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Vaughan MM, Christensen S, Schmelz EA, Huffaker A, McAuslane HJ, Alborn HT, Romero M, Allen LH, Teal PEA. Accumulation of terpenoid phytoalexins in maize roots is associated with drought tolerance. Plant Cell Environ 2015; 38:2195-207. [PMID: 25392907 DOI: 10.1111/pce.12482] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Revised: 11/04/2014] [Accepted: 11/05/2014] [Indexed: 05/25/2023]
Abstract
Maize (Zea mays) production, which is of global agro-economic importance, is largely limited by herbivore pests, pathogens and environmental conditions, such as drought. Zealexins and kauralexins belong to two recently identified families of acidic terpenoid phytoalexins in maize that mediate defence against both pathogen and insect attacks in aboveground tissues. However, little is known about their function in belowground organs and their potential to counter abiotic stress. In this study, we show that zealexins and kauralexins accumulate in roots in response to both biotic and abiotic stress including, Diabrotica balteata herbivory, Fusarium verticillioides infection, drought and high salinity. We find that the quantity of drought-induced phytoalexins is positively correlated with the root-to-shoot ratio of different maize varieties, and further demonstrate that mutant an2 plants deficient in kauralexin production are more sensitive to drought. The induction of phytoalexins in response to drought is root specific and does not influence phytoalexin levels aboveground; however, the accumulation of phytoalexins in one tissue may influence the induction capacity of other tissues.
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Affiliation(s)
- Martha M Vaughan
- Bacterial Foodborne Pathogens and Mycology, Agricultural Research Service, United States Department of Agriculture, Peoria, IL, 61604, USA
| | - Shawn Christensen
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, Agricultural Research Service, United States Department of Agriculture, Gainesville, FL, 32608, USA
| | - Eric A Schmelz
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, Agricultural Research Service, United States Department of Agriculture, Gainesville, FL, 32608, USA
| | - Alisa Huffaker
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, Agricultural Research Service, United States Department of Agriculture, Gainesville, FL, 32608, USA
| | - Heather J McAuslane
- Department of Entomology and Nematology, University of Florida, Gainesville, FL, 32611, USA
| | - Hans T Alborn
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, Agricultural Research Service, United States Department of Agriculture, Gainesville, FL, 32608, USA
| | - Maritza Romero
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, Agricultural Research Service, United States Department of Agriculture, Gainesville, FL, 32608, USA
| | - Leon Hartwell Allen
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, Agricultural Research Service, United States Department of Agriculture, Gainesville, FL, 32608, USA
| | - Peter E A Teal
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, Agricultural Research Service, United States Department of Agriculture, Gainesville, FL, 32608, USA
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