Transcriptomic changes during the establishment of long‐term methyl jasmonate‐induced resistance in Norway spruce

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.

Genotype-Dependent Jasmonic Acid Effect on Pinus sylvestris L. Growth and Induced Systemic Resistance Indicators

“…Jasmonic acid itself and related jasmonates are plant growth regulators linked with stress mediation and, more specifically, resistance to pathogen attacks and herbivores [ 23 , 24 , 25 ]. As reported by Zas et al [ 4 ], Thaler et al [ 11 ], Sabbagh et al [ 7 ] and others, jasmonates are an effective ISR elicitor that can help with plant response to abiotic and biotic stressors.…”

“…As reported by Zas et al [ 4 ], Thaler et al [ 11 ], Sabbagh et al [ 7 ] and others, jasmonates are an effective ISR elicitor that can help with plant response to abiotic and biotic stressors. Jasmonates were even shown to work in several studies on pines and other conifers [ 4 , 8 , 24 , 25 , 26 , 27 ]. However, while previous studies have examined ISR‘s importance for plant resistance mechanisms to biotic and abiotic stress, there is a gap in analyzing its impact on conifer species.…”

Methyl jasmonate, salicylic acid, and oxalic acid affects growth, inducible defenses, and pine weevil resistance in Norway spruce

“…Stem treatment of mature Norway spruce trees with 5 to 100 mM MeJA reduced symptoms of fungal infection in a dose-dependent manner ( Zeneli et al., 2006 ). Additionally, foliar treatment of 2-year-old plants with 10 mM MeJA reduced stem colonization of the bluestain fungus Grosmannia penicillata ( Wilkinson et al., 2022 ). These previous studies demonstrate that even low MeJA concentrations can induce pathogen resistance in Norway spruce.…”

Transcriptional Analysis of Tea Plants (Camellia sinensis) in Response to Salicylic Acid Treatment

“…Plants always face various challenging environmental conditions during natural growth, and plant hormones play a significant role in plant immune response following different pathogen infections and attack of plant diseases or fungus. − To protect from the attack of different pathogens, plants have evolved multiple defense mechanisms, one is pathogen-associated molecular pattern-triggered immunity (PTI), which is also called basal resistance and enables plants to defend against a large number of pathogens; another one is effector-triggered immunity (ETI), which relies on host resistance (R) proteins to induce a more durable immune response. Pathogen invasion can trigger rapid localized necrotic lesions and cell death, termed the hypersensitive response (HR), which is one of the visible manifestations of ETI.…”