1
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Cho Y. Arabidopsis AGB1 participates in salinity response through bZIP17-mediated unfolded protein response. BMC PLANT BIOLOGY 2024; 24:586. [PMID: 38902609 PMCID: PMC11191249 DOI: 10.1186/s12870-024-05296-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Accepted: 06/13/2024] [Indexed: 06/22/2024]
Abstract
BACKGROUND Plant heterotrimeric G proteins respond to various environmental stresses, including high salinity. It is known that Gβ subunit AGB1 functions in maintaining local and systemic Na+/K+ homeostasis to accommodate ionic toxicity under salt stress. However, whether AGB1 contributes to regulating gene expression for seedling's survival under high salinity remains unclear. RESULTS We showed that AGB1-Venus localized to nuclei when facing excessive salt, and the induction of a set of bZIP17-dependent salt stress-responsive genes was reduced in the agb1 mutant. We confirmed both genetic and physical interactions of AGB1 and bZIP17 in plant salinity response by comparing salt responses in the single and double mutants of agb1 and bzip17 and by BiFC assay, respectively. In addition, we show that AGB1 depletion decreases nuclei-localization of transgenic mRFP-bZIP17 under salt stress, as shown in s1p s2p double mutant in the Agrobacteria-mediated transient mRFP-bZIP17 expression in young seedlings. CONCLUSIONS Our results indicate that AGB1 functions in S1P and/or S2P-mediated proteolytic processing of bZIP17 under salt stress to regulate the induction of salinity-responsive gene expression.
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Affiliation(s)
- Yueh Cho
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, 115201, Taiwan.
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2
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Gookin TE, Chakravorty D, Assmann SM. Influence of expression and purification protocols on Gα biochemical activity: kinetics of plant and mammalian G protein cycles. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.05.10.540258. [PMID: 37214830 PMCID: PMC10197700 DOI: 10.1101/2023.05.10.540258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Heterotrimeric G proteins are a class of signal transduction complexes with broad roles in human health and agriculturally important plant traits. In the classic paradigm, guanine nucleotide binding to the Gα subunit regulates the activation status of the complex. Using the Arabidopsis thaliana Gα subunit, GPA1, we developed a rapid StrepII-tag mediated purification method that facilitates isolation of protein with increased enzymatic activities as compared to conventional methods, and is demonstrably also applicable to mammalian Gα subunits. We subsequently utilized domain swaps of GPA1 and human GNAO1 to demonstrate the instability of recombinant GPA1 is a function of the interaction between the Ras and helical domains, and can be partially uncoupled from the rapid nucleotide binding kinetics displayed by GPA1.
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Affiliation(s)
- Timothy E. Gookin
- Biology Department, Pennsylvania State University, University Park, Pennsylvania 16802
- These authors contributed equally to the article
| | - David Chakravorty
- Biology Department, Pennsylvania State University, University Park, Pennsylvania 16802
- These authors contributed equally to the article
| | - Sarah M. Assmann
- Biology Department, Pennsylvania State University, University Park, Pennsylvania 16802
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3
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Zou W, Yu Q, Ma Y, Sun G, Feng X, Ge L. Pivotal role of heterotrimeric G protein in the crosstalk between sugar signaling and abiotic stress response in plants. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2024; 210:108567. [PMID: 38554538 DOI: 10.1016/j.plaphy.2024.108567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 03/12/2024] [Accepted: 03/25/2024] [Indexed: 04/01/2024]
Abstract
Heterotrimeric G-proteins are key modulators of multiple signaling and developmental pathways in plants, in which they act as molecular switches to engage in transmitting various stimuli signals from outside into the cells. Substantial studies have identified G proteins as essential components of the organismal response to abiotic stress, leading to adaptation and survival in plants. Meanwhile, sugars are also well acknowledged key players in stress perception, signaling, and gene expression regulation. Connections between the two significant signaling pathways in stress response are of interest to a general audience in plant biology. In this article, advances unraveling a pivotal role of G proteins in the process of sugar signals outside the cells being translated into the operation of autophagy in cells during stress are reviewed. In addition, we have presented recent findings on G proteins regulating the response to drought, salt, alkali, cold, heat and other abiotic stresses. Perspectives on G-protein research are also provided in the end. Since G protein signaling regulates many agronomic traits, elucidation of detailed mechanism of the related pathways would provide useful insights for the breeding of abiotic stress resistant and high-yield crops.
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Affiliation(s)
- Wenjiao Zou
- Collaborative Innovation Center for Ecological Protection and High Quality Development of Characteristic Traditional Chinese Medicine in the Yellow River Basin, Institute of Pharmaceutical Research, Shandong University of Traditional Chinese Medicine, Jinan, 250355, China
| | - Qian Yu
- The Characteristic Laboratory of Crop Germplasm Innovation and Application, Provincial Department of Education, College of Agronomy, Qingdao Agricultural University, Qingdao, 266109, China
| | - Yu Ma
- The Characteristic Laboratory of Crop Germplasm Innovation and Application, Provincial Department of Education, College of Agronomy, Qingdao Agricultural University, Qingdao, 266109, China
| | - Guoning Sun
- The Characteristic Laboratory of Crop Germplasm Innovation and Application, Provincial Department of Education, College of Agronomy, Qingdao Agricultural University, Qingdao, 266109, China
| | - Xue Feng
- The Characteristic Laboratory of Crop Germplasm Innovation and Application, Provincial Department of Education, College of Agronomy, Qingdao Agricultural University, Qingdao, 266109, China
| | - Lei Ge
- The Characteristic Laboratory of Crop Germplasm Innovation and Application, Provincial Department of Education, College of Agronomy, Qingdao Agricultural University, Qingdao, 266109, China; Academician Workstation of Agricultural High-tech Industrial Area of the Yellow River Delta, National Center of Technology Innovation for Comprehensive Utilization of Saline-Alkali Land, Dongying, Shandong, 257300, China.
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4
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Yadav P, Khatri N, Gupta R, Mudgil Y. Proteomic profiling of Arabidopsis G-protein β subunit AGB1 mutant under salt stress. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2024; 30:571-586. [PMID: 38737318 PMCID: PMC11087450 DOI: 10.1007/s12298-024-01448-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Revised: 03/26/2024] [Accepted: 04/06/2024] [Indexed: 05/14/2024]
Abstract
Salt stress is a limiting environmental factor that inhibits plant growth in most ecological environments. The functioning of G-proteins and activated downstream signaling during salt stress is well established and different G-protein subunits and a few downstream effectors have been identified. Arabidopsis G-protein β-subunit (AGB1) regulates the movement of Na+ from roots to shoots along with a significant role in controlling Na+ fluxes in roots, however, the molecular mechanism of AGB1 mediated salt stress regulation is not well understood. Here, we report the comparative proteome profiles of Arabidopsis AGB1 null mutant agb1-2 to investigate how the absence of AGB1 modulates the protein repertoire in response to salt stress. High-resolution two-dimensional gel electrophoresis (2-DE) showed 27 protein spots that were differentially modulated between the control and NaCl treated agb1-2 seedlings of which seven were identified by mass spectrometry. Functional annotation and interactome analysis indicated that the salt-responsive proteins were majorly associated with cellulose synthesis, structural maintenance of chromosomes, DNA replication/repair, organellar RNA editing and indole glucosinolate biosynthesis. Further exploration of the functioning of these proteins could serve as a potential stepping stone for dissection of molecular mechanism of AGB1 functions during salt stress and in long run could be extrapolated to crop plants for salinity stress management.
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Affiliation(s)
- Poonam Yadav
- Department of Botany, University of Delhi, New Delhi, 110007 India
| | - Nisha Khatri
- Department of Botany, University of Delhi, New Delhi, 110007 India
| | - Ravi Gupta
- College of General Education, Kookmin University, Seoul, 02707 South Korea
| | - Yashwanti Mudgil
- Department of Botany, University of Delhi, New Delhi, 110007 India
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5
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Yang S, Jung S, Lee H. Heterotrimeric G Protein-Mediated Signaling Is Involved in Stress-Mediated Growth Inhibition in Arabidopsis thaliana. Int J Mol Sci 2023; 24:11027. [PMID: 37446209 DOI: 10.3390/ijms241311027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 06/30/2023] [Accepted: 07/01/2023] [Indexed: 07/15/2023] Open
Abstract
Heterotrimeric G protein-mediated signaling plays a vital role in physiological and developmental processes in eukaryotes. On the other hand, because of the absence of a G protein-coupled receptor and self-activating mechanism of the Gα subunit, plants appear to have different regulatory mechanisms, which remain to be elucidated, compared to canonical G protein signaling established in animals. Here we report that Arabidopsis heterotrimeric G protein subunits, such as Gα (GPA1) and Gβ (AGB1), regulate plant growth under stress conditions through the analysis of heterotrimeric G protein mutants. Flg22-mediated growth inhibition in wild-type roots was found to be caused by a defect in the elongation zone, which was partially blocked in agb1-2 but not gpa1-4. These results suggest that AGB1 may negatively regulate plant growth under biotic stress conditions. In addition, GPA1 and AGB1 exhibited genetically opposite effects on FCA-mediated growth inhibition under heat stress conditions. Therefore, these results suggest that plant G protein signaling is probably related to stress-mediated growth regulation for developmental plasticity in response to biotic and abiotic stress conditions.
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Affiliation(s)
- Soeun Yang
- Department of Biotechnology, Duksung Women's University, Seoul 03169, Republic of Korea
| | - Seohee Jung
- Department of Biotechnology, Duksung Women's University, Seoul 03169, Republic of Korea
| | - Horim Lee
- Department of Biotechnology, Duksung Women's University, Seoul 03169, Republic of Korea
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6
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Xiong XX, Liu Y, Zhang LL, Li XJ, Zhao Y, Zheng Y, Yang QH, Yang Y, Min DH, Zhang XH. G-Protein β-Subunit Gene TaGB1-B Enhances Drought and Salt Resistance in Wheat. Int J Mol Sci 2023; 24:ijms24087337. [PMID: 37108500 PMCID: PMC10138664 DOI: 10.3390/ijms24087337] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Revised: 03/28/2023] [Accepted: 04/05/2023] [Indexed: 04/29/2023] Open
Abstract
In the hexaploid wheat genome, there are three Gα genes, three Gβ and twelve Gγ genes, but the function of Gβ in wheat has not been explored. In this study, we obtained the overexpression of TaGB1 Arabidopsis plants through inflorescence infection, and the overexpression of wheat lines was obtained by gene bombardment. The results showed that under drought and NaCl treatment, the survival rate of Arabidopsis seedlings' overexpression of TaGB1-B was higher than that of the wild type, while the survival rate of the related mutant agb1-2 was lower than that of the wild type. The survival rate of wheat seedlings with TaGB1-B overexpression was higher than that of the control. In addition, under drought and salt stress, the levels of superoxide dismutase (SOD) and proline (Pro) in the wheat overexpression of TaGB1-B were higher than that of the control, and the concentration of malondialdehyde (MDA) was lower than that of the control. This indicates that TaGB1-B could improve the drought resistance and salt tolerance of Arabidopsis and wheat by scavenging active oxygen. Overall, this work provides a theoretical basis for wheat G-protein β-subunits in a further study, and new genetic resources for the cultivation of drought-tolerant and salt-tolerant wheat varieties.
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Affiliation(s)
- Xin-Xin Xiong
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling 712100, China
| | - Yang Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling 712100, China
| | - Li-Li Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling 712100, China
| | - Xiao-Jian Li
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling 712100, China
| | - Yue Zhao
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling 712100, China
| | - Yan Zheng
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling 712100, China
| | - Qian-Hui Yang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling 712100, China
| | - Yan Yang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling 712100, China
| | - Dong-Hong Min
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling 712100, China
| | - Xiao-Hong Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling 712100, China
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7
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Li H, Feng B, Li J, Fu W, Wang W, Chen T, Liu L, Wu Z, Peng S, Tao L, Fu G. RGA1 alleviates low-light-repressed pollen tube elongation by improving the metabolism and allocation of sugars and energy. PLANT, CELL & ENVIRONMENT 2023; 46:1363-1383. [PMID: 36658612 DOI: 10.1111/pce.14547] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 01/08/2023] [Accepted: 01/18/2023] [Indexed: 06/17/2023]
Abstract
Low-light stress compromises photosynthetic and energy efficiency and leads to spikelet sterility; however, the effect of low-light stress on pollen tube elongation in the pistil remains poorly understood. The gene RGA1, which encodes a Gα-subunit of the heterotrimeric G-protein, enhanced low-light tolerance at anthesis by preventing the cessation of pollen tube elongation in the pistil of rice plants. In this process, marked increases in the activities of acid invertase (INV), sucrose synthase (SUS) and mitochondrial respiratory electron transport chain complexes, as well as the relative expression levels of SUTs (sucrose transporter), SWEETs (sugars will eventually be exported transporters), SUSs, INVs, CINs (cell-wall INV 1), SnRK1A (sucrose-nonfermenting 1-related kinase 1) and SnRK1B, were observed in OE-1 plants. Accordingly, notable increases in contents of ATP and ATPase were presented in OE-1 plants under low-light conditions, while they were decreased in d1 plants. Importantly, INV and ATPase activators (sucrose and Na2 SO3 , respectively) increased spikelet fertility by improving the energy status in the pistil under low-light conditions, and the ATPase inhibitor Na2 VO4 induced spikelet sterility and decreased ATPase activity. These results suggest that RGA1 could alleviate the low-light stress-induced impairment of pollen tube elongation to increase spikelet fertility by promoting sucrose unloading in the pistil and improving the metabolism and allocation of energy.
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Affiliation(s)
- Hubo Li
- National Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China
- Crop Production and Physiology Center (CPPC), College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Baohua Feng
- National Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China
| | - Juncai Li
- National Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China
- Agronomy College, Jilin Agricultural University, Changchun, China
| | - Weimeng Fu
- National Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China
| | - Wenting Wang
- National Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China
| | - Tingting Chen
- National Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China
| | - Lianmeng Liu
- National Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China
| | - Zhihai Wu
- Agronomy College, Jilin Agricultural University, Changchun, China
| | - Shaobing Peng
- Crop Production and Physiology Center (CPPC), College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Longxing Tao
- National Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China
| | - Guanfu Fu
- National Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China
- Agronomy College, Jilin Agricultural University, Changchun, China
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8
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Taugbøl A, Solbakken MH, Jakobsen KS, Vøllestad LA. Salinity-induced transcriptome profiles in marine and freshwater threespine stickleback after an abrupt 6-hour exposure. Ecol Evol 2022; 12:e9395. [PMID: 36311407 PMCID: PMC9596333 DOI: 10.1002/ece3.9395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 09/20/2022] [Indexed: 11/09/2022] Open
Abstract
Saltwater and freshwater environments have opposing physiological challenges, yet, there are fish species that are able to enter both habitats during short time spans, and as individuals they must therefore adjust quickly to osmoregulatory contrasts. In this study, we conducted an experiment to test for plastic responses to abrupt salinity changes in two populations of threespine stickleback, Gasterosteus aculeatus, representing two ecotypes (freshwater and ancestral saltwater). We exposed both ecotypes to abrupt native (control treatment) and non-native salinities (0‰ and 30‰) and sampled gill tissue for transcriptomic analyses after 6 h of exposure. To investigate genomic responses to salinity, we analyzed four different comparisons; one for each ecotype (in their control and exposure salinity; (1) and (2), one between ecotypes in their control salinity (3), and the fourth comparison included all transcripts identified in (3) that did not show any expressional changes within ecotype in either the control or the exposed salinity (4)). Abrupt salinity transfer affected the expression of 10 and 1530 transcripts for the saltwater and freshwater ecotype, respectively, and 1314 were differentially expressed between the controls, including 502 that were not affected by salinity within ecotype (fixed expression). In total, these results indicate that factors other than genomic expressional plasticity are important for osmoregulation in stickleback, due to the need for opposite physiological pathways to survive the abrupt change in salinity.
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Affiliation(s)
- Annette Taugbøl
- Department of Biosciences, Centre for Ecological and Evolutionary Synthesis (CEES)University of OsloBlindernNorway
- Norwegian Institute for Nature Research (NINA)LillehammerNorway
| | - Monica Hongrø Solbakken
- Department of Biosciences, Centre for Ecological and Evolutionary Synthesis (CEES)University of OsloBlindernNorway
| | - Kjetill S. Jakobsen
- Department of Biosciences, Centre for Ecological and Evolutionary Synthesis (CEES)University of OsloBlindernNorway
| | - Leif Asbjørn Vøllestad
- Department of Biosciences, Centre for Ecological and Evolutionary Synthesis (CEES)University of OsloBlindernNorway
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9
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Interacting partners of Brassica juncea Regulator of G-protein Signaling protein suggest its role in cell wall metabolism and cellular signaling. Biosci Rep 2022; 42:231472. [PMID: 35737296 PMCID: PMC9284343 DOI: 10.1042/bsr20220302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Revised: 06/08/2022] [Accepted: 06/21/2022] [Indexed: 11/26/2022] Open
Abstract
Heterotrimeric G-proteins interact with various upstream and downstream effectors to regulate various aspects of plant growth and development. G-protein effectors have been recently reported in Arabidopsis thaliana; however, less information is available from polyploid crop species having complex networks of G-protein components. Regulator of G-protein signaling (RGS) is a well-characterized GTPase accelerating protein, which plays an important role in the regulation of the G-protein cycle in plants. In the present study, four homologs encoding RGS proteins were isolated from the allotetraploid Brassica juncea, a globally important oilseed, vegetable, and condiment crop. The B. juncea RGS proteins were grouped into distinct BjuRGS1 and BjuRGS2 orthologous clades, and the expression of BjuRGS1 homologs was predominantly higher than BjuRGS2 homologs across the tested tissue types of B. juncea. Utilizing B. juncea Y2H library screening, a total of 30 nonredundant interacting proteins with the RGS-domain of the highly expressed BjuA.RGS1 was identified. Gene ontology analysis indicated that these effectors exerted various molecular, cellular, and physiological functions. Many of them were known to regulate cell wall metabolism (BjuEXP6, Bju-α-MAN, BjuPGU4, BjuRMS3) and phosphorylation-mediated cell signaling (BjuMEK4, BjuDGK3, and BjuKinase). Furthermore, transcript analysis indicated that the identified interacting proteins have a coexpression pattern with the BjuRGS homologs. These findings increase our knowledge about the novel targets of G-protein components from a globally cultivated Brassica crop and provide an important resource for developing a plant G-protein interactome network.
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10
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Wang Y, Botella JR. Heterotrimeric G Protein Signaling in Abiotic Stress. PLANTS 2022; 11:plants11070876. [PMID: 35406855 PMCID: PMC9002505 DOI: 10.3390/plants11070876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 03/17/2022] [Accepted: 03/21/2022] [Indexed: 11/16/2022]
Abstract
As sessile organisms, plants exhibit extraordinary plasticity and have evolved sophisticated mechanisms to adapt and mitigate the adverse effects of environmental fluctuations. Heterotrimeric G proteins (G proteins), composed of α, β, and γ subunits, are universal signaling molecules mediating the response to a myriad of internal and external signals. Numerous studies have identified G proteins as essential components of the organismal response to stress, leading to adaptation and ultimately survival in plants and animal systems. In plants, G proteins control multiple signaling pathways regulating the response to drought, salt, cold, and heat stresses. G proteins signal through two functional modules, the Gα subunit and the Gβγ dimer, each of which can start either independent or interdependent signaling pathways. Improving the understanding of the role of G proteins in stress reactions can lead to the development of more resilient crops through traditional breeding or biotechnological methods, ensuring global food security. In this review, we summarize and discuss the current knowledge on the roles of the different G protein subunits in response to abiotic stress and suggest future directions for research.
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11
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Tiwari R, Bisht NC. The multifaceted roles of heterotrimeric G-proteins: lessons from models and crops. PLANTA 2022; 255:88. [PMID: 35304667 DOI: 10.1007/s00425-022-03868-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 03/04/2022] [Indexed: 06/14/2023]
Abstract
The review summarizes our advanced understanding of the heterotrimeric G-protein research from model plants and their emerging roles in modulating various plant architecture and agronomical traits in crop species. Heterotrimeric G-proteins (hereafter G-proteins), consisting of G-alpha (Gα), G-beta (Gβ) and G-gamma (Gγ) subunits, are key signal transducers conserved across different forms of life. The discovery of plant lineage-specific G-protein components (extra-large G-proteins and type-C Gγ subunits), inherent polyploidy in angiosperms, and unique modes of G-protein cycle regulation in plants pointed out to a few fundamental differences of plant G-protein signaling from its animal counterpart. Over the last 2 decades, extensive studies in the model plant Arabidopsis thaliana have confirmed the involvement of G-proteins in a wide range of plant growth and development, and stress adaptation processes. The G-protein research in crop species, however, is still in its infancy, and a handful of studies suggest important roles of G-proteins in regulating plant architectural and key agronomical traits including plant's response to abiotic and biotic factors. We propose that the advancement made in plant G-proteins research will facilitate the development of novel approaches to manage plant yield and fitness in changing environments.
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Affiliation(s)
- Ruchi Tiwari
- National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Naveen C Bisht
- National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi, 110067, India.
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12
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Bhuria M, Goel P, Kumar S, Singh AK. AtUSP17 negatively regulates salt stress tolerance through modulation of multiple signaling pathways in Arabidopsis. PHYSIOLOGIA PLANTARUM 2022; 174:e13635. [PMID: 35080785 DOI: 10.1111/ppl.13635] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 12/23/2021] [Accepted: 01/20/2022] [Indexed: 06/14/2023]
Abstract
AtUSP17 is a multiple stress-inducible gene that encodes a universal stress protein (USP) in Arabidopsis thaliana. In the present study, we functionally characterized AtUSP17 using its knock-down mutant, Atusp17, and AtUSP17-overexpression lines (WTOE). The overexpression of AtUSP17 in wild-type and Atusp17 mutant Arabidopsis plants resulted in higher sensitivity to salt stress during seed germination than WT and Atusp17 mutant lines. In addition, the WTOE and FC lines exhibited higher abscisic acid (ABA) sensitivity than Atusp17 mutant during germination. The exogenous application of ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) was able to rescue the salt hypersensitive phenotype of WTOE lines. In contrast, AgNO3 , an ethylene action inhibitor, further blocked the effect of ACC during germination. The addition of ACC under salt stress resulted in reduced reactive oxygen species (ROS) accumulation, expression of ABA-responsive genes, improved proline synthesis, increased expression of positive regulators of ethylene signaling and antioxidant defense genes with enhanced antioxidant enzyme activities. The WTOE lines exhibited salt sensitivity even at the adult plant stage, while Atusp17 mutant exhibited higher salt tolerance with higher chlorophyll, relative water content and lower electrolyte leakage as compared with WT. The BAR interaction viewer database and available literature mining identified AtUSP17-interacting proteins, which include RGS1, RACK1C and PRN1 involved in G-protein signaling, which play a crucial role in salt stress responses. Based on the present study and available literature, we proposed a model in which AtUSP17 negatively mediates salt tolerance in Arabidopsis through modulation of ethylene, ABA, ROS, and G-protein signaling and responses.
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Affiliation(s)
- Monika Bhuria
- Department of Biotechnology, CSIR-Institute of Himalayan Bioresource Technology, Palampur, India
- Academy of Scientific and Innovative Research, Ghaziabad, India
| | - Parul Goel
- Department of Biotechnology, CSIR-Institute of Himalayan Bioresource Technology, Palampur, India
- Academy of Scientific and Innovative Research, Ghaziabad, India
| | - Sanjay Kumar
- Department of Biotechnology, CSIR-Institute of Himalayan Bioresource Technology, Palampur, India
- Academy of Scientific and Innovative Research, Ghaziabad, India
| | - Anil Kumar Singh
- Department of Biotechnology, CSIR-Institute of Himalayan Bioresource Technology, Palampur, India
- Academy of Scientific and Innovative Research, Ghaziabad, India
- ICAR-National Institute for Plant Biotechnology, New Delhi, India
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13
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Kocourková D, Kroumanová K, Podmanická T, Daněk M, Martinec J. Phospholipase Dα1 Acts as a Negative Regulator of High Mg 2+-Induced Leaf Senescence in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2021; 12:770794. [PMID: 34899793 PMCID: PMC8656112 DOI: 10.3389/fpls.2021.770794] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Accepted: 10/26/2021] [Indexed: 05/16/2023]
Abstract
Magnesium (Mg2+) is a macronutrient involved in essential cellular processes. Its deficiency or excess is a stress factor for plants, seriously affecting their growth and development and therefore, its accurate regulation is essential. Recently, we discovered that phospholipase Dα1 (PLDα1) activity is vital in the stress response to high-magnesium conditions in Arabidopsis roots. This study shows that PLDα1 acts as a negative regulator of high-Mg2+-induced leaf senescence in Arabidopsis. The level of phosphatidic acid produced by PLDα1 and the amount of PLDα1 in the leaves increase in plants treated with high Mg2+. A knockout mutant of PLDα1 (pldα1-1), exhibits premature leaf senescence under high-Mg2+ conditions. In pldα1-1 plants, higher accumulation of abscisic and jasmonic acid (JA) and impaired magnesium, potassium and phosphate homeostasis were observed under high-Mg2+ conditions. High Mg2+ also led to an increase of starch and proline content in Arabidopsis plants. While the starch content was higher in pldα1-1 plants, proline content was significantly lower in pldα1-1 compared with wild type plants. Our results show that PLDα1 is essential for Arabidopsis plants to cope with the pleiotropic effects of high-Mg2+ stress and delay the leaf senescence.
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Affiliation(s)
| | | | | | | | - Jan Martinec
- Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czechia
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14
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Gupta N, Kanojia A, Katiyar A, Mudgil Y. Molecular Characterization of NDL1-AGB1 Mediated Salt Stress Signaling: Further Exploration of the Role of NDL1 Interacting Partners. Cells 2021; 10:cells10092261. [PMID: 34571915 PMCID: PMC8472134 DOI: 10.3390/cells10092261] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 08/10/2021] [Accepted: 08/20/2021] [Indexed: 12/14/2022] Open
Abstract
Salt stress is considered to be the most severe abiotic stress. High soil salinity leads to osmotic and ionic toxicity, resulting in reduced plant growth and crop production. The role of G-proteins during salt stresses is well established. AGB1, a G-protein subunit, not only plays an important role during regulation of Na+ fluxes in roots, but is also involved in the translocation of Na+ from roots to shoots. N-Myc Downregulated like 1 (NDL1) is an interacting partner of G protein βγ subunits and C-4 domain of RGS1 in Arabidopsis. Our recent in-planta expression analysis of NDL1 reported changes in patterns during salt stress. Based on these expression profiles, we have carried out functional characterization of the AGB1-NDL1 module during salinity stress. Using various available mutant and overexpression lines of NDL1 and AGB1, we found that NDL1 acts as a negative regulator during salt stress response at the seedling stage, an opposite response to that of AGB1. On the other hand, during the germination phase of the plant, this role is reversed, indicating developmental and tissue specific regulation. To elucidate the mechanism of the AGB1-NDL1 module, we investigated the possible role of the three NDL1 stress specific interactors, namely ANNAT1, SLT1, and IDH-V, using yeast as a model. The present study revealed that NDL1 acts as a modulator of salt stress response, wherein it can have both positive as well as negative functions during salinity stress. Our findings suggest that the NDL1 mediated stress response depends on its developmental stage-specific expression patterns as well as the differential presence and interaction of the stress-specific interactors.
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15
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Zhang H, Xie P, Xu X, Xie Q, Yu F. Heterotrimeric G protein signalling in plant biotic and abiotic stress response. PLANT BIOLOGY (STUTTGART, GERMANY) 2021; 23 Suppl 1:20-30. [PMID: 33533569 DOI: 10.1111/plb.13241] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 01/25/2021] [Indexed: 05/20/2023]
Abstract
Heterotrimeric G proteins act as molecular switches to participate in transmitting various stimuli signals from outside of cells. G proteins have three subunits, Gα, Gβ and Gγ, which function mutually to modulate many biological processes in plants, including plant growth and development, as well as biotic and abiotic stress responses. In plants, the number of Gγ subunits is larger than that of the α and β subunits. Based on recent breakthroughs in studies of plant G protein signal perception, transduction and downstream effectors, this review summarizes and analyses the connections between different subunits and the interactions of G proteins with other signalling pathways, especially in plant biotic and abiotic stress responses. Based on current progress and unresolved questions in the field, we also suggest future research directions on G proteins in plants.
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Affiliation(s)
- H Zhang
- School of Agriculture, Ningxia University, Yinchuan, China
| | - P Xie
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
| | - X Xu
- School of Agriculture, Ningxia University, Yinchuan, China
- Breeding Base of State Key Laboratory of Land Degradation and Ecological Restoration of North Western China, Ningxia University, Yinchuan, China
| | - Q Xie
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
| | - F Yu
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
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16
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Ofoe R. Signal transduction by plant heterotrimeric G-protein. PLANT BIOLOGY (STUTTGART, GERMANY) 2021; 23:3-10. [PMID: 32803877 DOI: 10.1111/plb.13172] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 08/09/2020] [Indexed: 06/11/2023]
Abstract
Heterotrimeric G-proteins are complexes that regulate important signalling pathways essential for growth and development in both plants and animals. Although plant cells are composed of the core components (Gα, Gβ and Gγ subunits) found in animal G-proteins, the complexities of the architecture, function and signalling mechanisms of those in animals are dissimilar to those identified in some plants. Current studies on plant G-proteins have improved knowledge of the essential physiological and agronomic properties, which when harnessed, could potentially impact global food security. Extensive studies on the molecular mechanisms underlying these properties in diverse plant species will be imperative in improving our current understanding of G-protein signalling pathways involved in plant growth and development. The advancement of G-protein signalling networks in distinct plant species could significantly aid in better crop development. This review summarizes current progress, novel discoveries and future prospects for this area in potential crop improvement.
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Affiliation(s)
- R Ofoe
- Department of Biology and Biochemistry, University of Bath, Bath, UK
- West African Centre for Crop Improvement, University of Ghana, Legon, Accra, Ghana
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17
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Biswal AK, Wu TY, Urano D, Pelissier R, Morel JB, Jones AM, Biswal AK. Novel Mutant Alleles Reveal a Role of the Extra-Large G Protein in Rice Grain Filling, Panicle Architecture, Plant Growth, and Disease Resistance. FRONTIERS IN PLANT SCIENCE 2021; 12:782960. [PMID: 35046975 PMCID: PMC8761985 DOI: 10.3389/fpls.2021.782960] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Accepted: 11/10/2021] [Indexed: 05/02/2023]
Abstract
Plant growth and grain filling are the key agronomical traits for grain weight and yield of rice. The continuous improvement in rice yield is required for a future sustainable global economy and food security. The heterotrimeric G protein complex containing a canonical α subunit (RGA1) couples extracellular signals perceived by receptors to modulate cell function including plant development and grain weight. We hypothesized that, besides RGA1, three atypical, extra-large GTP-binding protein (XLG) subunits also regulate panicle architecture, plant growth, development, grain weight, and disease resistance. Here, we identified a role of XLGs in agronomic traits and stress tolerance by genetically ablating all three rice XLGs individually and in combination using the CRISPR/Cas9 genome editing in rice. For this study, eight (three single, two double, and three triple) null mutants were selected. Three XLG proteins combinatorically regulate seed filling, because loss confers a decrease in grain weight from 14% with loss of one XLG and loss of three to 32% decrease in grain weight. Null mutations in XLG2 and XLG4 increase grain size. The mutants showed significantly reduced panicle length and number per plant including lesser number of grains per panicle compared to the controls. Loss-of-function of all individual XLGs contributed to 9% more aerial biomass compared to wild type (WT). The double mutant showed improved salinity tolerance. Moreover, loss of the XLG gene family confers hypersensitivity to pathogens. Our findings suggest that the non-canonical XLGs play important roles in regulating rice plant growth, grain filling, panicle phenotype, stress tolerance, and disease resistance. Genetic manipulation of XLGs has the potential to improve agronomic properties in rice.
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Affiliation(s)
- Akshaya K. Biswal
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- International Maize and Wheat Improvement Center (CIMMYT), Texcoco, Mexico
| | - Ting-Ying Wu
- Temasek Life Sciences Laboratory, Singapore, Singapore
| | - Daisuke Urano
- Temasek Life Sciences Laboratory, Singapore, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Rémi Pelissier
- PHIM, CEFE, Institut Agro, INRAE, CIRAD, Université de Montpellier, Montpellier, France
| | - Jean-Benoit Morel
- PHIM, INRAE, CIRAD, Institut Agro, Université de Montpellier, Montpellier, France
| | - Alan M. Jones
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Ajaya K. Biswal
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States
- *Correspondence: Ajaya K. Biswal,
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18
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Yan Y, Sun M, Li Y, Wang J, He C, Yu X. The CsGPA1-CsAQPs module is essential for salt tolerance of cucumber seedlings. PLANT CELL REPORTS 2020; 39:1301-1316. [PMID: 32648011 DOI: 10.1007/s00299-020-02565-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 07/01/2020] [Indexed: 06/11/2023]
Abstract
CsGPA1 interacts with CsTIP1.1 (a member of CsAQPs) and suppression of CsGPA1 results the reverse expression of CsAQPs in leaves and roots, resulting in declining water content of cucumber seedlings under salt stress. Salt stress seriously affects cucumber growth and development. Whether the G-protein alpha subunit functions in cucumber during salt stress and its regulation mechanism remains unknown. We interrogated CsGPA1-RNAi lines to identify the role of CsGPA1 during salt stress. Phenotypically, compared with wild type, leaves were severely withered, and root cells showed signs of senescence under salt stress for RNAi lines. Compared with WT, SOD and CAT activity, soluble protein and proline contents all decreased in RNAi lines, while malondialdehyde and relative electrical conductivity increased. Through screening the yeast two-hybrid library and combined with yeast two-hybrid and GST pull-down, the interaction of CsGPA1 with CsTIP1.1 was found the first time in a plant. Then, the expression of aquaporin (AQP) family genes was detected. The expression of CsAQP genes in leaves and roots was primarily up-regulated in WT under salt stress. However, interference by CsGPA1 resulted in enhanced expression of CsAQPs except for CsTIP3.2 in leaves, but reduced expression of some CsAQPs in roots under salt stress. Furthermore, principal component analysis of CsAQP expression profiles and linear regression analysis between CsGPA1 and CsAQPs revealed that CsGPA1 reversely regulated the expression of CsAQPs in leaves and roots under salt stress. Moreover, the water content in leaves and roots of RNAi seedlings significantly decreased compared with WT under salt stress. Overall, CsGPA1 interacts with CsTIP1.1 and suppression of CsGPA1 results in opposite patterns of expression of CsAQPs in leaves and roots, resulting in declining water content of cucumber under salt stress.
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Affiliation(s)
- Yan Yan
- The Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Haidian District, Zhongguancun South St, Beijing, 100081, China
| | - Mintao Sun
- The Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Haidian District, Zhongguancun South St, Beijing, 100081, China
| | - Yansu Li
- The Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Haidian District, Zhongguancun South St, Beijing, 100081, China
| | - Jun Wang
- The Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Haidian District, Zhongguancun South St, Beijing, 100081, China
| | - Chaoxing He
- The Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Haidian District, Zhongguancun South St, Beijing, 100081, China.
| | - Xianchang Yu
- The Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Haidian District, Zhongguancun South St, Beijing, 100081, China.
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19
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Yan C, Cannon AE, Watkins J, Keereetaweep J, Khan BR, Jones AM, Blancaflor EB, Azad RK, Chapman KD. Seedling Chloroplast Responses Induced by N-Linolenoylethanolamine Require Intact G-Protein Complexes. PLANT PHYSIOLOGY 2020; 184:459-477. [PMID: 32665332 PMCID: PMC7479873 DOI: 10.1104/pp.19.01552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 07/05/2020] [Indexed: 05/10/2023]
Abstract
In animals, several long-chain N-acylethanolamines (NAEs) have been identified as endocannabinoids and are autocrine signals that operate through cell surface G-protein-coupled cannabinoid receptors. Despite the occurrence of NAEs in land plants, including nonvascular plants, their precise signaling properties and molecular targets are not well defined. Here we show that the activity of N-linolenoylethanolamine (NAE 18:3) requires an intact G-protein complex. Specifically, genetic ablation of the Gβγ dimer or loss of the full set of atypical Gα subunits strongly attenuates an NAE-18:3-induced degreening of cotyledons in Arabidopsis (Arabidopsis thaliana) seedlings. This effect involves, at least in part, transcriptional regulation of chlorophyll biosynthesis and catabolism genes. In addition, there is feedforward transcriptional control of G-protein signaling components and G-protein interactors. These results are consistent with NAE 18:3 being a lipid signaling molecule in plants with a requirement for G-proteins to mediate signal transduction, a situation similar, but not identical, to the action of NAE endocannabinoids in animal systems.
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Affiliation(s)
- Chengshi Yan
- Department of Biological Sciences and BioDiscovery Institute, University of North Texas, Denton, Texas 76203
| | - Ashley E Cannon
- Department of Biological Sciences and BioDiscovery Institute, University of North Texas, Denton, Texas 76203
| | - Justin Watkins
- Departments of Biology, and Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - Jantana Keereetaweep
- Department of Biological Sciences and BioDiscovery Institute, University of North Texas, Denton, Texas 76203
| | | | - Alan M Jones
- Departments of Biology, and Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | | | - Rajeev K Azad
- Department of Biological Sciences and BioDiscovery Institute, University of North Texas, Denton, Texas 76203
- Noble Research Institute LLC, Ardmore, Oklahoma 73401
- Department of Mathematics, University of North Texas, Denton, Texas 76203
| | - Kent D Chapman
- Department of Biological Sciences and BioDiscovery Institute, University of North Texas, Denton, Texas 76203
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20
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Adem GD, Chen G, Shabala L, Chen ZH, Shabala S. GORK Channel: A Master Switch of Plant Metabolism? TRENDS IN PLANT SCIENCE 2020; 25:434-445. [PMID: 31964604 DOI: 10.1016/j.tplants.2019.12.012] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 11/23/2019] [Accepted: 12/10/2019] [Indexed: 05/18/2023]
Abstract
Potassium regulates a plethora of metabolic and developmental response in plants, and upon exposure to biotic and abiotic stresses a substantial K+ loss occurs from plant cells. The outward-rectifying potassium efflux GORK channels are central to this stress-induced K+ loss from the cytosol. In the mammalian systems, signaling molecules such as gamma-aminobutyric acid, G-proteins, ATP, inositol, and protein phosphatases were shown to operate as ligands controlling many K+ efflux channels. Here we present the evidence that the same molecules may also regulate GORK channels in plants. This mechanism enables operation of the GORK channels as a master switch of the cell metabolism, thus adjusting intracellular K+ homeostasis to altered environmental conditions, to maximize plant adaptive potential.
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Affiliation(s)
- Getnet D Adem
- Tasmanian Institute for Agriculture, University of Tasmania, Hobart, TAS 7001, Australia
| | - Guang Chen
- Collaborative Innovation Centre for Grain Industry, College of Agriculture, Yangtze University, Jingzhou 434025, China; College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Lana Shabala
- Tasmanian Institute for Agriculture, University of Tasmania, Hobart, TAS 7001, Australia
| | - Zhong-Hua Chen
- School of Science and Health, Western Sydney University, Penrith, NSW 2751, Australia; Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW 2751, Australia.
| | - Sergey Shabala
- Tasmanian Institute for Agriculture, University of Tasmania, Hobart, TAS 7001, Australia; International Research Centre for Environmental Membrane Biology, Foshan University, Foshan 528000, China.
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21
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Siddiqui H, Sami F, Hayat S. Glucose: Sweet or bitter effects in plants-a review on current and future perspective. Carbohydr Res 2019; 487:107884. [PMID: 31811968 DOI: 10.1016/j.carres.2019.107884] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 11/28/2019] [Accepted: 11/28/2019] [Indexed: 01/09/2023]
Abstract
Sugars are metabolic substrates playing a part in modulating various processes in plants during different phases of development. Thus, modulating the sugar metabolism can have intense effects on the plant metabolism. Glucose is a soluble sugar, found throughout the plant kingdom. Apart from being a universal carbon source, glucose also operates as a signaling molecule modulating various metabolic processes in plants. From germination to senescence, wide range of processes in plants is regulated by glucose. The effect of glucose is found to be concentration dependent. Photosynthesis and its related attributes, respiration and nitrogen metabolism are influenced by glucose application. Endogenous content of glucose increases upon exposure of plant to various abiotic stresses and also when glucose is supplied exogenously. Glucose accumulation alleviates the damaging effects of stress by enhancing production of antioxidants and compounds similar to that of photosynthetic CO2 fixation which act as an osmoticum by maintaining osmotic pressure inside the cell, pH homeostasis regulator and reduce membrane permeability during stress. Glucose interaction with various phytohormones has also been discussed in this review.
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Affiliation(s)
- Husna Siddiqui
- Plant Physiology Section, Department of Botany, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, 202002, India.
| | - Fareen Sami
- Plant Physiology Section, Department of Botany, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, 202002, India
| | - Shamsul Hayat
- Plant Physiology Section, Department of Botany, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, 202002, India
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22
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Biswas S, Islam MN, Sarker S, Tuteja N, Seraj ZI. Overexpression of heterotrimeric G protein beta subunit gene (OsRGB1) confers both heat and salinity stress tolerance in rice. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2019; 144:334-344. [PMID: 31622936 DOI: 10.1016/j.plaphy.2019.10.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Revised: 10/02/2019] [Accepted: 10/02/2019] [Indexed: 06/10/2023]
Abstract
Constitutive overexpression of the rice heterotrimeric G protein beta subunit gene (RGB1) in the commercial rice cultivar BRRI Dhan 55 resulted in improved tolerance to heat or salinity or their combination. Two independently in planta transformed plants with the gene confirmed to be integrated at T2 by Southern hybridization and showing high expression at the T3 seedling stage showed better physiological performance after 8 days in 120 mM salt stress than the wild type. The plants had significantly lower electrolyte leakage and malondialdehyde production, while showing higher levels of chlorophyll. Significantly higher germination at 48 °C or with combined stresses of 42/40 °C day/night stress in the presence of 120 mM salt for 2 days was also observed. Stress responsive genes such as OsAPX1, OsSOD, OsHKT1, OsHSP1, OsHSP2 and OsCOR47 showed higher expression in the RGB1 positive plants. These RGB1 transgenic plants can likely provide a strong defense against climate change.
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Affiliation(s)
- Sudip Biswas
- Plant Biotechnology Laboratory, Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, 1000, Bangladesh
| | - Md Nazrul Islam
- Plant Biotechnology Laboratory, Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, 1000, Bangladesh; National Institute of Biotechnology, Ganakbari, Ashulia, Savar, Bangladesh
| | - Sarah Sarker
- Plant Biotechnology Laboratory, Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, 1000, Bangladesh; National Institute of Biotechnology, Ganakbari, Ashulia, Savar, Bangladesh
| | - Narendra Tuteja
- International Center for Genetic Engineering and Biotechnology, New Delhi, India
| | - Zeba I Seraj
- Plant Biotechnology Laboratory, Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, 1000, Bangladesh.
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23
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Swain DM, Sahoo RK, Chandan RK, Ghosh S, Kumar R, Jha G, Tuteja N. Concurrent overexpression of rice G-protein β and γ subunits provide enhanced tolerance to sheath blight disease and abiotic stress in rice. PLANTA 2019; 250:1505-1520. [PMID: 31332521 DOI: 10.1007/s00425-019-03241-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 07/15/2019] [Indexed: 05/12/2023]
Abstract
Our study demonstrates that simultaneous overexpression of RGB1 and RGG1 genes provides multiple stress tolerance in rice by inducing stress responsive genes and better management of ROS scavenging/photosynthetic machineries. The heterotrimeric G-proteins act as signalling molecules and modulate various cellular responses including stress tolerance in eukaryotes. The gamma (γ) subunit of rice G-protein (RGG1) was earlier reported to promote salinity stress tolerance in rice. In the present study, we report that a rice gene-encoding beta (β) subunit of G-protein (RGB1) gets upregulated during both biotic (upon a necrotrophic fungal pathogen, Rhizoctonia solani infection) and drought stresses. Marker-free transgenic IR64 rice lines that simultaneously overexpress both RGB1 and RGG1 genes under CaMV35S promoter were raised. The overexpressing (OE) lines showed enhanced tolerance to R. solani infection and salinity/drought stresses. Several defense marker genes including OsMPK3 were significantly upregulated in the R. solani-infected OE lines. We also found the antioxidant machineries to be upregulated during salinity as well as drought stress in the OE lines. Overall, the present study provides evidence that concurrent overexpression of G-protein subunits (RGG1 and RGB1) impart multiple (both biotic and abiotic) stress tolerance in rice which could be due to the enhanced expression of stress-marker genes and better management of reactive oxygen species (ROS)-scavenging/photosynthetic machinery. The current study suggests an improved approach for simultaneous improvement of biotic and abiotic stress tolerance in rice which remains a major challenge for its sustainable cultivation.
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Affiliation(s)
- Durga Madhab Swain
- Plant Microbe Interactions Laboratory, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
- Department of Biotechnology, Ravenshaw University, Cuttack, 753003, Odisha, India
| | - Ranjan Kumar Sahoo
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Ravindra Kumar Chandan
- Plant Microbe Interactions Laboratory, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
- School of Life Sciences, Central University of Gujrat, Sector-30, Gandhinagar, 382030, India
| | - Srayan Ghosh
- Plant Microbe Interactions Laboratory, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Rahul Kumar
- Plant Microbe Interactions Laboratory, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Gopaljee Jha
- Plant Microbe Interactions Laboratory, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India.
| | - Narendra Tuteja
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
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24
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Liu C, Fan W, Zhu P, Xia Z, Hu J, Zhao A. Mulberry RGS negatively regulates salt stress response and tolerance. PLANT SIGNALING & BEHAVIOR 2019; 14:1672512. [PMID: 31559897 PMCID: PMC6866688 DOI: 10.1080/15592324.2019.1672512] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 09/17/2019] [Accepted: 09/20/2019] [Indexed: 06/10/2023]
Abstract
Regulator of G-protein signaling (RGS) protein, the best-characterized accelerating GTPase protein in plants, regulates G-protein signaling and plays important role in abiotic stress tolerance. However, the detailed molecular mechanism of RGS involved in G-protein signaling mediated abiotic stress responses remains unclear. In this study, a mulberry (Morus alba L.) RGS gene (MaRGS) was transformed into tobacco, and the ectopic expression of MaRGS in tobacco decreased the tolerance to salt stress. The transgenic tobacco plants had lower proline content, higher malonaldehyde and H2O2 contents than wild type plants under salt stress condition. Meanwhile, MaRGS overexpression in mulberry seedlings enhances the sensitivity to salt stress and RNAi-silenced expression of MaRGS improves the salt stress response and tolerance. These results suggested that MaRGS negatively regulates salt stress tolerance. Further analysis suggested that D-glucose and autophagy may involve in the response of RGS to salt stress. This study revealed the role of MaRGS in salt stress tolerance and provides a proposed model for RGS regulates G-protein signaling in response to salt stress.
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Affiliation(s)
- Changying Liu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
| | - Wei Fan
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
| | - Panpan Zhu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
| | - Zhongqiang Xia
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
| | - Jie Hu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
| | - Aichun Zhao
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, China
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Arabidopsis NDL-AGB1 modules Play Role in Abiotic Stress and Hormonal Responses Along with Their Specific Functions. Int J Mol Sci 2019; 20:ijms20194736. [PMID: 31554237 PMCID: PMC6801982 DOI: 10.3390/ijms20194736] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Revised: 09/17/2019] [Accepted: 09/19/2019] [Indexed: 12/15/2022] Open
Abstract
Arabidopsis N-MYC Downregulated Like Proteins (NDLs) are interacting partners of G-Protein core components. Animal homologs of the gene family N-myc downstream regulated gene (NDRG) has been found to be induced during hypoxia, DNA damage, in presence of reducing agent, increased intracellular calcium level and in response to metal ions like nickel and cobalt, which indicates the involvement of the gene family during stress responses. ArabidopsisNDL gene family contains three homologs NDL1, NDL2 and NDL3 which share up to 75% identity at protein level. Previous studies on NDL proteins involved detailed characterization of the role of NDL1; roles of other two members were also established in root and shoot development using miRNA knockdown approach. Role of entire family in development has been established but specific functions of NDL2 and NDL3 if any are still unknown. Our in-silico analysis of NDLs promoters reveled that all three members share some common and some specific transcription factors (TFs) binding sites, hinting towards their common as well as specific functions. Based on promoter elements characteristics, present study was designed to carry out comparative analysis of the Arabidopsis NDL family during different stages of plant development, under various abiotic stresses and plant hormonal responses, in order to find out their specific and combined roles in plant growth and development. Developmental analysis using GUS fusion revealed specific localization/expression during different stages of development for all three family members. Stress analysis after treatment with various hormonal and abiotic stresses showed stress and tissue-specific differential expression patterns for all three NDL members. All three NDL members were collectively showed role in dehydration stress along with specific responses to various treatments. Their specific expression patterns were affected by presence of interacting partner the Arabidopsis heterotrimeric G-protein β subunit 1 (AGB1). The present study will improve our understanding of the possible molecular mechanisms of action of the independent NDL–AGB1 modules during stress and hormonal responses. These findings also suggest potential use of this knowledge for crop improvement.
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JA-Induced Endocytosis of AtRGS1 Is Involved in G-Protein Mediated JA Responses. Int J Mol Sci 2019; 20:ijms20153779. [PMID: 31382426 PMCID: PMC6695760 DOI: 10.3390/ijms20153779] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 07/27/2019] [Accepted: 07/29/2019] [Indexed: 12/17/2022] Open
Abstract
Arabidopsis heterotrimeric G proteins regulate diverse plant growth and defense processes by coupling to 7TM AtRGS1 proteins. Although G protein mutants display alterations in response to multiple plant hormones, the underlying mechanism by which G proteins participate in the regulation of hormone responses remains elusive. Here, we show that genetic disruption of Gα and Gβ subunits results in reduced sensitivity to JA treatment. Furthermore, using confocal microscopy, VA-TIRFM, and FRET-FLIM, we provide evidence that stimulation by JA induces phosphorylation- and C-terminus-dependent endocytosis of AtRGS1, which then promotes dissociation of AtRGS1 from AtGPA1. In addition, SPT analysis reveals that JA treatment affects the diffusion dynamics of AtRGS1 and AtRGS1-ΔCt. Taken together, these findings suggest that the JA signal activates heterotrimeric G proteins through the endocytosis of AtRGS1 and dissociation of AtRGS1 from AtGPA1, thus providing valuable insight into the mechanisms of how the G protein system perceives and transduces phytohormone signals.
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GCR1 and GPA1 coupling regulates nitrate, cell wall, immunity and light responses in Arabidopsis. Sci Rep 2019; 9:5838. [PMID: 30967583 PMCID: PMC6456573 DOI: 10.1038/s41598-019-42084-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 03/25/2019] [Indexed: 12/27/2022] Open
Abstract
G-protein signaling components have been attributed many biological roles in plants, but the extent of involvement of G-protein coupled receptor 1 (GCR1) with the Gα (GPA1) remained unknown. To address this, we have performed transcriptomic analyses on Arabidopsis gpa1-5gcr1-5 double mutant and identified 656 differentially expressed genes (DEGs). MapMan and Gene Ontology analyses revealed global transcriptional changes associated with external stimulus, cell wall organization/biogenesis and secondary metabolite process among others. Comparative transcriptomic analyses using the single and double mutants of gcr1-5 and gpa1-5 identified 194, 139 and 391 exclusive DEGs respectively, whereas 64 DEGs were common to all three mutants. Further, pair wise comparison of DEGs of double mutant with single mutants of gcr1-5 or gpa1-5 showed about one-third and over half common DEGs, respectively. Further analysis of the DEGs exclusive to the double mutant using protein-protein interaction networks revealed molecular complexes associated with nitrate and light signaling and plant-pathogen interactions among others. Physiological and molecular validation of nitrate-response revealed the sensitivity of germination to low N in the double mutant and differential expression of nitrate transporter (and nitrate reductase in all three mutants). Taken together, GCR1 and GPA1 work in partnership as well as independently to regulate different pathways.
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Liu C, Xu Y, Feng Y, Long D, Cao B, Xiang Z, Zhao A. Ectopic Expression of Mulberry G-Proteins Alters Drought and Salt Stress Tolerance in Tobacco. Int J Mol Sci 2018; 20:E89. [PMID: 30587818 PMCID: PMC6337368 DOI: 10.3390/ijms20010089] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 12/15/2018] [Accepted: 12/22/2018] [Indexed: 11/20/2022] Open
Abstract
Heterotrimeric guanine-nucleotide-binding proteins (G-proteins) play key roles in responses to various abiotic stress responses and tolerance in plants. However, the detailed mechanisms behind these roles remain unclear. Mulberry (Morus alba L.) can adapt to adverse abiotic stress conditions; however, little is known regarding the associated molecular mechanisms. In this study, mulberry G-protein genes, MaGα, MaGβ, MaGγ1, and MaGγ2, were independently transformed into tobacco, and the transgenic plants were used for resistance identification experiments. The ectopic expression of MaGα in tobacco decreased the tolerance to drought and salt stresses, while the overexpression of MaGβ, MaGγ1, and MaGγ2 increased the tolerance. Further analysis showed that mulberry G-proteins may regulate drought and salt tolerances by modulating reactive oxygen species' detoxification. This study revealed the roles of each mulberry G-protein subunit in abiotic stress tolerance and advances our knowledge of the molecular mechanisms underlying G-proteins' regulation of plant abiotic stress tolerance.
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Affiliation(s)
- Changying Liu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China.
| | - Yazhen Xu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China.
| | - Yang Feng
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China.
| | - Dingpei Long
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China.
| | - Boning Cao
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China.
| | - Zhonghuai Xiang
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China.
| | - Aichun Zhao
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China.
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Yu Y, Assmann SM. Inter-relationships between the heterotrimeric Gβ subunit AGB1, the receptor-like kinase FERONIA, and RALF1 in salinity response. PLANT, CELL & ENVIRONMENT 2018; 41:2475-2489. [PMID: 29907954 PMCID: PMC6150805 DOI: 10.1111/pce.13370] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 06/04/2018] [Accepted: 06/08/2018] [Indexed: 05/06/2023]
Abstract
Plant heterotrimeric G proteins modulate numerous developmental stress responses. Recently, receptor-like kinases (RLKs) have been implicated as functioning with G proteins and may serve as plant G-protein-coupled-receptors. The RLK FERONIA (FER), in the Catharantus roseus RLK1-like subfamily, is activated by a family of polypeptides called rapid alkalinization factors (RALFs). We previously showed that the Arabidopsis G protein β subunit, AGB1, physically interacts with FER, and that RALF1 regulation of stomatal movement through FER requires AGB1. Here, we investigated genetic interactions of AGB1 and FER in plant salinity response by comparing salt responses in the single and double mutants of agb1 and fer. We show that AGB1 and FER act additively or synergistically depending on the conditions of the NaCl treatments. We further show that the synergism likely occurs through salt-induced ROS production. In addition, we show that RALF1 enhances salt toxicity through increasing Na+ accumulation and decreasing K+ accumulation rather than by inducing ROS production, and that the RALF1 effect on salt response occurs in an AGB1-independent manner. Our results indicate that RLK epistatic relationships are not fixed, as AGB1 and FER display different genetic relationships to RALF1 in stomatal versus salinity responses.
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Affiliation(s)
| | - Sarah M. Assmann
- To whom correspondence should be addressed: , tel. 814-863-9579, fax. 814-865-9131
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Wu TY, Urano D. Genetic and Systematic Approaches Toward G Protein-Coupled Abiotic Stress Signaling in Plants. FRONTIERS IN PLANT SCIENCE 2018; 9:1378. [PMID: 30294337 PMCID: PMC6158310 DOI: 10.3389/fpls.2018.01378] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 08/29/2018] [Indexed: 05/15/2023]
Abstract
Heterotrimeric G protein, composed of Gα, Gβ, and Gγ subunits, modulates plant adaptations to environmental stresses such as high salinity, drought, extreme temperatures and high light intensity. Most of these evidence were however derived solely from conventional genetics methods with which stress-associated phenotypes were compared between wild type and various G protein mutant plants. Recent advances in systematic approaches, mainly transcriptome and proteome, have contributed to in-depth understanding of molecular linkages between G proteins and environmental changes. Here, we update our knowledge on the roles of G proteins in abiotic stress responses. Furthermore, we highlight the current whole genome studies and integrated omics approach to better understand the fundamental G protein functions involved in abiotic stress responses. It is our purpose here to bridge the gap between molecular mechanisms in G protein science and stress biology and pave the way toward crop improvement researches in the future.
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Affiliation(s)
- Ting-Ying Wu
- Temasek Life Sciences Laboratory, Singapore, Singapore
| | - Daisuke Urano
- Temasek Life Sciences Laboratory, Singapore, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
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Tunc‐Ozdemir M, Liao K, Ross‐Elliott TJ, Elston TC, Jones AM. Long-distance communication in Arabidopsis involving a self-activating G protein. PLANT DIRECT 2018; 2:e00037. [PMID: 31245704 PMCID: PMC6508511 DOI: 10.1002/pld3.37] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 12/18/2017] [Accepted: 12/31/2017] [Indexed: 05/06/2023]
Abstract
In plant cells, heterotrimeric G protein signaling mediates development, biotic/abiotic stress responsiveness, hormone signaling, and extracellular sugar sensing. The amount of sugar in plant cells fluctuates from nanomolar to high millimolar concentrations over time depending on changes in the light environment. Arabidopsis thaliana Regulator of G Signaling protein 1 (AtRGS1) modulates G protein activation and detects the concentration and the exposure time of sugars. This is called dose-duration reciprocity in sugar sensing and occurs through AtRGS1 internalization which is directly proportional to G protein activation. One source of sugars is from CO 2 fixation by photosynthesis. Through a simple set of experiments, we show that sugars made in cotyledons that are undergoing photomorphogenesis activate G signaling in cells distal to the nascent photosynthesis center. This occurs with sufficient speed to enable distal cells to monitor changes in photosynthetic activity in the leaves.
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Affiliation(s)
- Meral Tunc‐Ozdemir
- Department of BiologyUniversity of North Carolina at Chapel HillChapel HillNCUSA
| | - Kang‐Ling Liao
- Department of BiologyUniversity of North Carolina at Chapel HillChapel HillNCUSA
| | | | - Timothy C. Elston
- Department of PharmacologyUniversity of North Carolina at Chapel HillChapel HillNCUSA
| | - Alan M. Jones
- Department of BiologyUniversity of North Carolina at Chapel HillChapel HillNCUSA
- Department of PharmacologyUniversity of North Carolina at Chapel HillChapel HillNCUSA
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Duplicated RGS (Regulator of G-protein signaling) proteins exhibit conserved biochemical but differential transcriptional regulation of heterotrimeric G-protein signaling in Brassica species. Sci Rep 2018; 8:2176. [PMID: 29391473 PMCID: PMC5794992 DOI: 10.1038/s41598-018-20500-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 01/18/2018] [Indexed: 12/18/2022] Open
Abstract
G-alpha (Gα) and ‘Regulator of G-protein Signaling (RGS)’ proteins are the two key components primarily involved in regulation of heterotrimeric G-proteins signaling across phyla. Unlike Arabidopsis thaliana, our knowledge about G-protein regulation in polyploid Brassica species is sparse. In this study, we identified one Gα and two RGS genes each from three species of Brassica ‘U’ triangle and assessed the effects of whole genome triplication on the divergence of gene sequence and structure, protein-protein interaction, biochemical activities, and gene expression. Sequence and phylogenetic analysis revealed that the deduced Gα and RGS proteins are evolutionarily conserved across Brassica species. The duplicated RGS proteins of each Brassica species interacted with their cognate Gα but displayed varying levels of interaction strength. The Gα and the duplicated RGS proteins of Brassica species exhibited highly conserved G-protein activities when tested under in-vitro conditions. Expression analysis of the B. rapa RGS genes revealed a high degree of transcriptional differentiation across the tested tissue types and in response to various elicitors, particularly under D-glucose, salt and phytohormone treatments. Taken together, our results suggest that the RGS-mediated regulation of G-protein signaling in Brassica species is predominantly governed by stage and condition-specific expression differentiation of the duplicated RGS genes.
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Liao KL, Melvin CE, Sozzani R, Jones RD, Elston TC, Jones AM. Dose-Duration Reciprocity for G protein activation: Modulation of kinase to substrate ratio alters cell signaling. PLoS One 2017; 12:e0190000. [PMID: 29287086 PMCID: PMC5747438 DOI: 10.1371/journal.pone.0190000] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 12/06/2017] [Indexed: 12/12/2022] Open
Abstract
In animal cells, activation of heterotrimeric G protein signaling generally occurs when the system's cognate signal exceeds a threshold, whereas in plant cells, both the amount and the exposure time of at least one signal, D-glucose, are used toward activation. This unusual signaling property called Dose-Duration Reciprocity, first elucidated in the genetic model Arabidopsis thaliana, is achieved by a complex that is comprised of a 7-transmembrane REGULATOR OF G SIGNALING (RGS) protein (AtRGS1), a Gα subunit that binds and hydrolyzes nucleotide, a Gβγ dimer, and three WITH NO LYSINE (WNK) kinases. D-glucose is one of several signals such as salt and pathogen-derived molecular patterns that operates through this protein complex to activate G protein signaling by WNK kinase transphosphorylation of AtRGS1. Because WNK kinases compete for the same substrate, AtRGS1, we hypothesize that activation is sensitive to the AtRGS1 amount and that modulation of the AtRGS1 pool affects the response to the stimulant. Mathematical simulation revealed that the ratio of AtRGS1 to the kinase affects system sensitivity to D-glucose, and therefore illustrates how modulation of the cellular AtRGS1 level is a means to change signal-induced activation. AtRGS1 levels change under tested conditions that mimic physiological conditions therefore, we propose a previously-unknown mechanism by which plants react to changes in their environment.
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Affiliation(s)
- Kang-Ling Liao
- Departments of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Charles E. Melvin
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, United States of America
| | - Rosangela Sozzani
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, United States of America
| | - Roger D. Jones
- Center for Complex Systems and Enterprises, Stevens Institute of Technology, Hoboken, NJ, United States of America
| | - Timothy C. Elston
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Alan M. Jones
- Departments of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
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Palmer IA, Shang Z, Fu ZQ. Salicylic acid-mediated plant defense: Recent developments, missing links, and future outlook. ACTA ACUST UNITED AC 2017. [DOI: 10.1007/s11515-017-1460-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Liu C, Xu Y, Long D, Cao B, Hou J, Xiang Z, Zhao A. Plant G-protein β subunits positively regulate drought tolerance by elevating detoxification of ROS. Biochem Biophys Res Commun 2017; 491:897-902. [PMID: 28754592 DOI: 10.1016/j.bbrc.2017.07.133] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 07/21/2017] [Indexed: 11/16/2022]
Abstract
Heterotrimeric guanine-nucleotide-binding proteins (G-proteins) consist of α, β and γ subunits and play important roles in response and tolerance to abiotic stresses in plants, but the function of the heterotrimeric G-protein β subunit in response to drought remains unclear. In the present study, the AGB1 mutants (agb1-2-1 and agb1-3-2) were more sensitive to drought than the wild-type. The overexpression of mulberry (Morus alba L.) G-protein β subunit in transgenic tobacco (Nicotiana tabacum L.) significantly enhanced the plants' drought tolerance. The transgenic tobacco plants had higher proline contents and peroxidase activities, and lower malonaldehyde and hydrogen peroxide contents and superoxide free radical accumulations under drought conditions. Additionally, transcript levels of the tobacco antioxidative genes, NtSOD and NtCAT, increased in drought-stressed transgenic tobacco plants. Thus, the heterotrimeric G-protein β subunits positively regulate drought tolerance in plants.
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Affiliation(s)
- Changying Liu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China
| | - Yazhen Xu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China
| | - Dingpei Long
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China
| | - Boning Cao
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China
| | - Jiamin Hou
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China
| | - Zhonghuai Xiang
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China
| | - Aichun Zhao
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China.
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Tunc-Ozdemir M, Jones AM. BRL3 and AtRGS1 cooperate to fine tune growth inhibition and ROS activation. PLoS One 2017; 12:e0177400. [PMID: 28545052 PMCID: PMC5436702 DOI: 10.1371/journal.pone.0177400] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 04/26/2017] [Indexed: 12/26/2022] Open
Abstract
Plasma membrane-localized leucine-rich repeat receptor-like kinases directly activates G protein complex via interaction with seven transmembrane domain Regulator of G-protein Signaling 1 (AtRGS1) protein. Brassinosteroid insensitive 1 (BRI1) LIKE3 (BRL3) phosphorylates AtRGS1 in vitro. FRET analysis showed that BRL3 and AtRGS1 interaction dynamics change in response to glucose and flg22. Both BRL3 and AtRGS1 function in glucose sensing and brl3 and rgs1-2 single mutants are hyposensitive to high glucose as well as the brl3/rgs1 double mutant. BRL3 and AtRGS1 function in the same pathway linked to high glucose sensing. Hypocotyl elongation, another sugar-mediated pathway, is also implicated to be partially mediated by BRL3 and AtRGS1 because rgs1-2, brl3-2 and brl3-2/ rgs1-2 mutants share the long hypocotyl phenotype. BRL3 and AtRGS1 modulate the flg22-induced ROS burst and block one or more components positively regulating ROS production because the brl3/rgs1 double mutant has ~60% more ROS production than wild type while rgs1-2 has a partial ROS burst impairment and brl3 has slightly more ROS production. Here, we proposed a simple model where both BRL3 and AtRGS1 are part of a fine-tuning mechanism sensing glucose and flg22 to prevent excess ROS burst and control growth inhibition.
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Affiliation(s)
- Meral Tunc-Ozdemir
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Alan M. Jones
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
- * E-mail:
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Razzaque S, Haque T, Elias SM, Rahman MS, Biswas S, Schwartz S, Ismail AM, Walia H, Juenger TE, Seraj ZI. Reproductive stage physiological and transcriptional responses to salinity stress in reciprocal populations derived from tolerant (Horkuch) and susceptible (IR29) rice. Sci Rep 2017; 7:46138. [PMID: 28397857 PMCID: PMC5387399 DOI: 10.1038/srep46138] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 03/13/2017] [Indexed: 12/29/2022] Open
Abstract
Global increase in salinity levels has made it imperative to identify novel sources of genetic variation for tolerance traits, especially in rice. The rice landrace Horkuch, endemic to the saline coastal area of Bangladesh, was used in this study as the source of tolerance in reciprocal crosses with the sensitive but high-yielding IR29 variety for discovering transcriptional variation associated with salt tolerance in the resulting populations. The cytoplasmic effect of the Horkuch background in leaves under stress showed functional enrichment for signal transduction, DNA-dependent regulation and transport activities. In roots the enrichment was for cell wall organization and macromolecule biosynthesis. In contrast, the cytoplasmic effect of IR29 showed upregulation of apoptosis and downregulation of phosphorylation across tissues relative to Horkuch. Differential gene expression in leaves of the sensitive population showed downregulation of GO processes like photosynthesis, ATP biosynthesis and ion transport. Roots of the tolerant plants conversely showed upregulation of GO terms like G-protein coupled receptor pathway, membrane potential and cation transport. Furthermore, genes involved in regulating membrane potentials were constitutively expressed only in the roots of tolerant individuals. Overall our work has developed genetic resources and elucidated the likely mechanisms associated with the tolerance response of the Horkuch genotype.
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Affiliation(s)
- Samsad Razzaque
- Plant Biotechnology Lab, Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, 1000, Bangladesh
- Department of Integrative Biology and Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712, USA
| | - Taslima Haque
- Plant Biotechnology Lab, Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, 1000, Bangladesh
- Department of Integrative Biology and Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712, USA
| | - Sabrina M. Elias
- Plant Biotechnology Lab, Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, 1000, Bangladesh
- Department of Agronomy and Horticulture, University of Nebraska, Lincoln, Nebraska 68583, USA
| | - Md. Sazzadur Rahman
- Plant Physiology Division, Bangladesh Rice Research Institute, Gazipur, Bangladesh
| | - Sudip Biswas
- Plant Biotechnology Lab, Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, 1000, Bangladesh
| | - Scott Schwartz
- Department of Integrative Biology and Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712, USA
| | | | - Harkamal Walia
- Department of Agronomy and Horticulture, University of Nebraska, Lincoln, Nebraska 68583, USA
| | - Thomas E. Juenger
- Department of Integrative Biology and Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712, USA
| | - Zeba I. Seraj
- Plant Biotechnology Lab, Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, 1000, Bangladesh
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Tunc-Ozdemir M, Jones AM. Ligand-induced dynamics of heterotrimeric G protein-coupled receptor-like kinase complexes. PLoS One 2017; 12:e0171854. [PMID: 28187200 PMCID: PMC5302818 DOI: 10.1371/journal.pone.0171854] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 01/26/2017] [Indexed: 02/08/2023] Open
Abstract
Background Arabidopsis, 7-transmembrane Regulator of G signaling protein 1 (AtRGS1) modulates canonical G protein signaling by promoting the inactive state of heterotrimeric G protein complex on the plasma membrane. It is known that plant leucine-rich repeat receptor–like kinases (LRR RLKs) phosphorylate AtRGS1 in vitro but little is known about the in vivo interaction, molecular dynamics, or the cellular consequences of this interaction. Methods Therefore, a subset of the known RLKs that phosphorylate AtRGS1 were selected for elucidation, namely, BAK1, BIR1, FLS2. Several microscopies for both static and dynamic protein-protein interactions were used to follow in vivo interactions between the RLKs and AtRGS1 after the presentation of the Pathogen-associated Molecular Pattern, Flagellin 22 (Flg22). These microscopies included Förster Resonance Energy Transfer, Bimolecular Fluoresence Complementation, and Cross Number and Brightness Fluorescence Correlation Spectroscopy. In addition, reactive oxygen species and calcium changes in living cells were quantitated using luminometry and R-GECO1 microscopy. Results The LRR RLKs BAK1 and BIR1, interact with AtRGS1 at the plasma membrane. The RLK ligand flg22 sets BAK1 in motion toward AtRGS1 and BIR1 away, both returning to the baseline orientations by 10 minutes. The C-terminal tail of AtRGS1 is important for the interaction with BAK1 and for the tempo of the AtRGS1/BIR1 dynamics. This window of time corresponds to the flg22-induced transient production of reactive oxygen species and calcium release which are both attenuated in the rgs1 and the bak1 null mutants. Conclusions A temporal model of these interactions is proposed. flg22 binding induces nearly instantaneous dimerization between FLS2 and BAK1. Phosphorylated BAK1 interacts with and enables AtRGS1 to move away from BIR1 and AtRGS1 becomes phosphorylated leading to its endocytosis thus leading to de-repression by permitting AtGPA1 to exchange GDP for GTP. Finally, the G protein complex becomes dissociated thus AGB1 interacts with its effector proteins leading to changes in reactive oxygen species and calcium.
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Affiliation(s)
- Meral Tunc-Ozdemir
- Department of Biology University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Alan M. Jones
- Department of Biology University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- * E-mail:
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Swain DM, Sahoo RK, Srivastava VK, Tripathy BC, Tuteja R, Tuteja N. Function of heterotrimeric G-protein γ subunit RGG1 in providing salinity stress tolerance in rice by elevating detoxification of ROS. PLANTA 2017; 245:367-383. [PMID: 27785615 DOI: 10.1007/s00425-016-2614-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 10/20/2016] [Indexed: 05/07/2023]
Abstract
The present study provides evidence of a unique function of RGG1 in providing salinity stress tolerance in transgenic rice without affecting yield. It also provides a good example for signal transduction from the external environment to inside for enhanced agricultural production that withstands the extreme climatic conditions and ensures food security. The role of heterotrimeric G-proteins functioning as signalling molecules has not been studied as extensively in plants as in animals. Recently, their importance in plant stress signalling has been emerging. In this study, the function of rice G-protein γ subunit (RGG1) in the promotion of salinity tolerance in rice (Oryza sativa L. cv. IR64) was investigated. The overexpression of RGG1 driven by the CaMV35S promoter in transgenic rice conferred high salinity tolerance even in the presence of 200 mM NaCl. Transcript levels of antioxidative genes, i.e., CAT, APX, and GR, and their enzyme activities increased in salinity-stressed transgenic rice plants suggesting a better antioxidant system to cope the oxidative-damages caused by salinity stress. The RGG1-induced signalling events that conferred tolerance to salinity was mediated by increased gene expression of the enzymes that scavenged reactive oxygen species. In salinity-stressed RGG1 transgenic lines, the transcript levels of RGG2, RGB, RGA, DEP1, and GS3 also increased in addition to RGG1. These observations suggest that most likely the stoichiometry of the G-protein complex was not disturbed under stress. Agronomic parameters, endogenous sugar content (glucose and fructose) and hormones (GA3, zeatin and IAA) were also higher in the transgenic plants compared with the wild-type plants. A BiFC assay confirmed the interaction of RGG1 with different stress-responsive proteins which play active roles in signalling and prevention of aggregation of proteins under stress-induced perturbation. The present study will help in understanding the G-protein-mediated stress tolerance in plants.
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Affiliation(s)
- Durga Madhab Swain
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
- Department of Biotechnology, Ravenshaw University, Cuttack, Odisha, 753003, India
| | - Ranjan Kumar Sahoo
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Vineet Kumar Srivastava
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Baishnab Charan Tripathy
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
- Department of Biotechnology, Ravenshaw University, Cuttack, Odisha, 753003, India
| | - Renu Tuteja
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Narendra Tuteja
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
- Amity Institute of Microbial Technology, Amity University, Noida, 201313, India.
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Liang Y, Gao Y, Jones AM. Extra Large G-Protein Interactome Reveals Multiple Stress Response Function and Partner-Dependent XLG Subcellular Localization. FRONTIERS IN PLANT SCIENCE 2017; 8:1015. [PMID: 28659958 PMCID: PMC5469152 DOI: 10.3389/fpls.2017.01015] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Accepted: 05/26/2017] [Indexed: 05/09/2023]
Abstract
The three-member family of Arabidopsis extra-large G proteins (XLG1-3) defines the prototype of an atypical Gα subunit in the heterotrimeric G protein complex. Recent evidence indicate that XLG subunits operate along with its Gβγ dimer in root morphology, stress responsiveness, and cytokinin induced development, however downstream targets of activated XLG proteins in the stress pathways are rarely known. To assemble a set of candidate XLG-targeted proteins, a yeast two-hybrid complementation-based screen was performed using XLG protein baits to query interactions between XLG and partner protein found in glucose-treated seedlings, roots, and Arabidopsis cells in culture. Seventy two interactors were identified and >60% of a test set displayed in vivo interaction with XLG proteins. Gene co-expression analysis shows that >70% of the interactors are positively correlated with the corresponding XLG partners. Gene Ontology enrichment for all the candidates indicates stress responses and posits a molecular mechanism involving a specific set of transcription factor partners to XLG. Genes encoding two of these transcription factors, SZF1 and 2, require XLG proteins for full NaCl-induced expression. The subcellular localization of the XLG proteins in the nucleus, endosome, and plasma membrane is dependent on the specific interacting partner.
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Affiliation(s)
- Ying Liang
- College of Natural Resources and Environment, Northwest A&F UniversityXianyang, China
- Department of Biology University of North Carolina at Chapel HillChapel Hill, NC, United States
| | - Yajun Gao
- College of Natural Resources and Environment, Northwest A&F UniversityXianyang, China
- *Correspondence: Yajun Gao
| | - Alan M. Jones
- Department of Biology University of North Carolina at Chapel HillChapel Hill, NC, United States
- Department of Pharmacology, University of North Carolina at Chapel HillChapel Hill, NC, United States
- Alan M. Jones
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Tunc-Ozdemir M, Li B, Jaiswal DK, Urano D, Jones AM, Torres MP. Predicted Functional Implications of Phosphorylation of Regulator of G Protein Signaling Protein in Plants. FRONTIERS IN PLANT SCIENCE 2017; 8:1456. [PMID: 28890722 PMCID: PMC5575782 DOI: 10.3389/fpls.2017.01456] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 08/04/2017] [Indexed: 05/22/2023]
Abstract
Heterotrimeric G proteins function in development, biotic, and abiotic stress responses, hormone signaling as well as sugar sensing. We previously proposed that discrimination of these various external signals in the G protein pathway is accomplished in plants by membrane-localized receptor-like kinases (RLKs) rather than G-protein-coupled receptors. Arabidopsis thaliana Regulator of G Signaling protein 1 (AtRGS1) modulates G protein activation and is phosphorylated by several RLKs and by WITH-NO-LYSINE kinases (WNKs). Here, a combination of in vitro kinase assays, mass spectrometry, and computational bioinformatics identified and functionally prioritized phosphorylation sites in AtRGS1. Phosphosites for two more RLKs (BRL3 and PEPR1) were identified and added to the AtRGS1 phosphorylation profile. Bioinformatics analyses revealed that RLKs and WNK kinases phosphorylate plant RGS proteins within regions that are conserved across eukaryotes and at a high frequency. Four phospho-sites among 14 identified are proximal to equivalent mammalian phosphosites that impact RGS function, including: pS437 and pT267 in GmRGS2, and pS339 and pS436 in AtRGS1. Based on these analyses, we propose that pS437 and pS436 regulate GmRGS2 and AtRGS1 protein interactions and/or localization, whereas pT267 is important for modulation of GmRGS2 GAP activity and localization. Moreover, pS339 most likely affects AtRGS1 activation.
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Affiliation(s)
- Meral Tunc-Ozdemir
- Department of Biology, University of North Carolina at Chapel Hill, Chapel HillNC, United States
| | - Bo Li
- Department of Biology, University of North Carolina at Chapel Hill, Chapel HillNC, United States
| | - Dinesh K. Jaiswal
- Department of Biology, University of North Carolina at Chapel Hill, Chapel HillNC, United States
| | - Daisuke Urano
- Department of Biology, University of North Carolina at Chapel Hill, Chapel HillNC, United States
- Temasek Life Sciences Laboratory, National University of SingaporeSingapore, Singapore
| | - Alan M. Jones
- Department of Biology, University of North Carolina at Chapel Hill, Chapel HillNC, United States
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel HillNC, United States
- *Correspondence: Alan M. Jones, Matthew P. Torres,
| | - Matthew P. Torres
- School of Biological Sciences, Georgia Institute of Technology, AtlantaGA, United States
- *Correspondence: Alan M. Jones, Matthew P. Torres,
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Urano D, Maruta N, Trusov Y, Stoian R, Wu Q, Liang Y, Jaiswal DK, Thung L, Jackson D, Botella JR, Jones AM. Saltational evolution of the heterotrimeric G protein signaling mechanisms in the plant kingdom. Sci Signal 2016; 9:ra93. [DOI: 10.1126/scisignal.aaf9558] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Jangam AP, Pathak RR, Raghuram N. Microarray Analysis of Rice d1 (RGA1) Mutant Reveals the Potential Role of G-Protein Alpha Subunit in Regulating Multiple Abiotic Stresses Such as Drought, Salinity, Heat, and Cold. FRONTIERS IN PLANT SCIENCE 2016; 7:11. [PMID: 26858735 PMCID: PMC4729950 DOI: 10.3389/fpls.2016.00011] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 01/07/2016] [Indexed: 05/18/2023]
Abstract
The genome-wide role of heterotrimeric G-proteins in abiotic stress response in rice has not been examined from a functional genomics perspective, despite the availability of mutants and evidences involving individual genes/processes/stresses. Our rice whole transcriptome microarray analysis (GSE 20925 at NCBI GEO) using the G-alpha subunit (RGA1) null mutant (Daikoku 1 or d1) and its corresponding wild type (Oryza sativa Japonica Nipponbare) identified 2270 unique differentially expressed genes (DEGs). Out of them, we mined for all the potentially abiotic stress-responsive genes using Gene Ontology terms, STIFDB2.0 and Rice DB. The first two approaches produced smaller subsets of the 1886 genes found at Rice DB. The GO approach revealed similar regulation of several families of stress-responsive genes in RGA1 mutant. The Genevestigator analysis of the stress-responsive subset of the RGA1-regulated genes from STIFDB revealed cold and drought-responsive clusters. Meta data analysis at Rice DB revealed large stress-response categories such as cold (878 up/810 down), drought (882 up/837 down), heat (913 up/777 down), and salt stress (889 up/841 down). One thousand four hundred ninety-eight of them are common to all the four abiotic stresses, followed by fewer genes common to smaller groups of stresses. The RGA1-regulated genes that uniquely respond to individual stresses include 111 in heat stress, eight each in cold only and drought only stresses, and two genes in salt stress only. The common DEGs (1498) belong to pathways such as the synthesis of polyamine, glycine-betaine, proline, and trehalose. Some of the common DEGs belong to abiotic stress signaling pathways such as calcium-dependent pathway, ABA independent and dependent pathway, and MAP kinase pathway in the RGA1 mutant. Gene ontology of the common stress responsive DEGs revealed 62 unique molecular functions such as transporters, enzyme regulators, transferases, hydrolases, carbon and protein metabolism, binding to nucleotides, carbohydrates, receptors and lipids, morphogenesis, flower development, and cell homeostasis. We also mined 63 miRNAs that bind to the stress responsive transcripts identified in this study, indicating their post-transcriptional regulation. Overall, these results indicate the potentially extensive role of RGA1 in the regulation of multiple abiotic stresses in rice for further validation.
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Chakraborty N, Sharma P, Kanyuka K, Pathak RR, Choudhury D, Hooley R, Raghuram N. G-protein α-subunit (GPA1) regulates stress, nitrate and phosphate response, flavonoid biosynthesis, fruit/seed development and substantially shares GCR1 regulation in A. thaliana. PLANT MOLECULAR BIOLOGY 2015; 89:559-76. [PMID: 26346778 DOI: 10.1007/s11103-015-0374-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 08/28/2015] [Indexed: 05/09/2023]
Abstract
Heterotrimeric G-proteins are implicated in several plant processes, but the mechanisms of signal-response coupling and the roles of G-protein coupled receptors in general and GCR1 in particular, remain poorly understood. We isolated a knock-out mutant of the Arabidopsis G-protein α subunit (gpa1-5) and analysed its transcriptome to understand the genomewide role of GPA1 and compared it with that of our similar analysis of a GCR1 mutant (Chakraborty et al. 2015, PLoS ONE 10(2):e0117819). We found 394 GPA1-regulated genes spanning 79 biological processes, including biotic and abiotic stresses, development, flavonoid biosynthesis, transcription factors, transporters and nitrate/phosphate responses. Many of them are either unknown or unclaimed explicitly in other published gpa1 mutant transcriptome analyses. A comparison of all known GPA1-regulated genes (including the above 394) with 350 GCR1-regulated genes revealed 114 common genes. This can be best explained by GCR1-GPA1 coupling, or by convergence of their independent signaling pathways. Though the common genes in our GPA1 and GCR1 mutant datasets constitute only 26% of the GPA1-regulated and 30% of the GCR1-responsive genes, they belong to nearly half of all the processes affected in both the mutants. Thus, GCR1 and GPA1 regulate not only some common genes, but also different genes belonging to the same processes to achieve similar outcomes. Overall, we validate some known and report many hitherto unknown roles of GPA1 in plants, including agronomically important ones such as biotic stress and nutrient response, and also provide compelling genetic evidence to revisit the role of GCR1 in G-protein signalling.
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Affiliation(s)
- Navjyoti Chakraborty
- University School of Biotechnology, G.G.S. Indraprastha University, Sector 16 C, Dwarka, New Delhi, 110078, India
| | - Priyanka Sharma
- University School of Biotechnology, G.G.S. Indraprastha University, Sector 16 C, Dwarka, New Delhi, 110078, India
| | - Kostya Kanyuka
- Department of Plant Biology and Crop Science, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK
| | - Ravi Ramesh Pathak
- University School of Biotechnology, G.G.S. Indraprastha University, Sector 16 C, Dwarka, New Delhi, 110078, India
| | | | - Richard Hooley
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - Nandula Raghuram
- University School of Biotechnology, G.G.S. Indraprastha University, Sector 16 C, Dwarka, New Delhi, 110078, India.
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Chakraborty N, Singh N, Kaur K, Raghuram N. G-protein Signaling Components GCR1 and GPA1 Mediate Responses to Multiple Abiotic Stresses in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2015; 6:1000. [PMID: 26635828 PMCID: PMC4649046 DOI: 10.3389/fpls.2015.01000] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 10/30/2015] [Indexed: 05/27/2023]
Abstract
G-protein signaling components have been implicated in some individual stress responses in Arabidopsis, but have not been comprehensively evaluated at the genetic and biochemical level. Stress emerged as the largest functional category in our whole transcriptome analyses of knock-out mutants of GCR1 and/or GPA1 in Arabidopsis (Chakraborty et al., 2015a,b). This led us to ask whether G-protein signaling components offer converging points in the plant's response to multiple abiotic stresses. In order to test this hypothesis, we carried out detailed analysis of the abiotic stress category in the present study, which revealed 144 differentially expressed genes (DEGs), spanning a wide range of abiotic stresses, including heat, cold, salt, light stress etc. Only 10 of these DEGs are shared by all the three mutants, while the single mutants (GCR1/GPA1) shared more DEGs between themselves than with the double mutant (GCR1-GPA1). RT-qPCR validation of 28 of these genes spanning different stresses revealed identical regulation of the DEGs shared between the mutants. We also validated the effects of cold, heat and salt stresses in all the 3 mutants and WT on % germination, root and shoot length, relative water content, proline content, lipid peroxidation and activities of catalase, ascorbate peroxidase and superoxide dismutase. All the 3 mutants showed evidence of stress tolerance, especially to cold, followed by heat and salt, in terms of all the above parameters. This clearly shows the role of GCR1 and GPA1 in mediating the plant's response to multiple abiotic stresses for the first time, especially cold, heat and salt stresses. This also implies a role for classical G-protein signaling pathways in stress sensitivity in the normal plants of Arabidopsis. This is also the first genetic and biochemical evidence of abiotic stress tolerance rendered by knock-out mutation of GCR1 and/or GPA1. This suggests that G-protein signaling pathway could offer novel common targets for the development of tolerance/resistance to multiple abiotic stresses.
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46
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Yu Y, Assmann SM. The heterotrimeric G-protein β subunit, AGB1, plays multiple roles in the Arabidopsis salinity response. PLANT, CELL & ENVIRONMENT 2015; 38:2143-56. [PMID: 25808946 DOI: 10.1111/pce.12542] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 02/20/2015] [Accepted: 03/05/2015] [Indexed: 05/07/2023]
Abstract
Salinity stress includes both osmotic and ionic toxicity. Sodium homeostasis is influenced by Na(+) uptake and extrusion, vacuolar Na(+) compartmentation and root to shoot Na(+) translocation via transpiration. The knockout mutant of the Arabidopsis heterotrimeric G-protein Gβ subunit, agb1, is hypersensitive to salt, exhibiting a leaf bleaching phenotype. We show that AGB1 is mainly involved in the ionic toxicity component of salinity stress and plays roles in multiple processes of Na(+) homeostasis. agb1 mutants accumulate more Na(+) and less K(+) in both shoots and roots of hydroponically grown plants, as measured by inductively coupled plasma atomic emission spectrometry. agb1 plants have higher root to shoot translocation rates of radiolabelled (24) Na(+) under transpiring conditions, as a result of larger stomatal apertures and increased stomatal conductance. (24) Na(+) tracer experiments also show that (24) Na(+) uptake rates by excised roots of agb1 and wild type are initially equal, but that agb1 has higher net Na(+) uptake at 90 min, implicating possible involvement of AGB1 in the regulation of Na(+) efflux. Calcium alleviates the salt hypersensitivity of agb1 by reducing Na(+) accumulation to below the toxicity threshold. Our results provide new insights into the regulatory pathways underlying plant responses to salinity stress, an important agricultural problem.
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Affiliation(s)
- Yunqing Yu
- Biology Department, Pennsylvania State University, University Park, PA, 16802-5301, USA
| | - Sarah M Assmann
- Biology Department, Pennsylvania State University, University Park, PA, 16802-5301, USA
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47
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Chakravorty D, Gookin TE, Milner MJ, Yu Y, Assmann SM. Extra-Large G Proteins Expand the Repertoire of Subunits in Arabidopsis Heterotrimeric G Protein Signaling. PLANT PHYSIOLOGY 2015; 169:512-29. [PMID: 26157115 PMCID: PMC4577375 DOI: 10.1104/pp.15.00251] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 07/06/2015] [Indexed: 05/21/2023]
Abstract
Heterotrimeric G proteins, consisting of Gα, Gβ, and Gγ subunits, are a conserved signal transduction mechanism in eukaryotes. However, G protein subunit numbers in diploid plant genomes are greatly reduced as compared with animals and do not correlate with the diversity of functions and phenotypes in which heterotrimeric G proteins have been implicated. In addition to GPA1, the sole canonical Arabidopsis (Arabidopsis thaliana) Gα subunit, Arabidopsis has three related proteins: the extra-large GTP-binding proteins XLG1, XLG2, and XLG3. We demonstrate that the XLGs can bind Gβγ dimers (AGB1 plus a Gγ subunit: AGG1, AGG2, or AGG3) with differing specificity in yeast (Saccharomyces cerevisiae) three-hybrid assays. Our in silico structural analysis shows that XLG3 aligns closely to the crystal structure of GPA1, and XLG3 also competes with GPA1 for Gβγ binding in yeast. We observed interaction of the XLGs with all three Gβγ dimers at the plasma membrane in planta by bimolecular fluorescence complementation. Bioinformatic and localization studies identified and confirmed nuclear localization signals in XLG2 and XLG3 and a nuclear export signal in XLG3, which may facilitate intracellular shuttling. We found that tunicamycin, salt, and glucose hypersensitivity and increased stomatal density are agb1-specific phenotypes that are not observed in gpa1 mutants but are recapitulated in xlg mutants. Thus, XLG-Gβγ heterotrimers provide additional signaling modalities for tuning plant G protein responses and increase the repertoire of G protein heterotrimer combinations from three to 12. The potential for signal partitioning and competition between the XLGs and GPA1 is a new paradigm for plant-specific cell signaling.
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Affiliation(s)
- David Chakravorty
- Biology Department, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Timothy E Gookin
- Biology Department, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Matthew J Milner
- Biology Department, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Yunqing Yu
- Biology Department, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Sarah M Assmann
- Biology Department, Pennsylvania State University, University Park, Pennsylvania 16802
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Baral A, Shruthi KS, Mathew MK. Vesicular trafficking and salinity responses in plants. IUBMB Life 2015; 67:677-86. [PMID: 26314939 DOI: 10.1002/iub.1425] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 08/11/2015] [Indexed: 01/09/2023]
Abstract
Research spanning three decades has demonstrated that vesicles pinch off from the plasma membrane and traffic through the cytoplasm of plant cells, much as previously reported in animal cells. Although the well-conserved clathrin-mediated mechanism of endocytosis has been well characterized, relatively little is known about clathrin-independent pathways in plants. Modulation of endocytosis by both physical stimuli and chemical ligands has been reported in plants. Here, we review the effect of salinity-one of the most deleterious environmental assaults-on endocytosis and intracellular trafficking.
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Affiliation(s)
- Anirban Baral
- National Centre for Biological Sciences (Tata Institute of Fundamental Research), Bellary Road, Bangalore, Karnataka, India
| | - K S Shruthi
- National Centre for Biological Sciences (Tata Institute of Fundamental Research), Bellary Road, Bangalore, Karnataka, India.,School of Bio-Sciences and Technology, VIT University, Vellore, Tamil Nadu, India
| | - M K Mathew
- National Centre for Biological Sciences (Tata Institute of Fundamental Research), Bellary Road, Bangalore, Karnataka, India
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Jamsheer K M, Laxmi A. Expression of Arabidopsis FCS-Like Zinc finger genes is differentially regulated by sugars, cellular energy level, and abiotic stress. FRONTIERS IN PLANT SCIENCE 2015; 6:746. [PMID: 26442059 PMCID: PMC4585328 DOI: 10.3389/fpls.2015.00746] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 08/31/2015] [Indexed: 05/19/2023]
Abstract
Cellular energy status is an important regulator of plant growth, development, and stress mitigation. Environmental stresses ultimately lead to energy deficit in the cell which activates the SNF1-RELATED KINASE 1 (SnRK1) signaling cascade which eventually triggering a massive reprogramming of transcription to enable the plant to survive under low-energy conditions. The role of Arabidopsis thaliana FCS-Like Zinc finger (FLZ) gene family in energy and stress signaling is recently come to highlight after their interaction with kinase subunits of SnRK1 were identified. In a detailed expression analysis in different sugars, energy starvation, and replenishment series, we identified that the expression of most of the FLZ genes is differentially modulated by cellular energy level. It was found that FLZ gene family contains genes which are both positively and negatively regulated by energy deficit as well as energy-rich conditions. Genetic and pharmacological studies identified the role of HEXOKINASE 1- dependent and energy signaling pathways in the sugar-induced expression of FLZ genes. Further, these genes were also found to be highly responsive to different stresses as well as abscisic acid. In over-expression of kinase subunit of SnRK1, FLZ genes were found to be differentially regulated in accordance with their response toward energy fluctuation suggesting that these genes may work downstream to the established SnRK1 signaling under low-energy stress. Taken together, the present study provides a conceptual framework for further studies related to SnRK1-FLZ interaction in relation to sugar and energy signaling and stress response.
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Affiliation(s)
| | - Ashverya Laxmi
- *Correspondence: Ashverya Laxmi, National Institute of Plant Genome Research, Aruna Asaf Ali Road, New Delhi-110067, India,
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50
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Huang JP, Tunc-Ozdemir M, Chang Y, Jones AM. Cooperative control between AtRGS1 and AtHXK1 in a WD40-repeat protein pathway in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2015; 6:851. [PMID: 26528314 PMCID: PMC4602111 DOI: 10.3389/fpls.2015.00851] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 09/28/2015] [Indexed: 05/18/2023]
Abstract
HEXOKINASE 1 (AtHXK1) and Regulator of G-protein Signaling 1 (AtRGS1) pathways, mediate D-glucose signaling in Arabidopsis. However, it is not known the degree, if any, that these pathways overlap and how. We show modest signaling crosstalk between these pathways, albeit complex with both epistatic interactions and additive effects that may be indirect. The action of HXK1 on AtRGS1 signaling lies downstream of the primary step in G protein-mediated sugar signaling in which the WD-repeat protein, AGB1, is the propelling signaling element. RHIP1, a previously unknown protein predicted here to have a 3-stranded helical structure, interacts with both AtRGS1 and AtHXK1 in planta and is required for some glucose-regulated gene expression, providing a physical connection between these two proteins in sugar signaling. The rhip1 null mutant displays similar seedling growth phenotypes as rgs1-2 in response to glucose, further suggesting a role for RHIP1 in glucose signaling. In conclusion, glucose signaling is a complex hierarchical relationship which is specific to the target gene and sugar phenotype and suggests that there are two glycolysis-independent glucose signaling sensors: AtRGS1 and AtHXK1 that weakly communicate with each other via feed-back and feed-forward loops to fine tune the response to glucose.
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Affiliation(s)
- Jian-Ping Huang
- College of Life Science, Northeast Agricultural UniversityHarbin, China
- Department of Biology, University of North Carolina, Chapel HillNC, USA
| | | | - Ying Chang
- College of Life Science, Northeast Agricultural UniversityHarbin, China
- *Correspondence: Ying Chang, ; Alan M. Jones,
| | - Alan M. Jones
- Department of Biology, University of North Carolina, Chapel HillNC, USA
- Department of Pharmacology, University of North Carolina, Chapel HillNC, USA
- *Correspondence: Ying Chang, ; Alan M. Jones,
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