1
|
Li D, Jia Z. How do plant roots overcome physical barriers? JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:4612-4614. [PMID: 35950462 PMCID: PMC9366319 DOI: 10.1093/jxb/erac238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
This article comments on: Bello-Bello E, Rico-Chambrón TY, Ortiz Ramírez LA, Rellán Álvarez R, Herrera Estrella L. 2022. ROOT PENETRATION INDEX 3, a major quantitative trait locus associated with root system penetrability in Arabidopsis. Journal of Experimental Botany 73, 4716–4732.
Collapse
Affiliation(s)
- Daiyan Li
- Triticeae Research Institute, Sichuan Agricultural University, 611130 Chengdu, China
| | | |
Collapse
|
2
|
Bello Bello E, Rico Cambron TY, Ortiz Ramírez LA, Rellán Álvarez R, Herrera-Estrella L. ROOT PENETRATION INDEX 3, a major quantitative trait locus associated with root system penetrability in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:4716-4732. [PMID: 35512438 PMCID: PMC9366324 DOI: 10.1093/jxb/erac188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Accepted: 05/03/2022] [Indexed: 05/07/2023]
Abstract
Soil mechanical impedance precludes root penetration, confining root system development to shallow soil horizons where mobile nutrients are scarce. Using a two-phase-agar system, we characterized Arabidopsis responses to low and high mechanical impedance at three root penetration stages. We found that seedlings whose roots fail to penetrate agar barriers show a significant reduction in leaf area, root length, and elongation zone and an increment in root diameter, while those capable of penetrating show only minor morphological effects. Analyses using different auxin-responsive reporter lines, exogenous auxins, and inhibitor treatments suggest that auxin responsiveness and PIN-mediated auxin distribution play an important role in regulating root responses to mechanical impedance. The assessment of 21 Arabidopsis accessions revealed that primary root penetrability varies widely among accessions. To search for quantitative trait loci (QTLs) associated to root system penetrability, we evaluated a recombinant inbred population derived from Landsberg erecta (Ler-0, with a high primary root penetrability) and Shahdara (Sha, with a low primary root penetrability) accessions. QTL analysis revealed a major-effect QTL localized in chromosome 3, ROOT PENETRATION INDEX 3 (q-RPI3), which accounted for 29.98% (logarithm of odds=8.82) of the total phenotypic variation. Employing an introgression line (IL-321) with a homozygous q-RPI3 region from Sha in the Ler-0 genetic background, we demonstrated that q-RPI3 plays a crucial role in root penetrability. This multiscale study reveals new insights into root plasticity during the penetration process in hard agar layers, natural variation, and genetic architecture behind primary root penetrability in Arabidopsis.
Collapse
Affiliation(s)
- Elohim Bello Bello
- Unidad de Genómica Avanzada/LANGEBIO, Centro de Investigación y de Estudios Avanzados, Irapuato, México
| | - Thelma Y Rico Cambron
- Unidad de Genómica Avanzada/LANGEBIO, Centro de Investigación y de Estudios Avanzados, Irapuato, México
| | - Lesly Abril Ortiz Ramírez
- Unidad de Genómica Avanzada/LANGEBIO, Centro de Investigación y de Estudios Avanzados, Irapuato, México
| | - Rubén Rellán Álvarez
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC, USA
| | | |
Collapse
|
3
|
Bello-Bello E, López-Arredondo D, Rico-Chambrón TY, Herrera-Estrella L. Conquering compacted soils: uncovering the molecular components of root soil penetration. TRENDS IN PLANT SCIENCE 2022; 27:814-827. [PMID: 35525799 DOI: 10.1016/j.tplants.2022.04.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 03/28/2022] [Accepted: 04/04/2022] [Indexed: 06/14/2023]
Abstract
Global agriculture and food security face paramount challenges due to climate change and land degradation. Human-induced soil compaction severely affects soil fertility, impairing root system development and crop yield. There is a need to design compaction-resilient crops that can thrive in degraded soils and maintain high yields. To address plausible solutions to this challenging scenario, we discuss current knowledge on plant root penetration ability and delineate potential approaches based on root-targeted genetic engineering (RGE) and genomics-assisted breeding (GAB) for developing crops with enhanced root system penetrability (RSP) into compacted soils. Such approaches could lead to crops with improved resilience to climate change and marginal soils, which can help to boost CO2 sequestration and storage in deeper soil strata.
Collapse
Affiliation(s)
- Elohim Bello-Bello
- Unidad de Genómica Avanzada/LANGEBIO, Centro de Investigación y de Estudios Avanzados, Irapuato, México
| | - Damar López-Arredondo
- Institute of Genomics for Crop Abiotic Stress Tolerance, Department of Plant and Soil Science, Texas Tech University, Lubbock, TX 79409, USA
| | - Thelma Y Rico-Chambrón
- Unidad de Genómica Avanzada/LANGEBIO, Centro de Investigación y de Estudios Avanzados, Irapuato, México
| | - Luis Herrera-Estrella
- Unidad de Genómica Avanzada/LANGEBIO, Centro de Investigación y de Estudios Avanzados, Irapuato, México; Institute of Genomics for Crop Abiotic Stress Tolerance, Department of Plant and Soil Science, Texas Tech University, Lubbock, TX 79409, USA.
| |
Collapse
|
4
|
Vanhees DJ, Schneider HM, Sidhu JS, Loades KW, Bengough AG, Bennett MJ, Pandey BK, Brown KM, Mooney SJ, Lynch JP. Soil penetration by maize roots is negatively related to ethylene-induced thickening. PLANT, CELL & ENVIRONMENT 2022; 45:789-804. [PMID: 34453329 PMCID: PMC9291135 DOI: 10.1111/pce.14175] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 08/20/2021] [Accepted: 08/22/2021] [Indexed: 05/22/2023]
Abstract
Radial expansion is a classic response of roots to a mechanical impedance that has generally been assumed to aid penetration. We analysed the response of maize nodal roots to impedance to test the hypothesis that radial expansion is not related to the ability of roots to cross a compacted soil layer. Genotypes varied in their ability to cross the compacted layer, and those with a steeper approach to the compacted layer or less radial expansion in the compacted layer were more likely to cross the layer and achieve greater depth. Root radial expansion was due to cortical cell size expansion, while cortical cell file number remained constant. Genotypes and nodal root classes that exhibited radial expansion in the compacted soil layer generally also thickened in response to exogenous ethylene in hydroponic culture, that is, radial expansion in response to ethylene was correlated with the thickening response to impedance in soil. We propose that ethylene insensitive roots, that is, those that do not thicken and can overcome impedance, have a competitive advantage under mechanically impeded conditions as they can maintain their elongation rates. We suggest that prolonged exposure to ethylene could function as a stop signal for axial root growth.
Collapse
Affiliation(s)
- Dorien J. Vanhees
- School of BiosciencesUniversity of Nottingham, Sutton Bonington CampusLeicestershireUK
- The James Hutton InstituteInvergowrieUK
| | - Hannah M. Schneider
- Department of Plant ScienceThe Pennsylvania State UniversityUniversity ParkPennsylvaniaUSA
- Centre for Crop Systems AnalysisWageningen University & ResearchWageningenThe Netherlands
| | - Jagdeep Singh Sidhu
- Department of Plant ScienceThe Pennsylvania State UniversityUniversity ParkPennsylvaniaUSA
| | | | - A. Glyn Bengough
- The James Hutton InstituteInvergowrieUK
- School of Science and EngineeringThe University of DundeeDundeeUK
| | - Malcolm J. Bennett
- School of BiosciencesUniversity of Nottingham, Sutton Bonington CampusLeicestershireUK
| | - Bipin K. Pandey
- School of BiosciencesUniversity of Nottingham, Sutton Bonington CampusLeicestershireUK
| | - Kathleen M. Brown
- Department of Plant ScienceThe Pennsylvania State UniversityUniversity ParkPennsylvaniaUSA
| | - Sacha J. Mooney
- School of BiosciencesUniversity of Nottingham, Sutton Bonington CampusLeicestershireUK
| | - Jonathan P. Lynch
- School of BiosciencesUniversity of Nottingham, Sutton Bonington CampusLeicestershireUK
- Department of Plant ScienceThe Pennsylvania State UniversityUniversity ParkPennsylvaniaUSA
| |
Collapse
|
5
|
Kumar V, Singh D, Majee A, Singh S, Asif MH, Sane AP, Sane VA. Identification of tomato root growth regulatory genes and transcription factors through comparative transcriptomic profiling of different tissues. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2021; 27:1173-1189. [PMID: 34177143 PMCID: PMC8212336 DOI: 10.1007/s12298-021-01015-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 05/07/2021] [Accepted: 05/27/2021] [Indexed: 06/13/2023]
Abstract
UNLABELLED Tomato is an economically important vegetable crop and a model for development and stress response studies. Although studied extensively for understanding fruit ripening and pathogen responses, its role as a model for root development remains less explored. In this study, an Illumina-based comparative differential transcriptomic analysis of tomato root with different aerial tissues was carried out to identify genes that are predominantly expressed during root growth. Sequential comparisons revealed ~ 15,000 commonly expressed genes and ~ 3000 genes of several classes that were mainly expressed or regulated in roots. These included 1069 transcription factors (TFs) of which 100 were differentially regulated. Prominent amongst these were members of families encoding Zn finger, MYB, ARM, bHLH, AP2/ERF, WRKY and NAC proteins. A large number of kinases, phosphatases and F-box proteins were also expressed in the root transcriptome. The major hormones regulating root growth were represented by the auxin, ethylene, JA, ABA and GA pathways with root-specific expression of certain components. Genes encoding carbon metabolism and photosynthetic components showed reduced expression while several protease inhibitors were amongst the most highly expressed. Overall, the study sheds light on genes governing root growth in tomato and provides a resource for manipulation of root growth for plant improvement. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s12298-021-01015-0.
Collapse
Affiliation(s)
- Vinod Kumar
- Plant Gene Expression Lab, Molecular Biology and Biotechnology, CSIR-National Botanical Research Institute, Lucknow, 226001 India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002 India
| | - Deepika Singh
- Plant Gene Expression Lab, Molecular Biology and Biotechnology, CSIR-National Botanical Research Institute, Lucknow, 226001 India
- Integral University, Lucknow, 226026 India
| | - Adity Majee
- Plant Gene Expression Lab, Molecular Biology and Biotechnology, CSIR-National Botanical Research Institute, Lucknow, 226001 India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002 India
| | - Shikha Singh
- Plant Gene Expression Lab, Molecular Biology and Biotechnology, CSIR-National Botanical Research Institute, Lucknow, 226001 India
| | - Mehar Hasan Asif
- Plant Gene Expression Lab, Molecular Biology and Biotechnology, CSIR-National Botanical Research Institute, Lucknow, 226001 India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002 India
| | - Aniruddha P. Sane
- Plant Gene Expression Lab, Molecular Biology and Biotechnology, CSIR-National Botanical Research Institute, Lucknow, 226001 India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002 India
| | - Vidhu A. Sane
- Plant Gene Expression Lab, Molecular Biology and Biotechnology, CSIR-National Botanical Research Institute, Lucknow, 226001 India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002 India
| |
Collapse
|
6
|
Sharma K, Gupta S, Sarma S, Rai M, Sreelakshmi Y, Sharma R. Mutations in tomato 1-aminocyclopropane carboxylic acid synthase2 uncover its role in development beside fruit ripening. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 106:95-112. [PMID: 33370496 DOI: 10.1111/tpj.15148] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 11/26/2020] [Accepted: 12/03/2020] [Indexed: 06/12/2023]
Abstract
The role of ethylene in plant development is mostly inferred from its exogenous application. The usage of mutants affecting ethylene biosynthesis proffers a better alternative to decipher its role. In tomato (Solanum lycopersicum), 1-aminocyclopropane carboxylic acid synthase2 (ACS2) is a key enzyme regulating ripening-specific ethylene biosynthesis. We characterised two contrasting acs2 mutants; acs2-1 overproduces ethylene, has higher ACS activity, and has increased protein levels, while acs2-2 is an ethylene underproducer, displays lower ACS activity, and has lower protein levels than wild type. Consistent with high/low ethylene emission, the mutants show opposite phenotypes, physiological responses, and metabolomic profiles compared with the wild type. The acs2-1 mutant shows early seed germination, faster leaf senescence, and accelerated fruit ripening. Conversely, acs2-2 has delayed seed germination, slower leaf senescence, and prolonged fruit ripening. The phytohormone profiles of mutants were mostly opposite in the leaves and fruits. The faster/slower senescence of acs2-1/acs2-2 leaves correlated with the endogenous ethylene/zeatin ratio. The genetic analysis showed that the metabolite profiles of respective mutants co-segregated with the homozygous mutant progeny. Our results uncover that besides ripening, ACS2 participates in the vegetative and reproductive development of tomato. The distinct influence of ethylene on phytohormone profiles indicates the intertwining of ethylene action with other phytohormones in regulating plant development.
Collapse
Affiliation(s)
- Kapil Sharma
- Repository of Tomato Genomics Resources, Department of Plant Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Soni Gupta
- Repository of Tomato Genomics Resources, Department of Plant Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Supriya Sarma
- Repository of Tomato Genomics Resources, Department of Plant Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Meenakshi Rai
- Repository of Tomato Genomics Resources, Department of Plant Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Yellamaraju Sreelakshmi
- Repository of Tomato Genomics Resources, Department of Plant Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Rameshwar Sharma
- Repository of Tomato Genomics Resources, Department of Plant Sciences, University of Hyderabad, Hyderabad, 500046, India
| |
Collapse
|
7
|
Sharma K, Gupta S, Sarma S, Rai M, Sreelakshmi Y, Sharma R. Mutations in tomato 1-aminocyclopropane carboxylic acid synthase2 uncover its role in development beside fruit ripening. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 106:95-112. [PMID: 33370496 DOI: 10.1101/2020.05.12.090431] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 11/26/2020] [Accepted: 12/03/2020] [Indexed: 05/24/2023]
Abstract
The role of ethylene in plant development is mostly inferred from its exogenous application. The usage of mutants affecting ethylene biosynthesis proffers a better alternative to decipher its role. In tomato (Solanum lycopersicum), 1-aminocyclopropane carboxylic acid synthase2 (ACS2) is a key enzyme regulating ripening-specific ethylene biosynthesis. We characterised two contrasting acs2 mutants; acs2-1 overproduces ethylene, has higher ACS activity, and has increased protein levels, while acs2-2 is an ethylene underproducer, displays lower ACS activity, and has lower protein levels than wild type. Consistent with high/low ethylene emission, the mutants show opposite phenotypes, physiological responses, and metabolomic profiles compared with the wild type. The acs2-1 mutant shows early seed germination, faster leaf senescence, and accelerated fruit ripening. Conversely, acs2-2 has delayed seed germination, slower leaf senescence, and prolonged fruit ripening. The phytohormone profiles of mutants were mostly opposite in the leaves and fruits. The faster/slower senescence of acs2-1/acs2-2 leaves correlated with the endogenous ethylene/zeatin ratio. The genetic analysis showed that the metabolite profiles of respective mutants co-segregated with the homozygous mutant progeny. Our results uncover that besides ripening, ACS2 participates in the vegetative and reproductive development of tomato. The distinct influence of ethylene on phytohormone profiles indicates the intertwining of ethylene action with other phytohormones in regulating plant development.
Collapse
Affiliation(s)
- Kapil Sharma
- Repository of Tomato Genomics Resources, Department of Plant Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Soni Gupta
- Repository of Tomato Genomics Resources, Department of Plant Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Supriya Sarma
- Repository of Tomato Genomics Resources, Department of Plant Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Meenakshi Rai
- Repository of Tomato Genomics Resources, Department of Plant Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Yellamaraju Sreelakshmi
- Repository of Tomato Genomics Resources, Department of Plant Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Rameshwar Sharma
- Repository of Tomato Genomics Resources, Department of Plant Sciences, University of Hyderabad, Hyderabad, 500046, India
| |
Collapse
|
8
|
Liu S, Chen H. Ethylene Signaling Facilitates Plant Adaption to Physical Barriers. FRONTIERS IN PLANT SCIENCE 2021; 12:697988. [PMID: 34394151 PMCID: PMC8358396 DOI: 10.3389/fpls.2021.697988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 07/02/2021] [Indexed: 05/11/2023]
Abstract
The morphological changes are usually observed in the terrestrial plants to respond to physical barriers. The phytohormone ethylene plays an essential role in the morphological development of plants encountering exogenous mechanical impedance, which enables plants to grow optimally in response to physical barriers. Ethylene is shown to regulate these developmental processes directly or in concert with other phytohormones, especially auxin. In this mini review, the involvement of ethylene action in seedling emergence from the soil, root movement within the soil, and parasitic plant invasion of the host plant are described.
Collapse
Affiliation(s)
- Simu Liu
- Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China
- *Correspondence: Simu Liu,
| | - Hui Chen
- Guangdong Key Laboratory of Genome Instability and Human Disease, School of Medicine, Shenzhen University, Shenzhen, China
- Hui Chen, ;
| |
Collapse
|
9
|
Nongmaithem S, Devulapalli S, Sreelakshmi Y, Sharma R. Is naphthylphthalamic acid a specific phytotropin? It elevates ethylene and alters metabolic homeostasis in tomato. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2020; 291:110358. [PMID: 31928666 DOI: 10.1016/j.plantsci.2019.110358] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 09/17/2019] [Accepted: 11/22/2019] [Indexed: 06/10/2023]
Abstract
In higher plants, phytohormone indole-3-acetic acid is characteristically transported from the apex towards the base of the plant, termed as polar auxin transport (PAT). Among the inhibitors blocking PAT, N-1-naphthylphthalamic acid (NPA) that targets ABCB transporters is most commonly used. NPA-treated light-grown Arabidopsis seedlings show severe inhibition of hypocotyl and root elongation. In light-grown tomato seedlings, NPA inhibited root growth, but contrary to Arabidopsis stimulated hypocotyl elongation. The NPA-stimulation of hypocotyl elongation was milder in blue, red, and far-red light-grown seedlings. The NPA-treatment stimulated emission of ethylene from the seedlings. The scrubbing of ethylene by mercuric perchlorate reduced NPA-stimulated hypocotyl elongation. NPA action on hypocotyl elongation was antagonized by 1-methylcyclopropene, an inhibitor of ethylene action. NPA-treated seedlings had reduced levels of indole-3-butyric acid and higher levels of zeatin in the shoots. NPA did not alter indole-3-acetic levels in shoots. The analysis of metabolic networks indicated that NPA-treatment induced moderate shifts in the networks compared to exogenous ethylene that induced a drastic shift in metabolic networks. Our results indicate that in addition to ethylene, NPA-stimulated hypocotyl elongation in tomato may also involve zeatin and indole-3- butyric acid. Our results indicate that NPA-mediated physiological responses may vary in a species-specific fashion.
Collapse
Affiliation(s)
- Sapana Nongmaithem
- Repository of Tomato Genomics Resources, Department of Plant Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Sameera Devulapalli
- Repository of Tomato Genomics Resources, Department of Plant Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Yellamaraju Sreelakshmi
- Repository of Tomato Genomics Resources, Department of Plant Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Rameshwar Sharma
- Repository of Tomato Genomics Resources, Department of Plant Sciences, University of Hyderabad, Hyderabad, 500046, India.
| |
Collapse
|
10
|
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.
Collapse
Affiliation(s)
- Izabela Potocka
- Department of Cell Biology, University of Silesia, Katowice, Poland
| | | |
Collapse
|
11
|
Nziengui H, Lasok H, Kochersperger P, Ruperti B, Rébeillé F, Palme K, Ditengou FA. Root Gravitropism Is Regulated by a Crosstalk between para-Aminobenzoic Acid, Ethylene, and Auxin. PLANT PHYSIOLOGY 2018; 178:1370-1389. [PMID: 30275058 PMCID: PMC6236604 DOI: 10.1104/pp.18.00126] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 09/13/2018] [Indexed: 05/04/2023]
Abstract
Plants respond to gravitational force through directional growth along the gravity vector. Although auxin is the central component of the root graviresponse, it works in concert with other plant hormones. Here, we show that the folate precursor para-aminobenzoic acid (PABA) is a key modulator of the auxin-ethylene interplay during root gravitropism in Arabidopsis (Arabidopsis thaliana). In gravistimulated roots, PABA promotes an asymmetric auxin response, which causes the asymmetric growth responsible for root curvature. This activity requires the auxin response transcription factors AUXIN RESPONSE FACTOR7 (ARF7) and ARF19 as well as ethylene biosynthesis and signaling, indicating that PABA activity requires both auxin and ethylene pathways. Similar to ethylene, exogenous PABA reverses the agravitropic root growth of the auxin transport mutant pin-formed2 (pin2) and the auxin biosynthetic double mutant with loss of function of weak ethylene insensitive (wei) genes, wei8wei2, but not the pin2wei8wei2 triple mutant. This finding suggests that PABA regulates the ethylene-dependent reciprocal compensation between auxin transport and biosynthesis. Furthermore, manipulation of endogenous free PABA levels by modulating the expression of the gene encoding its glucosylation enzyme, UDP-GLYCOSYL TRANSFERASE75B1, impacts the root graviresponse, suggesting that endogenous free PABA levels may play a crucial role in modulating the auxin-ethylene cross talk necessary for root gravitropism.
Collapse
Affiliation(s)
- Hugues Nziengui
- Institute of Biology II, Faculty of Biology, University of Freiburg, D-79104 Freiburg, Germany
| | - Hanna Lasok
- Institute of Biology II, Faculty of Biology, University of Freiburg, D-79104 Freiburg, Germany
| | - Philip Kochersperger
- Institute of Biology II, Faculty of Biology, University of Freiburg, D-79104 Freiburg, Germany
| | - Benedetto Ruperti
- Department of Agronomy, Food, Natural Resources, Animals, and Environment, University of Padova, 35020 Legnaro (Padova), Italy
| | - Fabrice Rébeillé
- Laboratoire de Physiologie Cellulaire Végétale, Unité Mixte de Recherche 5168, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Universite Grenoble Alpes, Bioscience and Biotechnologies Institute of Grenoble, Commissariat à l'Energie Atomique-Grenoble, F-38054 Grenoble cedex 9, France
| | - Klaus Palme
- Institute of Biology II, Faculty of Biology, University of Freiburg, D-79104 Freiburg, Germany
- Centre for Biological Systems Analysis, Albert-Ludwigs-University of Freiburg, 79104 Freiburg, Germany
- BIOSS Centre for Biological Signaling Studies, Albert-Ludwigs-University of Freiburg, 79104 Freiburg, Germany
| | - Franck Anicet Ditengou
- Institute of Biology II, Faculty of Biology, University of Freiburg, D-79104 Freiburg, Germany
| |
Collapse
|
12
|
Karban R, Orrock JL. A judgment and decision‐making model for plant behavior. Ecology 2018; 99:1909-1919. [DOI: 10.1002/ecy.2418] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Revised: 03/20/2018] [Accepted: 05/14/2018] [Indexed: 11/05/2022]
Affiliation(s)
- Richard Karban
- Department of Entomology and Nematology University of California, Davis Davis California 95616 USA
| | - John L. Orrock
- Department of Integrative Biology University of Wisconsin Madison Wisconsin 53704 USA
| |
Collapse
|
13
|
Santisree P, Bhatnagar-Mathur P, Sharma KK. Molecular insights into the functional role of nitric oxide (NO) as a signal for plant responses in chickpea. FUNCTIONAL PLANT BIOLOGY : FPB 2018; 45:267-283. [PMID: 32291041 DOI: 10.1071/fp16324] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 03/14/2017] [Indexed: 06/11/2023]
Abstract
The molecular mechanisms and targets of nitric oxide (NO) are not fully known in plants. Our study reports the first large-scale quantitative proteomic analysis of NO donor responsive proteins in chickpea. Dose response studies carried out using NO donors, sodium nitroprusside (SNP), diethylamine NONOate (DETA) and S-nitrosoglutathione (GSNO) in chickpea genotype ICCV1882, revealed a dose dependent positive impact on seed germination and seedling growth. SNP at 0.1mM concentration proved to be most appropriate following confirmation using four different chickpea genotypes. while SNP treatment enhanced the percentage of germination, chlorophyll and nitrogen contents in chickpea, addition of NO scavenger, cPTIO reverted its impact under abiotic stresses. Proteome profiling revealed 172 downregulated and 76 upregulated proteins, of which majority were involved in metabolic processes (118) by virtue of their catalytic (145) and binding (106) activity. A few crucial proteins such as S-adenosylmethionine synthase, dehydroascorbate reductase, pyruvate kinase fragment, 1-aminocyclopropane-1-carboxylic acid oxidase, 1-pyrroline-5-carboxylate synthetase were less abundant whereas Bowman-Birk type protease inhibitor, non-specific lipid transfer protein, chalcone synthase, ribulose-1-5-bisphosphate carboxylase oxygenase large subunit, PSII D2 protein were highly abundant in SNP treated samples. This study highlights the protein networks for a better understanding of possible NO induced regulatory mechanisms in plants.
Collapse
Affiliation(s)
- Parankusam Santisree
- International Crops Research Institute for the Semiarid Tropics (ICRISAT), Patancheru, Hyderabad-502324, Telangana, India
| | - Pooja Bhatnagar-Mathur
- International Crops Research Institute for the Semiarid Tropics (ICRISAT), Patancheru, Hyderabad-502324, Telangana, India
| | - Kiran K Sharma
- International Crops Research Institute for the Semiarid Tropics (ICRISAT), Patancheru, Hyderabad-502324, Telangana, India
| |
Collapse
|
14
|
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.
Collapse
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
| |
Collapse
|
15
|
Yruela I. Plant development regulation: Overview and perspectives. JOURNAL OF PLANT PHYSIOLOGY 2015; 182:62-78. [PMID: 26056993 DOI: 10.1016/j.jplph.2015.05.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 04/28/2015] [Accepted: 05/04/2015] [Indexed: 05/07/2023]
Abstract
Plant development, as occur in other eukaryotes, is conducted through a complex network of hormones, transcription factors, enzymes and micro RNAs, among other cellular components. They control developmental processes such as embryo, apical root and shoot meristem, leaf, flower, or seed formation, among others. The research in these topics has been very active in last decades. Recently, an explosion of new data concerning regulation mechanisms as well as the response of these processes to environmental changes has emerged. Initially, most of investigations were carried out in the model eudicot Arabidopsis but currently data from other plant species are available in the literature, although they are still limited. The aim of this review is focused on summarize the main molecular actors involved in plant development regulation in diverse plant species. A special attention will be given to the major families of genes and proteins participating in these regulatory mechanisms. The information on the regulatory pathways where they participate will be briefly cited. Additionally, the importance of certain structural features of such proteins that confer ductility and flexibility to these mechanisms will also be reported and discussed.
Collapse
Affiliation(s)
- Inmaculada Yruela
- Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas (EEAD-CSIC), Avda. Montañana 1005, 50059 Zaragoza, Spain; Instituto de Biocomputacióon y Física de Sistemas Complejos, Mariano Esquillor, Edificio I+D, 50018 Zaragoza, Spain.
| |
Collapse
|
16
|
Kumar R, Khurana A, Sharma AK. Role of plant hormones and their interplay in development and ripening of fleshy fruits. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:4561-75. [PMID: 25028558 DOI: 10.1093/jxb/eru277] [Citation(s) in RCA: 261] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Plant hormones have been extensively studied for their roles in the regulation of various aspects of plant development. However, in the last decade important new insights have been made into their action during development and ripening, in both dry and fleshy fruits. Emerging evidence suggests that relative functions of plant hormones are not restricted to a particular stage, and a complex network of more than one plant hormone is involved in controlling various aspects of fruit development. Though some areas are extensively covered, considerable gaps in our knowledge and understanding still exist in the control of hormonal networks and crosstalk between different hormones during fruit expansion, maturation, and various other aspects of ripening. Here, we evaluate the new knowledge on their relative roles during tomato fruit development with a view to understand their mechanism of action in fleshy fruits. For a better understanding, pertinent evidences available on hormonal crosstalk during fruit development in other species are also discussed. We envisage that such detailed knowledge will help design new strategies for effective manipulation of fruit ripening.
Collapse
Affiliation(s)
- Rahul Kumar
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi 110021, India. Current address: Repository of Tomato Genomics Resources, Department of Plant Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Ashima Khurana
- Zakir Husain Delhi College, University of Delhi, New Delhi 110002, India
| | - Arun K Sharma
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi 110021, India.
| |
Collapse
|
17
|
Gupta SK, Sharma S, Santisree P, Kilambi HV, Appenroth K, Sreelakshmi Y, Sharma R. Complex and shifting interactions of phytochromes regulate fruit development in tomato. PLANT, CELL & ENVIRONMENT 2014; 37:1688-702. [PMID: 24433205 DOI: 10.1111/pce.12279] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 01/05/2014] [Indexed: 05/22/2023]
Abstract
Tomato fruit ripening is a complex metabolic process regulated by a genetical hierarchy. A subset of this process is also modulated by light signalling, as mutants encoding negative regulators of phytochrome signal transduction show higher accumulation of carotenoids. In tomato, phytochromes are encoded by a multi-gene family, namely PHYA, PHYB1, PHYB2, PHYE and PHYF; however, their contribution to fruit development and ripening has not been examined. Using single phytochrome mutants phyA, phyB1 and phyB2 and multiple mutants phyAB1, phyB1B2 and phyAB1B2, we compared the on-vine transitory phases of ripening until fruit abscission. The phyAB1B2 mutant showed accelerated transitions during ripening, with shortest time to fruit abscission. Comparison of transition intervals in mutants indicated a phase-specific influence of different phytochrome species either singly or in combination on the ripening process. Examination of off-vine ripened fruits indicated that ripening-specific carotenoid accumulation was not obligatorily dependent upon light and even dark-incubated fruits accumulated carotenoids. The accumulation of transcripts and carotenoids in off-vine and on-vine ripened mutant fruits indicated a complex and shifting phase-dependent modulation by phytochromes. Our results indicate that, in addition to regulating carotenoid levels in tomato fruits, phytochromes also regulate the time required for phase transitions during ripening.
Collapse
Affiliation(s)
- Suresh Kumar Gupta
- Repository of Tomato Genomics Resources, Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India
| | | | | | | | | | | | | |
Collapse
|
18
|
Thomas S, Sreelakshmi Y, Sharma R. Light modulates the root tip excision induced lateral root formation in tomato. PLANT SIGNALING & BEHAVIOR 2014; 9:e970098. [PMID: 25482798 PMCID: PMC4623053 DOI: 10.4161/15592316.2014.970098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 07/02/2014] [Accepted: 07/02/2014] [Indexed: 05/07/2023]
Abstract
During plant growth and development, root tip performs multifarious functions integrating diverse external and internal stimuli to regulate root elongation and architecture. It is believed that a signal originating from root tip inhibits lateral root formation (LRF). The excision of root tip induced LRF in tomato seedlings associated with accumulation of auxin in pericycle founder cells. The excision of cotyledons slightly reduced LRF, whereas severing shoot from root completely abolished LRF. Exogenous ethylene application did not alter LRF. The response was modulated by light with higher LRF in seedlings exposed to light. Our results indicate that light plays a role in LRF in seedlings by likely modulating shoot derived auxin.
Collapse
Affiliation(s)
- Sherinmol Thomas
- Repository of Tomato Genomics Resources; Department of Plant Sciences; University of Hyderabad; Hyderabad, India
| | - Yellamaraju Sreelakshmi
- Repository of Tomato Genomics Resources; Department of Plant Sciences; University of Hyderabad; Hyderabad, India
| | - Rameshwar Sharma
- Repository of Tomato Genomics Resources; Department of Plant Sciences; University of Hyderabad; Hyderabad, India
| |
Collapse
|
19
|
|
20
|
Huang SJ, Chang CL, Wang PH, Tsai MC, Hsu PH, Chang IF. A type III ACC synthase, ACS7, is involved in root gravitropism in Arabidopsis thaliana. JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:4343-60. [PMID: 23943848 PMCID: PMC3808318 DOI: 10.1093/jxb/ert241] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Ethylene is an important plant hormone that regulates developmental processes in plants. The ethylene biosynthesis pathway is a highly regulated process at both the transcriptional and post-translational level. The transcriptional regulation of these ethylene biosynthesis genes is well known. However, post-translational modifications of the key ethylene biosynthesis enzyme 1-aminocyclopropane-1-carboxylate (ACC) synthase (ACS) are little understood. In vitro kinase assays were conducted on the type III ACS, AtACS7, fusion protein and peptides to determine whether the AtACS7 protein can be phosphorylated by calcium-dependent protein kinase (CDPK). AtACS7 was phosphorylated at Ser216, Thr296, and Ser299 by AtCDPK16 in vitro. To investigate further the function of the ACS7 gene in Arabidopsis, an acs7-1 loss-of-function mutant was isolated. The acs7-1 mutant exhibited less sensitivity to the inhibition of root gravitropism by treatment with the calcium chelator ethylene glycol tetraacetic acid (EGTA). Seedlings were treated with gradient concentrations of ACC. The results showed that a certain concentration of ethylene enhanced the gravity response. Moreover, the acs7-1 mutant was less sensitive to inhibition of the gravity response by treatment with the auxin polar transport inhibitor 1-naphthylphthalamic acid, but exogenous ACC application recovered root gravitropism. Altogether, the results indicate that AtACS7 is involved in root gravitropism in a calcium-dependent manner in Arabidopsis.
Collapse
Affiliation(s)
- Shih-Jhe Huang
- Institute of Plant Biology, National Taiwan University, Taipei, Taiwan
| | - Chia-Lun Chang
- Institute of Plant Biology, National Taiwan University, Taipei, Taiwan
| | - Po-Hsun Wang
- Institute of Plant Biology, National Taiwan University, Taipei, Taiwan
| | - Min-Chieh Tsai
- Institute of Plant Biology, National Taiwan University, Taipei, Taiwan
| | - Pang-Hung Hsu
- Institute of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan
| | - Ing-Feng Chang
- Institute of Plant Biology, National Taiwan University, Taipei, Taiwan
- Department of Life Science, National Taiwan University, Taipei, Taiwan
- * To whom correspondence should be addressed. E-mail:
| |
Collapse
|
21
|
Jin K, Shen J, Ashton RW, Dodd IC, Parry MAJ, Whalley WR. How do roots elongate in a structured soil? JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:4761-4777. [PMID: 24043852 DOI: 10.1093/jxb/ert286] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In this review, we examine how roots penetrate a structured soil. We first examine the relationship between soil water status and its mechanical strength, as well as the ability of the soil to supply water to the root. We identify these as critical soil factors, because it is primarily in drying soil that mechanical constraints limit root elongation. Water supply to the root is important because root water status affects growth pressures and root stiffness. To simplify the bewildering complexity of soil-root interactions, the discussion is focused around the special cases of root elongation in soil with pores much smaller than the root diameter and the penetration of roots at interfaces within the soil. While it is often assumed that the former case is well understood, many unanswered questions remain. While low soil-root friction is often viewed as a trait conferring better penetration of strong soils, it may also increase the axial pressure on the root tip and in so doing reduce the rate of cell division and/or expansion. The precise trade-off between various root traits involved in root elongation in homogeneous soil remains to be determined. There is consensus that the most important factors determining root penetration at an interface are the angle at which the root attempts to penetrate the soil, root stiffness, and the strength of the soil to be penetrated. The effect of growth angle on root penetration implicates gravitropic responses in improved root penetration ability. Although there is no work that has explored the effect of the strength of the gravitropic responses on penetration of hard layers, we attempt to outline possible interactions. Impacts of soil drying and strength on phytohormone concentrations in roots, and consequent root-to-shoot signalling, are also considered.
Collapse
Affiliation(s)
- Kemo Jin
- Department of Plant Nutrition, College of Resource and Environmental Sciences, China Agricultural University, Beijing 100193, PR China
| | | | | | | | | | | |
Collapse
|
22
|
|
23
|
Kilambi HV, Kumar R, Sharma R, Sreelakshmi Y. Chromoplast-specific carotenoid-associated protein appears to be important for enhanced accumulation of carotenoids in hp1 tomato fruits. PLANT PHYSIOLOGY 2013; 161:2085-101. [PMID: 23400702 PMCID: PMC3613478 DOI: 10.1104/pp.112.212191] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 02/09/2013] [Indexed: 05/18/2023]
Abstract
Tomato (Solanum lycopersicum) high-pigment mutants with lesions in diverse loci such as DNA Damage-Binding Protein1 (high pigment1 [hp1]), Deetiolated1 (hp2), Zeaxanthin Epoxidase (hp3), and Intense pigment (Ip; gene product unknown) exhibit increased accumulation of fruit carotenoids coupled with an increase in chloroplast number and size. However, little is known about the underlying mechanisms exaggerating the carotenoid accumulation and the chloroplast number in these mutants. A comparison of proteome profiles from the outer pericarp of hp1 mutant and wild-type (cv Ailsa Craig) fruits at different developmental stages revealed at least 72 differentially expressed proteins during ripening. Hierarchical clustering grouped these proteins into three clusters. We found an increased abundance of chromoplast-specific carotenoid-associated protein (CHRC) in hp1 fruits at red-ripe stage that is also reflected in its transcript level. Western blotting using CHRC polyclonal antibody from bell pepper (Capsicum annuum) revealed a 2-fold increase in the abundance of CHRC protein in the red-ripe stage of hp1 fruits compared with the wild type. CHRC levels in hp2 were found to be similar to that of hp1, whereas hp3 and Ip showed intermediate levels to those in hp1, hp2, and wild-type fruits. Both CHRC and carotenoids were present in the isolated plastoglobules. Overall, our results suggest that loss of function of DDB1, DET1, Zeaxanthin Epoxidase, and Ip up-regulates CHRC levels. Increase in CHRC levels may contribute to the enhanced carotenoid content in these high-pigment fruits by assisting in the sequestration and stabilization of carotenoids.
Collapse
Affiliation(s)
- Himabindu Vasuki Kilambi
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Rakesh Kumar
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Rameshwar Sharma
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Yellamaraju Sreelakshmi
- Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| |
Collapse
|
24
|
Muday GK, Rahman A, Binder BM. Auxin and ethylene: collaborators or competitors? TRENDS IN PLANT SCIENCE 2012; 17:181-95. [PMID: 22406007 DOI: 10.1016/j.tplants.2012.02.001] [Citation(s) in RCA: 217] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Revised: 02/01/2012] [Accepted: 02/03/2012] [Indexed: 05/18/2023]
Abstract
The individual roles of auxin and ethylene in controlling the growth and development of young seedlings have been well studied. In recent years, these two hormones have been shown to act synergistically to control specific growth and developmental processes, such as root elongation and root hair formation, as well as antagonistically in other processes, such as lateral root formation and hypocotyl elongation. This review examines the growth and developmental processes that are regulated by crosstalk between these two hormones and explores the mechanistic basis for the regulation of these processes. The emerging trend from these experiments is that ethylene modulates auxin synthesis, transport, and signaling with unique targets and responses in a range of tissues to fine-tune seedling growth and development.
Collapse
Affiliation(s)
- Gloria K Muday
- Department of Biology, Wake Forest University, Winston-Salem, NC 27106, USA.
| | | | | |
Collapse
|
25
|
Jiang J, Su M, Wang L, Jiao C, Sun Z, Cheng W, Li F, Wang C. Exogenous hydrogen peroxide reversibly inhibits root gravitropism and induces horizontal curvature of primary root during grass pea germination. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2012; 53:84-93. [PMID: 22342943 DOI: 10.1016/j.plaphy.2012.01.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2011] [Accepted: 01/24/2012] [Indexed: 05/07/2023]
Abstract
During germination in distilled water (dH(2)O) on a horizontally positioned Petri dish, emerging primary roots of grass pea (Lathyrus sativus L.) grew perpendicular to the bottom of the Petri dish, due to gravitropism. However, when germinated in exogenous hydrogen peroxide (H(2)O(2)), the primary roots grew parallel to the bottom of the Petri dish and asymmetrically, forming a horizontal curvature. Time-course experiments showed that the effect was strongest when H(2)O(2) was applied prior to the emergence of the primary root. H(2)O(2) failed to induce root curvature when applied post-germination. Dosage studies revealed that the frequency of primary root curvature was significantly enhanced with increased H(2)O(2) concentrations. This curvature could be directly counteracted by dimethylthiourea (DMTU), a scavenger of H(2)O(2), but not by diphenylene iodonium (DPI) and pyridine, inhibitors of H(2)O(2) production. Exogenous H(2)O(2) treatment caused both an increase in the activities of H(2)O(2)-scavenging enzymes [including ascorbate peroxidase (APX: EC 1.11.1.11), catalase (CAT: EC 1.11.1.6) and peroxidase (POD: EC 1.11.1.7)] and a reduction in endogenous H(2)O(2) levels and root vitality. Although grass pea seeds absorbed exogenous H(2)O(2) during seed germination, DAB staining of paraffin sections revealed that exogenous H(2)O(2) only entered the root epidermis and not inner tissues. These data indicated that exogenously applied H(2)O(2) could lead to a reversible loss of the root gravitropic response and a horizontal curvature in primary roots during radicle emergence of the seedling.
Collapse
Affiliation(s)
- Jinglong Jiang
- School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | | | | | | | | | | | | | | |
Collapse
|
26
|
Santisree P, Nongmaithem S, Sreelakshmi Y, Ivanchenko M, Sharma R. The root as a drill: an ethylene-auxin interaction facilitates root penetration in soil. PLANT SIGNALING & BEHAVIOR 2012; 7:151-6. [PMID: 22415043 PMCID: PMC3405696 DOI: 10.4161/psb.18936] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Plant roots forage the soil for water and nutrients and overcome the soil's physical compactness. Roots are endowed with a mechanism that allows them to penetrate and grow in dense media such as soil. However, the molecular mechanisms underlying this process are still poorly understood. The nature of the media in which roots grow adds to the difficulty to in situ analyze the mechanisms underlying root penetration. Inhibition of ethylene perception by application of 1-methyl cyclopropene (1-MCP) to tomato seedlings nearly abolished the root penetration in Soilrite. The reversal of this process by auxin indicated operation of an auxin-ethylene signaling pathway in the regulation of root penetration. The tomato pct1-2 mutant that exhibits an enhanced polar transport of auxin required higher doses of 1-MCP to inhibit root penetration, indicating a pivotal role of auxin transport in this process. In this update we provide a brief review of our current understanding of molecular processes underlying root penetration in higher plants.
Collapse
Affiliation(s)
| | | | | | - Maria Ivanchenko
- Department of Botany and Plant Pathology; Oregon State University; Corvallis, OR USA
| | - Rameshwar Sharma
- School of Life Sciences; University of Hyderabad; Hyderabad, India
| |
Collapse
|