51
|
Ahkami AH, Wang W, Wietsma TW, Winkler T, Lange I, Jansson C, Lange BM, McDowell NG. Metabolic shifts associated with drought-induced senescence in Brachypodium. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2019; 289:110278. [PMID: 31623774 DOI: 10.1016/j.plantsci.2019.110278] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Revised: 09/05/2019] [Accepted: 09/15/2019] [Indexed: 05/13/2023]
Abstract
The metabolic underpinnings of plant survival under severe drought-induced senescence conditions are poorly understood. In this study, we assessed the morphological, physiological and metabolic responses to sustained water deficit in Brachypodium distachyon, a model organism for research on temperate grasses. Relative to control plants, fresh biomass, leaf water potential, and chlorophyll levels decreased rapidly in plants grown under drought conditions, demonstrating an early onset of senescence. The leaf C/N ratio and protein content showed an increase in plants subjected to drought stress. The concentrations of several small molecule carbohydrates and amino acid-derived metabolites previously implicated in osmotic protection increased rapidly in plants experiencing water deficit. Malic acid, a low molecular weight organic acid with demonstrated roles in stomatal closure, also increased rapidly as a response to drought treatment. The concentrations of prenyl lipids, such as phytol and α-tocopherol, increased early during the drought treatment but then dropped dramatically. Surprisingly, continued changes in the quantities of metabolites were observed, even in samples harvested from visibly senesced plants. The data presented here provide insights into the processes underlying persistent metabolic activity during sustained water deficit and can aid in identifying mechanisms of drought tolerance in plants.
Collapse
Affiliation(s)
- Amir H Ahkami
- The Environmental Molecular Sciences Laboratory (EMSL), Pacific Northwest National Laboratory (PNNL), Richland, WA, USA.
| | - Wenzhi Wang
- Earth Systems Science Division, Pacific Northwest National Laboratory (PNNL), Richland, WA, USA
| | - Thomas W Wietsma
- The Environmental Molecular Sciences Laboratory (EMSL), Pacific Northwest National Laboratory (PNNL), Richland, WA, USA
| | - Tanya Winkler
- The Environmental Molecular Sciences Laboratory (EMSL), Pacific Northwest National Laboratory (PNNL), Richland, WA, USA
| | - Iris Lange
- Institute of Biological Chemistry and M.J. Murdock Metabolomics Laboratory, Washington State University, Pullman, WA, USA
| | - Christer Jansson
- The Environmental Molecular Sciences Laboratory (EMSL), Pacific Northwest National Laboratory (PNNL), Richland, WA, USA
| | - B Markus Lange
- Institute of Biological Chemistry and M.J. Murdock Metabolomics Laboratory, Washington State University, Pullman, WA, USA
| | - Nate G McDowell
- Earth Systems Science Division, Pacific Northwest National Laboratory (PNNL), Richland, WA, USA.
| |
Collapse
|
52
|
Abstract
Drought stress affects growth, morphological and biochemical properties in plants. To develop resistance and adapt to drought, plants need metabolic changes. Adaptations to stress involve changes to gene expression that activate metabolic processes that promote drought resistance and that may include biosynthesis and accumulation of specialized metabolites. Such adaptations in specialized metabolism may be important mechanisms leading to plant stress resistance and involve production of phenolics, flavonoids, terpenoid and nitrogen containing compounds that are species and genotype specific. Most plants having special metabolites to adapt to drought stress belong to different botanical families. C3, C4 and CAM plants, apply both morphological and metabolic mechanisms to adapt to drought as well as to accumulate specialized metabolites. Generally, medicinal plants increase their functional metabolites content, when exposed to drought stress. During drought stress, transcription factors and related pathways for biosynthesis of phenolics, flavonoids, anthocyanins as well as for stress jasmonate and abscisic acid stress hormones are activated.
Collapse
Affiliation(s)
- Seyed Morteza Zahedi
- Department of Horticultural Science, Faculty of Agriculture, University of Maragheh, Maragheh, Iran
| | - Mahdieh Karimi
- Department of Horticultural Sciences, Bu-Ali Sina University, Hamedan, Iran
| | | |
Collapse
|
53
|
Ding Y, Murphy KM, Poretsky E, Mafu S, Yang B, Char SN, Christensen SA, Saldivar E, Wu M, Wang Q, Ji L, Schmitz RJ, Kremling KA, Buckler ES, Shen Z, Briggs SP, Bohlmann J, Sher A, Castro-Falcon G, Hughes CC, Huffaker A, Zerbe P, Schmelz EA. Multiple genes recruited from hormone pathways partition maize diterpenoid defences. NATURE PLANTS 2019; 5:1043-1056. [PMID: 31527844 DOI: 10.1038/s41477-019-0509-6] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 07/26/2019] [Indexed: 06/10/2023]
Abstract
Duplication and divergence of primary pathway genes underlie the evolution of plant specialized metabolism; however, mechanisms partitioning parallel hormone and defence pathways are often speculative. For example, the primary pathway intermediate ent-kaurene is essential for gibberellin biosynthesis and is also a proposed precursor for maize antibiotics. By integrating transcriptional coregulation patterns, genome-wide association studies, combinatorial enzyme assays, proteomics and targeted mutant analyses, we show that maize kauralexin biosynthesis proceeds via the positional isomer ent-isokaurene formed by a diterpene synthase pair recruited from gibberellin metabolism. The oxygenation and subsequent desaturation of ent-isokaurene by three promiscuous cytochrome P450s and a new steroid 5α reductase indirectly yields predominant ent-kaurene-associated antibiotics required for Fusarium stalk rot resistance. The divergence and differential expression of pathway branches derived from multiple duplicated hormone-metabolic genes minimizes dysregulation of primary metabolism via the circuitous biosynthesis of ent-kaurene-related antibiotics without the production of growth hormone precursors during defence.
Collapse
Affiliation(s)
- Yezhang Ding
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA
| | - Katherine M Murphy
- Department of Plant Biology, University of California Davis, Davis, CA, USA
| | - Elly Poretsky
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA
| | - Sibongile Mafu
- Department of Plant Biology, University of California Davis, Davis, CA, USA
| | - Bing Yang
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, USA
| | - Si Nian Char
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA, USA
| | - Shawn A Christensen
- Chemistry Research Unit, Center for Medical, Agricultural, and Veterinary Entomology, US Department of Agriculture-Agricultural Research Service, Gainesville, FL, USA
| | - Evan Saldivar
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA
| | - Mengxi Wu
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA
| | - Qiang Wang
- Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Lexiang Ji
- Institute of Bioinformatics, University of Georgia, Athens, GA, USA
| | | | - Karl A Kremling
- Department of Plant Breeding and Genetics, Cornell University, Ithaca, NY, USA
| | - Edward S Buckler
- Department of Plant Breeding and Genetics, Cornell University, Ithaca, NY, USA
- Robert W. Holley Center for Agriculture and Health, US Department of Agriculture-Agricultural Research Service, Ithaca, NY, USA
| | - Zhouxin Shen
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA
| | - Steven P Briggs
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA
| | - Jörg Bohlmann
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - Andrew Sher
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA
| | - Gabriel Castro-Falcon
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Chambers C Hughes
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Alisa Huffaker
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA
| | - Philipp Zerbe
- Department of Plant Biology, University of California Davis, Davis, CA, USA
| | - Eric A Schmelz
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA.
| |
Collapse
|
54
|
Conserved bases for the initial cyclase in gibberellin biosynthesis: from bacteria to plants. Biochem J 2019; 476:2607-2621. [PMID: 31484677 DOI: 10.1042/bcj20190479] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 09/02/2019] [Accepted: 09/03/2019] [Indexed: 12/21/2022]
Abstract
All land plants contain at least one class II diterpene cyclase (DTC), which utilize an acid-base catalytic mechanism, for the requisite production of ent-copalyl diphosphate (ent-CPP) in gibberellin A (GA) phytohormone biosynthesis. These ent-CPP synthases (CPSs) are hypothesized to be derived from ancient bacterial origins and, in turn, to have given rise to the frequently observed additional DTCs utilized in more specialized plant metabolism. However, such gene duplication and neo-functionalization has occurred repeatedly, reducing the utility of phylogenetic analyses. Support for evolutionary scenarios can be found in more specific conservation of key enzymatic features. While DTCs generally utilize a DxDD motif as the catalytic acid, the identity of the catalytic base seems to vary depending, at least in part, on product outcome. The CPS from Arabidopsis thaliana has been found to utilize a histidine-asparagine dyad to ligate a water molecule that serves as the catalytic base, with alanine substitution leading to the production of 8β-hydroxy-ent-CPP. Here this dyad and effect of Ala substitution is shown to be specifically conserved in plant CPSs involved in GA biosynthesis, providing insight into plant DTC evolution and assisting functional assignment. Even more strikingly, while GA biosynthesis arose independently in plant-associated bacteria and fungi, the catalytic base dyad also is specifically found in the relevant bacterial, but not fungal, CPSs. This suggests functional conservation of CPSs from bacteria to plants, presumably reflecting an early role for derived diterpenoids in both plant development and plant-microbe interactions, eventually leading to GA, and a speculative evolutionary scenario is presented.
Collapse
|
55
|
Isah T. Stress and defense responses in plant secondary metabolites production. Biol Res 2019; 52:39. [PMID: 31358053 PMCID: PMC6661828 DOI: 10.1186/s40659-019-0246-3] [Citation(s) in RCA: 429] [Impact Index Per Article: 85.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 07/23/2019] [Indexed: 01/25/2023] Open
Abstract
In the growth condition(s) of plants, numerous secondary metabolites (SMs) are produced by them to serve variety of cellular functions essential for physiological processes, and recent increasing evidences have implicated stress and defense response signaling in their production. The type and concentration(s) of secondary molecule(s) produced by a plant are determined by the species, genotype, physiology, developmental stage and environmental factors during growth. This suggests the physiological adaptive responses employed by various plant taxonomic groups in coping with the stress and defensive stimuli. The past recent decades had witnessed renewed interest to study abiotic factors that influence secondary metabolism during in vitro and in vivo growth of plants. Application of molecular biology tools and techniques are facilitating understanding the signaling processes and pathways involved in the SMs production at subcellular, cellular, organ and whole plant systems during in vivo and in vitro growth, with application in metabolic engineering of biosynthetic pathways intermediates.
Collapse
Affiliation(s)
- Tasiu Isah
- Department of Botany, School of Chemical and Life Sciences, Hamdard University, New Delhi, 110 062, India.
| |
Collapse
|
56
|
Wang P, Marsh EL, Kruger G, Lorenz A, Schachtman DP. Belowground microbial communities respond to water deficit and are shaped by decades of maize hybrid breeding. Environ Microbiol 2019; 22:889-904. [DOI: 10.1111/1462-2920.14701] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 05/31/2019] [Accepted: 06/01/2019] [Indexed: 12/28/2022]
Affiliation(s)
- Peng Wang
- Department of Agronomy and Horticulture University of Nebraska Lincoln Lincoln NE 68588 USA
| | - Ellen L. Marsh
- Department of Agronomy and Horticulture University of Nebraska Lincoln Lincoln NE 68588 USA
| | - Greg Kruger
- Department of Agronomy and Horticulture University of Nebraska Lincoln Lincoln NE 68588 USA
| | - Aaron Lorenz
- Department of Agronomy and Plant Genetics University of Minnesota St. Paul MN 55108
| | - Daniel P. Schachtman
- Department of Agronomy and Horticulture University of Nebraska Lincoln Lincoln NE 68588 USA
| |
Collapse
|
57
|
Yuan J, Zhang W, Sun K, Tang MJ, Chen PX, Li X, Dai CC. Comparative Transcriptomics and Proteomics of Atractylodes lancea in Response to Endophytic Fungus Gilmaniella sp. AL12 Reveals Regulation in Plant Metabolism. Front Microbiol 2019; 10:1208. [PMID: 31191508 PMCID: PMC6546907 DOI: 10.3389/fmicb.2019.01208] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 05/13/2019] [Indexed: 12/16/2022] Open
Abstract
The fungal endophyte Gilmaniella sp. AL12 can establish a beneficial association with the medicinal herb Atractylodes lancea, and improve plant growth and sesquiterpenoids accumulation, which is termed “double promotion.” Our previous studies have uncovered the underling primary mechanism based on some physiological evidences. However, a global understanding of gene or protein expression regulation in primary and secondary metabolism and related regulatory processes is still lacking. In this study, we employed transcriptomics and proteomics of Gilmaniella sp. AL12-inoculated and Gilmaniella sp. AL12-free plants to study the impact of endophyte inoculation at the transcriptional and translational levels. The results showed that plant genes involved in plant immunity and signaling were suppressed, similar to the plant response caused by some endophytic fungi and biotroph pathogen. The downregulated plant immunity may contribute to plant-endophyte beneficial interaction. Additionally, genes and proteins related to primary metabolism (carbon fixation, carbohydrate metabolism, and energy metabolism) tended to be upregulated after Gilmaniella sp. AL12 inoculation, which was consistent with our previous physiological evidences. And, Gilmaniella sp. AL12 upregulated genes involved in terpene skeleton biosynthesis, and upregulated genes annotated as β-farnesene synthase and β-caryophyllene synthase. Based on the above results, we proposed that endophyte-plant associations may improve production (biomass and sesquiterpenoids accumulation) by increasing the source (photosynthesis), expanding the sink (glycolysis and tricarboxylic acid cycle), and enhancing the metabolic flux (sesquiterpenoids biosynthesis pathway) in A. lancea. And, this study will help to further clarify plant-endophyte interactions.
Collapse
Affiliation(s)
- Jie Yuan
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Wei Zhang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Kai Sun
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Meng-Jun Tang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Piao-Xue Chen
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Xia Li
- Jiangsu High Quality Rice Research and Development Center, Nanjing Branch of Chinese National Center Rice Improvement, Institute of Food Crops, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Chuan-Chao Dai
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Nanjing, China
| |
Collapse
|
58
|
Block AK, Vaughan MM, Schmelz EA, Christensen SA. Biosynthesis and function of terpenoid defense compounds in maize (Zea mays). PLANTA 2019; 249:21-30. [PMID: 30187155 DOI: 10.1007/s00425-018-2999-2] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 08/30/2018] [Indexed: 05/19/2023]
Abstract
Maize produces an array of herbivore-induced terpene volatiles that attract parasitoids to infested plants and a suite of pathogen-induced non-volatile terpenoids with antimicrobial activity to defend against pests. Plants rely on complex blends of constitutive and dynamically produced specialized metabolites to mediate beneficial ecological interactions and protect against biotic attack. One such class of metabolites are terpenoids, a large and structurally diverse class of molecules shown to play significant defensive and developmental roles in numerous plant species. Despite this, terpenoids have only recently been recognized as significant contributors to pest resistance in maize (Zea mays), a globally important agricultural crop. The current review details recent advances in our understanding of biochemical structures, pathways and functional roles of maize terpenoids. Dependent upon the lines examined, maize can harbor more than 30 terpene synthases, underlying the inherent diversity of maize terpene defense systems. Part of this defensive arsenal is the inducible production of volatile bouquets that include monoterpenes, homoterpenes and sesquiterpenes, which often function in indirect defense by enabling the attraction of parasitoids and predators. More recently discovered are a subset of sesquiterpene and diterpene hydrocarbon olefins modified by cytochrome P450s to produce non-volatile end-products such kauralexins, zealexins, dolabralexins and β-costic acid. These non-volatile terpenoid phytoalexins often provide effective defense against both microbial and insect pests via direct antimicrobial and anti-feedant activity. The diversity and promiscuity of maize terpene synthases, coupled with a variety of secondary modifications, results in elaborate defensive layers whose identities, regulation and precise functions are continuing to be elucidated.
Collapse
Affiliation(s)
- Anna K Block
- Center for Medical, Agricultural and Veterinary Entomology, U.S. Department of Agriculture-Agricultural Research Service, 1700 SW 23rd Drive, Gainesville, FL, 32608, USA.
| | - Martha M Vaughan
- National Center for Agricultural Utilization Research, U.S. Department of Agriculture-Agricultural Research Service, 1815 N. University Street, Peoria, IL, 61604, USA
| | - Eric A Schmelz
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, 92093, USA
| | - Shawn A Christensen
- Center for Medical, Agricultural and Veterinary Entomology, U.S. Department of Agriculture-Agricultural Research Service, 1700 SW 23rd Drive, Gainesville, FL, 32608, USA
| |
Collapse
|
59
|
Karunanithi PS, Zerbe P. Terpene Synthases as Metabolic Gatekeepers in the Evolution of Plant Terpenoid Chemical Diversity. FRONTIERS IN PLANT SCIENCE 2019; 10:1166. [PMID: 31632418 PMCID: PMC6779861 DOI: 10.3389/fpls.2019.01166] [Citation(s) in RCA: 133] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 08/26/2019] [Indexed: 05/18/2023]
Abstract
Terpenoids comprise tens of thousands of small molecule natural products that are widely distributed across all domains of life. Plants produce by far the largest array of terpenoids with various roles in development and chemical ecology. Driven by selective pressure to adapt to their specific ecological niche, individual species form only a fraction of the myriad plant terpenoids, typically representing unique metabolite blends. Terpene synthase (TPS) enzymes are the gatekeepers in generating terpenoid diversity by catalyzing complex carbocation-driven cyclization, rearrangement, and elimination reactions that enable the transformation of a few acyclic prenyl diphosphate substrates into a vast chemical library of hydrocarbon and, for a few enzymes, oxygenated terpene scaffolds. The seven currently defined clades (a-h) forming the plant TPS family evolved from ancestral triterpene synthase- and prenyl transferase-type enzymes through repeated events of gene duplication and subsequent loss, gain, or fusion of protein domains and further functional diversification. Lineage-specific expansion of these TPS clades led to variable family sizes that may range from a single TPS gene to families of more than 100 members that may further function as part of modular metabolic networks to maximize the number of possible products. Accompanying gene family expansion, the TPS family shows a profound functional plasticity, where minor active site alterations can dramatically impact product outcome, thus enabling the emergence of new functions with minimal investment in evolving new enzymes. This article reviews current knowledge on the functional diversity and molecular evolution of the plant TPS family that underlies the chemical diversity of bioactive terpenoids across the plant kingdom.
Collapse
Affiliation(s)
- Prema S Karunanithi
- Department of Plant Biology, University of California Davis, Davis, CA, United States
| | - Philipp Zerbe
- Department of Plant Biology, University of California Davis, Davis, CA, United States
| |
Collapse
|
60
|
Shen Q, Liu L, Wang L, Wang Q. Indole primes plant defense against necrotrophic fungal pathogen infection. PLoS One 2018; 13:e0207607. [PMID: 30444911 PMCID: PMC6239302 DOI: 10.1371/journal.pone.0207607] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Accepted: 11/02/2018] [Indexed: 12/20/2022] Open
Abstract
Indole is a volatile compound and emitted from plants challenged by insect infestation or mechanic wounding. It has been shown to prime defense against herbivory. Here we identified that indole induced defense either directly or as a priming agent against necrotrophic pathogens Fusarium graminearum and F. moniliforme in maize and Magnaporthe oryzae in rice. With indole pretreatment, smaller lesions were developed in infected leaves, as well as less fungal growth. Indole induced H2O2 burst in the priming stage like other priming substances did. Such priming relied on mitogen-activated protein kinase (MAPK) cascade, which potentially activated downstream defense signaling. In addition, indole priming resulted in earlier and stronger defensive gene expression upon pathogen infection, including genes of jasmonate and phytoalexin biosynthesis, pathogenesis-related proteins (PRs) and anti-oxidant enzymes, which enhanced plant resistance. Meanwhile, H2O2 was also identified as the priming agent to induce plant defense. Taken together, indole exhibited priming function not only against herbivory but also necrotrophic pathogens. The common emission of indole in plants suggests that it plays important roles as the universal and endogenous priming substance in plant defense.
Collapse
Affiliation(s)
- Qinqin Shen
- Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Lijun Liu
- Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Liping Wang
- Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Qiang Wang
- Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China
- * E-mail:
| |
Collapse
|
61
|
Beck JJ, Alborn HT, Block AK, Christensen SA, Hunter CT, Rering CC, Seidl-Adams I, Stuhl CJ, Torto B, Tumlinson JH. Interactions Among Plants, Insects, and Microbes: Elucidation of Inter-Organismal Chemical Communications in Agricultural Ecology. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:6663-6674. [PMID: 29895142 DOI: 10.1021/acs.jafc.8b01763] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The last 2 decades have witnessed a sustained increase in the study of plant-emitted volatiles and their role in plant-insect, plant-microbe, and plant-plant interactions. While each of these binary systems involves complex chemical and biochemical processes between two organisms, the progression of increasing complexity of a ternary system (i.e., plant-insect-microbe), and the study of a ternary system requires nontrivial planning. This planning can include an experimental design that factors in potential overarching ecological interactions regarding the binary or ternary system, correctly identifying and understanding unexpected observations that may occur during the experiment and thorough interpretation of the resultant data. This challenge of planning, performing, and interpreting a plant's defensive response to multiple biotic stressors will be even greater when abiotic stressors (i.e., temperature or water) are factored into the system. To fully understand the system, we need to not only continue to investigate and understand the volatile profiles but also include and understand the biochemistry of the plant's response to these stressors. In this review, we provide examples and discuss interaction considerations with respect to how readers and future authors of the Journal of Agricultural and Food Chemistry can contribute their expertise toward the extraction and interpretation of chemical information exchanged between agricultural commodities and their associated pests. This holistic, multidisciplinary, and thoughtful approach to interactions of plants, insects, and microbes, and the resultant response of the plants can lead to a better understanding of agricultural ecology, in turn leading to practical and viable solutions to agricultural problems.
Collapse
Affiliation(s)
- John J Beck
- Chemistry Research Unit, Center for Medical, Agricultural and Veterinary Entomology, Agricultural Research Service , U.S. Department of Agriculture , 1700 SW 23rd Drive , Gainesville , Florida 32608 , United States
| | - Hans T Alborn
- Chemistry Research Unit, Center for Medical, Agricultural and Veterinary Entomology, Agricultural Research Service , U.S. Department of Agriculture , 1700 SW 23rd Drive , Gainesville , Florida 32608 , United States
| | - Anna K Block
- Chemistry Research Unit, Center for Medical, Agricultural and Veterinary Entomology, Agricultural Research Service , U.S. Department of Agriculture , 1700 SW 23rd Drive , Gainesville , Florida 32608 , United States
| | - Shawn A Christensen
- Chemistry Research Unit, Center for Medical, Agricultural and Veterinary Entomology, Agricultural Research Service , U.S. Department of Agriculture , 1700 SW 23rd Drive , Gainesville , Florida 32608 , United States
| | - Charles T Hunter
- Chemistry Research Unit, Center for Medical, Agricultural and Veterinary Entomology, Agricultural Research Service , U.S. Department of Agriculture , 1700 SW 23rd Drive , Gainesville , Florida 32608 , United States
| | - Caitlin C Rering
- Chemistry Research Unit, Center for Medical, Agricultural and Veterinary Entomology, Agricultural Research Service , U.S. Department of Agriculture , 1700 SW 23rd Drive , Gainesville , Florida 32608 , United States
| | - Irmgard Seidl-Adams
- Center for Chemical Ecology , Penn State University , University Park , Pennsylvania 16802 , United States
| | - Charles J Stuhl
- Chemistry Research Unit, Center for Medical, Agricultural and Veterinary Entomology, Agricultural Research Service , U.S. Department of Agriculture , 1700 SW 23rd Drive , Gainesville , Florida 32608 , United States
| | - Baldwyn Torto
- International Centre of Insect Physiology and Ecology (icipe) , 30772-00100 , Nairobi , Kenya
| | - James H Tumlinson
- Center for Chemical Ecology , Penn State University , University Park , Pennsylvania 16802 , United States
| |
Collapse
|
62
|
Guyer A, Hibbard BE, Holzkämper A, Erb M, Robert CAM. Influence of drought on plant performance through changes in belowground tritrophic interactions. Ecol Evol 2018; 8:6756-6765. [PMID: 30038772 PMCID: PMC6053580 DOI: 10.1002/ece3.4183] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 04/10/2018] [Accepted: 04/19/2018] [Indexed: 11/23/2022] Open
Abstract
Climate change is predicted to increase the risk of drought in many temperate agroecosystems. While the impact of drought on aboveground plant-herbivore-natural enemy interactions has been studied, little is known about its effects on belowground tritrophic interactions and root defense chemistry. We investigated the effects of low soil moisture on the interaction between maize, the western corn rootworm (WCR, Diabrotica virgifera), and soil-borne natural enemies of WCR. In a manipulative field experiment, reduced soil moisture and WCR attack reduced plant performance and increased benzoxazinoid levels. The negative effects of WCR on cob dry weight and silk emergence were strongest at low moisture levels. Inoculation with entomopathogenic nematodes (EPNs, Heterorhabditis bacteriophora) was ineffective in controlling WCR, and the EPNs died rapidly in the warm and dry soil. However, ants of the species Solenopsis molesta invaded the experiment, were more abundant in WCR-infested pots and predated WCR independently of soil moisture. Ant presence increased root and shoot biomass and was associated with attenuated moisture-dependent effects of WCR on maize cob weight. Our study suggests that apart from directly reducing plant performance, drought can also increase the negative effects of root herbivores such as WCR. It furthermore identifies S. molesta as a natural enemy of WCR that can protect maize plants from the negative impact of herbivory under drought stress. Robust herbivore natural enemies may play an important role in buffering the impact of climate change on plant-herbivore interactions.
Collapse
Affiliation(s)
- Anouk Guyer
- Institute of Plant SciencesUniversity of BernBernSwitzerland
- Oeschger Centre for Climate Change Research (OCCR)University of BernBernSwitzerland
| | - Bruce E. Hibbard
- Plant Genetics Research UnitUSDA‐ARSUniversity of MissouriColumbiaMissouri
| | - Annelie Holzkämper
- Oeschger Centre for Climate Change Research (OCCR)University of BernBernSwitzerland
- Institute for Sustainability Sciences ISSAgroscopeZürichSwitzerland
| | - Matthias Erb
- Institute of Plant SciencesUniversity of BernBernSwitzerland
- Oeschger Centre for Climate Change Research (OCCR)University of BernBernSwitzerland
| | - Christelle A. M. Robert
- Institute of Plant SciencesUniversity of BernBernSwitzerland
- Oeschger Centre for Climate Change Research (OCCR)University of BernBernSwitzerland
| |
Collapse
|
63
|
Liang J, Liu J, Brown R, Jia M, Zhou K, Peters RJ, Wang Q. Direct production of dihydroxylated sesquiterpenoids by a maize terpene synthase. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 94:847-856. [PMID: 29570233 PMCID: PMC6020683 DOI: 10.1111/tpj.13901] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Accepted: 02/20/2018] [Indexed: 05/21/2023]
Abstract
The astounding structural and biological diversities of the large class of terpenoid natural products are imparted by both their complex hydrocarbon backbones and further elaboration by the addition of multiple hydroxyl groups, which provide both solubility and specific binding properties. While the role of terpene synthases (TPSs) in generating hydrocarbons with complex backbones is well known, these also are known to generate (singly) hydroxylated products by the addition of water prior to terminating deprotonation. Here a maize sesquiterpene synthase was unexpectedly found to generate dually hydroxylated products directly from (E,E)-farnesyl diphosphate, primarily eudesmane-2,11-diol, along with two closely related structural isomers. The unprecedented formation of these diols was proposed to proceed via initial addition of water to a germacradienyl+ intermediate, followed by protonation of the internal carbon-6,7-double-bond in the resulting hedycarol, with subsequent cyclization and further addition of water to an eudesmolyl+ intermediate. Evidence for the proposed mechanism was provided by labeling studies, as well as site-directed mutagenesis, based on structural modeling, which identified an active site phenylalanine required for the protonation and further elaboration of hedycaryol. This dihydroxylated sesquiterpenoid synthase was specifically expressed in maize roots and induced by pathogen infection, with its major enzymatic product only detected in root exudates or infected roots, suggesting a role in defense. Regardless of the ultimate metabolic fate or physiological role of these diols, this report not only reveals an unanticipated extension of the catalytic prowess of TPSs, but also provides insight into the underlying enzymatic mechanism.
Collapse
Affiliation(s)
- Jin Liang
- Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Jiang Liu
- Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Reid Brown
- Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, Ames, IA 50011 USA
| | - Meirong Jia
- Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, Ames, IA 50011 USA
| | - Ke Zhou
- The Multidisciplinary Research Center, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Reuben J. Peters
- Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, Ames, IA 50011 USA
| | - Qiang Wang
- Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| |
Collapse
|
64
|
Expression profile analysis of maize in response to Setosphaeria turcica. Gene 2018; 659:100-108. [DOI: 10.1016/j.gene.2018.03.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 02/27/2018] [Accepted: 03/12/2018] [Indexed: 01/04/2023]
|
65
|
Yang L, Wen KS, Ruan X, Zhao YX, Wei F, Wang Q. Response of Plant Secondary Metabolites to Environmental Factors. Molecules 2018; 23:E762. [PMID: 29584636 PMCID: PMC6017249 DOI: 10.3390/molecules23040762] [Citation(s) in RCA: 518] [Impact Index Per Article: 86.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Revised: 03/21/2018] [Accepted: 03/23/2018] [Indexed: 01/20/2023] Open
Abstract
Plant secondary metabolites (SMs) are not only a useful array of natural products but also an important part of plant defense system against pathogenic attacks and environmental stresses. With remarkable biological activities, plant SMs are increasingly used as medicine ingredients and food additives for therapeutic, aromatic and culinary purposes. Various genetic, ontogenic, morphogenetic and environmental factors can influence the biosynthesis and accumulation of SMs. According to the literature reports, for example, SMs accumulation is strongly dependent on a variety of environmental factors such as light, temperature, soil water, soil fertility and salinity, and for most plants, a change in an individual factor may alter the content of SMs even if other factors remain constant. Here, we review with emphasis how each of single factors to affect the accumulation of plant secondary metabolites, and conduct a comparative analysis of relevant natural products in the stressed and unstressed plants. Expectantly, this documentary review will outline a general picture of environmental factors responsible for fluctuation in plant SMs, provide a practical way to obtain consistent quality and high quantity of bioactive compounds in vegetation, and present some suggestions for future research and development.
Collapse
Affiliation(s)
- Li Yang
- Ningbo Institute of Technology, Zhejiang University, Ningbo 315100, China.
| | - Kui-Shan Wen
- Ningbo Institute of Technology, Zhejiang University, Ningbo 315100, China.
| | - Xiao Ruan
- Ningbo Institute of Technology, Zhejiang University, Ningbo 315100, China.
| | - Ying-Xian Zhao
- Ningbo Institute of Technology, Zhejiang University, Ningbo 315100, China.
| | - Feng Wei
- Ningbo Institute of Technology, Zhejiang University, Ningbo 315100, China.
| | - Qiang Wang
- Ningbo Institute of Technology, Zhejiang University, Ningbo 315100, China.
| |
Collapse
|
66
|
Christensen SA, Sims J, Vaughan MM, Hunter C, Block A, Willett D, Alborn HT, Huffaker A, Schmelz EA. Commercial hybrids and mutant genotypes reveal complex protective roles for inducible terpenoid defenses in maize. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:1693-1705. [PMID: 29361044 DOI: 10.1093/jxb/erx495] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 12/21/2017] [Indexed: 06/07/2023]
Abstract
Plant defense research is facilitated by the use of genome-sequenced inbred lines; however, a foundational knowledge of interactions in commercial hybrids remains relevant to understanding mechanisms present in crops. Using an array of commercial maize hybrids, we quantified the accumulation patterns of defense-related metabolites and phytohormones in tissues challenged with diverse fungal pathogens. Across hybrids, Southern leaf blight (Cochliobolus heterostrophus) strongly elicited specific sesqui- and diterpenoid defenses, namely zealexin A4 (ZA4) and kauralexin diacids, compared with the stalk-rotting agents Fusarium graminearum and Colletotrichum graminicola. With respect to biological activity, ZA4 and kauralexin diacids demonstrated potent antimicrobial action against F. graminearum. Unexpectedly, ZA4 displayed an opposite effect on C. graminicola by promoting growth. Overall, a negative correlation was observed between total analyzed terpenoids and fungal growth. Statistical analyses highlighted kauralexin A3 and abscisic acid as metabolites most associated with fungal suppression. As an empirical test, mutants of the ent-copalyl diphosphate synthase Anther ear 2 (An2) lacking kauralexin biosynthetic capacity displayed increased susceptibility to C. heterostrophus and Fusarium verticillioides. Our results highlight a widely occurring defensive function of acidic terpenoids in commercial hybrids and the complex nature of elicited pathway products that display selective activities on fungal pathogen species.
Collapse
Affiliation(s)
- Shawn A Christensen
- Chemistry Research Unit, Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture - Agricultural Research Service, Gainesville, FL, USA
| | - James Sims
- Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerl
| | - Martha M Vaughan
- Mycotoxin Prevention and Applied Microbiology Research, United States Department of Agriculture - Agricultural Research Service, N. University St. Peoria, IL, USA
| | - Charles Hunter
- Chemistry Research Unit, Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture - Agricultural Research Service, Gainesville, FL, USA
| | - Anna Block
- Chemistry Research Unit, Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture - Agricultural Research Service, Gainesville, FL, USA
| | - Denis Willett
- Chemistry Research Unit, Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture - Agricultural Research Service, Gainesville, FL, USA
| | - Hans T Alborn
- Chemistry Research Unit, Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture - Agricultural Research Service, Gainesville, FL, USA
| | - Alisa Huffaker
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA
| | - Eric A Schmelz
- Section of Cell and Developmental Biology, University of California at San Diego, La Jolla, CA, USA
| |
Collapse
|
67
|
Yusuf CYL, Abdullah JO, Shaharuddin NA, Abu Seman I, Abdullah MP. Characterization of promoter of EgPAL1, a novel PAL gene from the oil palm Elaeis guineensis Jacq. PLANT CELL REPORTS 2018; 37:265-278. [PMID: 29090330 DOI: 10.1007/s00299-017-2228-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 10/18/2017] [Indexed: 06/07/2023]
Abstract
The oil palm EgPAL1 gene promoter and its regulatory region were functional as a promoter in the heterologous system of Arabidopsis according to the cis-acting elements present in that region. The promoter was developmentally regulated, vascular tissue specific and responsive to water stress agents. Phenylalanine ammonia lyase (PAL, EC 4.3.1.24) is the key enzyme of the phenylpropanoid pathway which plays important roles in plant development and adaptation. To date, there is no report on the study of PAL from oil palm (Elaeis guineensis), an economically important oil crop. In this study, the 5' regulatory sequence of a highly divergent oil palm PAL gene (EgPAL1) was isolated and fused with GUS in Arabidopsis to create two transgenic plants carrying the minimal promoter with (2302 bp) and without its regulatory elements (139 bp). The regulatory sequence contained cis-acting elements known to be important for plant development and stress response including the AC-II element for lignin biosynthesis and several stress responsive elements. The promoter and its regulatory region were fully functional in Arabidopsis. Its activities were characterised by two common fundamental features of PAL which are responsive to plant internal developmental programme and external factors. The promoter was developmentally regulated in certain organs; highly active in young organs but less active or inactive in mature organs. The presence of the AC elements and global activity of the EgPAL1 promoter in all organs resembled the property of lignin-related genes. The existence of the MBS element and enhancement of the promoter activity by PEG reflected the behaviour of drought-responsive genes. Our findings provide a platform for evaluating oil palm gene promoters in the heterologous system of Arabidopsis and give insights into the activities of EgPAL1 promoter in oil palm.
Collapse
Affiliation(s)
- Chong Yu Lok Yusuf
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
- Faculty of Plantation and Agrotechnology, Universiti Teknologi MARA, Kampus Jasin, 77300, Merlimau, Melaka, Malaysia
| | - Janna Ong Abdullah
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
| | - Noor Azmi Shaharuddin
- Department of Biochemistry, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
- Institute of Plantation Studies, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
| | - Idris Abu Seman
- Malaysian Palm Oil Board (MPOB), No. 6, Persiaran Institusi, Bandar Baru Bangi, 43000, Kajang, Selangor, Malaysia
| | - Mohd Puad Abdullah
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia.
| |
Collapse
|
68
|
Fu J, Liu Q, Wang C, Liang J, Liu L, Wang Q. ZmWRKY79 positively regulates maize phytoalexin biosynthetic gene expression and is involved in stress response. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:497-510. [PMID: 29281032 DOI: 10.1093/jxb/erx436] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 11/15/2017] [Indexed: 05/03/2023]
Abstract
Maize (Zea mays) accumulates maize terpenoid phytoalexins (MTPs), kauralexins and zealexins in response to various elicitations. Although the key biosynthetic genes for these have been characterized, the regulatory mechanism remains unclear. Through co-correlation analysis, a transcription factor (TF), ZmWRKY79, was identified as highly correlated with expression of MTP biosynthetic genes. Gene expression analysis indicated that ZmWRKY79 was induced by Fusarium graminearum infection, phytohormone treatment, and multiple stresses. Overexpression of ZmWRKY79 in maize protoplasts increased expression of genes involved in MTP biosynthesis, jasmonic acid and ethylene pathways, and scavenging of reactive oxygen species (ROS). Subsequent transient RNAi in maize protoplast compromised the induction of MTP biosynthetic genes by jasmonic acid and ethylene combined treatment. Such regulation was further demonstrated to be dependent on a W-box or WLE cis-element. Transient overexpression of ZmWRKY79 in tobacco conferred resistance against Rhizoctonia solani infection through reducing ROS production. Our results indicate that MTP biosynthesis is regulated by the common transcription factor ZmWRKY79, which plays a broad role as a potential master regulator in stress response through involvement in phytohormone metabolism or signaling and ROS scavenging.
Collapse
Affiliation(s)
- Jingye Fu
- Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Qin Liu
- Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Chang Wang
- Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Jin Liang
- Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Lijun Liu
- Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China
| | - Qiang Wang
- Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, China
| |
Collapse
|
69
|
Murphy KM, Ma LT, Ding Y, Schmelz EA, Zerbe P. Functional Characterization of Two Class II Diterpene Synthases Indicates Additional Specialized Diterpenoid Pathways in Maize ( Zea mays). FRONTIERS IN PLANT SCIENCE 2018; 9:1542. [PMID: 30405674 PMCID: PMC6206430 DOI: 10.3389/fpls.2018.01542] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 10/02/2018] [Indexed: 05/18/2023]
Abstract
As a major staple food, maize (Zea mays) is critical to food security. Shifting environmental pressures increasingly hamper crop defense capacities, causing expanded harvest loss. Specialized labdane-type diterpenoids are key components of maize chemical defense and ecological adaptation. Labdane diterpenoid biosynthesis most commonly requires the pairwise activity of class II and class I diterpene synthases (diTPSs) that convert the central precursor geranylgeranyl diphosphate into distinct diterpenoid scaffolds. Two maize class II diTPSs, ANTHER EAR 1 and 2 (ZmAN1/2), have been previously identified as catalytically redundant ent-copalyl diphosphate (CPP) synthases. ZmAN1 is essential for gibberellin phytohormone biosynthesis, whereas ZmAN2 is stress-inducible and governs the formation of defensive kauralexin and dolabralexin diterpenoids. Here, we report the biochemical characterization of the two remaining class II diTPSs present in the maize genome, COPALYL DIPHOSPHATE SYNTHASE 3 (ZmCPS3) and COPALYL DIPHOSPHATE SYNTHASE 4 (ZmCPS4). Functional analysis via microbial co-expression assays identified ZmCPS3 as a (+)-CPP synthase, with functionally conserved orthologs occurring in wheat (Triticum aestivum) and numerous dicot species. ZmCPS4 formed the unusual prenyl diphosphate, 8,13-CPP (labda-8,13-dien-15-yl diphosphate), as verified by mass spectrometry and nuclear magnetic resonance. As a minor product, ZmCPS4 also produced labda-13-en-8-ol diphosphate (LPP). Root gene expression profiles did not indicate an inducible role of ZmCPS3 in maize stress responses. By contrast, ZmCPS4 showed a pattern of inducible gene expression in roots exposed to oxidative stress, supporting a possible role in abiotic stress responses. Identification of the catalytic activities of ZmCPS3 and ZmCPS4 clarifies the first committed reactions controlling the diversity of defensive diterpenoids in maize, and suggests the existence of additional yet undiscovered diterpenoid pathways.
Collapse
Affiliation(s)
- Katherine M. Murphy
- Department of Plant Biology, University of California, Davis, Davis, CA, United States
| | - Li-Ting Ma
- Department of Plant Biology, University of California, Davis, Davis, CA, United States
- School of Forestry and Resource Conservation, National Taiwan University, Taipei, Taiwan
| | - Yezhang Ding
- Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, United States
| | - Eric A. Schmelz
- Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, United States
| | - Philipp Zerbe
- Department of Plant Biology, University of California, Davis, Davis, CA, United States
- *Correspondence: Philipp Zerbe,
| |
Collapse
|
70
|
Meyer J, Berger DK, Christensen SA, Murray SL. RNA-Seq analysis of resistant and susceptible sub-tropical maize lines reveals a role for kauralexins in resistance to grey leaf spot disease, caused by Cercospora zeina. BMC PLANT BIOLOGY 2017; 17:197. [PMID: 29132306 PMCID: PMC5683525 DOI: 10.1186/s12870-017-1137-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 10/18/2017] [Indexed: 05/20/2023]
Abstract
BACKGROUND Cercospora zeina is a foliar pathogen responsible for maize grey leaf spot in southern Africa that negatively impacts maize production. Plants use a variety of chemical and structural mechanisms to defend themselves against invading pathogens such as C. zeina, including the production of secondary metabolites with antimicrobial properties. In maize, a variety of biotic and abiotic stressors induce the accumulation of the terpenoid phytoalexins, zealexins and kauralexins. RESULTS C. zeina-susceptible line displayed pervasive rectangular grey leaf spot lesions, running parallel with the leaf veins in contrast to C. zeina-resistant line that had restricted disease symptoms. Analysis of the transcriptome of both lines indicated that genes involved in primary and secondary metabolism were up-regualted, and although different pathways were prioritized in each line, production of terpenoid compounds were common to both. Targeted phytoalexin analysis revealed that C. zeina-inoculated leaves accumulated zealexins and kauralexins. The resistant line shows a propensity toward accumulation of the kauralexin B series metabolites in response to infection, which contrasts with the susceptible line that preferentially accumulates the kauralexin A series. Kauralexin accumulation was correlated to expression of the kauralexin biosynthetic gene, ZmAn2 and a candidate biosynthetic gene, ZmKSL2. We report the expression of a putative copalyl diphosphate synthase gene that is induced by C. zeina in the resistant line exclusively. DISCUSSION This study shows that zealexins and kauralexins, and expression of their biosynthetic genes, are induced by C. zeina in both resistant and susceptible germplasm adapted to the southern African climate. The data presented here indicates that different forms of kauralexins accumulate in the resistant and susceptible maize lines in response to C. zeina, with the accumulation of kauralexin B compounds in a resistant maize line and kauralexin A compounds accumulating in the susceptible line.
Collapse
Affiliation(s)
- Jacqueline Meyer
- Department of Plant and Soil Sciences, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, P/Bag X20, Hatfield, Gauteng, 0028, South Africa
- Centre for Proteomic and Genomic Research, Upper Level, St Peter's Mall, Cnr Anzio and Main Road, Observatory, Cape Town, 7925, South Africa
| | - Dave K Berger
- Department of Plant and Soil Sciences, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, P/Bag X20, Hatfield, Gauteng, 0028, South Africa
| | - Shawn A Christensen
- Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, Chemistry Research Unit, Gainesville, Florida, 32608, USA
| | - Shane L Murray
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag, Rondebosch, Cape Town, 7701, South Africa.
- Centre for Proteomic and Genomic Research, Upper Level, St Peter's Mall, Cnr Anzio and Main Road, Observatory, Cape Town, 7925, South Africa.
| |
Collapse
|
71
|
Massalha H, Korenblum E, Tholl D, Aharoni A. Small molecules below-ground: the role of specialized metabolites in the rhizosphere. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 90:788-807. [PMID: 28333395 DOI: 10.1111/tpj.13543] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 03/17/2017] [Accepted: 03/21/2017] [Indexed: 05/18/2023]
Abstract
Soil communities are diverse taxonomically and functionally. This ecosystem experiences highly complex networks of interactions, but may also present functionally independent entities. Plant roots, a metabolically active hotspot in the soil, take an essential part in below-ground interactions. While plants are known to release an extremely high portion of the fixated carbon to the soil, less information is known about the composition and role of C-containing compounds in the rhizosphere, in particular those involved in chemical communication. Specialized metabolites (or secondary metabolites) produced by plants and their associated microbes have a critical role in various biological activities that modulate the behavior of neighboring organisms. Thus, elucidating the chemical composition and function of specialized metabolites in the rhizosphere is a key element in understanding interactions in this below-ground environment. Here, we review key classes of specialized metabolites that occur as mostly non-volatile compounds in root exudates or are emitted as volatile organic compounds (VOCs). The role of these metabolites in below-ground interactions and response to nutrient deficiency, as well as their tissue and cell type-specific biosynthesis and release are discussed in detail.
Collapse
Affiliation(s)
- Hassan Massalha
- Department of Plant Sciences, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Elisa Korenblum
- Department of Plant Sciences, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Dorothea Tholl
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA
| | - Asaph Aharoni
- Department of Plant Sciences, Weizmann Institute of Science, Rehovot, 76100, Israel
| |
Collapse
|
72
|
Alptekin B, Langridge P, Budak H. Abiotic stress miRNomes in the Triticeae. Funct Integr Genomics 2017; 17:145-170. [PMID: 27665284 PMCID: PMC5383695 DOI: 10.1007/s10142-016-0525-9] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 09/02/2016] [Accepted: 09/09/2016] [Indexed: 12/14/2022]
Abstract
The continued growth in world population necessitates increases in both the quantity and quality of agricultural production. Triticeae members, particularly wheat and barley, make an important contribution to world food reserves by providing rich sources of carbohydrate and protein. These crops are grown over diverse production environments that are characterized by a range of environmental or abiotic stresses. Abiotic stresses such as drought, heat, salinity, or nutrient deficiencies and toxicities cause large yield losses resulting in economic and environmental damage. The negative effects of abiotic stresses have increased at an alarming rate in recent years and are predicted to further deteriorate due to climate change, land degradation, and declining water supply. New technologies have provided an important tool with great potential for improving crop tolerance to the abiotic stresses: microRNAs (miRNAs). miRNAs are small regulators of gene expression that act on many different molecular and biochemical processes such as development, environmental adaptation, and stress tolerance. miRNAs can act at both the transcriptional and post-transcriptional levels, although post-transcriptional regulation is the most common in plants where miRNAs can inhibit the translation of their mRNA targets via complementary binding and cleavage. To date, expression of several miRNA families such as miR156, miR159, and miR398 has been detected as responsive to environmental conditions to regulate stress-associated molecular mechanisms individually and/or together with their various miRNA partners. Manipulation of these miRNAs and their targets may pave the way to improve crop performance under several abiotic stresses. Here, we summarize the current status of our knowledge on abiotic stress-associated miRNAs in members of the Triticeae tribe, specifically in wheat and barley, and the miRNA-based regulatory mechanisms triggered by stress conditions. Exploration of further miRNA families together with their functions under stress will improve our knowledge and provide opportunities to enhance plant performance to help us meet global food demand.
Collapse
Affiliation(s)
- Burcu Alptekin
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, USA
| | - Peter Langridge
- School of Agriculture, Food and Wine, University of Adelaide, Adelaide, Australia
| | - Hikmet Budak
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, USA.
| |
Collapse
|
73
|
Ren F, Mao H, Liang J, Liu J, Shu K, Wang Q. Functional characterization of ZmTPS7 reveals a maize τ-cadinol synthase involved in stress response. PLANTA 2016; 244:1065-1074. [PMID: 27421723 DOI: 10.1007/s00425-016-2570-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Accepted: 07/11/2016] [Indexed: 05/14/2023]
Abstract
Maize ( Zea mays ) terpene synthase 7 (ZmTPS7) was characterized as a τ-cadinol synthase, which exhibited constitutive and inducible gene expression patterns, suggesting involvement in stress response. Maize produces a variety of terpenoids involved in defense response. Despite some terpene synthases (TPSs) responsible for these terpenoids have been characterized, biosynthesis of many terpenes, particularly sesquiterpenes, which were produced in response to biotic or abiotic stress, remains largely unknown. Here, we characterized ZmTPS7 biochemically through recombinant expression in Escherichia coli and detected that it catalyzed formation of a blend of sesquiterpenes and sesquiterpenoid alcohols as the sesquiterpene synthase through GC-MS analysis. Subsequently, the major product was purified and identified as τ-cadinol through nuclear magnetic resonance spectroscopy (NMR) analysis, which was also detected in maize tissues infected by pathogen fungus for the first time. ZmTPS7 constitutively expressed in aerial tissues while with trace amount of transcript in roots. Fungus spore inoculation and methyl jasmonate (MeJA) treatment induced gene expression of ZmTPS7 in leaves, while exogenous ABA induced ZmTPS7 dramatically in roots, suggesting that ZmTPS7 might be involved in stress response. τ-cadinol was quantified in infected maize tissues with the concentration of ~200 ng/g fresh weight, however, which was much lower than the inhibitory one on two tested necrotrophic fungi. Such evidences indicate that anti-fungal activity of τ-cadinol is not physiologically relevant, and further investigation is needed to clarify its biological functions in maize. Taken together, ZmTPS7 was characterized as the τ-cadinol synthase and suggested to be involved in stress response, which also increased the diversity of maize terpenoid profile.
Collapse
Affiliation(s)
- Fei Ren
- Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, 611130, China
| | - Hongjie Mao
- Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, 611130, China
| | - Jin Liang
- Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, 611130, China
| | - Jiang Liu
- Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, 611130, China
| | - Kai Shu
- Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, 611130, China
| | - Qiang Wang
- Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu, 611130, China.
| |
Collapse
|
74
|
Wen W, Brotman Y, Willmitzer L, Yan J, Fernie AR. Broadening Our Portfolio in the Genetic Improvement of Maize Chemical Composition. Trends Genet 2016; 32:459-469. [DOI: 10.1016/j.tig.2016.05.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 05/03/2016] [Accepted: 05/09/2016] [Indexed: 12/14/2022]
|
75
|
Vaughan MM, Huffaker A, Schmelz EA, Dafoe NJ, Christensen SA, McAuslane HJ, Alborn HT, Allen LH, Teal PEA. Interactive Effects of Elevated [CO2] and Drought on the Maize Phytochemical Defense Response against Mycotoxigenic Fusarium verticillioides. PLoS One 2016; 11:e0159270. [PMID: 27410032 PMCID: PMC4943682 DOI: 10.1371/journal.pone.0159270] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 06/29/2016] [Indexed: 01/21/2023] Open
Abstract
Changes in climate due to rising atmospheric carbon dioxide concentration ([CO2]) are predicted to intensify episodes of drought, but our understanding of how these combined conditions will influence crop-pathogen interactions is limited. We recently demonstrated that elevated [CO2] alone enhances maize susceptibility to the mycotoxigenic pathogen, Fusarium verticillioides (Fv) but fumonisin levels remain unaffected. In this study we show that maize simultaneously exposed to elevated [CO2] and drought are even more susceptible to Fv proliferation and also prone to higher levels of fumonisin contamination. Despite the increase in fumonisin levels, the amount of fumonisin produced in relation to pathogen biomass remained lower than corresponding plants grown at ambient [CO2]. Therefore, the increase in fumonisin contamination was likely due to even greater pathogen biomass rather than an increase in host-derived stimulants. Drought did not negate the compromising effects of elevated [CO2] on the accumulation of maize phytohormones and metabolites. However, since elevated [CO2] does not influence the drought-induced accumulation of abscisic acid (ABA) or root terpenoid phytoalexins, the effects elevated [CO2] are negated belowground, but the stifled defense response aboveground may be a consequence of resource redirection to the roots.
Collapse
Affiliation(s)
- Martha M. Vaughan
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture, Agricultural Research Service, 1815 N University St, Peoria, Illinois, 61604, United States of America
| | - Alisa Huffaker
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, 1600 SW 23 Drive, Gainesville, Florida, 32608, United States of America
| | - Eric A. Schmelz
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, 1600 SW 23 Drive, Gainesville, Florida, 32608, United States of America
| | - Nicole J. Dafoe
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, 1600 SW 23 Drive, Gainesville, Florida, 32608, United States of America
| | - Shawn A. Christensen
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, 1600 SW 23 Drive, Gainesville, Florida, 32608, United States of America
| | - Heather J. McAuslane
- Department of Nematology and Entomology, University of Florida, Gainesville, Florida, 32610, United States of America
| | - Hans T. Alborn
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, 1600 SW 23 Drive, Gainesville, Florida, 32608, United States of America
| | - Leon Hartwell Allen
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, 1600 SW 23 Drive, Gainesville, Florida, 32608, United States of America
| | - Peter E. A. Teal
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, 1600 SW 23 Drive, Gainesville, Florida, 32608, United States of America
| |
Collapse
|
76
|
Mahmoud MAB, Sharp RE, Oliver MJ, Finke DL, Ellersieck MR, Hibbard BE. The Effect of Western Corn Rootworm (Coleoptera: Chrysomelidae) and Water Deficit on Maize Performance Under Controlled Conditions. JOURNAL OF ECONOMIC ENTOMOLOGY 2016; 109:684-698. [PMID: 26896532 DOI: 10.1093/jee/tow011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The western corn rootworm, Diabrotica virgifera virgifera LeConte, is the most important insect of maize, Zea mays L., but knowledge of its interaction with water deficit on maize production is lacking. A series of greenhouse experiments using three infestation levels of the western corn rootworm, D. virgifera virgifera, under well-watered, moderately dry, and very dry soil moisture levels were conducted to quantify the interaction of western corn rootworm and soil water deficit on B73×Mo17 maize growth and physiology. Three separate experiments were conducted. Soil moisture regimes were initiated 30 d postplanting for experiments using neonate and second-instar larvae and 30 d postinfestation in the experiment using eggs. In the neonate and second-instar experiments, there were no significant differences among western corn rootworm levels in their effects on leaf water potential, shoot dry weight, and root dry weight. The interaction of western corn rootworm and soil moisture significantly impacted the larval recovery in the neonate experiment, but no other significant interactions were documented between soil moisture levels and rootworm infestation levels. Overall, the results indicate that under the conditions of these experiments, the effect of water deficit was much greater on plants than the effect of western corn rootworm and that the interactions between water deficit and western corn rootworm levels minimally affected the measured parameters of plant performance.
Collapse
|
77
|
Alptekin B, Budak H. Wheat miRNA ancestors: evident by transcriptome analysis of A, B, and D genome donors. Funct Integr Genomics 2016; 17:171-187. [PMID: 27032785 DOI: 10.1007/s10142-016-0487-y] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 03/06/2016] [Accepted: 03/14/2016] [Indexed: 12/24/2022]
Abstract
MicroRNAs are critical players of post-transcriptional gene regulation with profound effects on the fundamental processes of cellular life. Their identification and characterization, together with their targets, hold great significance in exploring and exploiting their roles on a functional context, providing valuable clues into the regulation of important biological processes, such as stress tolerance or environmental adaptation. Wheat is a hardy crop, extensively harvested in temperate regions, and is a major component of the human diet. With the advent of the next generation sequencing technologies considerably decreasing sequencing costs per base-pair, genomic, and transcriptomic data from several wheat species, including the progenitors and wild relatives have become available. In this study, we performed in silico identification and comparative analysis of microRNA repertoires of bread wheat (Triticum aestivum L.) and its diploid progenitors and relatives, Aegilops sharonensis, Aegilops speltoides, Aegilops tauschii, Triticum monococcum, and Triticum urartu through the utilization of publicly available transcriptomic data. Over 200 miRNA families were identified, majority of which have not previously been reported. Ancestral relationships expanded our understanding of wheat miRNA evolution, while T. monococcum miRNAs delivered important clues on the effects of domestication on miRNA expression. Comparative analyses on wild Ae. sharonensis accessions highlighted candidate miRNAs that can be linked to stress tolerance. The miRNA repertoires of bread wheat and its diploid progenitors and relatives provide important insight into the diversification and distribution of miRNA genes, which should contribute to the elucidation of miRNA evolution of Poaceae family. A thorough understanding of the convergent and divergent expression profiles of miRNAs in different genetic backgrounds can provide unique opportunities to modulation of gene regulation for better crop performance.
Collapse
Affiliation(s)
- Burcu Alptekin
- Molecular Biology, Genetics and Bioengineering Program, Sabanci University, 34956, Istanbul, Turkey
| | - Hikmet Budak
- Molecular Biology, Genetics and Bioengineering Program, Sabanci University, 34956, Istanbul, Turkey.
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, 59717, USA.
| |
Collapse
|
78
|
Rattanakon S, Ghan R, Gambetta GA, Deluc LG, Schlauch KA, Cramer GR. Abscisic acid transcriptomic signaling varies with grapevine organ. BMC PLANT BIOLOGY 2016; 16:72. [PMID: 27001301 PMCID: PMC4802729 DOI: 10.1186/s12870-016-0763-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 03/15/2016] [Indexed: 05/03/2023]
Abstract
BACKGROUND Abscisic acid (ABA) regulates various developmental processes and stress responses over both short (i.e. hours or days) and longer (i.e. months or seasons) time frames. To elucidate the transcriptional regulation of early responses of grapevine (Vitis vinifera) responding to ABA, different organs of grape (berries, shoot tips, leaves, roots and cell cultures) were treated with 10 μM (S)-(+)-ABA for 2 h. NimbleGen whole genome microarrays of Vitis vinifera were used to determine the effects of ABA on organ-specific mRNA expression patterns. RESULTS Transcriptomic analysis revealed 839 genes whose transcript abundances varied significantly in a specific organ in response to ABA treatment. No single gene exhibited the same changes in transcript abundance across all organs in response to ABA. The biochemical pathways affected by ABA were identified using the Cytoscape program with the BiNGO plug-in software. The results indicated that these 839 genes were involved in several biological processes such as flavonoid metabolism, response to reactive oxygen species, response to light, and response to temperature stimulus. ABA affected ion and water transporters, particularly in the root. The protein amino acid phosphorylation process was significantly overrepresented in shoot tips and roots treated with ABA. ABA affected mRNA abundance of genes (CYP707As, UGTs, and PP2Cs) associated with ABA degradation, conjugation, and the ABA signaling pathway. ABA also significantly affected the expression of several transcription factors (e.g. AP2/ERF, MYC/MYB, and bZIP/AREB). The greatest number of significantly differentially expressed genes was observed in the roots followed by cell cultures, leaves, berries, and shoot tips, respectively. Each organ had a unique set of gene responses to ABA. CONCLUSIONS This study examined the short-term effects of ABA on different organs of grapevine. The responses of each organ were unique indicating that ABA signaling varies with the organ. Understanding the ABA responses in an organ-specific manner is crucial to fully understand hormone action and plant responses to water deficit.
Collapse
Affiliation(s)
- Supakan Rattanakon
- />Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV 89557 USA
| | - Ryan Ghan
- />Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV 89557 USA
| | - Gregory A. Gambetta
- />Bordeaux Sciences Agro, Institut des Sciences de la Vigne et du Vin (ISVV), EGFV, UMR 1287, F-33140 Villenave d’Ornon, France
| | - Laurent G. Deluc
- />Department of Horticulture, Oregon State University, Corvallis, OR 97331 USA
| | - Karen A. Schlauch
- />Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV 89557 USA
| | - Grant R. Cramer
- />Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV 89557 USA
| |
Collapse
|
79
|
Mao H, Liu J, Ren F, Peters RJ, Wang Q. Characterization of CYP71Z18 indicates a role in maize zealexin biosynthesis. PHYTOCHEMISTRY 2016; 121:4-10. [PMID: 26471326 DOI: 10.1016/j.phytochem.2015.10.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Revised: 09/26/2015] [Accepted: 10/07/2015] [Indexed: 06/05/2023]
Abstract
Maize (Zea mays) produces zealexins as phytoalexins, with the inducible production of these antibiotics providing biochemical protection against fungal infection. However, the biosynthesis of these sesquiterpenoids has remained unclear. In particular, it is unclear how the olefinic precursor, (S)-β-macrocarpene produced by the characterized maize sesquiterpene synthases TPS6/11, is further elaborated to form the bioactive zealexins. The first step is likely to be conversion of carbon-15 (C15) from a methyl group to a carboxylic acid by a cytochrome P450 mono-oxygenase (CYP). In this study, CYP71Z18, whose transcription is strongly induced by fungal infection, was found to catalyze oxidation of C15 in (S)-β-macrocarpene, forming zealexin A1. The inducible transcription of CYP71Z18 matches that observed for TPS6/11 and the accumulation of zealexins, which is consistent with a role for CYP71Z18 in sesquiterpenoid phytoalexin production. This completes identification of zealexin A1 biosynthesis, and represents the initial CYP identified for the production of maize terpenoid phytoalexins.
Collapse
Affiliation(s)
- Hongjie Mao
- College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China.
| | - Jiang Liu
- College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China.
| | - Fei Ren
- College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China.
| | - Reuben J Peters
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA.
| | - Qiang Wang
- College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China; Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu 611130, China.
| |
Collapse
|
80
|
Wang Q, Jia M, Huh JH, Muchlinski A, Peters RJ, Tholl D. Identification of a Dolabellane Type Diterpene Synthase and other Root-Expressed Diterpene Synthases in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2016; 7:1761. [PMID: 27933080 PMCID: PMC5122590 DOI: 10.3389/fpls.2016.01761] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 11/08/2016] [Indexed: 05/20/2023]
Abstract
Arabidopsis thaliana maintains a complex metabolism for the production of secondary or specialized metabolites. Such metabolites include volatile and semivolatile terpenes, which have been associated with direct and indirect defensive activities in flowers and leaves. In comparison, the structural diversity and function of terpenes in Arabidopsis roots has remained largely unexplored despite a substantial number of root-expressed genes in the Arabidopsis terpene synthase (TPS) gene family. We show that five root-expressed TPSs of an expanded subfamily-a type clade in the Arabidopsis TPS family function as class I diterpene synthases that predominantly convert geranylgeranyl diphosphate (GGPP) to different semi-volatile diterpene products, which are in part detectable at low levels in the ecotypes Columbia (Col) and Cape Verde Island (Cvi). The enzyme TPS20 produces a macrocyclic dolabellane diterpene alcohol and a dolabellane-related diterpene olefin named dolathaliatriene with a so far unknown C6-C11 bicyclic scaffold besides several minor olefin products. The TPS20 compounds occur in all tissues of Cvi but are absent in the Col ecotype because of deletion and substitution mutations in the Col TPS20 sequence. The primary TPS20 diterpene products retard the growth of the root rot pathogen Pythium irregulare but only at concentrations exceeding those in planta. Together, our results demonstrate that divergence and pseudogenization in the Arabidopsis TPS gene family allow for structural plasticity in diterpene profiles of above- and belowground tissues.
Collapse
Affiliation(s)
- Qiang Wang
- Department of Biological Sciences, Virginia Tech, BlacksburgVA, USA
| | - Meirong Jia
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, AmesIA, USA
| | - Jung-Hyun Huh
- Department of Biological Sciences, Virginia Tech, BlacksburgVA, USA
| | | | - Reuben J. Peters
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, AmesIA, USA
| | - Dorothea Tholl
- Department of Biological Sciences, Virginia Tech, BlacksburgVA, USA
- *Correspondence: Dorothea Tholl,
| |
Collapse
|
81
|
Yamamura C, Mizutani E, Okada K, Nakagawa H, Fukushima S, Tanaka A, Maeda S, Kamakura T, Yamane H, Takatsuji H, Mori M. Diterpenoid phytoalexin factor, a bHLH transcription factor, plays a central role in the biosynthesis of diterpenoid phytoalexins in rice. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 84:1100-13. [PMID: 26506081 DOI: 10.1111/tpj.13065] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 10/19/2015] [Accepted: 10/21/2015] [Indexed: 05/22/2023]
Abstract
Rice (Oryza sativa) produces diterpenoid phytoalexins (DPs), momilactones and phytocassanes as major phytoalexins. Accumulation of DPs is induced in rice by blast fungus infection, copper chloride or UV light. Here, we describe a rice transcription factor named diterpenoid phytoalexin factor (DPF), which is a basic helix-loop-helix (bHLH) transcription factor. The gene encoding DPF is expressed mainly in roots and panicles, and is inducible in leaves by blast infection, copper chloride or UV. Expression of all DP biosynthetic genes and accumulation of momilactones and phytocassanes were remarkably increased and decreased in DPF over-expressing and DPF knockdown rice, respectively. These results clearly demonstrated that DPF positively regulates DP accumulation via transcriptional regulation of DP biosynthetic genes, and plays a central role in the biosynthesis of DPs in rice. Furthermore, DPF activated the promoters of COPALYL DIPHOSPHATE SYNTHASE2 (CPS2) and CYTOCHROME P450 MONOOXYGENASE 99A2 (CYP99A2), whose products are implicated in the biosynthesis of phytocassanes and momilactones, respectively. Mutations in the N-boxes in the CPS2 upstream region, to which several animal bHLH transcription factors bind, decreased CPS2 transcription, indicating that DPF positively regulates CPS2 transcription through the N-boxes. In addition, DPF partly regulates CYP99A2 through the N-box. This study demonstrates that DPF acts as a master transcription factor in DP biosynthesis.
Collapse
Affiliation(s)
- Chihiro Yamamura
- Disease Resistant Crops Research Unit, National Institute of Agrobiological Sciences, Tsukuba, 305-8602, Japan
- Faculty of Science and Technology, Tokyo University of Science, Noda, 278-8510, Japan
| | - Emi Mizutani
- Disease Resistant Crops Research Unit, National Institute of Agrobiological Sciences, Tsukuba, 305-8602, Japan
- Faculty of Science and Technology, Tokyo University of Science, Noda, 278-8510, Japan
| | - Kazunori Okada
- Biotechnology Research Center, The University of Tokyo, Tokyo, 113-8657, Japan
| | - Hitoshi Nakagawa
- Disease Resistant Crops Research Unit, National Institute of Agrobiological Sciences, Tsukuba, 305-8602, Japan
| | - Setsuko Fukushima
- Disease Resistant Crops Research Unit, National Institute of Agrobiological Sciences, Tsukuba, 305-8602, Japan
| | - Atsunori Tanaka
- Disease Resistant Crops Research Unit, National Institute of Agrobiological Sciences, Tsukuba, 305-8602, Japan
- Faculty of Science and Technology, Tokyo University of Science, Noda, 278-8510, Japan
| | - Satoru Maeda
- Disease Resistant Crops Research Unit, National Institute of Agrobiological Sciences, Tsukuba, 305-8602, Japan
| | - Takashi Kamakura
- Faculty of Science and Technology, Tokyo University of Science, Noda, 278-8510, Japan
| | - Hisakazu Yamane
- Department of Biosciences, Teikyo University, Utsunomiya, 320-8551, Japan
| | - Hiroshi Takatsuji
- Disease Resistant Crops Research Unit, National Institute of Agrobiological Sciences, Tsukuba, 305-8602, Japan
| | - Masaki Mori
- Disease Resistant Crops Research Unit, National Institute of Agrobiological Sciences, Tsukuba, 305-8602, Japan
| |
Collapse
|
82
|
Zerbe P. Small molecules with big impact: terpenoid phytoalexins as key factors in maize stress tolerance. PLANT, CELL & ENVIRONMENT 2015; 38:2193-2194. [PMID: 25754293 DOI: 10.1111/pce.12523] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 02/25/2015] [Indexed: 06/04/2023]
Affiliation(s)
- Philipp Zerbe
- Department of Plant Biology, University of California, Davis, CA, 95616, USA
| |
Collapse
|