ABSTRACT: The biosynthetic genes for cyanogenic glucosides in Phaseolus lunatus reveal evolutionary dynamics in oxime-based defences in the Phaseolus genus
Project description:Understanding the complex interactions between plants and herbivores is essential for improving crop resistance. To deep into the role of cyanogenesis in plant defence, we investigated the response of the cyanogenic Phaseolus lunatus (lima bean) and the non-cyanogenic Phaseolus vulgaris (common bean) to Tetranychus urticae infestation. Despite spider mite infesting both legumes, severity of leaf damage was reduced in lima bean. Comparative transcriptome analysis revealed that both species exhibited substantial metabolic and transcriptional changes upon infestation, yet the response in P. lunatus was significantly more pronounced. Specific differences in amino acid homeostasis and in the expression of key genes of the cyanogenic pathway were observed in P. lunatus. Moreover, the mandelonitrile lyase gene (PlMNL1) was upregulated following T. urticae feeding concomitantly to an enzyme activity increase. Lima bean plants also displayed an induction of β-cyanoalanine synthase (PlCYSC1), a key enzyme for cyanide detoxification, suggesting an internal regulatory mechanism to manage the toxicity of their defence responses. These findings contribute to have a major comprehension of the plant-insect interactions and underscore the potential role of cyanogenesis in the elaboration of unique specific defensive responses, even within the same genus, which may reflect distinctive evolutionary adaptations or varying metabolic capabilities between species.
Project description:250 adult T. urticae females from the London strain (grown on acyanogenic P. vulgaris cv. Prelude bean plants) were transferred to cyanogenic P. lunatus cv. 8078 bean plants. Thirty-five generations after the host transfer, total RNA was extracted from mites growing on both bean species (London and London-CYANO strain) and used in in a genome-wide gene expression microarray (Sureprint G3 microarray, Agilent) experiment to assess significantly differentially expressed genes (FC M-bM-^IM-% 2 and FDR-corrected p-value < 0.05) between mites grown on P. vulgaris (cv. Prelude) bean plants (London strain) and mites grown for 35 generations on P. lunatus (cv. 8078) bean plants (London-CYANO strain). 4 replicates for one comparison: mites of the London strain grown on P. lunatus for 35 generations (London-CYANO) compared to mites of the London strain grown on P. vulgaris bean plants (London)
Project description:250 adult T. urticae females from the London strain (grown on acyanogenic P. vulgaris cv. Prelude bean plants) were transferred to cyanogenic P. lunatus cv. 8078 bean plants. Thirty-five generations after the host transfer, total RNA was extracted from mites growing on both bean species (London and London-CYANO strain) and used in in a genome-wide gene expression microarray (Sureprint G3 microarray, Agilent) experiment to assess significantly differentially expressed genes (FC ≥ 2 and FDR-corrected p-value < 0.05) between mites grown on P. vulgaris (cv. Prelude) bean plants (London strain) and mites grown for 35 generations on P. lunatus (cv. 8078) bean plants (London-CYANO strain).
