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Juurakko CL, Bredow M, diCenzo GC, Walker VK. Cold-inducible promoter-driven knockdown of Brachypodium antifreeze proteins confers freezing and phytopathogen susceptibility. PLANT DIRECT 2022; 6:e449. [PMID: 36172079 PMCID: PMC9467863 DOI: 10.1002/pld3.449] [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: 04/30/2022] [Revised: 08/12/2022] [Accepted: 08/29/2022] [Indexed: 06/16/2023]
Abstract
The model forage crop, Brachypodium distachyon, has a cluster of ice recrystallization inhibition (BdIRI) genes, which encode antifreeze proteins that function by adsorbing to ice crystals and inhibiting their growth. The genes were targeted for knockdown using a cold-induced promoter from rice (prOsMYB1R35) to drive miRNA. The transgenic lines showed no apparent pleiotropic developmental defects but had reduced antifreeze activity as assessed by assays for ice-recrystallization inhibition, thermal hysteresis, electrolyte leakage, and leaf infrared thermography. Strikingly, the number of cold-acclimated transgenic plants that survived freezing at -8°C was reduced by half or killed entirely, depending on the line, compared with cold-acclimated wild type plants. In addition, more leaf damage was apparent at subzero temperatures in knockdowns after infection with an ice nucleating pathogen, Pseudomonas syringae. Although antifreeze proteins have been studied for almost 60 years, this is the first unequivocal demonstration of their function by knockdown in any organism, and their dual contribution to freeze protection as well as pathogen susceptibility, independent of obvious developmental defects. These proteins are thus of potential interest in a wide range of biotechnological applications from cryopreservation, to frozen product additives, to the engineering of transgenic crops with enhanced pathogen and freezing tolerance.
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Affiliation(s)
| | - Melissa Bredow
- Department of BiologyQueen's UniversityKingstonOntarioCanada
- Present address:
Department of Plant Pathology and MicrobiologyIowa State UniversityAmesIowaUSA
| | | | - Virginia K. Walker
- Department of BiologyQueen's UniversityKingstonOntarioCanada
- School of Environmental StudiesQueen's UniversityKingstonOntarioCanada
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Bahrani H, Båga M, Larsen J, Graf RJ, Laroche A, Chibbar RN. The Relationships between Plant Developmental Traits and Winter Field Survival in Rye (Secale cereale L.). PLANTS 2021; 10:plants10112455. [PMID: 34834817 PMCID: PMC8625450 DOI: 10.3390/plants10112455] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 11/09/2021] [Accepted: 11/09/2021] [Indexed: 11/17/2022]
Abstract
Overwintering cereals accumulate low temperature tolerance (LTT) during cold acclimation in the autumn. Simultaneously, the plants adjust to the colder season by making developmental changes at the shoot apical meristem. These processes lead to higher winter hardiness in winter rye varieties (Secale cereale L.) adapted to Northern latitudes as compared to other cereal crops. To dissect the winter-hardiness trait in rye, a panel of 96 genotypes of different origins and growth habits was assessed for winter field survival (WFS), LTT, and six developmental traits. Best Linear Unbiased Estimates for WFS determined from five field trials correlated strongly with LTT (r = 0.90, p < 0.001); thus, cold acclimation efficiency was the major contributor to WFS. WFS also correlated strongly (p < 0.001) with final leaf number (r = 0.80), prostrate growth habit (r = 0.61), plant height (r = 0.34), but showed weaker associations with top internode length (r = 0.30, p < 0.01) and days to anthesis (r = 0.25, p < 0.05). The heritability estimates (h2) for WFS-associated traits ranged from 0.45 (prostrate growth habit) to 0.81 (final leaf number) and were overall higher than for WFS (h2 = 0.48). All developmental traits associated with WFS and LTT are postulated to be regulated by phytohormone levels at shoot apical meristem.
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Affiliation(s)
- Hirbod Bahrani
- Department of Plant Sciences, University of Saskatchewan, Saskatoon, SK S7N 5A8, Canada; (H.B.); (M.B.)
| | - Monica Båga
- Department of Plant Sciences, University of Saskatchewan, Saskatoon, SK S7N 5A8, Canada; (H.B.); (M.B.)
| | - Jamie Larsen
- Harrow Research and Development Centre, Agriculture and Agri-Food Canada, Harrow, ON N0R 1G0, Canada;
| | - Robert J. Graf
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, Lethbridge, AB T1J 4B1, Canada; (R.J.G.); (A.L.)
| | - Andre Laroche
- Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, Lethbridge, AB T1J 4B1, Canada; (R.J.G.); (A.L.)
| | - Ravindra N. Chibbar
- Department of Plant Sciences, University of Saskatchewan, Saskatoon, SK S7N 5A8, Canada; (H.B.); (M.B.)
- Correspondence:
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Juurakko CL, Bredow M, Nakayama T, Imai H, Kawamura Y, diCenzo GC, Uemura M, Walker VK. The Brachypodium distachyon cold-acclimated plasma membrane proteome is primed for stress resistance. G3-GENES GENOMES GENETICS 2021; 11:6321953. [PMID: 34544140 PMCID: PMC8661430 DOI: 10.1093/g3journal/jkab198] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 06/04/2021] [Indexed: 11/25/2022]
Abstract
In order to survive subzero temperatures, some plants undergo cold acclimation (CA) where low, nonfreezing temperatures, and/or shortened day lengths allow cold-hardening and survival during subsequent freeze events. Central to this response is the plasma membrane (PM), where low temperature is perceived and cellular homeostasis must be preserved by maintaining membrane integrity. Here, we present the first PM proteome of cold-acclimated Brachypodium distachyon, a model species for the study of monocot crops. A time-course experiment investigated CA-induced changes in the proteome following two-phase partitioning PM enrichment and label-free quantification by nano-liquid chromatography-mass spectrophotometry. Two days of CA were sufficient for membrane protection as well as an initial increase in sugar levels and coincided with a significant change in the abundance of 154 proteins. Prolonged CA resulted in further increases in soluble sugars and abundance changes in more than 680 proteins, suggesting both a necessary early response to low-temperature treatment, as well as a sustained CA response elicited over several days. A meta-analysis revealed that the identified PM proteins have known roles in low-temperature tolerance, metabolism, transport, and pathogen defense as well as drought, osmotic stress, and salt resistance suggesting crosstalk between stress responses, such that CA may prime plants for other abiotic and biotic stresses. The PM proteins identified here present keys to an understanding of cold tolerance in monocot crops and the hope of addressing economic losses associated with modern climate-mediated increases in frost events.
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Affiliation(s)
- Collin L Juurakko
- Department of Biology, Queen's University, Kingston, ON K7L 3N6, Canada
| | - Melissa Bredow
- Department of Biology, Queen's University, Kingston, ON K7L 3N6, Canada
| | - Takato Nakayama
- Department of Plant-Bioscience, Faculty of Agriculture, Iwate University, Morioka, Iwate 020-8550, Japan
| | - Hiroyuki Imai
- United Graduate School of Agricultural Sciences, Iwate University, Morioka, Iwate 020-8550, Japan
| | - Yukio Kawamura
- Department of Plant-Bioscience, Faculty of Agriculture, Iwate University, Morioka, Iwate 020-8550, Japan.,United Graduate School of Agricultural Sciences, Iwate University, Morioka, Iwate 020-8550, Japan
| | - George C diCenzo
- Department of Biology, Queen's University, Kingston, ON K7L 3N6, Canada
| | - Matsuo Uemura
- Department of Plant-Bioscience, Faculty of Agriculture, Iwate University, Morioka, Iwate 020-8550, Japan.,United Graduate School of Agricultural Sciences, Iwate University, Morioka, Iwate 020-8550, Japan
| | - Virginia K Walker
- Department of Biology, Queen's University, Kingston, ON K7L 3N6, Canada.,Department of Biomedical and Molecular Sciences, School of Environmental Studies, Queen's University, Kingston, ON K7L 3N6, Canada
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Mayer BF, Charron J. Transcriptional memories mediate the plasticity of cold stress responses to enable morphological acclimation in Brachypodium distachyon. THE NEW PHYTOLOGIST 2021; 229:1615-1634. [PMID: 32966623 PMCID: PMC7820978 DOI: 10.1111/nph.16945] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 09/04/2020] [Indexed: 05/03/2023]
Abstract
Plants that successfully acclimate to stress can resume growth under stressful conditions. The grass Brachypodium distachyon can grow a cold-adaptive morphology during cold acclimation. Studies on transcriptional memory (TM) have revealed that plants can be primed for stress by adjusting their transcriptional responses, but the function of TM in stress acclimation is not well understood. We investigated the function of TM during cold acclimation in B. distachyon. Quantitative polymerase chain reaction (qPCR), RNA-seq and chromatin immunoprecipitation qPCR analyses were performed on plants exposed to repeated episodes of cold to characterize the presence and stability of TM during the stress and growth responses of cold acclimation. Transcriptional memory mainly dampened stress responses as growth resumed and as B. distachyon became habituated to cold stress. Although permanent on vernalization gene VRN1, TMs were short-term and reversible on cold-stress genes. Growing under cold conditions also coincided with the acquisition of new and targeted cold-induced transcriptional responses. Overall, TM provided plasticity to cold stress responses during cold acclimation in B. distachyon, leading to stress habituation, acquired stress responses, and resumed growth. Our study shows that chromatin-associated TMs are involved in tuning plant responses to environmental change and, as such, regulate both stress and developmental components that characterize cold-climate adaptation in B. distachyon.
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Affiliation(s)
- Boris F. Mayer
- Department of Plant ScienceMcGill University21, 111 LakeshoreSainte‐Anne‐de‐BellevueCanada
| | - Jean‐Benoit Charron
- Department of Plant ScienceMcGill University21, 111 LakeshoreSainte‐Anne‐de‐BellevueCanada
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