
| | - Andrés Guerrero
- Department of Chemistry, University of California, DavisDavis, CA, USA
| | - Aye M. Tu
- Department of Plant Science, University of California, DavisDavis, CA, USA
| | - Bryce Hashimoto
- Department of Chemical Engineering, University of California, DavisDavis, CA, USA
| | - Min Sook Hwang
- Department of Plant Pathology, University of California, DavisDavis, CA, USA
| | - My L. Phu
- Department of Plant Science, University of California, DavisDavis, CA, USA
| | - Lucas Arzola
- Department of Chemical Engineering, University of California, DavisDavis, CA, USA
| | | | - Abhaya M. Dandekar
- Department of Plant Science, University of California, DavisDavis, CA, USA
| | - Bryce W. Falk
- Department of Plant Pathology, University of California, DavisDavis, CA, USA
| | - Somen Nandi
- Department of Molecular and Cellular Biology, University of California, DavisDavis, CA, USA
- Department of Global HealthShare Initiative, University of California, DavisDavis, CA, USA
| | - Raymond L. Rodriguez
- Department of Molecular and Cellular Biology, University of California, DavisDavis, CA, USA
- Department of Global HealthShare Initiative, University of California, DavisDavis, CA, USA
| | - Karen A. McDonald
- Department of Chemical Engineering, University of California, DavisDavis, CA, USA
- Department of Global HealthShare Initiative, University of California, DavisDavis, CA, USA
- *Correspondence: Karen A. McDonald,
| |
Collapse
|
135
|
Höhner R, Aboukila A, Kunz HH, Venema K. Proton Gradients and Proton-Dependent Transport Processes in the Chloroplast. FRONTIERS IN PLANT SCIENCE 2016; 7:218. [PMID: 26973667 PMCID: PMC4770017 DOI: 10.3389/fpls.2016.00218] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 02/08/2016] [Indexed: 05/04/2023]
Abstract
Proton gradients are fundamental to chloroplast function. Across thylakoid membranes, the light induced -proton gradient is essential for ATP synthesis. As a result of proton pumping into the thylakoid lumen, an alkaline stromal pH develops, which is required for full activation of pH-dependent Calvin Benson cycle enzymes. This implies that a pH gradient between the cytosol (pH 7) and the stroma (pH 8) is established upon illumination. To maintain this pH gradient chloroplasts actively extrude protons. More than 30 years ago it was already established that these proton fluxes are electrically counterbalanced by Mg(2+), K(+), or Cl(-) fluxes, but only recently the first transport systems that regulate the pH gradient were identified. Notably several (Na(+),K(+))/H(+) antiporter systems where identified, that play a role in pH gradient regulation, ion homeostasis, osmoregulation, or coupling of secondary active transport. The established pH gradients are important to drive uptake of essential ions and solutes, but not many transporters involved have been identified to date. In this mini review we summarize the current status in the field and the open questions that need to be addressed in order to understand how pH gradients are maintained, how this is interconnected with other transport processes and what this means for chloroplast function.
Collapse
Affiliation(s)
- Ricarda Höhner
- Plant Physiology, School of Biological Sciences, Washington State University, PullmanWA, USA
| | - Ali Aboukila
- Departamento de Bioquímica, Biología Celular y Molecular de Plantas, Estacion Experimental del Zaidín, Consejo Superior de Investigaciones CientíficasGranada, Spain
| | - Hans-Henning Kunz
- Plant Physiology, School of Biological Sciences, Washington State University, PullmanWA, USA
- *Correspondence: Hans-Henning Kunz, Kees Venema,
| | - Kees Venema
- Departamento de Bioquímica, Biología Celular y Molecular de Plantas, Estacion Experimental del Zaidín, Consejo Superior de Investigaciones CientíficasGranada, Spain
- *Correspondence: Hans-Henning Kunz, Kees Venema,
| |
Collapse
|
136
|
Wang L, Wu X, Liu Y, Qiu QS. AtNHX5 and AtNHX6 Control Cellular K+ and pH Homeostasis in Arabidopsis: Three Conserved Acidic Residues Are Essential for K+ Transport. PLoS One 2015; 10:e0144716. [PMID: 26650539 PMCID: PMC4674129 DOI: 10.1371/journal.pone.0144716] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 11/23/2015] [Indexed: 11/22/2022] Open
Abstract
AtNHX5 and AtNHX6, the endosomal Na+,K+/H+ antiporters in Arabidopsis, play an important role in plant growth and development. However, their function in K+ and pH homeostasis remains unclear. In this report, we characterized the function of AtNHX5 and AtNHX6 in K+ and H+ homeostasis in Arabidopsis. Using a yeast expression system, we found that AtNHX5 and AtNHX6 recovered tolerance to high K+ or salt. We further found that AtNHX5 and AtNHX6 functioned at high K+ at acidic pH while AtCHXs at low K+ under alkaline conditions. In addition, we showed that the nhx5 nhx6 double mutant contained less K+ and was sensitive to low K+ treatment. Overexpression of AtNHX5 or AtNHX6 gene in nhx5 nhx6 recovered root growth to the wild-type level. Three conserved acidic residues, D164, E188, and D193 in AtNHX5 and D165, E189, and D194 in AtNHX6, were essential for K+ homeostasis and plant growth. nhx5 nhx6 had a reduced vacuolar and cellular pH as measured with the fluorescent pH indicator BCECF or semimicroelectrode. We further show that AtNHX5 and AtNHX6 are localized to Golgi and TGN. Taken together, AtNHX5 and AtNHX6 play an important role in K+ and pH homeostasis in Arabidopsis. Three conserved acidic residues are essential for K+ transport.
Collapse
Affiliation(s)
- Liguang Wang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, China, 73000
| | - Xuexia Wu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, China, 73000
| | - Yafen Liu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, China, 73000
| | - Quan-Sheng Qiu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, China, 73000
| |
Collapse
|
137
|
Shen Y, Shen L, Shen Z, Jing W, Ge H, Zhao J, Zhang W. The potassium transporter OsHAK21 functions in the maintenance of ion homeostasis and tolerance to salt stress in rice. PLANT, CELL & ENVIRONMENT 2015; 38:2766-79. [PMID: 26046379 DOI: 10.1111/pce.12586] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Revised: 05/28/2015] [Accepted: 06/01/2015] [Indexed: 05/20/2023]
Abstract
The intracellular potassium (K(+) ) homeostasis, which is crucial for plant survival in saline environments, is modulated by K(+) channels and transporters. Some members of the high-affinity K(+) transporter (HAK) family are believed to function in the regulation of plant salt tolerance, but the physiological mechanisms remain unclear. Here, we report a significant inducement of OsHAK21 expression by high-salinity treatment and provide genetic evidence of the involvement of OsHAK21 in rice salt tolerance. Disruption of OsHAK21 rendered plants sensitive to salt stress. Compared with the wild type, oshak21 accumulated less K(+) and considerably more Na(+) in both shoots and roots, and had a significantly lower K(+) net uptake rate but higher Na(+) uptake rate. Our analyses of subcellular localizations and expression patterns showed that OsHAK21 was localized in the plasma membrane and expressed in xylem parenchyma and individual endodermal cells (putative passage cells). Further functional characterizations of OsHAK21 in K(+) uptake-deficient yeast and Arabidopsis revealed that OsHAK21 possesses K(+) transporter activity. These results demonstrate that OsHAK21 may mediate K(+) absorption by the plasma membrane and play crucial roles in the maintenance of the Na(+) /K(+) homeostasis in rice under salt stress.
Collapse
Affiliation(s)
- Yue Shen
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Like Shen
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zhenxing Shen
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Wen Jing
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Hongliang Ge
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Jiangzhe Zhao
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Wenhua Zhang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| |
Collapse
|
138
|
Volkov V. Salinity tolerance in plants. Quantitative approach to ion transport starting from halophytes and stepping to genetic and protein engineering for manipulating ion fluxes. FRONTIERS IN PLANT SCIENCE 2015; 6:873. [PMID: 26579140 PMCID: PMC4621421 DOI: 10.3389/fpls.2015.00873] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 10/01/2015] [Indexed: 05/18/2023]
Abstract
Ion transport is the fundamental factor determining salinity tolerance in plants. The Review starts from differences in ion transport between salt tolerant halophytes and salt-sensitive plants with an emphasis on transport of potassium and sodium via plasma membranes. The comparison provides introductory information for increasing salinity tolerance. Effects of salt stress on ion transport properties of membranes show huge opportunities for manipulating ion fluxes. Further steps require knowledge about mechanisms of ion transport and individual genes of ion transport proteins. Initially, the Review describes methods to measure ion fluxes, the independent set of techniques ensures robust and reliable basement for quantitative approach. The Review briefly summarizes current data concerning Na(+) and K(+) concentrations in cells, refers to primary thermodynamics of ion transport and gives special attention to individual ion channels and transporters. Simplified scheme of a plant cell with known transport systems at the plasma membrane and tonoplast helps to imagine the complexity of ion transport and allows choosing specific transporters for modulating ion transport. The complexity is enhanced by the influence of cell size and cell wall on ion transport. Special attention is given to ion transporters and to potassium and sodium transport by HKT, HAK, NHX, and SOS1 proteins. Comparison between non-selective cation channels and ion transporters reveals potential importance of ion transporters and the balance between the two pathways of ion transport. Further on the Review describes in detail several successful attempts to overexpress or knockout ion transporters for changing salinity tolerance. Future perspectives are questioned with more attention given to promising candidate ion channels and transporters for altered expression. Potential direction of increasing salinity tolerance by modifying ion channels and transporters using single point mutations is discussed and questioned. An alternative approach from synthetic biology is to create new regulation networks using novel transport proteins with desired properties for transforming agricultural crops. The approach had not been widely used earlier; it leads also to theoretical and pure scientific aspects of protein chemistry, structure-function relations of membrane proteins, systems biology and physiology of stress and ion homeostasis. Summarizing, several potential ways are aimed at required increase in salinity tolerance of plants of interest.
Collapse
Affiliation(s)
- Vadim Volkov
- Faculty of Life Sciences and Computing, London Metropolitan UniversityLondon, UK
| |
Collapse
|
139
|
Das P, Nutan KK, Singla-Pareek SL, Pareek A. Understanding salinity responses and adopting 'omics-based' approaches to generate salinity tolerant cultivars of rice. FRONTIERS IN PLANT SCIENCE 2015; 6:712. [PMID: 26442026 PMCID: PMC4563168 DOI: 10.3389/fpls.2015.00712] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 08/25/2015] [Indexed: 05/21/2023]
Abstract
Soil salinity is one of the main constraints affecting production of rice worldwide, by reducing growth, pollen viability as well as yield of the plant. Therefore, detailed understanding of the response of rice towards soil salinity at the physiological and molecular level is a prerequisite for its effective management. Various approaches have been adopted by molecular biologists or breeders to understand the mechanism for salinity tolerance in plants and to develop salt tolerant rice cultivars. Genome wide analysis using 'omics-based' tools followed by identification and functional validation of individual genes is becoming one of the popular approaches to tackle this task. On the other hand, mutation breeding and insertional mutagenesis has also been exploited to obtain salinity tolerant crop plants. This review looks into various responses at cellular and whole plant level generated in rice plants toward salinity stress thus, evaluating the suitability of intervention of functional genomics to raise stress tolerant plants. We have tried to highlight the usefulness of the contemporary 'omics-based' approaches such as genomics, proteomics, transcriptomics and phenomics towards dissecting out the salinity tolerance trait in rice. In addition, we have highlighted the importance of integration of various 'omics' approaches to develop an understanding of the machinery involved in salinity response in rice and to move forward to develop salt tolerant cultivars of rice.
Collapse
Affiliation(s)
- Priyanka Das
- Stress Physiology and Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru UniversityNew Delhi, India
| | - Kamlesh K. Nutan
- Stress Physiology and Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru UniversityNew Delhi, India
| | - Sneh L. Singla-Pareek
- Plant Molecular Biology Group, International Centre for Genetic Engineering and BiotechnologyNew Delhi, India
| | - Ashwani Pareek
- Stress Physiology and Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru UniversityNew Delhi, India
| |
Collapse
|
140
|
Khan MS, Ahmad D, Khan MA. Trends in genetic engineering of plants with (Na+/H+) antiporters for salt stress tolerance. BIOTECHNOL BIOTEC EQ 2015. [DOI: 10.1080/13102818.2015.1060868] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
|
141
|
Rao ES, Kadirvel P, Symonds RC, Geethanjali S, Thontadarya RN, Ebert AW. Variations in DREB1A and VP1.1 Genes Show Association with Salt Tolerance Traits in Wild Tomato (Solanum pimpinellifolium). PLoS One 2015; 10:e0132535. [PMID: 26161546 PMCID: PMC4498769 DOI: 10.1371/journal.pone.0132535] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 06/15/2015] [Indexed: 12/23/2022] Open
Abstract
Association analysis was conducted in a core collection of 94 genotypes of Solanum pimpinellifolium to identify variations linked to salt tolerance traits (physiological and yield traits under salt stress) in four candidate genes viz., DREB1A, VP1.1, NHX1, and TIP. The candidate gene analysis covered a concatenated length of 4594 bp per individual and identified five SNP/Indels in DREB1A and VP1.1 genes explaining 17.0% to 25.8% phenotypic variation for various salt tolerance traits. Out of these five alleles, one at 297 bp in DREB1A had in-frame deletion of 6 bp (CTGCAT) or 12 bp (CTGCATCTGCAT), resulting in two alleles, viz., SpDREB1A_297_6 and SpDREB1A_297_12. These alleles individually or as haplotypes accounted for maximum phenotypic variance of about 25% for various salt tolerance traits. Design of markers for selection of the favorable alleles/haplotypes will hasten marker-assisted introgression of salt tolerance from S. pimpinellifolium into cultivated tomato.
Collapse
Affiliation(s)
- Eguru Sreenivasa Rao
- Division of Vegetable Crops, ICAR-Indian Institute of Horticultural Research, Bengaluru, India
- Genetic Resources and Seed Unit, AVRDC–The World Vegetable Center, Shanhua, Tainan, Taiwan
| | - Palchamy Kadirvel
- Crop Improvement Section, ICAR-Indian Institute of Oilseeds Research, Rajendranagar, Hyderabad, India
- Genetic Resources and Seed Unit, AVRDC–The World Vegetable Center, Shanhua, Tainan, Taiwan
| | - Rachael C. Symonds
- School of Biosciences, The University of Nottingham Malaysia Campus, Jalan Broga, Semenyih, Selangor, Darul Ehsan, Malaysia
- Genetic Resources and Seed Unit, AVRDC–The World Vegetable Center, Shanhua, Tainan, Taiwan
| | - Subramaniam Geethanjali
- Department of Millets, Centre for Plant Breeding and Genetics, Tamil Nadu Agricultural University, Coimbatore, India
- Genetic Resources and Seed Unit, AVRDC–The World Vegetable Center, Shanhua, Tainan, Taiwan
| | | | - Andreas W. Ebert
- Genetic Resources and Seed Unit, AVRDC–The World Vegetable Center, Shanhua, Tainan, Taiwan
- * E-mail: (AWE)
| |
Collapse
|
142
|
Kinclova-Zimmermannova O, Falson P, Cmunt D, Sychrova H. A Hydrophobic Filter Confers the Cation Selectivity of Zygosaccharomyces rouxii Plasma-Membrane Na+/H+ Antiporter. J Mol Biol 2015; 427:1681-94. [DOI: 10.1016/j.jmb.2015.02.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 02/10/2015] [Accepted: 02/11/2015] [Indexed: 10/24/2022]
|
143
|
Reguera M, Bassil E, Tajima H, Wimmer M, Chanoca A, Otegui MS, Paris N, Blumwald E. pH Regulation by NHX-Type Antiporters Is Required for Receptor-Mediated Protein Trafficking to the Vacuole in Arabidopsis. THE PLANT CELL 2015; 27:1200-17. [PMID: 25829439 PMCID: PMC4558692 DOI: 10.1105/tpc.114.135699] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 02/26/2015] [Accepted: 03/12/2015] [Indexed: 05/18/2023]
Abstract
Protein trafficking requires proper ion and pH homeostasis of the endomembrane system. The NHX-type Na(+)/H(+) antiporters NHX5 and NHX6 localize to the Golgi, trans-Golgi network, and prevacuolar compartments and are required for growth and trafficking to the vacuole. In the nhx5 nhx6 T-DNA insertional knockouts, the precursors of the 2S albumin and 12S globulin storage proteins accumulated and were missorted to the apoplast. Immunoelectron microscopy revealed the presence of vesicle clusters containing storage protein precursors and vacuolar sorting receptors (VSRs). Isolation and identification of complexes of VSRs with unprocessed 12S globulin by 2D blue-native PAGE/SDS-PAGE indicated that the nhx5 nhx6 knockouts showed compromised receptor-cargo association. In vivo interaction studies using bimolecular fluorescence complementation between VSR2;1, aleurain, and 12S globulin suggested that nhx5 nhx6 knockouts showed a significant reduction of VSR binding to both cargoes. In vivo pH measurements indicated that the lumens of VSR compartments containing aleurain, as well as the trans-Golgi network and prevacuolar compartments, were significantly more acidic in nhx5 nhx6 knockouts. This work demonstrates the importance of NHX5 and NHX6 in maintaining endomembrane luminal pH and supports the notion that proper vacuolar trafficking and proteolytic processing of storage proteins require endomembrane pH homeostasis.
Collapse
Affiliation(s)
- Maria Reguera
- Department of Plant Sciences, University of California, Davis, California 95616
| | - Elias Bassil
- Department of Plant Sciences, University of California, Davis, California 95616
| | - Hiromi Tajima
- Department of Plant Sciences, University of California, Davis, California 95616
| | - Monika Wimmer
- Institute of Crop Science and Resource Conservation, Division of Plant Nutrition, University of Bonn, D-53115 Bonn, Germany
| | - Alexandra Chanoca
- Departments of Botany and Genetics, University of Wisconsin, Madison, Wisconsin 53706
| | - Marisa S Otegui
- Departments of Botany and Genetics, University of Wisconsin, Madison, Wisconsin 53706
| | - Nadine Paris
- Biochemistry and Plant Molecular Biology Laboratory, Unité Mixte de Recherche 5004, 34060 Montpellier, France
| | - Eduardo Blumwald
- Department of Plant Sciences, University of California, Davis, California 95616
| |
Collapse
|
144
|
Xu H, Martinoia E, Szabo I. Organellar channels and transporters. Cell Calcium 2015; 58:1-10. [PMID: 25795199 DOI: 10.1016/j.ceca.2015.02.006] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 02/20/2015] [Indexed: 12/22/2022]
Abstract
Decades of intensive research have led to the discovery of most plasma membrane ion channels and transporters and the characterization of their physiological functions. In contrast, although over 80% of transport processes occur inside the cells, the ion flux mechanisms across intracellular membranes (the endoplasmic reticulum, Golgi apparatus, endosomes, lysosomes, mitochondria, chloroplasts, and vacuoles) are difficult to investigate and remain poorly understood. Recent technical advances in super-resolution microscopy, organellar electrophysiology, organelle-targeted fluorescence imaging, and organelle proteomics have pushed a large step forward in the research of intracellular ion transport. Many new organellar channels are molecularly identified and electrophysiologically characterized. Additionally, molecular identification of many of these ion channels/transporters has made it possible to study their physiological functions by genetic and pharmacological means. For example, organellar channels have been shown to regulate important cellular processes such as programmed cell death and photosynthesis, and are involved in many different pathologies. This special issue (SI) on organellar channels and transporters aims to provide a forum to discuss the recent advances and to define the standard and open questions in this exciting and rapidly developing field. Along this line, a new Gordon Research Conference dedicated to the multidisciplinary study of intracellular membrane transport proteins will be launched this coming summer.
Collapse
Affiliation(s)
- Haoxing Xu
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University Avenue, Ann Arbor, MI 48109-1048, USA.
| | - Enrico Martinoia
- Institute of Plant Biology, University of Zürich, Zollikerstr. 107, CH-8008 Zürich, Switzerland.
| | - Ildiko Szabo
- Department of Biology, University of Padova, Viale G. Colombo 3, 35121 Padova, Italy; CNR Neuroscience Institute, Viale G. Colombo 3, 35121 Padova, Italy.
| |
Collapse
|
145
|
Kizhakkedath P, Jegadeeson V, Venkataraman G, Parida A. A vacuolar antiporter is differentially regulated in leaves and roots of the halophytic wild rice Porteresia coarctata (Roxb.) Tateoka. Mol Biol Rep 2014; 42:1091-105. [PMID: 25481774 DOI: 10.1007/s11033-014-3848-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 11/25/2014] [Indexed: 12/28/2022]
Abstract
Vacuolar NHX-type antiporters play a role in Na(+)/K(+) uptake that contributes to growth, nutrition and development. Under salt/osmotic stress they mediate the vacuolar compartmentalization of K(+)/Na(+), thereby preventing toxic Na(+)K(+) ratios in the cytosol. Porteresia coarctata (Roxb.) Tateoka, a mangrove associate, is a distant wild relative of cultivated rice and is saline as well as submergence tolerant. A vacuolar NHX homolog isolated from a P. coarctata cDNA library (PcNHX1) shows 96 % identity (nucleotide level) to OsNHX1. Diurnal PcNHX1 expression in leaves was found to be largely unaltered, though damped by salinity. PcNHX1 promoter directed GUS expression is phloem-specific in leaves, stem and roots of transgenic plants in the absence of stress. Under NaCl stress, GUS expression was also seen in the epidermal and sub-epidermal layers (mesophyll, guard cells and trichomes) of leaves, root tip. The salinity in the rhizosphere of P. coarctata varies considerably due to diurnal/semi-diurnal tidal inundation. The diurnal expression of PcNHX1 in leaves and salinity induced expression in roots may have evolved in response to dynamic changes in salinity of in the P. coarctata rhizosphere. Despite high sequence conservation between OsNHX1 and PcNHX1, the distinctive expression pattern of PcNHX1 exemplifies how variation in expression is fine tuned to suit the halophytic growth habitat of a plant.
Collapse
Affiliation(s)
- Praseetha Kizhakkedath
- Department of Plant Molecular Biology, M.S. Swaminathan Research Foundation, III Cross Street, Taramani Institutional Area, Chennai, 600113, India
| | | | | | | |
Collapse
|
146
|
Bassil E, Blumwald E. The ins and outs of intracellular ion homeostasis: NHX-type cation/H(+) transporters. CURRENT OPINION IN PLANT BIOLOGY 2014; 22:1-6. [PMID: 25173972 DOI: 10.1016/j.pbi.2014.08.002] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 08/14/2014] [Accepted: 08/14/2014] [Indexed: 05/18/2023]
Abstract
The biochemical characterization of cation/H(+) exchange has been known since 1985 [1], yet only recently have we begun to understand the contribution of individual exchangers to ion homeostasis in plants. One particularly important class of exchangers is the NHX-type that is associated with Na(+) transport and therefore salinity tolerance. New evidence suggests that under normal growth conditions NHXs are critical regulators of K(+) and pH homeostasis and have important roles, depending on their cellular localization, in the generation of turgor as well as in vesicular trafficking. Recent advances highlight novel and exciting functions of intracellular NHXs in growth and development, stress adaptation and osmotic adjustment. Here, we elaborate on new and emerging cellular and physiological functions of this group of H(+)-coupled cation exchangers.
Collapse
Affiliation(s)
- Elias Bassil
- Department of Plant Sciences, University of California, Davis, CA 95616, United States
| | - Eduardo Blumwald
- Department of Plant Sciences, University of California, Davis, CA 95616, United States.
| |
Collapse
|
147
|
Bojórquez-Quintal E, Velarde-Buendía A, Ku-González Á, Carillo-Pech M, Ortega-Camacho D, Echevarría-Machado I, Pottosin I, Martínez-Estévez M. Mechanisms of salt tolerance in habanero pepper plants (Capsicum chinense Jacq.): Proline accumulation, ions dynamics and sodium root-shoot partition and compartmentation. FRONTIERS IN PLANT SCIENCE 2014; 5:605. [PMID: 25429292 PMCID: PMC4228851 DOI: 10.3389/fpls.2014.00605] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 10/17/2014] [Indexed: 05/04/2023]
Abstract
Despite its economic relevance, little is known about salt tolerance mechanisms in pepper plants. To address this question, we compared differences in responses to NaCl in two Capsicum chinense varieties: Rex (tolerant) and Chichen-Itza (sensitive). Under salt stress (150 mM NaCl over 7 days) roots of Rex variety accumulated 50 times more compatible solutes such as proline compared to Chichen-Itza. Mineral analysis indicated that Na(+) is restricted to roots by preventing its transport to leaves. Fluorescence analysis suggested an efficient Na(+) compartmentalization in vacuole-like structures and in small intracellular compartments in roots of Rex variety. At the same time, Na(+) in Chichen-Itza plants was compartmentalized in the apoplast, suggesting substantial Na(+) extrusion. Rex variety was found to retain more K(+) in its roots under salt stress according to a mineral analysis and microelectrode ion flux estimation (MIFE). Vanadate-sensitive H(+) efflux was higher in Chichen-Itza variety plants, suggesting a higher activity of the plasma membrane H(+)-ATPase, which fuels the extrusion of Na(+), and, possibly, also the re-uptake of K(+). Our results suggest a combination of stress tolerance mechanisms, in order to alleviate the salt-induced injury. Furthermore, Na(+) extrusion to apoplast does not appear to be an efficient strategy for salt tolerance in pepper plants.
Collapse
Affiliation(s)
- Emanuel Bojórquez-Quintal
- Unidad de Bioquímica y Biología Molecular de Plantas, Centro de Investigación Científica de YucatánYucatán, México
| | - Ana Velarde-Buendía
- Centro Universitario de Investigaciones Biomédicas, Universidad de ColimaColima, México
| | - Ángela Ku-González
- Unidad de Bioquímica y Biología Molecular de Plantas, Centro de Investigación Científica de YucatánYucatán, México
| | - Mildred Carillo-Pech
- Unidad de Bioquímica y Biología Molecular de Plantas, Centro de Investigación Científica de YucatánYucatán, México
| | - Daniela Ortega-Camacho
- Unidad de Ciencias del Agua, Centro de Investigación Científica de YucatánYucatán, México
| | - Ileana Echevarría-Machado
- Unidad de Bioquímica y Biología Molecular de Plantas, Centro de Investigación Científica de YucatánYucatán, México
| | - Igor Pottosin
- Centro Universitario de Investigaciones Biomédicas, Universidad de ColimaColima, México
| | - Manuel Martínez-Estévez
- Unidad de Bioquímica y Biología Molecular de Plantas, Centro de Investigación Científica de YucatánYucatán, México
| |
Collapse
|
148
|
Gong X, Zhang J, Liu JH. A stress responsive gene of Fortunella crassifolia FcSISP functions in salt stress resistance. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2014; 83:10-9. [PMID: 25054478 DOI: 10.1016/j.plaphy.2014.07.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2014] [Accepted: 07/03/2014] [Indexed: 05/23/2023]
Abstract
Exploration of genes functioning in salt tolerance is crucial for generating transgenic plants with enhanced salt tolerance. In this study, we report the isolation and functional characterization of a stress-responsive gene FcSISP from Meiwa kumquat (Fortunella crassifolia). FcSISP encodes a putative protein of 47 amino acids, with a calculated molecular mass of 4.94 kDa and theoretical isoelectric point of 3.76, and was localized in the nucleus. Transcript levels of FcSISP were induced by dehydration, cold, salt and bacterium causing citrus canker, and hormones (salicylic acid and abscisic acid), with the greatest induction under salt treatment. Overexpression of FcSISP in tobacco (Nicotiana nudicaulis) conferred enhanced salt tolerance. The transgenic lines accumulated lower Na(+) contents, leading to reduced Na/K ratio, but accumulated more proline than the wild type (WT). Steady state mRNA levels of genes involved in Na(+) exchange (three SOS genes and three NHX genes) and proline synthesis (P5CS and P5CR) were higher in the transgenic lines in comparison with WT. Moreover, overexpression of FcSISP in trifoliate orange [Poncirus trifoliata (L.) Raf.], a widely-used and salt-sensitive citrus rootstock, led to elevated salt tolerance. Taken together, the data demonstrate that FcSISP plays a positive role in salt tolerance and that it holds a great potential for engineering salt tolerance in crops.
Collapse
Affiliation(s)
- Xiaoqing Gong
- Key Laboratory of Horticultural Plant Biology (MOE), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan 430070, China
| | - Jingyan Zhang
- Key Laboratory of Horticultural Plant Biology (MOE), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan 430070, China
| | - Ji-Hong Liu
- Key Laboratory of Horticultural Plant Biology (MOE), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan 430070, China.
| |
Collapse
|
149
|
McCubbin T, Bassil E, Zhang S, Blumwald E. Vacuolar Na⁺/H⁺ NHX-Type Antiporters Are Required for Cellular K⁺ Homeostasis, Microtubule Organization and Directional Root Growth. PLANTS 2014; 3:409-26. [PMID: 27135511 PMCID: PMC4844347 DOI: 10.3390/plants3030409] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 08/07/2014] [Accepted: 08/18/2014] [Indexed: 12/13/2022]
Abstract
Na⁺/H⁺ antiporters (NHXs) are integral membrane transporters that catalyze the electroneutral exchange of K⁺ or Na⁺ for H⁺ and are implicated in cell expansion, development, pH and ion homeostasis and salt tolerance. Arabidopsis contains four vacuolar NHX isoforms (NHX1-NHX4), but only the functional roles for NHX1 and NHX2 have been assessed thus far. Colocalization studies indicated that NHX3 and NHX4 colocalize to the tonoplast. To investigate the role of all vacuolar NHX isoforms, a quadruple knockout nhx1nhx2nhx3nhx4, lacking all vacuolar NHXs, was generated. Seedlings of nhx1nhx2nhx3nhx4 displayed significantly reduced growth, with markedly shorter hypocotyls. Under high K⁺, but not Na⁺, pronounced root skewing occurred in nhx1nhx2nhx3nhx4, suggesting that the organization of the cytoskeleton might be perturbed. Whole mount immunolabeling of cortical microtubules indicated that high K⁺ caused significant microtubule reorganization in nhx1nhx2nhx3nhx4 root cells of the elongation zone. Using microtubule stabilizing (Taxol) and destabilizing (propyzamide) drugs, we found that the effect of K⁺ on nhx1nhx2nhx3nhx4 root growth was antagonistic to that of Taxol, whereas elevated K⁺ exacerbated the endogenous effect of propyzamide on root skewing. Collectively, our results suggest that altered K⁺ homeostasis leads to an increase in the dynamics of cortical microtubule reorganization in nhx1nhx2nhx3nhx4 root epidermal cells of the elongation zone.
Collapse
Affiliation(s)
- Tyler McCubbin
- Department of Plant Sciences, University of California, Davis, CA 95616, USA.
| | - Elias Bassil
- Department of Plant Sciences, University of California, Davis, CA 95616, USA.
| | - Shiqi Zhang
- Department of Plant Sciences, University of California, Davis, CA 95616, USA.
| | - Eduardo Blumwald
- Department of Plant Sciences, University of California, Davis, CA 95616, USA.
| |
Collapse
|
150
|
Wang L, Feng X, Zhao H, Wang L, An L, Qiu QS. Functional analysis of the Na+,K+/H+ antiporter PeNHX3 from the tree halophyte Populus euphratica in yeast by model-guided mutagenesis. PLoS One 2014; 9:e104147. [PMID: 25093858 PMCID: PMC4122410 DOI: 10.1371/journal.pone.0104147] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 07/08/2014] [Indexed: 01/08/2023] Open
Abstract
Na+,K+/H+ antiporters are H+-coupled cotransporters that are crucial for cellular homeostasis. Populus euphratica, a well-known tree halophyte, contains six Na+/H+ antiporter genes (PeNHX1-6) that have been shown to function in salt tolerance. However, the catalytic mechanisms governing their ion transport remain largely unknown. Using the crystal structure of the Na+/H+ antiporter from the Escherichia coli (EcNhaA) as a template, we built the three-dimensional structure of PeNHX3 from P. euphratica. The PeNHX3 model displays the typical TM4-TM11 assembly that is critical for ion binding and translocation. The PeNHX3 structure follows the 'positive-inside' rule and exhibits a typical physicochemical property of the transporter proteins. Four conserved residues, including Tyr149, Asn187, Asp188, and Arg356, are indentified in the TM4-TM11 assembly region of PeNHX3. Mutagenesis analysis showed that these reserved residues were essential for the function of PeNHX3: Asn187 and Asp188 (forming a ND motif) controlled ion binding and translocation, and Tyr149 and Arg356 compensated helix dipoles in the TM4-TM11 assembly. PeNHX3 mediated Na+, K+ and Li+ transport in a yeast growth assay. Domain-switch analysis shows that TM11 is crucial to Li+ transport. The novel features of PeNHX3 in ion binding and translocation are discussed.
Collapse
Affiliation(s)
- Liguang Wang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, China
| | - Xueying Feng
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, China
| | - Hong Zhao
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, China
| | - Lidong Wang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, China
| | - Lizhe An
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, China
| | - Quan-Sheng Qiu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, China
- * E-mail:
| |
Collapse
|