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Xu X, Fang P, Zhang H, Chi C, Song L, Xia X, Shi K, Zhou Y, Zhou J, Yu J. Strigolactones positively regulate defense against root-knot nematodes in tomato. J Exp Bot 2019; 70:1325-1337. [PMID: 30576511 PMCID: PMC6382333 DOI: 10.1093/jxb/ery439] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [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: 09/14/2018] [Accepted: 11/30/2018] [Indexed: 05/20/2023]
Abstract
Strigolactones (SLs) are carotenoid-derived phytohormones that are known to influence various aspects of plant growth and development. As root-derived signals, SLs can enhance symbiosis between plants and arbuscular mycorrhizal fungi (AMF). However, little is known about the roles of SLs in plant defense against soil-borne pathogens. Here, we determined that infection with root-knot nematodes (RKNs; Meloidogyne incognita) induced SL biosynthesis in roots of tomato (Solanum lycopersicum). Silencing of SL biosynthesis genes compromised plant defense against RKNs, whilst application of the SL analog racGR24 enhanced it. Accumulation of endogenous jasmonic acid (JA) and abscisic acid (ABA) in the roots in response to RKN infection was enhanced by silencing of SL biosynthetic genes and was suppressed by application of racGR24. Genetic evidence showed that JA was a positive regulator of defense against RKNs while ABA was a negative regulator. In addition, racGR24 enhanced the defense against nematode in a JA-deficient mutant but not in an ABA-deficient mutant. Silencing of SL biosynthetic genes resulted in up-regulation of MYC2, which negatively regulated defense against RKNs. Our results demonstrate that SLs play a positive role in nematode defense in tomato and that MYC2 negatively regulates this defense, potentially by mediating hormone crosstalk among SLs, ABA and JA.
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Affiliation(s)
- Xuechen Xu
- Department of Horticulture, Zijingang Campus, Zhejiang University, Hangzhou, P.R. China
| | - Pingping Fang
- Department of Horticulture, Zijingang Campus, Zhejiang University, Hangzhou, P.R. China
| | - Hui Zhang
- Department of Horticulture, Zijingang Campus, Zhejiang University, Hangzhou, P.R. China
| | - Cheng Chi
- Department of Horticulture, Zijingang Campus, Zhejiang University, Hangzhou, P.R. China
| | - Liuxia Song
- Department of Horticulture, Zijingang Campus, Zhejiang University, Hangzhou, P.R. China
| | - Xiaojian Xia
- Department of Horticulture, Zijingang Campus, Zhejiang University, Hangzhou, P.R. China
| | - Kai Shi
- Department of Horticulture, Zijingang Campus, Zhejiang University, Hangzhou, P.R. China
| | - Yanhong Zhou
- Department of Horticulture, Zijingang Campus, Zhejiang University, Hangzhou, P.R. China
| | - Jie Zhou
- Department of Horticulture, Zijingang Campus, Zhejiang University, Hangzhou, P.R. China
| | - Jingquan Yu
- Department of Horticulture, Zijingang Campus, Zhejiang University, Hangzhou, P.R. China
- Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Hangzhou, P.R. China
- Correspondence:
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