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Liu J, Li L, Xiong Z, Robert CAM, Li B, He S, Chen W, Bi J, Zhai G, Guo S, Zhang H, Li J, Zhou S, Zhang X, Song CP. Trade-offs between the accumulation of cuticular wax and jasmonic acid-mediated herbivory resistance in maize. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2024; 66:143-159. [PMID: 37975264 DOI: 10.1111/jipb.13586] [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: 07/19/2023] [Accepted: 11/14/2023] [Indexed: 11/19/2023]
Abstract
Plants have evolved complex physical and chemical defense systems that allow them to withstand herbivory infestation. Composed of a complex mixture of very-long-chain fatty acids (VLCFAs) and their derivatives, cuticular wax constitutes the first physical line of defense against herbivores. Here, we report the function of Glossy 8 (ZmGL8), which encodes a 3-ketoacyl reductase belonging to the fatty acid elongase complex, in orchestrating wax production and jasmonic acid (JA)-mediated defenses against herbivores in maize (Zea mays). The mutation of GL8 enhanced chemical defenses by activating the JA-dependent pathway. We observed a trade-off between wax accumulation and JA levels across maize glossy mutants and 24 globally collected maize inbred lines. In addition, we demonstrated that mutants defective in cuticular wax biosynthesis in Arabidopsis thaliana and maize exhibit enhanced chemical defenses. Comprehensive transcriptomic and lipidomic analyses indicated that the gl8 mutant confers chemical resistance to herbivores by remodeling VLCFA-related lipid metabolism and subsequent JA biosynthesis and signaling. These results suggest that VLCFA-related lipid metabolism has a critical role in regulating the trade-offs between cuticular wax and JA-mediated chemical defenses.
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Affiliation(s)
- Jiong Liu
- School of Life Sciences, Henan University, Kaifeng, 475004, China
- State Key Laboratory of Crop Stress Adaptation and Improvement, Henan University, Kaifeng, 475004, China
| | - Lu Li
- School of Life Sciences, Henan University, Kaifeng, 475004, China
- State Key Laboratory of Cotton Bio-Breeding and Integrated Utilization, Henan University, Kaifeng, 475004, China
| | - Zhilong Xiong
- School of Life Sciences, Henan University, Kaifeng, 475004, China
- State Key Laboratory of Cotton Bio-Breeding and Integrated Utilization, Henan University, Kaifeng, 475004, China
- Sanya Institute of Henan University, Sanya, 572025, China
| | | | - Baozhu Li
- School of Life Sciences, Henan University, Kaifeng, 475004, China
- State Key Laboratory of Crop Stress Adaptation and Improvement, Henan University, Kaifeng, 475004, China
- Sanya Institute of Henan University, Sanya, 572025, China
| | - Shan He
- School of Life Sciences, Henan University, Kaifeng, 475004, China
- State Key Laboratory of Cotton Bio-Breeding and Integrated Utilization, Henan University, Kaifeng, 475004, China
| | - Wenjie Chen
- School of Life Sciences, Henan University, Kaifeng, 475004, China
- State Key Laboratory of Cotton Bio-Breeding and Integrated Utilization, Henan University, Kaifeng, 475004, China
| | - Jiasheng Bi
- School of Life Sciences, Henan University, Kaifeng, 475004, China
- State Key Laboratory of Cotton Bio-Breeding and Integrated Utilization, Henan University, Kaifeng, 475004, China
| | - Guanqing Zhai
- School of Life Sciences, Henan University, Kaifeng, 475004, China
- State Key Laboratory of Cotton Bio-Breeding and Integrated Utilization, Henan University, Kaifeng, 475004, China
- Sanya Institute of Henan University, Sanya, 572025, China
| | - Siyi Guo
- School of Life Sciences, Henan University, Kaifeng, 475004, China
- State Key Laboratory of Crop Stress Adaptation and Improvement, Henan University, Kaifeng, 475004, China
- Sanya Institute of Henan University, Sanya, 572025, China
| | - Hui Zhang
- School of Life Sciences, Henan University, Kaifeng, 475004, China
- State Key Laboratory of Crop Stress Adaptation and Improvement, Henan University, Kaifeng, 475004, China
| | - Jieping Li
- School of Life Sciences, Henan University, Kaifeng, 475004, China
- State Key Laboratory of Crop Stress Adaptation and Improvement, Henan University, Kaifeng, 475004, China
| | - Shutang Zhou
- School of Life Sciences, Henan University, Kaifeng, 475004, China
- State Key Laboratory of Cotton Bio-Breeding and Integrated Utilization, Henan University, Kaifeng, 475004, China
- Sanya Institute of Henan University, Sanya, 572025, China
| | - Xi Zhang
- School of Life Sciences, Henan University, Kaifeng, 475004, China
- State Key Laboratory of Cotton Bio-Breeding and Integrated Utilization, Henan University, Kaifeng, 475004, China
- Sanya Institute of Henan University, Sanya, 572025, China
| | - Chun-Peng Song
- School of Life Sciences, Henan University, Kaifeng, 475004, China
- State Key Laboratory of Crop Stress Adaptation and Improvement, Henan University, Kaifeng, 475004, China
- Sanya Institute of Henan University, Sanya, 572025, China
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Chakraborty S, Gershenzon J, Schuster S. Selection pressure by specialist and generalist insect herbivores leads to optimal constitutive plant defense. A mathematical model. Ecol Evol 2023; 13:e10763. [PMID: 38058520 PMCID: PMC10695761 DOI: 10.1002/ece3.10763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 11/06/2023] [Accepted: 11/09/2023] [Indexed: 12/08/2023] Open
Abstract
Brassicaceae plants have the glucosinolate-myrosinase defense system, jointly active against herbivory. However, constitutive glucosinolate (GLS) defense is observed to occur at levels that do not deter all insects from feeding. That prompts the question of why Brassicaceae plants have not evolved a higher constitutive defense. The answer may lie in the contrasting relationship between plant defense and host plant preference of specialist and generalist herbivores. GLS content increases a plant's susceptibility to specialist insects. In contrast, generalists are deterred by the plant GLSs. Although GLSs can attract the natural enemies (predators and parasitoids) of these herbivores, enemies can reduce herbivore pressure to some extent only. So, plants can be overrun by specialists if GLS content is too high, whereas generalists can invade the plants if it is too low. Therefore, an optimal constitutive plant defense can minimize the overall herbivore pressure. To explain the optimal defense theoretically, we model the contrasting host selection behavior of insect herbivores and the emergence of their natural enemies by non-autonomous ordinary differential equations, where the independent variable is the plant GLS concentration. From the model, we quantify the optimal amount of GLSs, which minimizes total herbivore (specialists and generalists) pressure. That quite successfully explains the evolution of constitutive defense in plants from the perspective of optimality theory.
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Affiliation(s)
- Suman Chakraborty
- Department of Bioinformatics, Matthias Schleiden InstituteFriedrich Schiller University JenaJenaGermany
- International Max Planck Research School “Chemical Communication in Ecological Systems”JenaGermany
| | - Jonathan Gershenzon
- Department of BiochemistryMax Planck Institute for Chemical EcologyJenaGermany
| | - Stefan Schuster
- Department of Bioinformatics, Matthias Schleiden InstituteFriedrich Schiller University JenaJenaGermany
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MacTavish R, Anderson JT. Water and nutrient availability exert selection on reproductive phenology. AMERICAN JOURNAL OF BOTANY 2022; 109:1702-1716. [PMID: 36031862 DOI: 10.1002/ajb2.16057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 07/22/2022] [Accepted: 07/22/2022] [Indexed: 06/15/2023]
Abstract
PREMISE Global change has changed resource availability to plants, which could shift the adaptive landscape. We hypothesize that novel water and nutrient availability combinations alter patterns of natural selection on reproductive phenology in Boechera stricta (Brassicaceae) and influence the evolution of local adaptation. METHODS We conducted a multifactorial greenhouse study using 35 accessions of B. stricta sourced from a broad elevational gradient in the Rocky Mountains. We exposed full siblings to three soil water and two nutrient availability treatment levels, reflecting current and projected future conditions. In addition, we quantified fitness (seed count) and four phenological traits: the timing of first flowering, the duration of flowering, and height and leaf number at flowering. RESULTS Selection favored early flowering and longer duration of flowering, and the genetic correlation between these traits accorded with the direction of selection. In most treatments, we found selection for increased height, but selection on leaf number depended on water availability, with selection favoring more leaves in well-watered conditions and fewer leaves under severe drought. Low-elevation genotypes had the greatest fitness under drought stress, consistent with local adaptation. CONCLUSIONS We found evidence of strong selection on these heritable traits. Furthermore, the direction and strength of selection on size at flowering depended on the variable measured (height vs. leaf number). Finally, selection often favored both early flowering and a longer duration of flowering. Selection on these two components of phenology can be difficult to disentangle due to tight genetic correlations.
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Affiliation(s)
- Rachel MacTavish
- Department of Genetics and Odum School of Ecology, University of Georgia, Athens, GA, 30602, USA
| | - Jill T Anderson
- Department of Genetics and Odum School of Ecology, University of Georgia, Athens, GA, 30602, USA
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FytoSol, a Promising Plant Defense Elicitor, Controls Early Blight (Alternaria solani) Disease in the Tomato by Inducing Host Resistance-Associated Gene Expression. HORTICULTURAE 2022. [DOI: 10.3390/horticulturae8060484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Early blight (EB), caused by the necrotrophic pathogen Alternaria solani, is one of the most common and destructive diseases in the tomato (Solanum lycopersicum L.). The use of fungicides is a prominent tactic used to control EB; however, their undesirable effects on the environment and human health, as well as involvement in the development of resistant strains, have driven researchers to search for new alternatives. Plant defense elicitors are exogenous defense-triggering molecules that induce a plant’s defense system associated with extensive transcriptional- and metabolic reprogramming of the genome and do not cause direct toxicity to phytopathogens. Moreover, 2,6-dichloroisonicotinic acid (INA) was an early-identified and strong plant defense elicitor to various phytopathogens. Recently, the combination of chitosan oligomers and pectin-derived oligogalacturonides that can mimic the induction of plants by a pathogen or damaged-derived molecules (PAMP and DAMP) were characterized as defense elicitors, named FytoSol. In this study, the preventive roles of these two defense elicitors—FytoSol and INA—against EB disease and its molecular basis, were explored. According to the results, FytoSol significantly reduced disease severity by an average of 30% for almost one month with an AUDPC value of 399 compared to the control, which had an AUDPC value of 546. On the contrary, INA did not provide any protection against EB. Gene expression analyses of these two distinct plant defense elicitors indicated that the expression patterns of several SA-, JA-, or ET-pathway-related genes (Pti4, TPK1b, Pto kinase, TomloxD, PRB1-2, SABP2, WRKY33b, WRKY70, PR-5, and PR3) were induced by defense elicitors differently. FytoSol extensively upregulated gene expressions of PR3, downregulated the SA-related defense pathway, and provided remarkable protection against the necrotrophic pathogen Alternaria solani. On the contrary, INA mostly induced genes related to biotrophic and/or hemibiotrophic pathogen protection. Our results indicate that FytoSol is a promising plant defense elicitor against EB and the modes of action of the elicitors are important to characterize their effects against pathogens. Further research may extend the use of defense elicitors as alternatives to pesticides in agriculture.
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Panda S, Kazachkova Y, Aharoni A. Catch-22 in specialized metabolism: balancing defense and growth. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:6027-6041. [PMID: 34293097 DOI: 10.1093/jxb/erab348] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 07/21/2021] [Indexed: 05/25/2023]
Abstract
Plants are unsurpassed biochemists that synthesize a plethora of molecules in response to an ever-changing environment. The majority of these molecules, considered as specialized metabolites, effectively protect the plant against pathogens and herbivores. However, this defense most probably comes at a great expense, leading to reduction of growth (known as the 'growth-defense trade-off'). Plants employ several strategies to reduce the high metabolic costs associated with chemical defense. Production of specialized metabolites is tightly regulated by a network of transcription factors facilitating its fine-tuning in time and space. Multifunctionality of specialized metabolites-their effective recycling system by re-using carbon, nitrogen, and sulfur, thus re-introducing them back to the primary metabolite pool-allows further cost reduction. Spatial separation of biosynthetic enzymes and their substrates, and sequestration of potentially toxic substances and conversion to less toxic metabolite forms are the plant's solutions to avoid the detrimental effects of metabolites they produce as well as to reduce production costs. Constant fitness pressure from herbivores, pathogens, and abiotic stressors leads to honing of specialized metabolite biosynthesis reactions to be timely, efficient, and metabolically cost-effective. In this review, we assess the costs of production of specialized metabolites for chemical defense and the different plant mechanisms to reduce the cost of such metabolic activity in terms of self-toxicity and growth.
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Affiliation(s)
- Sayantan Panda
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
- Gilat Research Center, Agricultural Research Organization, Negev, Israel
| | - Yana Kazachkova
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Asaph Aharoni
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
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MacTavish R, Anderson JT. Resource availability alters fitness trade-offs: implications for evolution in stressful environments. AMERICAN JOURNAL OF BOTANY 2020; 107:308-318. [PMID: 31943133 DOI: 10.1002/ajb2.1417] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 09/16/2019] [Indexed: 05/22/2023]
Abstract
PREMISE Industrialization and human activities have elevated temperatures and caused novel precipitation patterns, altering soil moisture and nutrient availability. Predicting evolutionary responses to climate change requires information on the agents of selection that drive local adaptation and influence resource acquisition and allocation. Here, we examined the contribution of nutrient and drought stress to local adaptation, and we tested whether trade-offs across fitness components constrain or facilitate adaptation under resource stress. METHODS We exposed 35 families of Boechera stricta (Brassicaceae) to three levels of water and two levels of nutrient supply in a factorial design in the greenhouse. We sourced maternal families from a broad elevational gradient (2499-3530 m a.s.l.), representing disparate soil moisture and nutrient availability. RESULTS Concordant with local adaptation, maternal families from arid, low-elevation populations had enhanced fecundity under severe drought over those from more mesic, high-elevation sites. Furthermore, fitness trade-offs between growth and reproductive success depended on the environmental context. Under high, but not low, nutrient levels, we found a negative phenotypic relationship between the probability of reproduction and growth rate. Similarly, a negative phenotypic association only emerged between fecundity and growth under severe drought stress, not the benign water treatment levels, indicating that stressful resource environments alter the direction of trait correlations. Genetic covariances were broadly concordant with these phenotypic patterns. CONCLUSIONS Despite high heritabilities in all fitness components across treatments, trade-offs between growth and reproduction could constrain adaptation to increasing drought stress and novel nutrient levels.
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Affiliation(s)
- Rachel MacTavish
- Department of Genetics and Odum School of Ecology, University of Georgia, Athens, GA, USA
| | - Jill T Anderson
- Department of Genetics and Odum School of Ecology, University of Georgia, Athens, GA, USA
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War AR, Buhroo AA, Hussain B, Ahmad T, Nair RM, Sharma HC. Plant Defense and Insect Adaptation with Reference to Secondary Metabolites. REFERENCE SERIES IN PHYTOCHEMISTRY 2020. [DOI: 10.1007/978-3-319-96397-6_60] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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8
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Olsen J, Singh Gill G, Haugen R, Matzner SL, Alsdurf J, Siemens DH. Evolutionary constraint on low elevation range expansion: Defense-abiotic stress-tolerance trade-off in crosses of the ecological model Boechera stricta. Ecol Evol 2019; 9:11532-11544. [PMID: 31695866 PMCID: PMC6822064 DOI: 10.1002/ece3.5499] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 09/08/2018] [Accepted: 09/13/2018] [Indexed: 01/27/2023] Open
Abstract
Most transplant experiments across species geographic range boundaries indicate that adaptation to stressful environments outside the range is often constrained. However, the mechanisms of these constraints remain poorly understood. We used extended generation crosses from diverged high and low elevation populations. In experiments across low elevation range boundaries, there was selection on the parental lines for abiotic stress-tolerance and resistance to herbivores. However, in support of a defense-tolerance trade-off, extended generation crosses showed nonindependent segregation of these traits in the laboratory across a drought-stress gradient and in the field across the low elevation range boundary. Genotypic variation in a marker from a region of the genome containing a candidate gene (MYC2) was associated with change in the genetic trade-off. Thus, using crosses and forward genetics, we found experimental genetic and molecular evidence for a pleiotropic trade-off that could constrain the evolution of range expansion.
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Affiliation(s)
- Jason Olsen
- Integrative Genomics ProgramBlack Hills State UniversitySpearfishSDUSA
- Present address:
500 W Fort Street 111RBoiseID83702USA
| | - Gunbharpur Singh Gill
- Integrative Genomics ProgramBlack Hills State UniversitySpearfishSDUSA
- Present address:
Department of BiologyUtah State UniversityLoganUTUSA
| | - Riston Haugen
- Integrative Genomics ProgramBlack Hills State UniversitySpearfishSDUSA
| | | | - Jake Alsdurf
- Integrative Genomics ProgramBlack Hills State UniversitySpearfishSDUSA
- Present address:
Division of BiologyKansas State UniversityManhattanKSUSA
| | - David H. Siemens
- Integrative Genomics ProgramBlack Hills State UniversitySpearfishSDUSA
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Siemens DH, Haugen R. Plant chemical defense allocation constrains evolution of tolerance to community change across a range boundary. Ecol Evol 2013; 3:4339-47. [PMID: 24340176 PMCID: PMC3856735 DOI: 10.1002/ece3.657] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 05/24/2013] [Accepted: 05/31/2013] [Indexed: 11/07/2022] Open
Abstract
Because transplant experiments show that performance usually decreases across species range boundaries, some range limits might develop from factors and processes that prevent adaptation to stressful environments. Here, we determined whether an ecological cost of plant defense involving stress associated with changes in the local plant community may contribute to range limit development in the upland mustard species Boechera stricta. In a common garden experiment of 499 B. stricta plants, performance decreased and a multivariate axis of community structure increased across the boundary, indicating increased stress associated with the community change. There was also significant genetic variation (evolutionary potential) among marker-inferred inbred lines of B. stricta for tolerance to the stress; however, lines with high basal levels of glucosinolate toxins had lower tolerance to the change in community structure. We suggest that defense allocation, which is also needed across the range, may impede adaptation to the stress associated with the community change and thus contribute to range limit development.
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Affiliation(s)
- David H Siemens
- Biology, Integrative Genomics Program, Black Hills State University Spearfish, South Dakota, 57799
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Neilson EH, Goodger JQD, Woodrow IE, Møller BL. Plant chemical defense: at what cost? TRENDS IN PLANT SCIENCE 2013; 18:250-8. [PMID: 23415056 DOI: 10.1016/j.tplants.2013.01.001] [Citation(s) in RCA: 183] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 12/20/2012] [Accepted: 01/04/2013] [Indexed: 05/18/2023]
Abstract
Plants are sessile organisms and dependent on deployment of secondary metabolites for their response to biotic and abiotic challenges. A trade-off is envisioned between resources allocated to growth, development, and reproduction and to the biosynthesis, storage, and maintenance of secondary metabolites. However, increasing evidence suggests that secondary metabolites serve auxiliary roles, including functions associated with primary metabolism. In this opinion article, we examine how the costs of plant chemical defense can be offset by multifunctional biosynthesis and the optimization of primary metabolism. These additional benefits may negate the trade-off between primary and secondary metabolism, and provide plants with an innate plasticity required for growth, development, and interactions with their environment.
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Argueso CT, Ferreira FJ, Epple P, To JPC, Hutchison CE, Schaller GE, Dangl JL, Kieber JJ. Two-component elements mediate interactions between cytokinin and salicylic acid in plant immunity. PLoS Genet 2012; 8:e1002448. [PMID: 22291601 PMCID: PMC3266875 DOI: 10.1371/journal.pgen.1002448] [Citation(s) in RCA: 145] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Accepted: 11/16/2011] [Indexed: 11/19/2022] Open
Abstract
Recent studies have revealed an important role for hormones in plant immunity. We are now beginning to understand the contribution of crosstalk among different hormone signaling networks to the outcome of plant–pathogen interactions. Cytokinins are plant hormones that regulate development and responses to the environment. Cytokinin signaling involves a phosphorelay circuitry similar to two-component systems used by bacteria and fungi to perceive and react to various environmental stimuli. In this study, we asked whether cytokinin and components of cytokinin signaling contribute to plant immunity. We demonstrate that cytokinin levels in Arabidopsis are important in determining the amplitude of immune responses, ultimately influencing the outcome of plant–pathogen interactions. We show that high concentrations of cytokinin lead to increased defense responses to a virulent oomycete pathogen, through a process that is dependent on salicylic acid (SA) accumulation and activation of defense gene expression. Surprisingly, treatment with lower concentrations of cytokinin results in increased susceptibility. These functions for cytokinin in plant immunity require a host phosphorelay system and are mediated in part by type-A response regulators, which act as negative regulators of basal and pathogen-induced SA–dependent gene expression. Our results support a model in which cytokinin up-regulates plant immunity via an elevation of SA–dependent defense responses and in which SA in turn feedback-inhibits cytokinin signaling. The crosstalk between cytokinin and SA signaling networks may help plants fine-tune defense responses against pathogens. Plant hormones play an important role in many aspects of a plant's life cycle, from the regulation of development to responses to constantly changing environmental conditions. In the past decade, the importance of hormones in plant immunity against a variety of pathogens has been uncovered. In this manuscript, we demonstrate that in the model plant species Arabidopsis thaliana components of the signaling system of the plant hormone cytokinin also mediate plant immunity. We demonstrate that this involves the type-A class of Arabidopsis response regulators in a process that occurs downstream of the plant defense hormone salicylic acid and involves a host two-component phosphorelay. Moreover, we show that the levels of cytokinin are important in determining the amplitude of plant immunity, ultimately influencing the outcome of plant–pathogen interactions. Finally, our results indicate that salicylic acid negatively regulates cytokinin signaling, which may serve to fine-tune the effects of cytokinin in plant immunity. Given the high energy costs of defense responses and the role of cytokinins in carbon partitioning and energy allocation, we hypothesize that the mechanisms uncovered here may help regulate the levels of energy that can be allocated into defense responses, an important aspect in the biology of plants.
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Affiliation(s)
- Cristiana T. Argueso
- Biology Department, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Fernando J. Ferreira
- Biology Department, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Petra Epple
- Biology Department, University of North Carolina, Chapel Hill, North Carolina, United States of America
- Howard Hughes Medical Institute, Chapel Hill, North Carolina, United States of America
| | - Jennifer P. C. To
- Biology Department, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Claire E. Hutchison
- Biology Department, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - G. Eric Schaller
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, United States of America
| | - Jeffery L. Dangl
- Biology Department, University of North Carolina, Chapel Hill, North Carolina, United States of America
- Howard Hughes Medical Institute, Chapel Hill, North Carolina, United States of America
| | - Joseph J. Kieber
- Biology Department, University of North Carolina, Chapel Hill, North Carolina, United States of America
- * E-mail:
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Siemens DH, Duvall-Jisha J, Jacobs J, Manthey J, Haugen R, Matzner S. Water deficiency induces evolutionary tradeoff between stress tolerance and chemical defense allocation that may help explain range limits in plants. OIKOS 2012. [DOI: 10.1111/j.1600-0706.2011.19944.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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13
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The Balance Between Resource Sequestration and Retention: A Challenge in Plant Science. GROWTH AND DEFENCE IN PLANTS 2012. [DOI: 10.1007/978-3-642-30645-7_1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Abstract
The selection and development of a study system for evolutionary and ecological functional genomics (EEFG) depend on a variety of factors. Here, we present the genus Boechera as an exemplary system with which to address ecological and evolutionary questions. Our focus on Boechera is based on several characteristics as follows: (i) native populations in undisturbed habitats where current environments reflect historical conditions over several thousand years; (ii) functional genomics benefitting from its close relationship to Arabidopsis thaliana; (iii) inbreeding tolerance enabling development of recombinant inbred lines, near-isogenic lines and positional cloning; (iv) interspecific crosses permitting mapping for genetic analysis of speciation; (v) apomixis (asexual reproduction by seeds) in a genetically tractable diploid; and (vi) broad geographic distribution in North America, permitting ecological genetics for a large research community. These characteristics, along with the current sequencing of three Boechera species by the Joint Genome Institute, position Boechera as a rapidly advancing system for EEFG studies.
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Affiliation(s)
- Catherine A Rushworth
- Department of Biology, Institute for Genome Sciences and Policy, Duke University, PO Box 90338, Durham, NC 27708, USA
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15
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Garbuzov M, Reidinger S, Hartley SE. Interactive effects of plant-available soil silicon and herbivory on competition between two grass species. ANNALS OF BOTANY 2011; 108:1355-63. [PMID: 21868406 PMCID: PMC3197457 DOI: 10.1093/aob/mcr230] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Accepted: 07/25/2011] [Indexed: 05/02/2023]
Abstract
BACKGROUND AND AIMS The herbivore defence system of true grasses (Poaceae) is predominantly based on silicon that is taken up from the soil and deposited in the leaves in the form of abrasive phytoliths. Silicon uptake mechanisms can be both passive and active, with the latter suggesting that there is an energetic cost to silicon uptake. This study assessed the effects of plant-available soil silicon and herbivory on the competitive interactions between the grasses Poa annua, a species that has previously been reported to accumulate only small amounts of silicon, and Lolium perenne, a high silicon accumulator. METHODS Plants were grown in mono- and mixed cultures under greenhouse conditions. Plant-available soil silicon levels were manipulated by adding silicon to the soil in the form of sodium silicate. Subsets of mixed culture pots were exposed to above-ground herbivory by desert locusts (Schistocerca gregaria). KEY RESULTS In the absence of herbivory, silicon addition increased biomass of P. annua but decreased biomass of L. perenne. Silicon addition increased foliar silicon concentrations of both grass species >4-fold. Under low soil-silicon availability the herbivores removed more leaf biomass from L. perenne than from P. annua, whereas under high silicon availability the reverse was true. Consequently, herbivory shifted the competitive balance between the two grass species, with the outcome depending on the availability of soil silicon. CONCLUSIONS It is concluded that a complex interplay between herbivore abundance, growth-defence trade-offs and the availability of soil silicon in the grasses' local environment affects the outcome of inter-specific competition, and so has the potential to impact on plant community structure.
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