Wilkinson SW, Dalen LS, Skrautvol TO, Ton J, Krokene P, Mageroy MH. Transcriptomic changes during the establishment of long-term methyl jasmonate-induced resistance in Norway spruce.
Plant Cell Environ 2022;
45:1891-1913. [PMID:
35348221 PMCID:
PMC9321552 DOI:
10.1111/pce.14320]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 03/15/2022] [Indexed: 06/14/2023]
Abstract
Norway spruce (Picea abies) is an economically and ecologically important tree species that grows across northern and central Europe. Treating Norway spruce with jasmonate has long-lasting beneficial effects on tree resistance to damaging pests, such as the European spruce bark beetle Ips typographus and its fungal associates. The (epi)genetic mechanisms involved in such long-lasting jasmonate induced resistance (IR) have gained much recent interest but remain largely unknown. In this study, we treated 2-year-old spruce seedlings with methyl jasmonate (MeJA) and challenged them with the I. typographus vectored necrotrophic fungus Grosmannia penicillata. MeJA treatment reduced the extent of necrotic lesions in the bark 8 weeks after infection and thus elicited long-term IR against the fungus. The transcriptional response of spruce bark to MeJA treatment was analysed over a 4-week time course using mRNA-seq. This analysis provided evidence that MeJA treatment induced a transient upregulation of jasmonic acid, salicylic acid and ethylene biosynthesis genes and downstream signalling genes. Our data also suggests that defence-related genes are induced while genes related to growth are repressed by methyl jasmonate treatment. These results provide new clues about the potential underpinning mechanisms and costs associated with long-term MeJA-IR in Norway spruce.
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