Expression of PmACRE1 in Arabidopsis thaliana enables host defence against Bursaphelenchus xylophilus infection

Abstract

Background Pine wilt disease (PWD) is a destructive disease that endangers pine trees, resulting in the wilting, with yellowing and browning of the needles, and eventually the death of the trees. Previous studies showed that the Avr9/Cf-9 rapidly elicited (PmACRE1) gene was downregulated by Bursaphelenchus xylophilus infection, suggesting a correlation between PmACRE1 expression and pine tolerance. Here, we used the expression of PmACRE1 in Arabidopsis thaliana to evaluate the role of PmACRE1 in the regulation of host defence against B. xylophilus infection. Results Our results showed that the transformation of PmACRE1 into A. thaliana enhanced plant resistance to the pine wood nematode (PWN); that is, the leaves of the transgenic line remained healthy for a longer period than those of the blank vector group. Ascorbate peroxidase (APX) activity and total phenolic acid and total flavonoid contents were higher in the transgenic line than in the control line. Widely targeted metabolomics analysis of the global secondary metabolites in the transgenic line and the vector control line showed that the contents of 30 compounds were significantly different between these two lines; specifically, the levels of crotaline, neohesperidin, nobiletin, vestitol, and 11 other compounds were significantly increased in the transgenic line. The studies also showed that the ACRE1 protein interacted with serine hydroxymethyltransferase, catalase domain-containing protein, myrosinase, dihydrolipoyl dehydrogenase, ketol-acid reductoisomerase, geranylgeranyl diphosphate reductase, S-adenosylmethionine synthase, glutamine synthetase, and others to comprehensively regulate plant resistance. Conclusions Taken together, these results indicate that PmACRE1 has a potential role in the regulation of plant defence against PWNs.

The novel nematicide chiricanine A suppresses Bursaphelenchus xylophilus pathogenicity in Pinus massoniana by inhibiting Aspergillus and its secondary metabolite, sterigmatocystin

“…Meanwhile, the amount of flavonoids was significantly increased by ST treatment, indicating that ST may serve as a signal to initiate the later stages of plant defense (Hedrich et al, 2016). Plant flavonoids have been widely demonstrated to be toxic to pests, including the Pine Wood Nematode (PWN) (Shen et al, 2022;Xie et al, 2022). However, over a long period of co-evolution, pests have developed efficient detoxification systems to counteract the toxic effects of secondary metabolites, including flavonoids (Souto et al, 2021).…”

The novel nematicide chiricanine A suppressesBursaphelenchus xylophiluspathogenicity inPinus massonianaby inhibitingAspergillusand its secondary metabolite, sterigmatocystin

“…Meanwhile, the amount of flavonoids is reduced substantially by ST, together with ROS accumulation being suppressed in host pine tree, implies that ST could also halt or paralyze the later stages of plant defense response 52 . Plant flavonoids are widely proven to be toxic to pests, including PWN 53,54 . This suggests that PWN may have a highly effective detoxification system to withstand flavonoids and survive in the host plant by hijacking microbes.…”