Full-length transcriptome and targeted metabolome analyses provide insights into defense mechanisms of Malus sieversii against Agrilus mali

Abstract

Malus sieversii is the wild progenitor for many cultivars of domesticated apple and an important germplasm resource for breeding. However, this valuable species faces a significant threat in the areas north of the Tianshan Mountains in China, by the invasion of Agrilus mali, a destructive pest of apple trees belonging to the family Buprestidae. Our preliminary study has has shown that there may be resistance to this insect in M. sieversii plants in the field, but the corresponding molecular mechanisms remain unclear. In this study, we compared the response of insect-resistant and insect-susceptible plants of M. sieversii to insect feeding using full-length transcriptome and targeted metabolome. 112,103 non-chimeric full-length reads (FLNC) totaling 10.52 Gb of data were generating with Pacific Biosciences SingleMolecule, Real-Time (PacBio SMRT) sequencing. A total of 130.06 Gb data of long reads were acquired with an Illumina HiSeq. Function annotation indicated that the different expressed genes (DEGs) were mainly involved in signal transduction pathway of plant hormones and in the synthesis of compounds such as terpenes, quinones, flavonoids, and jasmonic acid. Through targeted metabolome analysis resistant strains showed higher levels of trans-cinnamic acid, caffeine and ferulic acid after pest infestation. This study helps to decipher the transcriptional changes and related signaling paths in M. sieversii after an insect feeding, which lays a foundation for further research on molecular mechanisms of insect resistance in apples.

Integrated analysis of transcriptome, metabolome, and histochemistry reveals the response mechanisms of different ages Panax notoginseng to root-knot nematode infection

“…These results aligned with previous studies indicating that plants can activate the phenylpropanoid biosynthesis and flavonoid biosynthesis pathways in response to pathogen infection. This resulted in the production of various compounds such as phenolics, flavonoids, lignin, and anthocyanin pigments ( Chen et al., 2019 ; 2020; Mei et al., 2020 ; Sudheeran et al., 2021 ). However, the specific alterations in genes and metabolites in the phenylpropanoid biosynthesis and flavonoid biosynthesis pathways in different age groups of P. notoginseng under RKN infection remain unclear, and further investigation is required to identify the key genes and metabolites associated with the defense against RKN damage.…”

“…The usability of the RNA-Seq data and the results of the differential expression analysis were validated through the application of quantitative real-time reverse-transcription PCR (qRT-PCR) technology ( Mei et al., 2020 ; Xin et al., 2021 ). Twelve disease-resistant-related DEGs from the phenylpropanoid biosynthesis pathway were specifically selected for qRT-PCR verification.…”

Cyclocarya paliurus Reprograms the Flavonoid Biosynthesis Pathway Against Colletotrichum fructicola

“…For further metabolomics analysis of secondary metabolites, 2-year-old C. paliurus seedlings of resistant (Wufeng) and susceptible (Jinggangshan) cultivars were inoculated following the IPI method as described earlier. The sample preparation, extract analysis, metabolite separation, and detection were conducted by MetWare Biological Science and Technology (Wuhan, China) following their standard procedures, which were previously described by Li et al (2021) and Mei et al (2020) . In brief, 100 mg crushed, freeze-dried sample was extracted overnight at 4°C with 0.6 mL 70% (v/v) aqueous methanol.…”

MePAL6 regulates lignin accumulation to shape cassava resistance against two-spotted spider mite

“…Apart from lignin, several intermediate compounds during lignin biosynthesis also possess the pest resistance capacity. For examples, the resistant cotton varieties presented high content of ferulic acid, which significantly delayed the larval weight gain and increased the mortality of cotton bollworm (Helicoverpa armigera) (Mao et al, 2007), moreover, targeted metabolome analysis showed higher elevation of trans-cinnamic acid, caffeine and ferulic acid after the Malus sieversii resistant strains were infested by Agrilus mali (Mei et al, 2020).…”