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Gifford ML, Xu G, Dupuy LX, Vissenberg K, Rebetzke G. Root architecture and rhizosphere-microbe interactions. J Exp Bot 2024; 75:503-507. [PMID: 38197460 PMCID: PMC10773993 DOI: 10.1093/jxb/erad488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 12/08/2023] [Indexed: 01/11/2024]
Abstract
Plant roots fulfil crucial tasks during a plant's life. As roots encounter very diverse conditions while exploring the soil for resources, their growth and development must be responsive to changes in the rhizosphere, resulting in root architectures that are tailor-made for all prevailing circumstances. Using multi-disciplinary approaches, we are gaining more intricate insights into the regulatory mechanisms directing root system architecture. This Special Issue provides insights into our advancement of knowledge on different aspects of root development and identifies opportunities for future research.
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Affiliation(s)
- Miriam L Gifford
- School of Life Sciences, The University of Warwick, Coventry, UK
| | - Guohua Xu
- National Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing 210095, China
| | - Lionel X Dupuy
- Department of Conservation of Natural Resources, Neiker, Derio, Spain
- Ikerbasque, Basque Foundation for Science, Bilbao, Spain
| | - Kris Vissenberg
- Integrated Molecular Plant Physiology Research, Department of Biology, University of Antwerp, Antwerp, Belgium
- Plant Biochemistry and Biotechnology Lab, Department of Agriculture, Hellenic Mediterranean University, Stavromenos PC 71410, Heraklion, Crete, Greece
| | - Greg Rebetzke
- CSIRO Agriculture and Food, PO Box 1700, Canberra ACT 2601, Australia
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Fletcher A, Christopher J, Hunter M, Rebetzke G, Chenu K. A low-cost method to rapidly and accurately screen for transpiration efficiency in wheat. Plant Methods 2018; 14:77. [PMID: 30181766 PMCID: PMC6116455 DOI: 10.1186/s13007-018-0339-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 08/14/2018] [Indexed: 05/26/2023]
Abstract
BACKGROUND Wheat (Triticum aestivum L.) productivity is commonly limited by the availability of water. Increasing transpiration efficiency (biomass produced per unit of water used, TE) can potentially lead to increased grain yield in water-limited environments ('more crop per drop'). Currently, the ability to screen large populations for TE is limited by slow, low-throughput and/or expensive screening procedures. Here, we propose a low-cost, low-technology, rapid, and scalable method to screen for TE. The method uses a Pot-in-Bucket system that allows continuous watering of the pots and frequent monitoring of water use. To investigate the robustness of the method across environments, and to determine the shortest trial duration required to get accurate and repeatable TE estimates in wheat, plants from 11 genotypes varying in phenology were sown at three dates and grown for different durations in a polyhouse with partial environmental control. RESULTS The method revealed significant genotypic variations in TE among the 11 studied wheat genotypes. Genotype rankings for TE were consistent when plants were harvested the same day, at the flag-leaf stage or later. For these harvests, genotype rankings were consistent across experiments despite changes in environmental conditions, such as evaporative demand. CONCLUSIONS These results indicate that (1) the Pot-In-Bucket system is suitable to screen TE for breeding purposes in populations with varying phenology, (2) multiple short trials can be carried out within a season to allow increased throughput of genotypes for TE screening, and (3) root biomass measurement is not required to screen for TE, as whole-plant TE and shoot-only TE are highly correlated, at least in wheat. The method is particularly relevant in developing countries where low-cost and relatively high labour input may be most applicable.
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Affiliation(s)
- Andrew Fletcher
- Queensland Alliance for Agriculture and Food Innovation (QAAFI), The University of Queensland, 203 Tor Street, Toowoomba, QLD 4350 Australia
| | - Jack Christopher
- Queensland Alliance for Agriculture and Food Innovation (QAAFI), The University of Queensland, 13 Holberton Street, Toowoomba, QLD 4350 Australia
| | - Mal Hunter
- School of Agriculture and Food Sciences, The University of Queensland, St Lucia, 4072 Australia
| | - Greg Rebetzke
- CSIRO Plant Industry, PO Box 1600, Canberra, ACT 2601 Australia
| | - Karine Chenu
- Queensland Alliance for Agriculture and Food Innovation (QAAFI), The University of Queensland, 203 Tor Street, Toowoomba, QLD 4350 Australia
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Christy B, Tausz-Posch S, Tausz M, Richards R, Rebetzke G, Condon A, McLean T, Fitzgerald G, Bourgault M, O'Leary G. Benefits of increasing transpiration efficiency in wheat under elevated CO 2 for rainfed regions. Glob Chang Biol 2018; 24:1965-1977. [PMID: 29331062 DOI: 10.1111/gcb.14052] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 12/20/2017] [Accepted: 12/22/2017] [Indexed: 06/07/2023]
Abstract
Higher transpiration efficiency (TE) has been proposed as a mechanism to increase crop yields in dry environments where water availability usually limits yield. The application of a coupled radiation and TE simulation model shows wheat yield advantage of a high-TE cultivar (cv. Drysdale) over its almost identical low-TE parent line (Hartog), from about -7 to 558 kg/ha (mean 187 kg/ha) over the rainfed cropping region in Australia (221-1,351 mm annual rainfall), under the present-day climate. The smallest absolute yield response occurred in the more extreme drier and wetter areas of the wheat belt. However, under elevated CO2 conditions, the response of Drysdale was much greater overall, ranging from 51 to 886 kg/ha (mean 284 kg/ha) with the greatest response in the higher rainfall areas. Changes in simulated TE under elevated CO2 conditions are seen across Australia with notable increased areas of higher TE under a drier climate in Western Australia, Queensland and parts of New South Wales and Victoria. This improved efficiency is subtly deceptive, with highest yields not necessarily directly correlated with highest TE. Nevertheless, the advantage of Drysdale over Hartog is clear with the benefit of the trait advantage attributed to TE ranging from 102% to 118% (mean 109%). The potential annual cost-benefits of this increased genetic TE trait across the wheat growing areas of Australia (5 year average of area planted to wheat) totaled AUD 631 MIL (5-year average wheat price of AUD/260 t) with an average of 187 kg/ha under the present climate. The benefit to an individual farmer will depend on location but elevated CO2 raises this nation-wide benefit to AUD 796 MIL in a 2°C warmer climate, slightly lower (AUD 715 MIL) if rainfall is also reduced by 20%.
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Affiliation(s)
- Brendan Christy
- Department of Economic Development, Jobs, Transport and Resources, Agriculture Victoria Research, Rutherglen, Vic., Australia
| | - Sabine Tausz-Posch
- School of Agriculture and Food, The University of Melbourne, Creswick, Vic., Australia
| | - Michael Tausz
- School of Agriculture and Food, The University of Melbourne, Creswick, Vic., Australia
| | | | | | | | - Terry McLean
- Department of Economic Development, Jobs, Transport and Resources, Agriculture Victoria Research, Rutherglen, Vic., Australia
| | - Glenn Fitzgerald
- School of Agriculture and Food, The University of Melbourne, Creswick, Vic., Australia
- Department of Economic Development, Jobs, Transport and Resources, Agriculture Victoria Research, Horsham, Vic., Australia
| | - Maryse Bourgault
- School of Agriculture and Food, The University of Melbourne, Creswick, Vic., Australia
| | - Garry O'Leary
- Department of Economic Development, Jobs, Transport and Resources, Agriculture Victoria Research, Horsham, Vic., Australia
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Robertson M, Kirkegaard J, Rebetzke G, Llewellyn R, Wark T. Prospects for yield improvement in the Australian wheat industry: a perspective. Food Energy Secur 2016. [DOI: 10.1002/fes3.81] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
| | - John Kirkegaard
- CSIRO Agriculture Wembley Western Australia Australia
- CSIRO Agriculture PO Box 1600 Canberra Australian Capital Territory 2601 Australia
| | - Greg Rebetzke
- CSIRO Agriculture Wembley Western Australia Australia
- CSIRO Agriculture PO Box 1600 Canberra Australian Capital Territory 2601 Australia
| | - Rick Llewellyn
- CSIRO Agriculture Wembley Western Australia Australia
- CSIRO Agriculture Urrbrae South Australia Australia
| | - Tim Wark
- CSIRO Data 61 Pullenvale Queensland Australia
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Moeller C, Evers JB, Rebetzke G. Canopy architectural and physiological characterization of near-isogenic wheat lines differing in the tiller inhibition gene tin. Front Plant Sci 2014; 5:617. [PMID: 25520724 PMCID: PMC4251293 DOI: 10.3389/fpls.2014.00617] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 10/21/2014] [Indexed: 05/02/2023]
Abstract
Tillering is a core constituent of plant architecture, and influences light interception to affect plant and crop performance. Near-isogenic lines (NILs) varying for a tiller inhibition (tin) gene and representing two genetic backgrounds were investigated for tillering dynamics, organ size distribution, leaf area, light interception, red: far-red ratio, and chlorophyll content. Tillering ceased earlier in the tin lines to reduce the frequencies of later primary and secondary tillers compared to the free-tillering NILs, and demonstrated the genetically lower tillering plasticity of tin-containing lines. The distribution of organ sizes along shoots varied between NILs contrasting for tin. Internode elongation commenced at a lower phytomer, and the peduncle was shorter in the tin lines. The flag leaves of tin lines were larger, and the longest leaf blades were observed at higher phytomers in the tin than in free-tillering lines. Total leaf area was reduced in tin lines, and non-tin lines invested more leaf area at mid-canopy height. The tiller economy (ratio of seed-bearing shoots to numbers of shoots produced) was 10% greater in the tin lines (0.73-0.76) compared to the free-tillering sisters (0.62-0.63). At maximum tiller number, the red: far-red ratio (light quality stimulus that is thought to induce the cessation of tillering) at the plant-base was 0.18-0.22 in tin lines and 0.09-0.11 in free-tillering lines at levels of photosynthetic active radiation of 49-53% and 30-33%, respectively. The tin lines intercepted less radiation compared to their free-tillering sisters once genotypic differences in tiller numbers had established, and maintained green leaf area in the lower canopy later into the season. Greater light extinction coefficients (k) in tin lines prior to, but reduced k after, spike emergence indicated that differences in light interception between NILs contrasting in tin cannot be explained by leaf area alone but that geometric and optical canopy properties contributed. The careful characterization of specifically-developed NILs is refining the development of a physiology-based model for tillering to improve understanding of the value of architectural traits for use in cereal improvement.
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Affiliation(s)
- Carina Moeller
- Tasmanian Institute of Agriculture, University of TasmaniaHobart, TAS, Australia
| | - Jochem B. Evers
- Centre for Crop Systems Analysis, Wageningen UniversityWageningen, Netherlands
| | - Greg Rebetzke
- Commonwealth Scientific and Industrial Research Organisation Plant Industry, Black Mountain LaboratoriesBlack Mountain, ACT, Australia
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Burdon JJ, Barrett LG, Rebetzke G, Thrall PH. Guiding deployment of resistance in cereals using evolutionary principles. Evol Appl 2014; 7:609-24. [PMID: 25067946 PMCID: PMC4105914 DOI: 10.1111/eva.12175] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 05/14/2014] [Indexed: 11/28/2022] Open
Abstract
Genetically controlled resistance provides plant breeders with an efficient means of controlling plant disease, but this approach has been constrained by practical difficulties associated with combining many resistance genes together and strong evolutionary responses from pathogen populations leading to subsequent resistance breakdown. However, continuing advances in molecular marker technologies are revolutionizing the ability to rapidly and reliably manipulate resistances of all types - major gene, adult plant and quantitative resistance loci singly or multiply into individual host lines. Here, we argue that these advances provide major opportunities to deliberately design deployment strategies in cereals that can take advantage of the evolutionary pressures faced by target pathogens. Different combinations of genes deployed either within single host individuals or between different individuals within or among crops, can be used to reduce the size of pathogen populations and generate patterns of disruptive selection. This will simultaneously limit immediate epidemic development and reduce the probability of subsequent evolutionary change in the pathogen for broader infectivity or increased aggressiveness. The same general principles are relevant to the control of noncereal diseases, but the most efficacious controls will vary reflecting the range of genetic options available and their fit with specific ecology and life-history combinations.
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Affiliation(s)
- Jeremy J Burdon
- CSIRO, Plant Industry Canberra, ACT, Australia ; CSIRO Biosecurity Flagship Canberra, ACT, Australia
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