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Maric A. The underground tango: How ethylene and auxin interact to regulate cereal root angle. PLANT PHYSIOLOGY 2024; 195:1757-1758. [PMID: 38558264 PMCID: PMC11213240 DOI: 10.1093/plphys/kiae194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Revised: 03/26/2023] [Accepted: 03/26/2024] [Indexed: 04/04/2024]
Affiliation(s)
- Aida Maric
- Assistant Features Editor, Plant Physiology, American Society of Plant Biologists
- CIBSS—Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104, Freiburg, Germany
- Plant Environmental Signalling and Development, Institute of Biology III, University of Freiburg, 79104 Freiburg, Germany
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2
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Porat A, Tekinalp A, Bhosale Y, Gazzola M, Meroz Y. On the mechanical origins of waving, coiling and skewing in Arabidopsis thaliana roots. Proc Natl Acad Sci U S A 2024; 121:e2312761121. [PMID: 38446852 PMCID: PMC10945788 DOI: 10.1073/pnas.2312761121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 12/07/2023] [Indexed: 03/08/2024] Open
Abstract
By masterfully balancing directed growth and passive mechanics, plant roots are remarkably capable of navigating complex heterogeneous environments to find resources. Here, we present a theoretical and numerical framework which allows us to interrogate and simulate the mechanical impact of solid interfaces on the growth pattern of plant organs. We focus on the well-known waving, coiling, and skewing patterns exhibited by roots of Arabidopsis thaliana when grown on inclined surfaces, serving as a minimal model of the intricate interplay with solid substrates. By modeling growing slender organs as Cosserat rods that mechanically interact with the environment, our simulations verify hypotheses of waving and coiling arising from the combination of active gravitropism and passive root-plane responses. Skewing is instead related to intrinsic twist due to cell file rotation. Numerical investigations are outfitted with an analytical framework that consistently relates transitions between straight, waving, coiling, and skewing patterns with substrate tilt angle. Simulations are found to corroborate theory and recapitulate a host of reported experimental observations, thus providing a systematic approach for studying in silico plant organs behavior in relation to their environment.
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Affiliation(s)
- Amir Porat
- Department of Condensed Matter, School of Physics and Astronomy, Tel Aviv University, Tel Aviv69978, Israel
- Center for Physics, Chemistry of Living Systems, Tel-Aviv University, Tel Aviv69978, Israel
| | - Arman Tekinalp
- Mechanical Sciences and Engineering, University of Illinois at Urbana–Champaign, Urbana, IL61801
| | - Yashraj Bhosale
- Mechanical Sciences and Engineering, University of Illinois at Urbana–Champaign, Urbana, IL61801
| | - Mattia Gazzola
- Mechanical Sciences and Engineering, University of Illinois at Urbana–Champaign, Urbana, IL61801
| | - Yasmine Meroz
- Center for Physics, Chemistry of Living Systems, Tel-Aviv University, Tel Aviv69978, Israel
- Faculty of Life Sciences, School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel
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3
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Cai Z, Dai Y, Jin X, Xu H, Huang Z, Xie Z, Yu X, Luo J. Ambient temperature regulates root circumnutation in rice through the ethylene pathway: transcriptome analysis reveals key genes involved. FRONTIERS IN PLANT SCIENCE 2024; 15:1348295. [PMID: 38525142 PMCID: PMC10957643 DOI: 10.3389/fpls.2024.1348295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Accepted: 02/20/2024] [Indexed: 03/26/2024]
Abstract
Plant roots are constantly prepared to adjust their growth trajectories to avoid unfavorable environments, and their ability to reorient is particularly crucial for survival. Under laboratory conditions, this continuous reorientation of the root tip is manifested as coiling or waving, which we refer to as root circumnutation. However, the effect of ambient temperature (AT) on root circumnutation remains unexplored. In this study, rice seedlings were employed to assess the impact of varying ATs on root circumnutation. The role of ethylene in mediating root circumnutation under elevated AT was examined using the ethylene biosynthesis inhibitor aminooxyacetic acid (AOA) and the ethylene perception antagonist silver thiosulfate (STS). Furthermore, transcriptome sequencing, weighted gene co-expression network analysis, and real-time quantitative PCR were utilized to analyze gene expressions in rice root tips under four distinct treatments: 25°C, 35°C, 35°C+STS, and 35°C+AOA. As a result, genes associated with ethylene synthesis and signaling (OsACOs and OsERFs), auxin synthesis and transport (OsYUCCA6, OsABCB15, and OsNPFs), cell elongation (OsEXPAs, OsXTHs, OsEGL1, and OsEXORDIUMs), as well as the inhibition of root curling (OsRMC) were identified. Notably, the expression levels of these genes increased with rising temperatures above 25°C. This study is the first to demonstrate that elevated AT can induce root circumnutation in rice via the ethylene pathway and proposes a potential molecular model through the identification of key genes. These findings offer valuable insights into the growth regulation mechanism of plant roots under elevated AT conditions.
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Affiliation(s)
- Zeping Cai
- School of Tropical Agriculture and Forestry, Hainan University, Hainan, China
| | - Yinuo Dai
- School of Tropical Agriculture and Forestry, Hainan University, Hainan, China
| | - Xia Jin
- School of Tropical Agriculture and Forestry, Hainan University, Hainan, China
| | - Hui Xu
- School of Tropical Agriculture and Forestry, Hainan University, Hainan, China
| | - Zhen Huang
- School of Tropical Agriculture and Forestry, Hainan University, Hainan, China
| | - Zhenyu Xie
- School of Tropical Agriculture and Forestry, Hainan University, Hainan, China
| | - Xudong Yu
- School of Tropical Agriculture and Forestry, Hainan University, Hainan, China
| | - Jiajia Luo
- School of Tropical Agriculture and Forestry, Hainan University, Hainan, China
- Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, Hainan, China
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4
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Wang H, Ye L, Zhou L, Yu J, Pang B, Zuo D, Gu L, Zhu B, Du X, Wang H. Co-Expression Network Analysis of the Transcriptome Identified Hub Genes and Pathways Responding to Saline-Alkaline Stress in Sorghum bicolor L. Int J Mol Sci 2023; 24:16831. [PMID: 38069156 PMCID: PMC10706439 DOI: 10.3390/ijms242316831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 11/20/2023] [Accepted: 11/24/2023] [Indexed: 12/18/2023] Open
Abstract
Soil salinization, an intractable problem, is becoming increasingly serious and threatening fragile natural ecosystems and even the security of human food supplies. Sorghum (Sorghum bicolor L.) is one of the main crops growing in salinized soil. However, the tolerance mechanisms of sorghum to saline-alkaline soil are still ambiguous. In this study, RNA sequencing was carried out to explore the gene expression profiles of sorghum treated with sodium bicarbonate (150 mM, pH = 8.0, treated for 0, 6, 12 and 24 h). The results show that 6045, 5122, 6804, 7978, 8080 and 12,899 differentially expressed genes (DEGs) were detected in shoots and roots after 6, 12 and 24 h treatments, respectively. GO, KEGG and weighted gene co-expression analyses indicate that the DEGs generated by saline-alkaline stress were primarily enriched in plant hormone signal transduction, the MAPK signaling pathway, starch and sucrose metabolism, glutathione metabolism and phenylpropanoid biosynthesis. Key pathway and hub genes (TPP1, WRKY61, YSL1 and NHX7) are mainly related to intracellular ion transport and lignin synthesis. The molecular and physiological regulation processes of saline-alkali-tolerant sorghum are shown by these results, which also provide useful knowledge for improving sorghum yield and quality under saline-alkaline conditions.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Xuye Du
- School of Life Sciences, Guizhou Normal University, Guiyang 550025, China; (H.W.); (L.Y.); (L.Z.); (J.Y.); (B.P.); (D.Z.); (L.G.); (B.Z.)
| | - Huinan Wang
- School of Life Sciences, Guizhou Normal University, Guiyang 550025, China; (H.W.); (L.Y.); (L.Z.); (J.Y.); (B.P.); (D.Z.); (L.G.); (B.Z.)
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5
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Tyagi A, Ali S, Park S, Bae H. Deciphering the role of mechanosensitive channels in plant root biology: perception, signaling, and adaptive responses. PLANTA 2023; 258:105. [PMID: 37878056 DOI: 10.1007/s00425-023-04261-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 10/02/2023] [Indexed: 10/26/2023]
Abstract
MAIN CONCLUSION Mechanosensitive channels are integral membrane proteins that rapidly translate extrinsic or intrinsic mechanical tensions into biological responses. They can serve as potential candidates for developing smart-resilient crops with efficient root systems. Mechanosensitive (MS) calcium channels are molecular switches for mechanoperception and signal transduction in all living organisms. Although tremendous progress has been made in understanding mechanoperception and signal transduction in bacteria and animals, this remains largely unknown in plants. However, identification and validation of MS channels such as Mid1-complementing activity channels (MCAs), mechanosensitive-like channels (MSLs), and Piezo channels (PIEZO) has been the most significant discovery in plant mechanobiology, providing novel insights into plant mechanoperception. This review summarizes recent advances in root mechanobiology, focusing on MS channels and their related signaling players, such as calcium ions (Ca2+), reactive oxygen species (ROS), and phytohormones. Despite significant advances in understanding the role of Ca2+ signaling in root biology, little is known about the involvement of MS channel-driven Ca2+ and ROS signaling. Additionally, the hotspots connecting the upstream and downstream signaling of MS channels remain unclear. In light of this, we discuss the present knowledge of MS channels in root biology and their role in root developmental and adaptive traits. We also provide a model highlighting upstream (cell wall sensors) and downstream signaling players, viz., Ca2+, ROS, and hormones, connected with MS channels. Furthermore, we highlighted the importance of emerging signaling molecules, such as nitric oxide (NO), hydrogen sulfide (H2S), and neurotransmitters (NTs), and their association with root mechanoperception. Finally, we conclude with future directions and knowledge gaps that warrant further research to decipher the complexity of root mechanosensing.
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Affiliation(s)
- Anshika Tyagi
- Department of Biotechnology, Yeungnam University, Gyeongsan Gyeongbuk, 38541, Republic of Korea.
| | - Sajad Ali
- Department of Biotechnology, Yeungnam University, Gyeongsan Gyeongbuk, 38541, Republic of Korea
| | - Suvin Park
- Department of Biotechnology, Yeungnam University, Gyeongsan Gyeongbuk, 38541, Republic of Korea
| | - Hanhong Bae
- Department of Biotechnology, Yeungnam University, Gyeongsan Gyeongbuk, 38541, Republic of Korea.
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6
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Ma D, Fukuda H, Sotta N, Fujiwara T. Arabidopsis thaliana RPL13aC affects root system architecture through shoot potassium accumulation. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 116:497-509. [PMID: 37433637 DOI: 10.1111/tpj.16386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 07/01/2023] [Accepted: 07/06/2023] [Indexed: 07/13/2023]
Abstract
Plant root system architecture shows complex patterns adapting to different nutritional conditions. In Arabidopsis thaliana, root slanting is a behaviour that is observed when plants are grown on a solid agar plate vertically. However, the regulatory mechanisms of root slanting in response to nutrient conditions are not fully understood. In this study, we found that mutants of A. thaliana ribosome protein RPL13aC, which is expressed in root tips and leaves, exhibit a decreased root-slanting phenotype. Ionomic analysis revealed that rpl13ac mutants have a reduced K content in shoots but not in roots. Because K+ availability has been suggested to affect root coiling, we hypothesized that the decreased root slanting of rpl13ac mutants is caused by the decrease in K content in their shoots. Decapitating shoots or limiting K supply dramatically decreased root slanting in wild-type (WT) plants. We found that the expression of HIGH-AFFINITY K+ TRANSPORTER 5 (HAK5) significantly decreased in the roots of rpl13ac mutants. Mutants of hak5 showed decreased shoot K contents and decreased root slanting, supporting that the decreased shoot K+ accumulation results in less root slanting. K+ replenishment to the shoots of rpl13ac, hak5 mutants and K-starved WT plants recovered their root slanting significantly. These results indicate that plants adjust root slanting in response to K+ accumulation in shoots. Further analysis showed that rpl13ac mutants have abnormal thigmotropic responses, which may be responsible for their defects in root slanting. Altogether, these results revealed K+ -dependent mechanisms that affect root system architecture.
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Affiliation(s)
- Dichao Ma
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Hirofumi Fukuda
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Naoyuki Sotta
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Toru Fujiwara
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
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7
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Guo R, Wen X, Zhang W, Huang L, Peng Y, Jin L, Han H, Zhang L, Li W, Guo H. Arabidopsis EIN2 represses ABA responses during germination and early seedling growth by inactivating HLS1 protein independently of the canonical ethylene pathway. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 115:1514-1527. [PMID: 37269223 DOI: 10.1111/tpj.16335] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Revised: 04/30/2023] [Accepted: 05/29/2023] [Indexed: 06/05/2023]
Abstract
The signaling pathways for the phytohormones ethylene and abscisic acid (ABA) have antagonistic effects on seed germination and early seedling establishment. However, the underlying molecular mechanisms remain unclear. In Arabidopsis thaliana, ETHYLENE INSENSITIVE 2 (EIN2) localizes to the endoplasmic reticulum (ER); although its biochemical function is unknown, it connects the ethylene signal with the key transcription factors EIN3 and EIN3-LIKE 1 (EIL1), leading to the transcriptional activation of ethylene-responsive genes. In this study, we uncovered an EIN3/EIL1-independent role for EIN2 in regulating the ABA response. Epistasis analysis demonstrated that this distinct role of EIN2 in the ABA response depends on HOOKLESS 1 (HLS1), the putative histone acetyltransferase acting as a positive regulator of ABA responses. Protein interaction assays supported a direct physical interaction between EIN2 and HLS1 in vitro and in vivo. Loss of EIN2 function resulted in an alteration of HLS1-mediated histone acetylation at the ABA-INSENSITIVE 3 (ABI3) and ABI5 loci, which promotes gene expression and the ABA response during seed germination and early seedling growth, indicating that the EIN2-HLS1 module contributes to ABA responses. Our study thus revealed that EIN2 modulates ABA responses by repressing HLS1 function, independently of the canonical ethylene pathway. These findings shed light on the intricate regulatory mechanisms underling the antagonistic interactions between ethylene and ABA signaling, with significant implications for our understanding of plant growth and development.
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Affiliation(s)
- Renkang Guo
- Harbin Institute of Technology, Harbin, 150001, China
- Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Xing Wen
- Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Wei Zhang
- Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Li Huang
- Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Yang Peng
- Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Lian Jin
- Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Huihui Han
- Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Linlin Zhang
- Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Wenyang Li
- Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Hongwei Guo
- Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
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8
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Liu Z, Zhou L, Gan C, Hu L, Pang B, Zuo D, Wang G, Wang H, Liu Y. Transcriptomic analysis reveals key genes and pathways corresponding to Cd and Pb in the hyperaccumulator Arabis paniculata. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 254:114757. [PMID: 36950987 DOI: 10.1016/j.ecoenv.2023.114757] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 02/15/2023] [Accepted: 03/07/2023] [Indexed: 06/18/2023]
Abstract
Soil and water are increasingly at risk of contamination from the toxic heavy metals lead (Pb) and cadmium (Cd). Arabis paniculata (Brassicaceae) is a hyperaccumulator of heavy metals (HMs) found widely distributed in areas impacts by mining activities. However, the mechanism by which A. paniculata tolerates HMs is still uncharacterized. For this experiment, we employed RNA sequencing (RNA-seq) in order to find Cd (0.25 mM)- and Pb (2.50 mM)-coresponsive genes A. paniculata. In total, 4490 and 1804 differentially expressed genes (DEGs) were identified in root tissue, and 955 and 2209 DEGs were identified in shoot tissue, after Cd and Pb exposure, respectively. Interestingly in root tissue, gene expression corresponded similarly to both Cd and Pd exposure, of which 27.48% were co-upregulated and 41.00% were co-downregulated. Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses showed that the co-regulated genes were predominantly involved in transcription factors (TFs), cell wall biosynthesis, metal transport, plant hormone signal transduction, and antioxidant enzyme activity. Many critical Pb/Cd-induced DEGs involved in phytohormone biosynthesis and signal transduction, HM transport, and transcription factors were also identified. Especially the gene ABCC9 was co-downregulated in root tissues but co-upregulated in shoot tissues. The co-downregulation of ABCC9 in the roots prevented Cd and Pb from entering the vacuole rather than the cytoplasm for transporting HMs to shoots. While in shoots, the ABCC9 co-upregulated results in vacuolar Cd and Pb accumulation, which may explain why A. paniculata is a hyperaccumulator. These results will help to reveal the molecular and physiological processes underlying tolerance to HM exposure in the hyperaccumulator A. paniculata, and aid in future efforts to utilize this plant in phytoremediation.
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Affiliation(s)
- Zhaochao Liu
- School of Life Science, Guizhou Normal University, Guiyang 550025, Guizhou, China
| | - Lizhou Zhou
- School of Life Science, Guizhou Normal University, Guiyang 550025, Guizhou, China
| | - Chenchen Gan
- School of Life Science, Guizhou Normal University, Guiyang 550025, Guizhou, China
| | - Lijuan Hu
- School of Life Science, Guizhou Normal University, Guiyang 550025, Guizhou, China
| | - Biao Pang
- School of Life Science, Guizhou Normal University, Guiyang 550025, Guizhou, China
| | - Dan Zuo
- School of Life Science, Guizhou Normal University, Guiyang 550025, Guizhou, China
| | - Guangyi Wang
- School of Life Science, Guizhou Normal University, Guiyang 550025, Guizhou, China
| | - Hongcheng Wang
- School of Life Science, Guizhou Normal University, Guiyang 550025, Guizhou, China.
| | - Yingliang Liu
- School of Life Science, Guizhou Normal University, Guiyang 550025, Guizhou, China.
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9
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Liu Y, Mu C, Du D, Yang Y, Li L, Xuan W, Kircher S, Palme K, Li X, Li R. Alkaline stress reduces root waving by regulating PIN7 vacuolar transport. FRONTIERS IN PLANT SCIENCE 2022; 13:1049144. [PMID: 36582637 PMCID: PMC9792863 DOI: 10.3389/fpls.2022.1049144] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 11/22/2022] [Indexed: 06/17/2023]
Abstract
Root development and plasticity are assessed via diverse endogenous and environmental cues, including phytohormones, nutrition, and stress. In this study, we observed that roots in model plant Arabidopsis thaliana exhibited waving and oscillating phenotypes under normal conditions but lost this pattern when subjected to alkaline stress. We later showed that alkaline treatment disturbed the auxin gradient in roots and increased auxin signal in columella cells. We further demonstrated that the auxin efflux transporter PIN-FORMED 7 (PIN7) but not PIN3 was translocated to vacuole lumen under alkaline stress. This process is essential for root response to alkaline stress because the pin7 knockout mutants retained the root waving phenotype. Moreover, we provided evidence that the PIN7 vacuolar transport might not depend on the ARF-GEFs but required the proper function of an ESCRT subunit known as FYVE domain protein required for endosomal sorting 1 (FREE1). Induced silencing of FREE1 disrupted the vacuolar transport of PIN7 and reduced sensitivity to alkaline stress, further highlighting the importance of this cellular process. In conclusion, our work reveals a new role of PIN7 in regulating root morphology under alkaline stress.
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Affiliation(s)
- Yu Liu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, China
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Sino-German Joint Research Center on Agricultural Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, China
| | - Chenglin Mu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, China
- Sino-German Joint Research Center on Agricultural Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, China
| | - Dongdong Du
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, China
- Sino-German Joint Research Center on Agricultural Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, China
| | - Yi Yang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, China
- Sino-German Joint Research Center on Agricultural Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, China
| | - Lixin Li
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Sciences, Northeast Forestry University, Harbin, China
| | - Wei Xuan
- State Key Laboratory of Crop Genetics and Germplasm Enhancement and MOA Key Laboratory of Plant Nutrition and Fertilization in Lower‐Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing, China
| | - Stefan Kircher
- Institute of Biology II/Molecular Plant Physiology, Faculty of Biology, Albert-Ludwigs-University of Freiburg, Schänzlestr. 1, Freiburg, Germany
| | - Klaus Palme
- Sino-German Joint Research Center on Agricultural Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, China
- Institute of Biology II/Molecular Plant Physiology, Faculty of Biology, Albert-Ludwigs-University of Freiburg, Schänzlestr. 1, Freiburg, Germany
| | - Xugang Li
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, China
- Sino-German Joint Research Center on Agricultural Biology, College of Life Sciences, Shandong Agricultural University, Tai’an, China
- Institute of Biology II/Molecular Plant Physiology, Faculty of Biology, Albert-Ludwigs-University of Freiburg, Schänzlestr. 1, Freiburg, Germany
| | - Ruixi Li
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
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10
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Jacobsen AGR, Jervis G, Xu J, Topping JF, Lindsey K. Root growth responses to mechanical impedance are regulated by a network of ROS, ethylene and auxin signalling in Arabidopsis. THE NEW PHYTOLOGIST 2021; 231:225-242. [PMID: 33428776 PMCID: PMC8651006 DOI: 10.1111/nph.17180] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 01/05/2021] [Indexed: 05/21/2023]
Abstract
The growth and development of root systems is influenced by mechanical properties of the substrate in which the plants grow. Mechanical impedance, such as by compacted soil, can reduce root elongation and limit crop productivity. To understand better the mechanisms involved in plant root responses to mechanical impedance stress, we investigated changes in the root transcriptome and hormone signalling responses of Arabidopsis to artificial root barrier systems in vitro. We demonstrate that upon encountering a barrier, reduced Arabidopsis root growth and a characteristic 'step-like' growth pattern is due to a reduction in cell elongation associated with changes in signalling gene expression. Data from RNA-sequencing combined with reporter line and mutant studies identified essential roles for reactive oxygen species, ethylene and auxin signalling during the barrier response. We propose a model in which early responses to mechanical impedance include reactive oxygen signalling integrated with ethylene and auxin responses to mediate root growth changes. Inhibition of ethylene responses allows improved growth in response to root impedance, an observation that may inform future crop breeding programmes.
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Affiliation(s)
| | - George Jervis
- Department of BiosciencesDurham UniversityDurhamDH1 3LEUK
| | - Jian Xu
- Department of Plant Systems PhysiologyInstitute for Water and Wetland ResearchRadboud UniversityHeyendaalseweg 135Nijmegen6525 AJthe Netherlands
- Department of Biological Sciences and Centre for BioImaging SciencesNational University of SingaporeSingapore117543Singapore
| | | | - Keith Lindsey
- Department of BiosciencesDurham UniversityDurhamDH1 3LEUK
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11
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Loshchilov I, Del Dottore E, Mazzolai B, Floreano D. Conditions for the emergence of circumnutations in plant roots. PLoS One 2021; 16:e0252202. [PMID: 34038485 PMCID: PMC8153425 DOI: 10.1371/journal.pone.0252202] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 05/11/2021] [Indexed: 11/28/2022] Open
Abstract
The plant root system shows remarkably complex behaviors driven by environmental cues and internal dynamics, whose interplay remains largely unknown. A notable example is circumnutation growth movements, which are growth oscillations from side to side of the root apex. Here we describe a model capable of replicating root growth behaviors, which we used to analyze the role of circumnuntations, revealing their emergence I) under gravitropic stress, as a combination of signal propagation and sensitivity to the signal carriers; II) as a result of the interplay between gravitropic and thigmotropic responses; and III) as a behavioral strategy to detect and react to resource gradients. The latter function requires the presence of a hypothetical internal oscillator whose parameters are regulated by the perception of environmental resources.
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Affiliation(s)
- Ilya Loshchilov
- Laboratory of Intelligent Systems, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | | | - Barbara Mazzolai
- Center for Micro-Biorobotics, Istituto Italiano di Tecnologia, Pontedera, Italy
| | - Dario Floreano
- Laboratory of Intelligent Systems, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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12
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Villaécija-Aguilar JA, Struk S, Goormachtig S, Gutjahr C. Bioassays for the Effects of Strigolactones and Other Small Molecules on Root and Root Hair Development. Methods Mol Biol 2021; 2309:129-142. [PMID: 34028684 DOI: 10.1007/978-1-0716-1429-7_11] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Growth and development of plant roots are highly dynamic and adaptable to environmental conditions. They are under the control of several plant hormone signaling pathways, and therefore root developmental responses can be used as bioassays to study the action of plant hormones and other small molecules. In this chapter, we present different procedures to measure root traits of the model plant Arabidopsis thaliana. We explain methods for phenotypic analysis of lateral root development, primary root length, root skewing and straightness, and root hair density and length. We describe optimal growth conditions for Arabidopsis seedlings for reproducible root and root hair developmental outputs; and how to acquire images and measure the different traits using image analysis with relatively low-tech equipment. We provide guidelines for a semiautomatic image analysis of primary root length, root skewing, and root straightness in Fiji and a script to automate the calculation of root angle deviation from the vertical and root straightness. By including mutants defective in strigolactone (SL) or KAI2 ligand (KL) synthesis and/or signaling, these methods can be used as bioassays for different SLs or SL-like molecules. In addition, the techniques described here can be used for studying seedling root system architecture, root skewing, and root hair development in any context.
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Affiliation(s)
| | - Sylwia Struk
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent,, Belgium
- Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Sofie Goormachtig
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent,, Belgium
- Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Caroline Gutjahr
- Plant Genetics, TUM School of Life Sciences Weihenstephan, Technical University of Munich (TUM), Freising, Germany.
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13
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Jose J, Roy Choudhury S. Heterotrimeric G-proteins mediated hormonal responses in plants. Cell Signal 2020; 76:109799. [PMID: 33011291 DOI: 10.1016/j.cellsig.2020.109799] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Revised: 09/27/2020] [Accepted: 09/28/2020] [Indexed: 01/27/2023]
Abstract
Phytohormones not only orchestrate intrinsic developmental programs from germination to senescence but also regulate environmental inputs through complex signalling pathways. Despite building an own signalling network, hormones mutually contribute several signalling systems, which are also essential for plant growth and development, defense, and responses to abiotic stresses. One of such important signalling cascades is G-proteins, which act as critical regulators of a wide range of fundamental cellular processes by transducing receptor signals to the intracellular environment. G proteins are composed of α, β, and γ subunits, and the molecular switching between active and inactive conformation of Gα controls the signalling cycle. The active GTP bound Gα and freed Gβγ have both independent and tightly coordinated roles in the regulation of effector molecules, thereby modulating multiple responses, including hormonal responses. Therefore, an interplay of hormones with G-proteins fine-tunes multiple biological processes of plants; however, their molecular mechanisms are largely unknown. Functional characterization of hormone biosynthesis, perception, and signalling components, as well as identification of few effector molecules of G-proteins and their interaction networks, reduces the complexity of the hormonal signalling networks related to G-proteins. In this review, we highlight a valuable insight into the mechanisms of how the G-protein signalling cascades connect with hormonal responses to regulate increased developmental flexibility as well as remarkable plasticity of plants.
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Affiliation(s)
- Jismon Jose
- Department of Biology, Indian Institute of Science Education and Research (IISER) Tirupati, Tirupati, Andhra Pradesh 517507, India
| | - Swarup Roy Choudhury
- Department of Biology, Indian Institute of Science Education and Research (IISER) Tirupati, Tirupati, Andhra Pradesh 517507, India.
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14
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Lucob-Agustin N, Kawai T, Takahashi-Nosaka M, Kano-Nakata M, Wainaina CM, Hasegawa T, Inari-Ikeda M, Sato M, Tsuji H, Yamauchi A, Inukai Y. WEG1, which encodes a cell wall hydroxyproline-rich glycoprotein, is essential for parental root elongation controlling lateral root formation in rice. PHYSIOLOGIA PLANTARUM 2020; 169:214-227. [PMID: 31925781 DOI: 10.1111/ppl.13063] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 12/18/2019] [Accepted: 12/19/2019] [Indexed: 05/25/2023]
Abstract
Lateral roots (LRs) determine the overall root system architecture, thus enabling plants to efficiently explore their underground environment for water and nutrients. However, the mechanisms regulating LR development are poorly understood in monocotyledonous plants. We characterized a rice mutant, wavy root elongation growth 1 (weg1), that produced higher number of long and thick LRs (L-type LRs) formed from the curvatures of its wavy parental roots caused by asymmetric cell growth in the elongation zone. Consistent with this phenotype, was the expression of the WEG1 gene, which encodes a putative member of the hydroxyproline-rich glycoprotein family that regulates cell wall extensibility, in the root elongation zone. The asymmetric elongation growth in roots is well known to be regulated by auxin, but we found that the distribution of auxin at the apical region of the mutant and the wild-type roots was symmetric suggesting that the wavy root phenotype in rice is independent of auxin. However, the accumulation of auxin at the convex side of the curvatures, the site of L-type LR formation, suggested that auxin likely induced the formation of L-type LRs. This was supported by the need of a high amount of exogenous auxin to induce the formation of L-type LRs. These results suggest that the MNU-induced weg1 mutated gene regulates the auxin-independent parental root elongation that controls the number of likely auxin-induced L-type LRs, thus reflecting its importance in improving rice root architecture.
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Affiliation(s)
- Nonawin Lucob-Agustin
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, 464-8601, Japan
| | - Tsubasa Kawai
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, 464-8601, Japan
| | - Misuzu Takahashi-Nosaka
- Department of Genomics and Evolutionary Biology, National Institute of Genetics, Mishima, Shizuoka, 411-8540, Japan
| | - Mana Kano-Nakata
- International Center for Research and Education in Agriculture, Nagoya University, Nagoya, Aichi, 464-8601, Japan
| | - Cornelius M Wainaina
- Department of Horticulture, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Tomomi Hasegawa
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, 464-8601, Japan
| | - Mayuko Inari-Ikeda
- International Center for Research and Education in Agriculture, Nagoya University, Nagoya, Aichi, 464-8601, Japan
| | - Moeko Sato
- Kihara Institute for Biological Research, Yokohama City University, Yokohama, Kanagawa, 244-0813, Japan
| | - Hiroyuki Tsuji
- Kihara Institute for Biological Research, Yokohama City University, Yokohama, Kanagawa, 244-0813, Japan
| | - Akira Yamauchi
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, 464-8601, Japan
| | - Yoshiaki Inukai
- International Center for Research and Education in Agriculture, Nagoya University, Nagoya, Aichi, 464-8601, Japan
- PREST, JST, Kawaguchi, Saitama, 332-0012, Japan
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15
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Martins AD, O'Callaghan F, Bengough AG, Loades KW, Pasqual M, Kolb E, Dupuy LX. The helical motions of roots are linked to avoidance of particle forces in soil. THE NEW PHYTOLOGIST 2020; 225:2356-2367. [PMID: 31693763 DOI: 10.1111/nph.16312] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 10/22/2019] [Indexed: 06/10/2023]
Abstract
Limitation to root growth results from forces required to overcome soil resistance to deformation. The variations in individual particle forces affects root development and often deflects the growth trajectory. We have developed transparent soil and optical projection tomography microscopy systems where measurements of growth trajectory and particle forces can be acquired in a granular medium at a range of confining pressures. We developed image-processing pipelines to analyse patterns in root trajectories and a stochastic-mechanical theory to establish how root deflections relate to particle forces and thickening of the root. Root thickening compensates for the increase in mean particle forces but does not prevent deflections from 5% of most extreme individual particle forces causing root deflection. The magnitude of deflections increases with pressure but they assemble into helices of conserved wavelength in response linked to gravitropism. The study reveals mechanisms for the understanding of root growth in mechanically impeding soil conditions and provides insights relevant to breeding of drought-resistant crops.
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Affiliation(s)
- Adalvan D Martins
- The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
- Federal University of Lavras, CP 3037, Lavras, MG 37.200-000, Brazil
| | | | - A Glyn Bengough
- The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
- School of Science and Engineering, University of Dundee, Dundee, DD1 4HN, UK
| | | | - Moacir Pasqual
- Federal University of Lavras, CP 3037, Lavras, MG 37.200-000, Brazil
| | - Evelyne Kolb
- Physics and Mechanics of Heterogeneous Materials (PMMH) Joint Research Program, Centre National de la Recherche Scientifique (CNRS, UMR 7636), Ecole Supérieure de Physique et Chimie Industrielle de Paris (ESPCI), Paris Sciences et Lettres Research University (PSL), Sorbonne Université - UPMC, Université Paris 06, Université Paris 07, 75005, Paris, France
| | - Lionel X Dupuy
- The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
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16
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Buschmann H, Borchers A. Handedness in plant cell expansion: a mutant perspective on helical growth. THE NEW PHYTOLOGIST 2020; 225:53-69. [PMID: 31254400 DOI: 10.1111/nph.16034] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 06/04/2019] [Indexed: 06/09/2023]
Abstract
Many plant mutants are known that exhibit some degree of helical growth. This 'twisted' phenotype has arisen frequently in mutant screens of model organisms, but it is also found in cultivars of ornamental plants, including trees. The phenomenon, in many cases, is based on defects in cell expansion symmetry. Any complete model which explains the anisotropy of plant cell growth must ultimately explain how helical cell expansion comes into existence - and how it is normally avoided. While the mutations observed in model plants mainly point to the microtubule system, additional affected components involve cell wall functions, auxin transport and more. Evaluation of published data suggests a two-way mechanism underlying the helical growth phenomenon: there is, apparently, a microtubular component that determines handedness, but there is also an influence arising in the cell wall that feeds back into the cytoplasm and affects cellular handedness. This idea is supported by recent reports demonstrating the involvement of the cell wall integrity pathway. In addition, there is mounting evidence that calcium is an important relayer of signals relating to the symmetry of cell expansion. These concepts suggest experimental approaches to untangle the phenomenon of helical cell expansion in plant mutants.
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Affiliation(s)
- Henrik Buschmann
- Botanical Institute, Biology and Chemistry Department, University of Osnabrück, 49076, Osnabrück, Germany
| | - Agnes Borchers
- Botanical Institute, Biology and Chemistry Department, University of Osnabrück, 49076, Osnabrück, Germany
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17
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Chai S, Li E, Zhang Y, Li S. NRT1.1-Mediated Nitrate Suppression of Root Coiling Relies on PIN2- and AUX1-Mediated Auxin Transport. FRONTIERS IN PLANT SCIENCE 2020; 11:671. [PMID: 32582237 PMCID: PMC7288464 DOI: 10.3389/fpls.2020.00671] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 04/29/2020] [Indexed: 05/03/2023]
Abstract
Asymmetric root growth (ARG) on tilted plates, or root coiling on horizontally placed plates, is proposed to be a combination of gravitropism, mechanical sensing, and "circumnutation," a word designated by Charles Darwin to describe the helical movement that all plant organs make around the growth direction. ARG is developmentally controlled in which microtubule-regulating proteins and the phytohormone auxin participates. Nutrient deficiency influences ARG. However, it is unclear which nutrients play key roles in regulating ARG, what endogenous components are involved in responding to nutrient deficiency for ARG, and how nutrient deficiency is translated into endogenous responses. We report here that nitrate deficiency resulted in a strong ARG in Arabidopsis. Nitrate deficiency caused root coiling on horizontal plates, which is inhibited by an auxin transport inhibitor, and by mutations in PIN-FORMED2 (PIN2) and AUXIN RESISTANT 1 (AUX1). We further show that suppression of ARG by nitrate is mediated by the nitrate transporter/sensor NRT1.1. In addition, PIN2- and AUX1-mediated auxin transports are epistatic to NRT1.1 in nitrate deficiency-induced ARG. This study reveals a signaling pathway in root growth by responding to exogenous nitrate and relaying it into altered auxin transport.
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18
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Villaécija-Aguilar JA, Hamon-Josse M, Carbonnel S, Kretschmar A, Schmidt C, Dawid C, Bennett T, Gutjahr C. SMAX1/SMXL2 regulate root and root hair development downstream of KAI2-mediated signalling in Arabidopsis. PLoS Genet 2019; 15:e1008327. [PMID: 31465451 PMCID: PMC6738646 DOI: 10.1371/journal.pgen.1008327] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 09/11/2019] [Accepted: 07/22/2019] [Indexed: 11/18/2022] Open
Abstract
Karrikins are smoke-derived compounds presumed to mimic endogenous signalling molecules (KAI2-ligand, KL), whose signalling pathway is closely related to that of strigolactones (SLs), important regulators of plant development. Both karrikins/KLs and SLs are perceived by closely related α/β hydrolase receptors (KAI2 and D14 respectively), and signalling through both receptors requires the F-box protein MAX2. Furthermore, both pathways trigger proteasome-mediated degradation of related SMAX1-LIKE (SMXL) proteins, to influence development. It has previously been suggested in multiple studies that SLs are important regulators of root and root hair development in Arabidopsis, but these conclusions are based on phenotypes observed in the non-specific max2 mutants and by use of racemic-GR24, a mixture of stereoisomers that activates both D14 and KAI2 signalling pathways. Here, we demonstrate that the majority of the effects on Arabidopsis root development previously attributed to SL signalling are actually mediated by the KAI2 signalling pathway. Using mutants defective in SL or KL synthesis and/or perception, we show that KAI2-mediated signalling alone regulates root hair density and root hair length as well as root skewing, straightness and diameter, while both KAI2 and D14 pathways regulate lateral root density and epidermal cell length. We test the key hypothesis that KAI2 signals by a non-canonical receptor-target mechanism in the context of root development. Our results provide no evidence for this, and we instead show that all effects of KAI2 in the root can be explained by canonical SMAX1/SMXL2 activity. However, we do find evidence for non-canonical GR24 ligand-receptor interactions in D14/KAI2-mediated root hair development. Overall, our results demonstrate that the KAI2 signalling pathway is an important new regulator of root hair and root development in Arabidopsis and lay an important basis for research into a molecular understanding of how very similar and partially overlapping hormone signalling pathways regulate different phenotypic outputs.
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Affiliation(s)
- José Antonio Villaécija-Aguilar
- Faculty of Biology, Genetics, LMU Munich, Biocenter Martinsried, Martinsried, Germany
- Plant Genetics, TUM School of Life Sciences Weihenstephan, Technical University of Munich (TUM), Freising, Germany
| | - Maxime Hamon-Josse
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Samy Carbonnel
- Faculty of Biology, Genetics, LMU Munich, Biocenter Martinsried, Martinsried, Germany
- Plant Genetics, TUM School of Life Sciences Weihenstephan, Technical University of Munich (TUM), Freising, Germany
| | - Annika Kretschmar
- Faculty of Biology, Genetics, LMU Munich, Biocenter Martinsried, Martinsried, Germany
| | - Christian Schmidt
- Chair of Food Chemistry and Molecular Sensory Science, TUM School of Life Sciences Weihenstephan, Technical University of Munich (TUM), Freising, Germany
| | - Corinna Dawid
- Chair of Food Chemistry and Molecular Sensory Science, TUM School of Life Sciences Weihenstephan, Technical University of Munich (TUM), Freising, Germany
| | - Tom Bennett
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
- Sainsbury Laboratory Cambridge University, Cambridge, United Kingdom
- * E-mail: (TB); (CG)
| | - Caroline Gutjahr
- Faculty of Biology, Genetics, LMU Munich, Biocenter Martinsried, Martinsried, Germany
- Plant Genetics, TUM School of Life Sciences Weihenstephan, Technical University of Munich (TUM), Freising, Germany
- * E-mail: (TB); (CG)
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19
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Swarbreck SM, Guerringue Y, Matthus E, Jamieson FJC, Davies JM. Impairment in karrikin but not strigolactone sensing enhances root skewing in Arabidopsis thaliana. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 98:607-621. [PMID: 30659713 PMCID: PMC6563046 DOI: 10.1111/tpj.14233] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 12/20/2018] [Accepted: 01/08/2019] [Indexed: 05/20/2023]
Abstract
Roots form highly complex systems varying in growth direction and branching pattern to forage for nutrients efficiently. Here mutations in the KAI2 (KARRIKIN INSENSITIVE) α/β-fold hydrolase and the MAX2 (MORE AXILLARY GROWTH 2) F-box leucine-rich protein, which together perceive karrikins (smoke-derived butenolides), caused alteration in root skewing in Arabidopsis thaliana. This phenotype was independent of endogenous strigolactones perception by the D14 α/β-fold hydrolase and MAX2. Thus, KAI2/MAX2 effect on root growth may be through the perception of endogenous KAI2-ligands (KLs), which have yet to be identified. Upon perception of a ligand, a KAI2/MAX2 complex is formed together with additional target proteins before ubiquitination and degradation through the 26S proteasome. Using a genetic approach, we show that SMAX1 (SUPPRESSOR OF MAX2-1)/SMXL2 and SMXL6,7,8 (SUPPRESSOR OF MAX2-1-LIKE) are also likely degradation targets for the KAI2/MAX2 complex in the context of root skewing. In A. thaliana therefore, KAI2 and MAX2 act to limit root skewing, while kai2's gravitropic and mechano-sensing responses remained largely unaffected. Many proteins are involved in root skewing, and we investigated the link between MAX2 and two members of the SKS/SKU family. Though KLs are yet to be identified in plants, our data support the hypothesis that they are present and can affect root skewing.
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Affiliation(s)
| | - Yannick Guerringue
- Department of Plant SciencesUniversity of CambridgeCambridgeCB2 3EAUK
- ENS de Lyon ‐ Site MonodLyon69007France
| | - Elsa Matthus
- Department of Plant SciencesUniversity of CambridgeCambridgeCB2 3EAUK
| | - Fiona J. C. Jamieson
- Department of Plant SciencesUniversity of CambridgeCambridgeCB2 3EAUK
- Department of Plant SciencesUniversity of OxfordSouth Parks RoadOxfordOX1 3RBUK
| | - Julia M. Davies
- Department of Plant SciencesUniversity of CambridgeCambridgeCB2 3EAUK
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20
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Matuszkiewicz M, Koter MD, Filipecki M. Limited ventilation causes stress and changes in Arabidopsis morphological, physiological and molecular phenotype during in vitro growth. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2019; 135:554-562. [PMID: 30459082 DOI: 10.1016/j.plaphy.2018.11.003] [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: 08/27/2018] [Revised: 10/23/2018] [Accepted: 11/02/2018] [Indexed: 06/09/2023]
Abstract
A huge number of experiments in plant biology are conducted in sterile, sealed containers, providing environmental stability and full control of factors influencing the plant system. With respect to roots the in vitro growth has another benefit - the ease of conducting visual observations when grown in transparent media. Moreover, straightforward measurements of in vitro grown root systems make them a sensitive and convenient sensor of multiple stresses which may occur during experiments. In order to optimize root nematode infection tests for Arabidopsis mutants with relatively mild phenotypes, two Petri dish sealing techniques were tested (permeable medical adhesive tape and a popular non-permeable plastic film). Using standard experimental settings applied for infection tests, the root architecture, nematode infections, ion leakage, efficiency of photosynthesis, ethylene (ET) production, and CO2 accumulation were monitored in Arabidopsis thaliana Ws-0 wild-type and lsd1 (lesion stimulating disease 1) plants, which is a conditional dependent programmed cell death mutant. All tested parameters gave statistically significant differences between the analyzed sealing tapes, indicating the importance of air exchange. This factor is quite obvious but often ignored in experiments performed in Petri dishes. The results clearly indicate that stress is greater in air-tight sealed plates. These observations were supported by the great expression variation of several marker genes associated with reactive oxygen species (ROS), ET, salicylic (SA), and jasmonic acid (JA) biosynthesis and signaling in two-week-old seedlings. These results are discussed in light of the observed changes in the ET and CO2 concentration. Our results clearly indicate the importance of culture parameters for monitoring of abiotic and biotic stress responses in laboratory conditions, including accurate mutant phenotyping.
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Affiliation(s)
- M Matuszkiewicz
- Department of Plant Genetics, Breeding, and Biotechnology, Faculty of Horticulture and Landscape Architecture, Warsaw University of Life Sciences - SGGW, Nowoursynowska Str. 159, Warszawa, 02-776, Poland
| | - M D Koter
- Department of Plant Genetics, Breeding, and Biotechnology, Faculty of Horticulture and Landscape Architecture, Warsaw University of Life Sciences - SGGW, Nowoursynowska Str. 159, Warszawa, 02-776, Poland
| | - M Filipecki
- Department of Plant Genetics, Breeding, and Biotechnology, Faculty of Horticulture and Landscape Architecture, Warsaw University of Life Sciences - SGGW, Nowoursynowska Str. 159, Warszawa, 02-776, Poland.
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21
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Harkey AF, Yoon GM, Seo DH, DeLong A, Muday GK. Light Modulates Ethylene Synthesis, Signaling, and Downstream Transcriptional Networks to Control Plant Development. FRONTIERS IN PLANT SCIENCE 2019; 10:1094. [PMID: 31572414 PMCID: PMC6751313 DOI: 10.3389/fpls.2019.01094] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Accepted: 08/09/2019] [Indexed: 05/17/2023]
Abstract
The inhibition of hypocotyl elongation by ethylene in dark-grown seedlings was the basis of elegant screens that identified ethylene-insensitive Arabidopsis mutants, which remained tall even when treated with high concentrations of ethylene. This simple approach proved invaluable for identification and molecular characterization of major players in the ethylene signaling and response pathway, including receptors and downstream signaling proteins, as well as transcription factors that mediate the extensive transcriptional remodeling observed in response to elevated ethylene. However, the dark-adapted early developmental stage used in these experiments represents only a small segment of a plant's life cycle. After a seedling's emergence from the soil, light signaling pathways elicit a switch in developmental programming and the hormonal circuitry that controls it. Accordingly, ethylene levels and responses diverge under these different environmental conditions. In this review, we compare and contrast ethylene synthesis, perception, and response in light and dark contexts, including the molecular mechanisms linking light responses to ethylene biology. One powerful method to identify similarities and differences in these important regulatory processes is through comparison of transcriptomic datasets resulting from manipulation of ethylene levels or signaling under varying light conditions. We performed a meta-analysis of multiple transcriptomic datasets to uncover transcriptional responses to ethylene that are both light-dependent and light-independent. We identified a core set of 139 transcripts with robust and consistent responses to elevated ethylene across three root-specific datasets. This "gold standard" group of ethylene-regulated transcripts includes mRNAs encoding numerous proteins that function in ethylene signaling and synthesis, but also reveals a number of previously uncharacterized gene products that may contribute to ethylene response phenotypes. Understanding these light-dependent differences in ethylene signaling and synthesis will provide greater insight into the roles of ethylene in growth and development across the entire plant life cycle.
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Affiliation(s)
- Alexandria F. Harkey
- Department of Biology and Center for Molecular Signaling, Wake Forest University, Winston-Salem, NC, United States
| | - Gyeong Mee Yoon
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, United States
| | - Dong Hye Seo
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, United States
| | - Alison DeLong
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, United States
| | - Gloria K. Muday
- Department of Biology and Center for Molecular Signaling, Wake Forest University, Winston-Salem, NC, United States
- *Correspondence: Gloria K. Muday,
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22
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Piya S, Binder BM, Hewezi T. Canonical and noncanonical ethylene signaling pathways that regulate Arabidopsis susceptibility to the cyst nematode Heterodera schachtii. THE NEW PHYTOLOGIST 2019; 221:946-959. [PMID: 30136723 DOI: 10.1111/nph.15400] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 07/13/2018] [Indexed: 05/29/2023]
Abstract
Plant-parasitic cyst nematodes successfully exploit various phytohormone signaling pathways to establish a new hormonal equilibrium that facilitates nematode parasitism. Although it is largely accepted that ethylene regulates plant responses to nematode infection, a mechanistic understanding of how ethylene shapes plant-nematode interactions remains largely unknown. In this study, we examined the involvement of various components regulating ethylene perception and signaling in establishing Arabidopsis susceptibility to the cyst nematode Heterodera schachtii using a large set of well-characterized single and higher order mutants. Our analyses revealed the existence of two pathways that separately engage ethylene with salicylic acid (SA) and cytokinin signaling during plant response to nematode infection. One pathway involves the canonical ethylene signaling pathway in which activation of ethylene signaling results in suppression of SA-based immunity. The second pathway involves the ethylene receptor ETR1, which signals independently of SA acid to affect immunity, instead altering cytokinin-mediated regulation of downstream components. Our results reveal important mechanisms through which cyst nematodes exploit components of ethylene perception and signaling to affect the balance of hormonal signaling through ethylene interaction with SA and cytokinin networks. This hormonal interaction overcomes plant defense and provokes a susceptible response.
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Affiliation(s)
- Sarbottam Piya
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, 37996, USA
| | - Brad M Binder
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Tarek Hewezi
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, 37996, USA
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Potocka I, Szymanowska-Pułka J. Morphological responses of plant roots to mechanical stress. ANNALS OF BOTANY 2018; 122:711-723. [PMID: 29471488 PMCID: PMC6215033 DOI: 10.1093/aob/mcy010] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 01/15/2018] [Indexed: 05/17/2023]
Abstract
Background Roots are continuously exposed to mechanical pressure and this often results in their morphological modification. Most obvious are changes in the overall form of the root system as well as in the shapes of particular roots. These changes are often accompanied by modifications of the cell pattern and cell morphology. Scope This review focuses on the morphological responses of roots to mechanical stress. Results of early and recent experiments in which roots have been exposed to mechanical pressure are assembled, analysed and discussed. Research applying different experimental sets, obstacles, media of various compactness and structure are reviewed. An effect of the combination of mechanical stresses with other abiotic stresses on roots, and results of estimating the force exerted by the roots are briefly discussed. Possible consequences of the cell pattern rearrangements are considered. Conclusions Several modifications in root morphology are commonly reported: (1) decreased root size, (2) radial swelling accompanied by increased radial dimension of the cortex cell layers and (3) enhanced cap cell sloughing. Nevertheless, because of differences between species and individual plants, a universal scenario for root morphological changes resulting from externally applied pressures is not possible. Thus, knowledge of the root response to mechanical impedance remains incomplete. Studies on the mechanical properties of the root as well as on possible modifications in cell wall structure and composition as the elements responsible for the mechanical properties of the plant tissue are required to understand the response of root tissue as a biomaterial.
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Affiliation(s)
- Izabela Potocka
- Department of Cell Biology, University of Silesia, Katowice, Poland
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Kimura T, Haga K, Shimizu-Mitao Y, Takebayashi Y, Kasahara H, Hayashi KI, Kakimoto T, Sakai T. Asymmetric Auxin Distribution is Not Required to Establish Root Phototropism in Arabidopsis. PLANT & CELL PHYSIOLOGY 2018; 59:823-835. [PMID: 29401292 DOI: 10.1093/pcp/pcy018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 01/25/2018] [Indexed: 05/11/2023]
Abstract
An asymmetric auxin distribution pattern is assumed to underlie the tropic responses of seed plants. It is unclear, however, whether this pattern is required for root negative phototropism. We here demonstrate that asymmetric auxin distribution is not required to establish root phototropism in Arabidopsis. Our detailed analyses of auxin reporter genes indicate that auxin accumulates on the irradiated side of roots in response to an incidental gravitropic stimulus caused by phototropic bending. Further, an agravitropic mutant showed a suppression of this accumulation with an enhancement of the phototropic response. In this context, our pharmacological and genetic analyses revealed that both polar auxin transport and auxin biosynthesis are critical for the establishment of root gravitropism, but not for root phototropism, and that defects in these processes actually enhance phototropic responses in roots. The auxin response factor double mutant arf7 arf19 and the auxin receptor mutant tir1 showed a slight reduction in phototropic curvatures in roots, suggesting that the transcriptional regulation by some specific ARF proteins and their regulators is at least partly involved in root phototropism. However, the auxin antagonist PEO-IAA [α-(phenylethyl-2-one)-indole-3-acetic acid] suppressed root gravitropism and enhanced root phototropism, suggesting that the TIR1/AFB auxin receptors and ARF transcriptional factors play minor roles in root phototropism. Taken together, we conclude from our current data that the phototropic response in Arabidopsis roots is induced by an unknown mechanism that does not require asymmetric auxin distribution and that the Cholodny-Went hypothesis probably does not apply to root phototropism.
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Affiliation(s)
- Taro Kimura
- Graduate School of Science and Technology, Niigata University, 8050 Ikarashi 2-no-cho, Nishi-ku, Niigata, 950-2181 Japan
- Research Fellow of Japan Society for the Promotion of Science, Kojimachi Business Center Building, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo, 102-0083 Japan
| | - Ken Haga
- Department of Human Science and Common Education, Nippon Institute of Technology, 4-1 Gakuendai, Miyashiro-cho, Minamisaitama-gun, Saitama, 345-8501 Japan
| | - Yasushi Shimizu-Mitao
- Department of Biological Science, Graduate School of Science, Osaka University, 1-4 Machikaneyama-cho, Toyonaka, Osaka, 560-0043 Japan
| | - Yumiko Takebayashi
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045 Japan
| | - Hiroyuki Kasahara
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045 Japan
- Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, 3-8-1 Harumi-cho, Fuchu-shi, Tokyo, 183-8538 Japan
| | - Ken-Ichiro Hayashi
- Department of Biochemistry, Okayama University of Science, 1-1 Ridaicho, Kita-ku, Okayama, 700-0005 Japan
| | - Tatsuo Kakimoto
- Department of Biological Science, Graduate School of Science, Osaka University, 1-4 Machikaneyama-cho, Toyonaka, Osaka, 560-0043 Japan
| | - Tatsuya Sakai
- Graduate School of Science and Technology, Niigata University, 8050 Ikarashi 2-no-cho, Nishi-ku, Niigata, 950-2181 Japan
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Lacey RF, Allen CJ, Bakshi A, Binder BM. Ethylene causes transcriptomic changes in Synechocystis during phototaxis. PLANT DIRECT 2018; 2:e00048. [PMID: 31245714 PMCID: PMC6508509 DOI: 10.1002/pld3.48] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 02/20/2018] [Accepted: 02/22/2018] [Indexed: 05/02/2023]
Abstract
Ethylene is well known as a plant hormone, but its role in bacteria is poorly studied. We recently showed that Synechocystis sp. Strain PCC 6803 has a functional receptor for ethylene, ethylene response 1 (Etr1), that is involved in various processes such as phototaxis in response to directional light and biofilm formation. Here, we use RNA sequencing to examine the changes in gene transcripts caused by ethylene under phototaxis conditions. Over 500 gene transcripts across many functional categories, of approximately 3700 protein-encoding genes, were altered by application of ethylene. In general, ethylene caused both up- and downregulation of genes within a functional category. However, the transcript levels of amino acid metabolism genes were mainly upregulated and cell envelope genes were mostly downregulated by ethylene. The changes in cell envelope genes correlate with our prior observation that ethylene affects cell surface properties to alter cell motility. Ethylene caused a twofold or more change in 62 transcripts with the largest category of upregulated genes annotated as transporters and the largest category of downregulated genes annotated as glycosyltransferases which sometimes are involved in changing the composition of sugars on the cell surface. Consistent with changes in cell envelope, glycosyltransferase, and transporter gene transcripts, application of ethylene altered the levels of specific sugar moieties on the surface of cells. Light signaling from Etr1 involves two proteins (Slr1213 and Slr1214) and a small, noncoding RNA, carbon stress-induced RNA1 (csiR1). Application of ethylene caused a rapid, but transient, decrease in the transcript levels of etr1, slr1213, and slr1214 and a rapid and prolonged decrease in csiR1 transcript. Deletion of Slr1214 caused a large increase in csiR1 transcript levels and ethylene lowered csiR1 transcript. These data combined with prior reports indicate that ethylene functions as a signal to affect a variety of processes altering the physiology of Synechocystis cells.
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Affiliation(s)
- Randy F. Lacey
- Department of Biochemistry & Cellular and Molecular BiologyUniversity of TennesseeKnoxvilleTNUSA
| | - Cidney J. Allen
- Department of Biochemistry & Cellular and Molecular BiologyUniversity of TennesseeKnoxvilleTNUSA
| | - Arkadipta Bakshi
- Genome Science and Technology ProgramUniversity of TennesseeKnoxvilleTNUSA
- Present address:
Department of BotanyUniversity of WisconsinMadisonWIUSA
| | - Brad M. Binder
- Department of Biochemistry & Cellular and Molecular BiologyUniversity of TennesseeKnoxvilleTNUSA
- Genome Science and Technology ProgramUniversity of TennesseeKnoxvilleTNUSA
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Bakshi A, Piya S, Fernandez JC, Chervin C, Hewezi T, Binder BM. Ethylene Receptors Signal via a Noncanonical Pathway to Regulate Abscisic Acid Responses. PLANT PHYSIOLOGY 2018; 176:910-929. [PMID: 29158332 PMCID: PMC5761792 DOI: 10.1104/pp.17.01321] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 11/17/2017] [Indexed: 05/04/2023]
Abstract
Ethylene is a gaseous plant hormone perceived by a family of receptors in Arabidopsis (Arabidopsis thaliana) including ETHYLENE RESPONSE1 (ETR1) and ETR2. Previously we showed that etr1-6 loss-of-function plants germinate better and etr2-3 loss-of-function plants germinate worse than wild-type under NaCl stress and in response to abscisic acid (ABA). In this study, we expanded these results by showing that ETR1 and ETR2 have contrasting roles in the control of germination under a variety of inhibitory conditions for seed germination such as treatment with KCl, CuSO4, ZnSO4, and ethanol. Pharmacological and molecular biology results support a model where ETR1 and ETR2 are indirectly affecting the expression of genes encoding ABA signaling proteins to affect ABA sensitivity. The receiver domain of ETR1 is involved in this function in germination under these conditions and controlling the expression of genes encoding ABA signaling proteins. Epistasis analysis demonstrated that these contrasting roles of ETR1 and ETR2 do not require the canonical ethylene signaling pathway. To explore the importance of receptor-protein interactions, we conducted yeast two-hybrid screens using the cytosolic domains of ETR1 and ETR2 as bait. Unique interacting partners with either ETR1 or ETR2 were identified. We focused on three of these proteins and confirmed the interactions with receptors. Loss of these proteins led to faster germination in response to ABA, showing that they are involved in ABA responses. Thus, ETR1 and ETR2 have both ethylene-dependent and -independent roles in plant cells that affect responses to ABA.
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Affiliation(s)
- Arkadipta Bakshi
- Genome Science and Technology Program, University of Tennessee, Knoxville, Tennessee, 37996
| | - Sarbottam Piya
- Department of Plant Sciences, University of Tennessee, Knoxville, Tennessee, 37996
| | - Jessica C Fernandez
- Department of Biochemistry, Cellular, and Molecular Biology, University of Tennessee, Knoxville, Tennessee, 37996
| | - Christian Chervin
- Université de Toulouse, INP-ENSAT, INRA, UMR 990 Génomique et Biotechnologie des Fruits, F-31326 Castanet-Tolosan Cedex, France
| | - Tarek Hewezi
- Genome Science and Technology Program, University of Tennessee, Knoxville, Tennessee, 37996
- Department of Plant Sciences, University of Tennessee, Knoxville, Tennessee, 37996
| | - Brad M Binder
- Genome Science and Technology Program, University of Tennessee, Knoxville, Tennessee, 37996
- Department of Biochemistry, Cellular, and Molecular Biology, University of Tennessee, Knoxville, Tennessee, 37996
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Mir R, Morris VH, Buschmann H, Rasmussen CG. Division Plane Orientation Defects Revealed by a Synthetic Double Mutant Phenotype. PLANT PHYSIOLOGY 2018; 176:418-431. [PMID: 29146775 PMCID: PMC5761783 DOI: 10.1104/pp.17.01075] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 11/13/2017] [Indexed: 05/09/2023]
Abstract
TANGLED1 (TAN1) and AUXIN-INDUCED-IN-ROOTS9 (AIR9) are microtubule-binding proteins that localize to the division site in plants. Their function in Arabidopsis (Arabidopsis thaliana) remained unclear because neither tan1 nor air9 single mutants have a strong phenotype. We show that tan1 air9 double mutants have a synthetic phenotype consisting of short, twisted roots with disordered cortical microtubule arrays that are hypersensitive to a microtubule-depolymerizing drug. The tan1 air9 double mutants have significant defects in division plane orientation due to failures in placing the new cell wall at the correct division site. Full-length TAN1 fused to yellow fluorescent protein, TAN1-YFP, and several deletion constructs were transformed into the double mutant to assess which regions of TAN1 are required for its function in root growth, root twisting, and division plane orientation. TAN1-YFP expressed in tan1 air9 significantly rescued the double mutant phenotype in all three respects. Interestingly, TAN1 missing the first 126 amino acids, TAN1-ΔI-YFP, failed to rescue the double mutant phenotype, while TAN1 missing a conserved middle region, TAN1-ΔII-YFP, significantly rescued the mutant phenotype in terms of root growth and division plane orientation but not root twisting. We use the tan1 air9 double mutant to discover new functions for TAN1 and AIR9 during phragmoplast guidance and root morphogenesis.
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Affiliation(s)
- Ricardo Mir
- Center for Plant Cell Biology, Institute for Integrative Genome Biology, Department of Botany and Plant Sciences, University of California, Riverside, California 92521
| | - Victoria H Morris
- Center for Plant Cell Biology, Institute for Integrative Genome Biology, Department of Botany and Plant Sciences, University of California, Riverside, California 92521
| | - Henrik Buschmann
- Osnabrück University, Department of Biology and Chemistry, 49076 Osnabrueck, Germany
| | - Carolyn G Rasmussen
- Center for Plant Cell Biology, Institute for Integrative Genome Biology, Department of Botany and Plant Sciences, University of California, Riverside, California 92521
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Del Dottore E, Mondini A, Sadeghi A, Mattoli V, Mazzolai B. An efficient soil penetration strategy for explorative robots inspired by plant root circumnutation movements. BIOINSPIRATION & BIOMIMETICS 2017; 13:015003. [PMID: 29123076 DOI: 10.1088/1748-3190/aa9998] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
This paper presents a comparative analysis in terms of energy required by an artificial probe to penetrate soil implementing two different strategies: a straight penetration movement and a circumnutation, which is an oscillatory movement performed by plant roots. The role of circumnutations in plant roots is still debated. We hypothesized that circumnutation movements can help roots in penetrating soil, and validated our assumption by testing the probe at three distinct soil densities and using various combinations of circumnutation amplitudes and periods for each soil. The comparison was based on the total work done by the system while circumnutating at its tip level with respect to that shown by the same system in straight penetration. The total energy evaluation confirmed an improvement obtained by circumnutations up to 33%. We also proposed a fitting model for our experimental data that was used to estimate energy needed by the probe to penetrate soil at different dimensions and circumnutation amplitudes. Results showed the existence of a trade-off among penetration velocity, circumnutation period, and amplitude toward an energy consumption optimization, expressed by the lead angle of the helical path that should stay in the range between 46° and 65°. Moreover, circumnutations with appropriate amplitude (~10°) and period (~80 s) values were more efficient than straight penetration also at different probe tip dimensions, up to a threshold diameter (from 2 mm to 55 mm). Based on the obtained results, we speculated that circumnutations can represent a strategy used by plant roots to reduce the pressure and energy needed to penetrate soil. The translation of this biological feature in robotic systems will allow improving their energetic efficiency in digging tasks, and thus open new scenarios for use in search and rescue, environmental monitoring, and soil exploration.
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Affiliation(s)
- Emanuela Del Dottore
- The BioRobotics Institute, Scuola Superiore Sant'Anna, Pontedera, Italy. Center for Micro-BioRobotics, Istituto Italiano di Tecnologia, Pontedera, Italy
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Singh M, Gupta A, Laxmi A. Striking the Right Chord: Signaling Enigma during Root Gravitropism. FRONTIERS IN PLANT SCIENCE 2017; 8:1304. [PMID: 28798760 PMCID: PMC5529344 DOI: 10.3389/fpls.2017.01304] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 07/11/2017] [Indexed: 05/29/2023]
Abstract
Plants being sessile can often be judged as passive acceptors of their environment. However, plants are actually even more active in responding to the factors from their surroundings. Plants do not have eyes, ears or vestibular system like animals, still they "know" which way is up and which way is down? This is facilitated by receptor molecules within plant which perceive changes in internal and external conditions such as light, touch, obstacles; and initiate signaling pathways that enable the plant to react. Plant responses that involve a definite and specific movement are called "tropic" responses. Perhaps the best known and studied tropisms are phototropism, i.e., response to light, and geotropism, i.e., response to gravity. A robust root system is vital for plant growth as it can provide physical anchorage to soil as well as absorb water, nutrients and essential minerals from soil efficiently. Gravitropic responses of both primary as well as lateral root thus become critical for plant growth and development. The molecular mechanisms of root gravitropism has been delved intensively, however, the mechanism behind how the potential energy of gravity stimulus converts into a biochemical signal in vascular plants is still unknown, due to which gravity sensing in plants still remains one of the most fascinating questions in molecular biology. Communications within plants occur through phytohormones and other chemical substances produced in plants which have a developmental or physiological effect on growth. Here, we review current knowledge of various intrinsic signaling mechanisms that modulate root gravitropism in order to point out the questions and emerging developments in plant directional growth responses. We are also discussing the roles of sugar signals and their interaction with phytohormone machinery, specifically in context of root directional responses.
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Affiliation(s)
- Manjul Singh
- National Institute of Plant Genome ResearchNew Delhi, India
- Interdisciplinary Centre for Plant Genomics, University of Delhi South CampusNew Delhi, India
| | - Aditi Gupta
- National Institute of Plant Genome ResearchNew Delhi, India
- Interdisciplinary Centre for Plant Genomics, University of Delhi South CampusNew Delhi, India
| | - Ashverya Laxmi
- National Institute of Plant Genome ResearchNew Delhi, India
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Roy R, Bassham DC. TNO1, a TGN-localized SNARE-interacting protein, modulates root skewing in Arabidopsis thaliana. BMC PLANT BIOLOGY 2017; 17:73. [PMID: 28399805 PMCID: PMC5387210 DOI: 10.1186/s12870-017-1024-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 04/05/2017] [Indexed: 05/23/2023]
Abstract
BACKGROUND The movement of plant roots within the soil is key to their ability to interact with the environment and maximize anchorage and nutrient acquisition. Directional growth of roots occurs by a combination of sensing external cues, hormonal signaling and cytoskeletal changes in the root cells. Roots growing on slanted, impenetrable growth medium display a characteristic waving and skewing, and mutants with deviations in these phenotypes assist in identifying genes required for root movement. Our study identifies a role for a trans-Golgi network-localized protein in root skewing. RESULTS We found that Arabidopsis thaliana TNO1 (TGN-localized SYP41-interacting protein), a putative tethering factor localized at the trans-Golgi network, affects root skewing. tno1 knockout mutants display enhanced root skewing and epidermal cell file rotation. Skewing of tno1 roots increases upon microtubule stabilization, but is insensitive to microtubule destabilization. Microtubule destabilization leads to severe defects in cell morphology in tno1 seedlings. Microtubule array orientation is unaffected in the mutant roots, suggesting that the increase in cell file rotation is independent of the orientation of microtubule arrays. CONCLUSIONS We conclude that TNO1 modulates root skewing in a mechanism that is dependent on microtubules but is not linked to disruption of the orientation of microtubule arrays. In addition, TNO1 is required for maintenance of cell morphology in mature regions of roots and the base of hypocotyls. The TGN-localized SNARE machinery might therefore be important for appropriate epidermal cell file rotation and cell expansion during root growth.
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Affiliation(s)
- Rahul Roy
- Department of Genetics, Development and Cell Biology, 1035B Roy J Carver Co-Lab, 1111 WOI Rd, Iowa State University, Ames, IA 50011 USA
- Interdepartmental Genetics Program, Iowa State University, Ames, IA USA
- Current Address: Department of Plant and Microbial Biology, University of Minnesota, Twin Cities, MN 55108 USA
| | - Diane C. Bassham
- Department of Genetics, Development and Cell Biology, 1035B Roy J Carver Co-Lab, 1111 WOI Rd, Iowa State University, Ames, IA 50011 USA
- Interdepartmental Genetics Program, Iowa State University, Ames, IA USA
- Plant Sciences Institute, Iowa State University, Ames, IA USA
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Schultz ER, Zupanska AK, Sng NJ, Paul AL, Ferl RJ. Skewing in Arabidopsis roots involves disparate environmental signaling pathways. BMC PLANT BIOLOGY 2017; 17:31. [PMID: 28143395 PMCID: PMC5286820 DOI: 10.1186/s12870-017-0975-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 01/12/2017] [Indexed: 05/20/2023]
Abstract
BACKGROUND Skewing root patterns provide key insights into root growth strategies and mechanisms that produce root architectures. Roots exhibit skewing and waving when grown on a tilted, impenetrable surface. The genetics guiding these morphologies have been examined, revealing that some Arabidopsis ecotypes skew and wave (e.g. WS), while others skew insignificantly but still wave (e.g. Col-0). The underlying molecular mechanisms of skewing and waving remain unclear. In this study, transcriptome data were derived from two Arabidopsis ecotypes, WS and Col-0, under three tilted growth conditions in order to identify candidate genes involved in skewing. RESULTS This work identifies a number of genes that are likely involved in skewing, using growth conditions that differentially affect skewing and waving. Comparing the gene expression profiles of WS and Col-0 in different tilted growth conditions identified 11 candidate genes as potentially involved in the control of skewing. These 11 genes are involved in several different cellular processes, including sugar transport, salt signaling, cell wall organization, and hormone signaling. CONCLUSIONS This study identified 11 genes whose change in expression level is associated with root skewing behavior. These genes are involved in signaling and perception, rather than the physical restructuring of root. Future work is needed to elucidate the potential role of these candidate genes during root skewing.
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Affiliation(s)
- Eric R. Schultz
- Department of Horticultural Sciences, Program in Plant Molecular and Cellular Biology, University of Florida, Gainesville, FL 32611 USA
- Present address: Department of Biology, Washington University in St. Louis, St. Louis, MO 63130 USA
| | - Agata K. Zupanska
- Department of Horticultural Sciences, Program in Plant Molecular and Cellular Biology, University of Florida, Gainesville, FL 32611 USA
| | - Natasha J. Sng
- Department of Horticultural Sciences, Program in Plant Molecular and Cellular Biology, University of Florida, Gainesville, FL 32611 USA
| | - Anna-Lisa Paul
- Department of Horticultural Sciences, Program in Plant Molecular and Cellular Biology, University of Florida, Gainesville, FL 32611 USA
| | - Robert J. Ferl
- Department of Horticultural Sciences, Program in Plant Molecular and Cellular Biology, University of Florida, Gainesville, FL 32611 USA
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, FL 32610 USA
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Mira MM, Hill RD, Stasolla C. Phytoglobins Improve Hypoxic Root Growth by Alleviating Apical Meristem Cell Death. PLANT PHYSIOLOGY 2016; 172:2044-2056. [PMID: 27702845 PMCID: PMC5100795 DOI: 10.1104/pp.16.01150] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 09/29/2016] [Indexed: 05/18/2023]
Abstract
Hypoxic root growth in maize (Zea mays) is influenced by the expression of phytoglobins (ZmPgbs). Relative to the wild type, suppression of ZmPgb1.1 or ZmPgb1.2 inhibits the growth of roots exposed to 4% oxygen, causing structural abnormalities in the root apical meristems. These effects were accompanied by increasing levels of reactive oxygen species (ROS), possibly through the transcriptional induction of four Respiratory Burst Oxidase Homologs TUNEL-positive nuclei in meristematic cells indicated the involvement of programmed cell death (PCD) in the process. These cells also accumulated nitric oxide and stained heavily for ethylene biosynthetic transcripts. A sharp increase in the expression level of several 1-aminocyclopropane synthase (ZmAcs2, ZmAcs6, and ZmAcs7), 1-aminocyclopropane oxidase (Aco15, Aco20, Aco31, and Aco35), and ethylene-responsive (ZmErf2 and ZmEbf1) genes was observed in hypoxic ZmPgb-suppressing roots, which overproduced ethylene. Inhibiting ROS synthesis with diphenyleneiodonium or ethylene perception with 1-methylcyclopropene suppressed PCD, increased BAX inhibitor-1, an effective attenuator of the death programs in eukaryotes, and restored root growth. Hypoxic roots overexpressing ZmPgbs had the lowest level of ethylene and showed a reduction in ROS staining and TUNEL-positive nuclei in the meristematic cells. These roots retained functional meristems and exhibited the highest growth performance when subjected to hypoxic conditions. Collectively, these results suggest a novel function of Pgbs in protecting root apical meristems from hypoxia-induced PCD through mechanisms initiated by nitric oxide and mediated by ethylene via ROS.
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Affiliation(s)
- Mohamed M Mira
- Department of Plant Science, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2
| | - Robert D Hill
- Department of Plant Science, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2
| | - Claudio Stasolla
- Department of Plant Science, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2
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Lacey RF, Binder BM. Ethylene Regulates the Physiology of the Cyanobacterium Synechocystis sp. PCC 6803 via an Ethylene Receptor. PLANT PHYSIOLOGY 2016; 171:2798-809. [PMID: 27246094 PMCID: PMC4972284 DOI: 10.1104/pp.16.00602] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 05/28/2016] [Indexed: 05/04/2023]
Abstract
Ethylene is a plant hormone that plays a crucial role in the growth and development of plants. The ethylene receptors in plants are well studied, and it is generally assumed that they are found only in plants. In a search of sequenced genomes, we found that many bacterial species contain putative ethylene receptors. Plants acquired many proteins from cyanobacteria as a result of the endosymbiotic event that led to chloroplasts. We provide data that the cyanobacterium Synechocystis (Synechocystis sp. PCC 6803) has a functional receptor for ethylene, Synechocystis Ethylene Response1 (SynEtr1). We first show that SynEtr1 directly binds ethylene. Second, we demonstrate that application of ethylene to Synechocystis cells or disruption of the SynEtr1 gene affects several processes, including phototaxis, type IV pilus biosynthesis, photosystem II levels, biofilm formation, and spontaneous cell sedimentation. Our data suggest a model where SynEtr1 inhibits downstream signaling and ethylene inhibits SynEtr1. This is similar to the inverse-agonist model of ethylene receptor signaling proposed for plants and suggests a conservation of structure and function that possibly originated over 1 billion years ago. Prior research showed that SynEtr1 also contains a light-responsive phytochrome-like domain. Thus, SynEtr1 is a bifunctional receptor that mediates responses to both light and ethylene. To our knowledge, this is the first demonstration of a functional ethylene receptor in a nonplant species and suggests that that the perception of ethylene is more widespread than previously thought.
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Affiliation(s)
- Randy F Lacey
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996-0840
| | - Brad M Binder
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996-0840
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35
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Harrison BR, Masson PH. Immunohistochemistry relative to gravity: a simple method to retain information about gravity for immunolocalization and histochemistry. Methods Mol Biol 2016; 1309:1-12. [PMID: 25981763 DOI: 10.1007/978-1-4939-2697-8_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
We describe a simple method to preserve information about a plant organ's orientation relative to the direction of the gravity vector during sample processing for immunolocalization or histochemical analysis of cell biological processes. This approach has been used in gravity stimulated roots of Arabidopsis thaliana and Zea mays to study PIN3 relocalization, study the asymmetrical remodeling of the actin network and the cortical microtubule array, and to reveal the asymmetrical expression of the auxin signaling reporter DR5::GUS. This method enables the rapid analysis of a large number of samples from a variety of genotypes, as well as from tissue that may be too thick for microscopy in live plants.
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Affiliation(s)
- Benjamin R Harrison
- Department of Biological Sciences, University of Alaska Anchorage, 3101 Science Circle, Anchorage, AK, 99504, USA,
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Barker R, Cox B, Silber L, Sangari A, Assadi A, Masson P. Assessing Gravitropic Responses in Arabidopsis. Methods Mol Biol 2016; 1398:11-20. [PMID: 26867611 DOI: 10.1007/978-1-4939-3356-3_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Arabidopsis thaliana was the first higher organism to have its genome sequenced and is now widely regarded as the model dicot. Like all plants, Arabidopsis develops distinct growth patterns in response to different environmental stimuli. This can be seen in the gravitropic response of roots. Methods to investigate this particular tropism are presented here. First, we describe a high-throughput time-lapse photographic analysis of root growth and curvature response to gravistimulation allowing the quantification of gravitropic kinetics and growth rate at high temporal resolution. Second, we present a protocol that allows a quantitative evaluation of gravitropic sensitivity using a homemade 2D clinostat. Together, these approaches allow an initial comparative analysis of the key phenomena associated with root gravitropism between different genotypes and/or accessions.
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Affiliation(s)
- Richard Barker
- Laboratory of Genetics, University of Wisconsin, 3302 Genetics/biotechnology center, 425 G Henry Mall, Madison, WI, 53706, USA.
| | - Benjamin Cox
- Medical Engineering Group, Morgridge Institute for Research, 330 N Orchard St., Madison, WI, 53715, USA
| | - Logan Silber
- Laboratory of Genetics, University of Wisconsin, 3302 Genetics/biotechnology center, 425 G Henry Mall, Madison, WI, 53706, USA
| | - Arash Sangari
- Department of Mathematics, University of Wisconsin, 480 Lincoln Drive, Madison, WI, 53706, USA
| | - Amir Assadi
- Department of Mathematics, University of Wisconsin, 480 Lincoln Drive, Madison, WI, 53706, USA
| | - Patrick Masson
- Laboratory of Genetics, University of Wisconsin, 3302 Genetics/biotechnology center, 425 G Henry Mall, Madison, WI, 53706, USA
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Wang S, Wang L, Hua W, Zhou M, Wang Q, Zhou Q, Huang X. Effects of bisphenol A, an environmental endocrine disruptor, on the endogenous hormones of plants. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:17653-62. [PMID: 26150296 DOI: 10.1007/s11356-015-4972-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 06/29/2015] [Indexed: 05/26/2023]
Abstract
Bisphenol A (BPA) is a ubiquitous endocrine-disrupting chemical in the environment that exerts potential harm to plants. Phytohormones play important roles both in regulating multiple aspects of plant growth and in plants' responses to environmental stresses. But how BPA affects plant growth by regulating endogenous hormones remains poorly understood. Here, we found that treatment with 1.5 mg L(-1) BPA improved the growth of soybean seedlings, companied by increases in the contents of indole-3-acetic acid (IAA) and zeatin (ZT), and decreases in the ratios of abscisic acid (ABA)/IAA, ABA/gibberellic acid (GA), ABA/ZT, ethylene (ETH)/GA, ETH/IAA, and ETH/ZT. Treatment with higher concentrations of BPA (from 3 to 96 mg L(-1)) inhibited the growth of soybean seedlings, meanwhile, decreased the contents of IAA, GA, ZT, and ETH, and increased the content of ABA and the ratios of ABA/IAA, ABA/GA, ABA/ZT, ETH/GA, ETH/IAA, and ETH/ZT. The increases in the ratios of growth and stress hormones were correlated with the increase in the BPA content of the roots. Thus, BPA could affect plant growth through changing the levels of single endogenous hormone and the ratios of growth and stress hormones in the roots because of BPA absorption by the roots.
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Affiliation(s)
- Shengman Wang
- State Key Laboratory of Food Science and Technology, Jiangsu Cooperative Innovation Center of Water Treatment Technology and Materials, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, China
| | - Lihong Wang
- State Key Laboratory of Food Science and Technology, Jiangsu Cooperative Innovation Center of Water Treatment Technology and Materials, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, China
| | - Weiqi Hua
- State Key Laboratory of Food Science and Technology, Jiangsu Cooperative Innovation Center of Water Treatment Technology and Materials, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, China
| | - Min Zhou
- State Key Laboratory of Food Science and Technology, Jiangsu Cooperative Innovation Center of Water Treatment Technology and Materials, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, China
| | - Qingqing Wang
- State Key Laboratory of Food Science and Technology, Jiangsu Cooperative Innovation Center of Water Treatment Technology and Materials, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, China
| | - Qing Zhou
- State Key Laboratory of Food Science and Technology, Jiangsu Cooperative Innovation Center of Water Treatment Technology and Materials, School of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, China.
| | - Xiaohua Huang
- Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, Jiangsu Key Laboratory of Biomedical Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing, 210046, People's Republic of China.
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Yang X, Wang B, Farris B, Clark G, Roux SJ. Modulation of Root Skewing in Arabidopsis by Apyrases and Extracellular ATP. PLANT & CELL PHYSIOLOGY 2015; 56:2197-206. [PMID: 26412783 DOI: 10.1093/pcp/pcv134] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 09/16/2015] [Indexed: 05/04/2023]
Abstract
When plant primary roots grow along a tilted surface that is impenetrable, they can undergo a slanted deviation from the direction of gravity called skewing. Skewing is induced by touch stimuli which the roots experience as they grow along the surface. Touch stimuli also induce the release of extracellular ATP (eATP) into the plant's extracellular matrix, and two apyrases (NTPDases) in Arabidopsis, APY1 and APY2, can help regulate the concentration of eATP. The primary roots of seedlings overexpressing APY1 show less skewing than wild-type plants. Plants suppressed in their expression of APY1 show more skewing than wild-type plants. Correspondingly, chemical inhibition of apyrase activity increased skewing in mutants and wild-type roots. Exogenous application of ATP or ATPγS also increased skewing in wild-type roots, which could be blocked by co-incubation with a purinergic receptor antagonist. These results suggest a model in which gradients of eATP set up by differential touch stimuli along roots help direct skewing in roots growing along an impenetrable surface.
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Affiliation(s)
- Xingyan Yang
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College, Chongqing University, Chongqing, 400030, China
| | - Bochu Wang
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College, Chongqing University, Chongqing, 400030, China
| | - Ben Farris
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| | - Greg Clark
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| | - Stanley J Roux
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
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39
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Chen HW, Shao KH, Wang SJ. Light-modulated seminal wavy roots in rice mediated by nitric oxide-dependent signaling. PROTOPLASMA 2015; 252:1291-1304. [PMID: 25619895 DOI: 10.1007/s00709-015-0762-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 01/12/2015] [Indexed: 06/04/2023]
Abstract
Rice (Oryza sativa L.) seminal roots from germinated seeds help establish seedlings, but the seminal root growth and morphology are sensitive to environmental factors. Our previous research showed that several indica-type rice varieties such as Taichung native 1 (TCN1) showed light-induced wavy roots. Also, auxin and oxylipins are two signaling factors regulating the wavy root photomorphology. To investigate the signaling pathway, here, we found that nitric oxide (NO) was a second messenger triggering the signal transduction of light stimuli to induce the wavy morphology of seminal roots in rice. Moreover, interactions between oxylipins and phytohormones such as ethylene and auxin participating in the NO-dependent regulatory pathway of light-induced wavy roots were examined. The order of action of signaling components in the pathway was NO, oxylipins, ethylene, and auxin.
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Affiliation(s)
- Hsiang-Wen Chen
- Department of Agronomy, National Taiwan University, No. 1, Section 4, Roosevelt Rd., Taipei, 10617, Taiwan
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Bakshi A, Wilson RL, Lacey RF, Kim H, Wuppalapati SK, Binder BM. Identification of Regions in the Receiver Domain of the ETHYLENE RESPONSE1 Ethylene Receptor of Arabidopsis Important for Functional Divergence. PLANT PHYSIOLOGY 2015; 169:219-32. [PMID: 26160962 PMCID: PMC4577405 DOI: 10.1104/pp.15.00626] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 07/09/2015] [Indexed: 05/08/2023]
Abstract
Ethylene influences the growth and development of Arabidopsis (Arabidopsis thaliana) via five receptor isoforms. However, the ETHYLENE RESPONSE1 (ETR1) ethylene receptor has unique, and sometimes contrasting, roles from the other receptor isoforms. Prior research indicates that the receiver domain of ETR1 is important for some of these noncanonical roles. We determined that the ETR1 receiver domain is not needed for ETR1's predominant role in mediating responses to the ethylene antagonist, silver. To understand the structure-function relationship underlying the unique roles of the ETR1 receiver domain in the control of specific traits, we performed alanine-scanning mutagenesis. We chose amino acids that are poorly conserved and are in regions predicted to have altered tertiary structure compared with the receiver domains of the other two receptors that contain a receiver domain, ETR2 and ETHYLENE INSENSITIVE4. The effects of these mutants on various phenotypes were examined in transgenic, receptor-deficient Arabidopsis plants. Some traits, such as growth in air and growth recovery after the removal of ethylene, were unaffected by these mutations. By contrast, three mutations on one surface of the receiver domain rendered the transgene unable to rescue ethylene-stimulated nutations. Additionally, several mutations on another surface altered germination on salt. Some of these mutations conferred hyperfunctionality to ETR1 in the context of seed germination on salt, but not for other traits, that correlated with increased responsiveness to abscisic acid. Thus, the ETR1 receiver domain has multiple functions where different surfaces are involved in the control of different traits. Models are discussed for these observations.
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Affiliation(s)
- Arkadipta Bakshi
- Genome Science and Technology Program (A.B., B.M.B.) and Department of Biochemistry, Cellular, and Molecular Biology (R.L.W., R.F.L., H.K., S.K.W., B.M.B.), University of Tennessee, Knoxville, Tennessee 37996
| | - Rebecca L Wilson
- Genome Science and Technology Program (A.B., B.M.B.) and Department of Biochemistry, Cellular, and Molecular Biology (R.L.W., R.F.L., H.K., S.K.W., B.M.B.), University of Tennessee, Knoxville, Tennessee 37996
| | - Randy F Lacey
- Genome Science and Technology Program (A.B., B.M.B.) and Department of Biochemistry, Cellular, and Molecular Biology (R.L.W., R.F.L., H.K., S.K.W., B.M.B.), University of Tennessee, Knoxville, Tennessee 37996
| | - Heejung Kim
- Genome Science and Technology Program (A.B., B.M.B.) and Department of Biochemistry, Cellular, and Molecular Biology (R.L.W., R.F.L., H.K., S.K.W., B.M.B.), University of Tennessee, Knoxville, Tennessee 37996
| | - Sai Keerthana Wuppalapati
- Genome Science and Technology Program (A.B., B.M.B.) and Department of Biochemistry, Cellular, and Molecular Biology (R.L.W., R.F.L., H.K., S.K.W., B.M.B.), University of Tennessee, Knoxville, Tennessee 37996
| | - Brad M Binder
- Genome Science and Technology Program (A.B., B.M.B.) and Department of Biochemistry, Cellular, and Molecular Biology (R.L.W., R.F.L., H.K., S.K.W., B.M.B.), University of Tennessee, Knoxville, Tennessee 37996
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41
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Rellán-Álvarez R, Lobet G, Lindner H, Pradier PL, Sebastian J, Yee MC, Geng Y, Trontin C, LaRue T, Schrager-Lavelle A, Haney CH, Nieu R, Maloof J, Vogel JP, Dinneny JR. GLO-Roots: an imaging platform enabling multidimensional characterization of soil-grown root systems. eLife 2015; 4:e07597. [PMID: 26287479 PMCID: PMC4589753 DOI: 10.7554/elife.07597] [Citation(s) in RCA: 152] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 08/18/2015] [Indexed: 12/16/2022] Open
Abstract
Root systems develop different root types that individually sense cues from their local environment and integrate this information with systemic signals. This complex multi-dimensional amalgam of inputs enables continuous adjustment of root growth rates, direction, and metabolic activity that define a dynamic physical network. Current methods for analyzing root biology balance physiological relevance with imaging capability. To bridge this divide, we developed an integrated-imaging system called Growth and Luminescence Observatory for Roots (GLO-Roots) that uses luminescence-based reporters to enable studies of root architecture and gene expression patterns in soil-grown, light-shielded roots. We have developed image analysis algorithms that allow the spatial integration of soil properties, gene expression, and root system architecture traits. We propose GLO-Roots as a system that has great utility in presenting environmental stimuli to roots in ways that evoke natural adaptive responses and in providing tools for studying the multi-dimensional nature of such processes.
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Affiliation(s)
- Rubén Rellán-Álvarez
- Department of Plant Biology, Carnegie Institution for Science, Stanford, United States
| | | | - Heike Lindner
- Department of Plant Biology, Carnegie Institution for Science, Stanford, United States
| | - Pierre-Luc Pradier
- Department of Plant Biology, Carnegie Institution for Science, Stanford, United States
| | - Jose Sebastian
- Department of Plant Biology, Carnegie Institution for Science, Stanford, United States
| | - Muh-Ching Yee
- Department of Plant Biology, Carnegie Institution for Science, Stanford, United States
| | - Yu Geng
- Department of Plant Biology, Carnegie Institution for Science, Stanford, United States
- Department of Energy, Department of Energy Joint Genome Institute, Walnut Creek, United States
| | - Charlotte Trontin
- Department of Plant Biology, Carnegie Institution for Science, Stanford, United States
| | - Therese LaRue
- Department of Biology, Stanford University, Stanford, United States
| | | | - Cara H Haney
- Department of Genetics, Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, United States
| | - Rita Nieu
- Western Regional Research Center, United States Department of Agriculture, Albany, United States
| | - Julin Maloof
- Department of Plant Biology, University of California, Davis, Davis, United States
| | - John P Vogel
- Department of Energy, Department of Energy Joint Genome Institute, Walnut Creek, United States
| | - José R Dinneny
- Department of Plant Biology, Carnegie Institution for Science, Stanford, United States
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42
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Zhao X, Wang J, Yuan J, Wang XL, Zhao QP, Kong PT, Zhang X. NITRIC OXIDE-ASSOCIATED PROTEIN1 (AtNOA1) is essential for salicylic acid-induced root waving in Arabidopsis thaliana. THE NEW PHYTOLOGIST 2015; 207:211-224. [PMID: 25690466 DOI: 10.1111/nph.13327] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 01/10/2015] [Indexed: 05/07/2023]
Abstract
Root waving responses have been attributed to both environmental and genetics factors, but the potential inducers and transducers of root waving remain elusive. Thus, the identification of novel signal elements related to root waving is an intriguing field of research. Genetic, physiological, cytological, live cell imaging, and pharmacological approaches provide strong evidence for the involvement of Arabidopsis thaliana NITRIC OXIDE-ASSOCIATED PROTEIN1 (AtNOA1) in salicylic acid (SA)-induced root waving. SA specially induced root waving, with an overall decrease in root elongation in A. thaliana, and this SA-induced response was disrupted in the Atnoa1 mutant, as well as in nonexpresser of pathogenesis-related genes 1 (npr1), which is defective in SA-mediated plant defense signal transduction, but not in npr3/4 single and double mutants. The expression assays revealed that the abundance of AtNOA1 was significantly increased by application of SA. Genetic and pharmacological analyses showed that SA-induced root waving involved an AtNOA1-dependent Ca(2+) signal transduction pathway, and PIN-FORMED2 (PIN2) -based polar auxin transport possibly plays a crucial role in this process. Our work suggests that SA signaling through NPR1 and AtNOA1 is involved in the control of root waving, which provides new insights into the mechanisms that control root growth behavior on a hard agar surface.
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Affiliation(s)
- Xiang Zhao
- Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, 475004, China
| | - Jin Wang
- Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, 475004, China
| | - Jing Yuan
- Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, 475004, China
| | - Xi-Li Wang
- Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, 475004, China
| | - Qing-Ping Zhao
- Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, 475004, China
| | - Pei-Tao Kong
- Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, 475004, China
| | - Xiao Zhang
- Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, 475004, China
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43
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Khan MIR, Trivellini A, Fatma M, Masood A, Francini A, Iqbal N, Ferrante A, Khan NA. Role of ethylene in responses of plants to nitrogen availability. FRONTIERS IN PLANT SCIENCE 2015; 6:927. [PMID: 26579172 PMCID: PMC4626634 DOI: 10.3389/fpls.2015.00927] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 10/14/2015] [Indexed: 05/05/2023]
Abstract
Ethylene is a plant hormone involved in several physiological processes and regulates the plant development during the whole life. Stressful conditions usually activate ethylene biosynthesis and signaling in plants. The availability of nutrients, shortage or excess, influences plant metabolism and ethylene plays an important role in plant adaptation under suboptimal conditions. Among the plant nutrients, the nitrogen (N) is one the most important mineral element required for plant growth and development. The availability of N significantly influences plant metabolism, including ethylene biology. The interaction between ethylene and N affects several physiological processes such as leaf gas exchanges, roots architecture, leaf, fruits, and flowers development. Low plant N use efficiency (NUE) leads to N loss and N deprivation, which affect ethylene biosynthesis and tissues sensitivity, inducing cell damage and ultimately lysis. Plants may respond differently to N availability balancing ethylene production through its signaling network. This review discusses the recent advances in the interaction between N availability and ethylene at whole plant and different organ levels, and explores how N availability induces ethylene biology and plant responses. Exogenously applied ethylene seems to cope the stress conditions and improves plant physiological performance. This can be explained considering the expression of ethylene biosynthesis and signaling genes under different N availability. A greater understanding of the regulation of N by means of ethylene modulation may help to increase NUE and directly influence crop productivity under conditions of limited N availability, leading to positive effects on the environment. Moreover, efforts should be focused on the effect of N deficiency or excess in fruit trees, where ethylene can have detrimental effects especially during postharvest.
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Affiliation(s)
- M. I. R. Khan
- Department of Botany, Aligarh Muslim UniversityAligarh, India
| | - Alice Trivellini
- Institute of Life Sciences, Scuola Superiore Sant’AnnaPisa, Italy
| | - Mehar Fatma
- Department of Botany, Aligarh Muslim UniversityAligarh, India
| | - Asim Masood
- Department of Botany, Aligarh Muslim UniversityAligarh, India
| | | | - Noushina Iqbal
- Department of Botany, Jamia Hamdard University New Delhi, India
| | - Antonio Ferrante
- Department of Agricultural and Environmental Sciences, Università degli Studi di MilanoMilan, Italy
| | - Nafees A. Khan
- Department of Botany, Aligarh Muslim UniversityAligarh, India
- *Correspondence: Nafees A. Khan,
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Wilson RL, Bakshi A, Binder BM. Loss of the ETR1 ethylene receptor reduces the inhibitory effect of far-red light and darkness on seed germination of Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2014; 5:433. [PMID: 25221561 PMCID: PMC4147998 DOI: 10.3389/fpls.2014.00433] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 08/13/2014] [Indexed: 05/18/2023]
Abstract
When exposed to far-red light followed by darkness, wild-type Arabidopsis thaliana seeds fail to germinate or germinate very poorly. We have previously shown that the ethylene receptor ETR1 (ETHYLENE RESPONSE1) inhibits and ETR2 stimulates seed germination of Arabidopsis during salt stress. This function of ETR1 requires the full-length receptor. These roles are independent of ethylene levels and sensitivity and are mainly mediated by a change in abscisic acid (ABA) sensitivity. In the current study we find that etr1-6 and etr1-7 loss-of-function mutant seeds germinate better than wild-type seeds after illumination with far-red light or when germinated in the dark indicating an inhibitory role for ETR1. Surprisingly, this function of ETR1 does not require the receiver domain. No differences between these mutants and wild-type are seen when germination proceeds after treatment with white, blue, green, or red light. Loss of any of the other four ethylene receptor isoforms has no measurable effect on germination after far-red light treatment. An analysis of the transcript abundance for genes encoding ABA and gibberellic acid (GA) metabolic enzymes indicates that etr1-6 mutants may produce more GA and less ABA than wild-type seeds after illumination with far-red light which correlates with the better germination of the mutants. Epistasis analysis suggests that ETR1 may genetically interact with the phytochromes (phy), PHYA and PHYB to control germination and growth. This study shows that of the five ethylene receptor isoforms in Arabidopsis, ETR1 has a unique role in modulating the effects of red and far-red light on plant growth and development.
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Affiliation(s)
| | | | - Brad M. Binder
- Department of Biochemistry, Cellular, and Molecular Biology, University of TennesseeKnoxville, TN, USA
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45
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Wilson RL, Kim H, Bakshi A, Binder BM. The Ethylene Receptors ETHYLENE RESPONSE1 and ETHYLENE RESPONSE2 Have Contrasting Roles in Seed Germination of Arabidopsis during Salt Stress. PLANT PHYSIOLOGY 2014; 165:1353-1366. [PMID: 24820022 PMCID: PMC4081342 DOI: 10.1104/pp.114.241695] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Accepted: 05/12/2014] [Indexed: 05/18/2023]
Abstract
In Arabidopsis (Arabidopsis thaliana), ethylene responses are mediated by a family of five receptors that have both overlapping and nonoverlapping roles. In this study, we used loss-of-function mutants for each receptor isoform to determine the role of individual isoforms in seed germination under salt stress. From this analysis, we found subfunctionalization of the receptors in the control of seed germination during salt stress. Specifically, loss of ETHYLENE RESPONSE1 (ETR1) or ETHYLENE INSENSITIVE4 (EIN4) leads to accelerated germination, loss of ETR2 delays germination, and loss of either ETHYLENE RESPONSE SENSOR1 (ERS1) or ERS2 has no measurable effect on germination. Epistasis analysis indicates that ETR1 and EIN4 function additively with ETR2 to control this trait. Interestingly, regulation of germination by ETR1 requires the full-length receptor. The differences in germination between etr1 and etr2 loss-of-function mutants under salt stress could not be explained by differences in the production of or sensitivity to ethylene, gibberellin, or cytokinin. Instead, etr1 loss-of-function mutants have reduced sensitivity to abscisic acid (ABA) and germinate earlier than the wild type, whereas etr2 loss-of-function mutants have increased sensitivity to ABA and germinate slower than the wild type. Additionally, the differences in seed germination on salt between the two mutants and the wild type are eliminated by the ABA biosynthetic inhibitor norflurazon. These data suggest that ETR1 and ETR2 have roles independent of ethylene signaling that affect ABA signaling and result in altered germination during salt stress.
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Affiliation(s)
- Rebecca L Wilson
- Department of Biochemistry, Cellular, and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996
| | - Heejung Kim
- Department of Biochemistry, Cellular, and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996
| | - Arkadipta Bakshi
- Department of Biochemistry, Cellular, and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996
| | - Brad M Binder
- Department of Biochemistry, Cellular, and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996
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46
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Singh M, Gupta A, Laxmi A. Glucose control of root growth direction in Arabidopsis thaliana. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:2981-93. [PMID: 24719453 PMCID: PMC4071822 DOI: 10.1093/jxb/eru146] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Directional growth of roots is a complex process that is modulated by various environmental signals. This work shows that presence of glucose (Glc) in the medium also extensively modulated seedling root growth direction. Glc modulation of root growth direction was dramatically enhanced by simultaneous brassinosteroid (BR) application. Glc enhanced BR receptor BRASSINOSTEROID INSENSITIVE1 (BRI1) endocytosis from plasma membrane to early endosomes. Glc-induced root deviation was highly enhanced in a PP2A-defective mutant, roots curl in naphthyl phthalamic acid 1-1 (rcn1-1) suggesting that there is a role of phosphatase in Glc-induced root-growth deviation. RCN1, therefore, acted as a link between Glc and the BR-signalling pathway. Polar auxin transport worked further downstream to BR in controlling Glc-induced root deviation response. Glc also affected other root directional responses such as root waving and coiling leading to altered root architecture. High light intensity mimicked the Glc-induced changes in root architecture that were highly reduced in Glc-signalling mutants. Thus, under natural environmental conditions, changing light flux in the environment may lead to enhanced Glc production/response and is a way to manipulate root architecture for optimized development via integrating several extrinsic and intrinsic signalling cues.
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Affiliation(s)
- Manjul Singh
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Aditi Gupta
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Ashverya Laxmi
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India
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47
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Roy R, Bassham DC. Root growth movements: waving and skewing. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2014; 221-222:42-7. [PMID: 24656334 DOI: 10.1016/j.plantsci.2014.01.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 01/11/2014] [Accepted: 01/22/2014] [Indexed: 05/20/2023]
Abstract
Roots anchor a plant in the soil, acquire nutrition and respond to environmental cues. Roots perform these functions using intricate movements and a variety of pathways have been implicated in mediating their growth patterns. These include endogenous genetic factors, perception of multiple environmental stimuli, signaling pathways interacting with hormonal dynamics and cellular processes of rapid cell elongation. In this review we attempt to consolidate our understanding of two specific types of root movements, waving and skewing, that arise on the surface of growth media, and how they are regulated by various genes and factors. These include crucial factors that are part of a complex nexus of processes including polar auxin transport and cytoskeletal dynamics. This knowledge can be extrapolated in the future for engineering plants with root architecture better suited for different soil and growth conditions such as abiotic stresses or even extended spaceflight. Technological innovations and interdisciplinary approaches promise to allow the tracking of root movements on a much finer scale, thus helping to expedite the discovery of more nodes in the regulation of root waving and skewing and movement in general.
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Affiliation(s)
- Rahul Roy
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA.
| | - Diane C Bassham
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA; Plant Sciences Institute, Iowa State University, Ames, IA 50011, USA.
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Kellermeier F, Armengaud P, Seditas TJ, Danku J, Salt DE, Amtmann A. Analysis of the Root System Architecture of Arabidopsis Provides a Quantitative Readout of Crosstalk between Nutritional Signals. THE PLANT CELL 2014; 26:1480-1496. [PMID: 24692421 PMCID: PMC4036566 DOI: 10.1105/tpc.113.122101] [Citation(s) in RCA: 148] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
As plant roots forage the soil for food and water, they translate a multifactorial input of environmental stimuli into a multifactorial developmental output that manifests itself as root system architecture (RSA). Our current understanding of the underlying regulatory network is limited because root responses have traditionally been studied separately for individual nutrient deficiencies. In this study, we quantified 13 RSA parameters of Arabidopsis thaliana in 32 binary combinations of N, P, K, S, and light. Analysis of variance showed that each RSA parameter was determined by a typical pattern of environmental signals and their interactions. P caused the most important single-nutrient effects, while N-effects were strongly light dependent. Effects of K and S occurred mostly through nutrient interactions in paired or multiple combinations. Several RSA parameters were selected for further analysis through mutant phenotyping, which revealed combinations of transporters, receptors, and kinases acting as signaling modules in K-N interactions. Furthermore, nutrient response profiles of individual RSA features across NPK combinations could be assigned to transcriptionally coregulated clusters of nutrient-responsive genes in the roots and to ionome patterns in the shoots. The obtained data set provides a quantitative basis for understanding how plants integrate multiple nutritional stimuli into complex developmental programs.
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Affiliation(s)
- Fabian Kellermeier
- Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Patrick Armengaud
- INRA, UMR1318 INRA-AgroParisTech, Institut Jean-Pierre Bourgin, INRA Centre de Versailles-Grignon, 78026 Versailles, France
| | - Triona J Seditas
- Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - John Danku
- Institute of Biological and Environmental Sciences, College of Life Sciences and Medicine, University of Aberdeen, Aberdeen AB24 3UU, United Kingdom
| | - David E Salt
- Institute of Biological and Environmental Sciences, College of Life Sciences and Medicine, University of Aberdeen, Aberdeen AB24 3UU, United Kingdom
| | - Anna Amtmann
- Institute of Molecular, Cell, and Systems Biology, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
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Scherer GFE, Pietrzyk P. Gravity-dependent differentiation and root coils in Arabidopsis thaliana wild type and phospholipase-A-I knockdown mutant grown on the International Space Station. PLANT BIOLOGY (STUTTGART, GERMANY) 2014; 16 Suppl 1:97-106. [PMID: 24373011 DOI: 10.1111/plb.12123] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 09/25/2013] [Indexed: 06/03/2023]
Abstract
Arabidopsis roots on 45° tilted agar in 1-g grow in wave-like figures. In addition to waves, formation of root coils is observed in several mutants compromised in gravitropism and/or auxin transport. The knockdown mutant ppla-I-1 of patatin-related phospholipase-A-I is delayed in root gravitropism and forms increased numbers of root coils. Three known factors contribute to waving: circumnutation, gravisensing and negative thigmotropism. In microgravity, deprivation of wild type (WT) and mutant roots of gravisensing and thigmotropism and circumnutation (known to slow down in microgravity, and could potentially lead to fewer waves or increased coiling in both WT and mutant). To resolve this, mutant ppla-I-1 and WT were grown in the BIOLAB facility in the International Space Station. In 1-g, roots of both types only showed waving. In the first experiment in microgravity, the mutant after 9 days formed far more coils than in 1-g but the WT also formed several coils. After 24 days in microgravity, in both types the coils were numerous with slightly more in the mutant. In the second experiment, after 9 days in microgravity only the mutant formed coils and the WT grew arcuated roots. Cell file rotation (CFR) on the mutant root surface in microgravity decreased in comparison to WT, and thus was not important for coiling. Several additional developmental responses (hypocotyl elongation, lateral root formation, cotyledon expansion) were found to be gravity-influenced. We tentatively discuss these in the context of disturbances in auxin transport, which are known to decrease through lack of gravity.
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Affiliation(s)
- G F E Scherer
- Leibniz Universität Hannover, Institut für Zierpflanzenbau und Gehölzwissenschaften, Abt. Molekulare Ertragsphysiologie, Hannover, Germany
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