title: Priming maize resistance by its neighbors: activating 1,4-benzoxazine-3-ones synthesis and defense gene expression to alleviate leaf disease.
abstract: Plant disease can be effectively suppressed in intercropping systems. Our previous study demonstrated that neighboring maize plants can restrict the spread of soil-borne pathogens of pepper plants by secreting defense compounds into the soil. However, whether maize plant can receive benefits from its neighboring pepper plants in an intercropping system is little attention. We examined the effects of maize roots treated with elicitors from the pepper pathogen Phytophthora capsici and pepper root exudates on the synthesis of 1,4-benzoxazine-3-ones (BXs), the expression of defense-related genes in maize, and their ability to alleviate the severity of southern corn leaf blight (SCLB) caused by Bipolaris maydis. We found that SCLB was significantly reduced after the above treatments. The contents of 1,4-benzoxazine-3-ones (BXs: DIBOA, DIMBOA, and MBOA) and the expression levels of BX synthesis and defense genes in maize roots and shoots were up-regulated. DIMBOA and MBOA effectively inhibited the mycelium growth of Bipolaris maydis at physiological concentrations in maize shoots. Further studies suggested that the defense related pathways or genes in maize roots and shoots were activated by elicitors from the P. capsici or pepper root exudates. In conclusion, maize increased the levels of BXs and defense gene expression both in roots and shoots after being triggered by root exudates and pathogen from neighboring pepper plants, eventually enhancing its resistance.
authors.affiliation: Key Laboratory of Agro-Biodiversity and Pest Management of Education Ministry of China, Yunnan Agricultural University Kunming, China.
authors.forename: Xupo
authors.initials: X
authors.lastname: Ding
authors.affiliation: Key Laboratory of Agro-Biodiversity and Pest Management of Education Ministry of China, Yunnan Agricultural University Kunming, China.
authors.forename: Min
authors.initials: M
authors.lastname: Yang
authors.affiliation: Key Laboratory of Agro-Biodiversity and Pest Management of Education Ministry of China, Yunnan Agricultural University Kunming, China.
authors.forename: Huichuan
authors.initials: H
authors.lastname: Huang
authors.affiliation: Key Laboratory of Agro-Biodiversity and Pest Management of Education Ministry of China, Yunnan Agricultural University Kunming, China.
authors.forename: Youcong
authors.initials: Y
authors.lastname: Chuan
authors.affiliation: Key Laboratory of Agro-Biodiversity and Pest Management of Education Ministry of China, Yunnan Agricultural University Kunming, China.
authors.forename: Xiahong
authors.initials: X
authors.lastname: He
authors.affiliation: Key Laboratory of Agro-Biodiversity and Pest Management of Education Ministry of China, Yunnan Agricultural University Kunming, China.
authors.forename: Chengyun
authors.initials: C
authors.lastname: Li
authors.affiliation: Key Laboratory of Agro-Biodiversity and Pest Management of Education Ministry of China, Yunnan Agricultural University Kunming, China.
authors.forename: Youyong
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Agro-Biodiversity and Pest Management of Education Ministry of China, Yunnan Agricultural University Kunming, China.
authors.forename: Shusheng
authors.initials: S
authors.lastname: Zhu
keywords: DIMBOA; antimicrobial activity; defense genes; intercropping; resistance induction