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Zeng D, Ford B, Doležel J, Karafiátová M, Hayden MJ, Rathjen TM, George TS, Brown LK, Ryan PR, Pettolino FA, Mathesius U, Delhaize E. A conditional mutation in a wheat (Triticum aestivum L.) gene regulating root morphology. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2024; 137:48. [PMID: 38345612 PMCID: PMC10861616 DOI: 10.1007/s00122-024-04555-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 01/12/2024] [Indexed: 02/15/2024]
Abstract
KEY MESSAGE Characterisation and genetic mapping of a key gene defining root morphology in bread wheat. Root morphology is central to plants for the efficient uptake up of soil water and mineral nutrients. Here we describe a conditional mutant of hexaploid wheat (Triticum aestivum L.) that when grown in soil with high Ca2+ develops a larger rhizosheath accompanied with shorter roots than the wild type. In wheat, rhizosheath size is a reliable surrogate for root hair length and this was verified in the mutant which possessed longer root hairs than the wild type when grown in high Ca2+ soil. We named the mutant Stumpy and showed it to be due to a single semi-dominant mutation. The short root phenotype at high Ca2+ was due to reduced cellular elongation which might also explain the long root hair phenotype. Analysis of root cell walls showed that the polysaccharide composition of Stumpy roots is remodelled when grown at non-permissive (high) Ca2+ concentrations. The mutation mapped to chromosome 7B and sequencing of the 7B chromosomes in both wild type and Stumpy identified a candidate gene underlying the Stumpy mutation. As part of the process to determine whether the candidate gene was causative, we identified wheat lines in a Cadenza TILLING population with large rhizosheaths but accompanied with normal root length. This finding illustrates the potential of manipulating the gene to disconnect root length from root hair length as a means of developing wheat lines with improved efficiency of nutrient and water uptake. The Stumpy mutant will be valuable for understanding the mechanisms that regulate root morphology in wheat.
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Affiliation(s)
- Deying Zeng
- Department of Biological Science, College of Life Sciences, Sichuan Normal University, Chengdu, Sichuan, 610101, China
| | - Brett Ford
- Grains Research and Development Corporation, Barton, ACT, 2600, Australia
- CSIRO Agriculture & Food, PO Box 1700, Canberra, ACT, 2601, Australia
| | - Jaroslav Doležel
- Centre of Plant Structural and Functional Genomics, Institute of Experimental Botany of the Czech Academy of Sciences, Olomouc, Czech Republic
| | - Miroslava Karafiátová
- Centre of Plant Structural and Functional Genomics, Institute of Experimental Botany of the Czech Academy of Sciences, Olomouc, Czech Republic
| | - Mathew J Hayden
- Department of Jobs, Precincts and Regions, Agriculture Victoria Research, AgriBio, Bundoora, VIC, Australia
- School of Applied Systems Biology, La Trobe University, Bundoora, VIC, Australia
| | - Tina M Rathjen
- CSIRO Agriculture & Food, PO Box 1700, Canberra, ACT, 2601, Australia
| | | | - Lawrie K Brown
- James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
| | - Peter R Ryan
- CSIRO Agriculture & Food, PO Box 1700, Canberra, ACT, 2601, Australia
| | | | - Ulrike Mathesius
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Emmanuel Delhaize
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia.
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Rathor P, Upadhyay P, Ullah A, Gorim LY, Thilakarathna MS. Humic acid improves wheat growth by modulating auxin and cytokinin biosynthesis pathways. AOB PLANTS 2024; 16:plae018. [PMID: 38601216 PMCID: PMC11005776 DOI: 10.1093/aobpla/plae018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 03/22/2024] [Indexed: 04/12/2024]
Abstract
Humic acids have been widely used for centuries to enhance plant growth and productivity. The beneficial effects of humic acids have been attributed to different functional groups and phytohormone-like compounds enclosed in macrostructure. However, the mechanisms underlying the plant growth-promoting effects of humic acids are only partially understood. We hypothesize that the bio-stimulatory effect of humic acids is mainly due to the modulation of innate pathways of auxin and cytokinin biosynthesis in treated plants. A physiological investigation along with molecular characterization was carried out to understand the mechanism of bio-stimulatory effects of humic acid. A gene expression analysis was performed for the genes involved in auxin and cytokinin biosynthesis pathways in wheat seedlings. Furthermore, Arabidopsis thaliana transgenic lines generated by fusing the auxin-responsive DR5 and cytokinin-responsive ARR5 promoter to ß-glucuronidase (GUS) reporter were used to study the GUS expression analysis in humic acid treated seedlings. This study demonstrates that humic acid treatment improved the shoot and root growth of wheat seedlings. The expression of several genes involved in auxin (Tryptophan Aminotransferase of Arabidopsis and Gretchen Hagen 3.2) and cytokinin (Lonely Guy3) biosynthesis pathways were up-regulated in humic acid-treated seedlings compared to the control. Furthermore, GUS expression analysis showed that bioactive compounds of humic acid stimulate endogenous auxin and cytokinin-like activities. This study is the first report in which using ARR5:GUS lines we demonstrate the biostimulants activity of humic acid.
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Affiliation(s)
- Pramod Rathor
- Department of Agricultural, Food and Nutritional Science, Agriculture/Forestry Centre, University of Alberta, 9011-116St, NW, Edmonton, AB T6G 2P5, Canada
| | - Punita Upadhyay
- Department of Agricultural, Food and Nutritional Science, Agriculture/Forestry Centre, University of Alberta, 9011-116St, NW, Edmonton, AB T6G 2P5, Canada
| | - Aman Ullah
- Department of Agricultural, Food and Nutritional Science, Agriculture/Forestry Centre, University of Alberta, 9011-116St, NW, Edmonton, AB T6G 2P5, Canada
| | - Linda Yuya Gorim
- Department of Agricultural, Food and Nutritional Science, Agriculture/Forestry Centre, University of Alberta, 9011-116St, NW, Edmonton, AB T6G 2P5, Canada
| | - Malinda S Thilakarathna
- Department of Agricultural, Food and Nutritional Science, Agriculture/Forestry Centre, University of Alberta, 9011-116St, NW, Edmonton, AB T6G 2P5, Canada
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Bowerman AF, Byrt CS, Roy SJ, Whitney SM, Mortimer JC, Ankeny RA, Gilliham M, Zhang D, Millar AA, Rebetzke GJ, Pogson BJ. Potential abiotic stress targets for modern genetic manipulation. THE PLANT CELL 2023; 35:139-161. [PMID: 36377770 PMCID: PMC9806601 DOI: 10.1093/plcell/koac327] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 11/03/2022] [Indexed: 05/06/2023]
Abstract
Research into crop yield and resilience has underpinned global food security, evident in yields tripling in the past 5 decades. The challenges that global agriculture now faces are not just to feed 10+ billion people within a generation, but to do so under a harsher, more variable, and less predictable climate, and in many cases with less water, more expensive inputs, and declining soil quality. The challenges of climate change are not simply to breed for a "hotter drier climate," but to enable resilience to floods and droughts and frosts and heat waves, possibly even within a single growing season. How well we prepare for the coming decades of climate variability will depend on our ability to modify current practices, innovate with novel breeding methods, and communicate and work with farming communities to ensure viability and profitability. Here we define how future climates will impact farming systems and growing seasons, thereby identifying the traits and practices needed and including exemplars being implemented and developed. Critically, this review will also consider societal perspectives and public engagement about emerging technologies for climate resilience, with participatory approaches presented as the best approach.
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Affiliation(s)
- Andrew F Bowerman
- ARC Training Centre for Accelerated Future Crops Development, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Caitlin S Byrt
- ARC Training Centre for Accelerated Future Crops Development, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Stuart John Roy
- ARC Training Centre for Accelerated Future Crops Development, University of Adelaide, South Australia, Australia
- School of Agriculture, Food and Wine & Waite Research Institute, University of Adelaide, Glen Osmond, South Australia, Australia
| | - Spencer M Whitney
- ARC Training Centre for Accelerated Future Crops Development, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Jenny C Mortimer
- ARC Training Centre for Accelerated Future Crops Development, University of Adelaide, South Australia, Australia
- School of Agriculture, Food and Wine & Waite Research Institute, University of Adelaide, Glen Osmond, South Australia, Australia
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Rachel A Ankeny
- ARC Training Centre for Accelerated Future Crops Development, University of Adelaide, South Australia, Australia
- School of Humanities, University of Adelaide, North Terrace, South Australia, Australia
| | - Matthew Gilliham
- ARC Training Centre for Accelerated Future Crops Development, University of Adelaide, South Australia, Australia
- School of Agriculture, Food and Wine & Waite Research Institute, University of Adelaide, Glen Osmond, South Australia, Australia
| | - Dabing Zhang
- ARC Training Centre for Accelerated Future Crops Development, University of Adelaide, South Australia, Australia
- School of Agriculture, Food and Wine & Waite Research Institute, University of Adelaide, Glen Osmond, South Australia, Australia
| | - Anthony A Millar
- ARC Training Centre for Accelerated Future Crops Development, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Greg J Rebetzke
- CSIRO Agriculture & Food, Canberra, Australian Capital Territory, Australia
| | - Barry J Pogson
- ARC Training Centre for Accelerated Future Crops Development, The Australian National University, Canberra, Australian Capital Territory, Australia
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Rebetzke GJ, Zhang H, Ingvordsen CH, Condon AG, Rich SM, Ellis MH. Genotypic variation and covariation in wheat seedling seminal root architecture and grain yield under field conditions. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2022; 135:3247-3264. [PMID: 35925366 DOI: 10.1007/s00122-022-04183-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Accepted: 07/14/2022] [Indexed: 06/15/2023]
Abstract
Greater embryo size in a large and carefully phenotyped mapping population was genetically associated with a greater number of longer seminal roots to increase grain yield in droughted field environments. Breeding modification of root architecture is challenging in field environments owing to genetic and phenotypic complexity, and poor repeatability with root sampling. Seeds from a large mapping population varying in embryo size were harvested from a common glasshouse and standardised to a common size before assessing in rolled germination paper at 12 and 20 °C for seedling growth. Differences in genotype means were large and heritabilities high (h2 = 0.55-0.93) indicating strong and repeatable genotypic differences for most root traits. Seminal roots 1 to 3 were produced on all seedlings, whereas growth of seminal roots 4, 5 and 6 was associated with differences in embryo size. Increases in seminal root number from 4 to 6 per plant were strongly, genetically correlated with increases in total seminal length (rg = 0.84, < 0.01). Multivariate analysis confirmed initiation and growth of seminal roots 1, 2 and 3, and of roots 4, 5 and 6 behaved as genetically independent (rPg = 0.15 ns) cohorts. Tails representing extremes in seedling root length and number were associated with significant differences in grain yield of up to 35% in droughted field environments but were not different in irrigated environments. Increases in grain yield were linked to greater lengths of seminal roots 4, 5 and 6 and were largely independent of plant height or development. This is the first report on the genetic relationship of seedling root architecture and embryo size, and potential in selection of seminal root size for accessing deep-soil moisture in droughted environments.
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Affiliation(s)
- G J Rebetzke
- CSIRO Agriculture and Food, PO Box 1700, Canberra, ACT, 2601, Australia.
| | - H Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - C H Ingvordsen
- Australian Grain Technologies, PO Box 341, Roseworthy, SA, 5371, Australia
| | - A G Condon
- CSIRO Agriculture and Food, PO Box 1700, Canberra, ACT, 2601, Australia
| | - S M Rich
- CSIRO Agriculture and Food, 147 Underwood Av, Floreat, WA, 6014, Australia
| | - M H Ellis
- Formerly CSIRO, Now 8 Avenue Piaton, Villeurbanne, France
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