Comparative transcriptomic responses of European and Japanese larches to infection by Phytophthora ramorum

<strong>Background and objectives<br></strong> Phytophthora ramorum severely affects both European larch (EL) and Japanese larch (JL) trees as indicated by high levels of mortality particularly in the UK. Field observations suggested that EL is less severely affected and so may be...

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Main Authors: Dun F, H, Hung, TIN, Green, S, Mackay, JJ
Format: Journal article
Language:English
Published: BioMed Central 2022
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author Dun F, H
Hung, TIN
Green, S
Mackay, JJ
author_facet Dun F, H
Hung, TIN
Green, S
Mackay, JJ
author_sort Dun F, H
collection OXFORD
description <strong>Background and objectives<br></strong> Phytophthora ramorum severely affects both European larch (EL) and Japanese larch (JL) trees as indicated by high levels of mortality particularly in the UK. Field observations suggested that EL is less severely affected and so may be less susceptible to P. ramorum than JL; however, controlled inoculations have produced inconsistent or non-statistically significant differences. The present study aimed to compare RNA transcript accumulation profiles in EL and JL in response to inoculation with P. ramorum to improve our understanding of their defence responses. <br><strong> Methodology<br></strong> RNA-sequencing was carried out on bark tissues following the inoculation with P. ramorum of potted saplings in both EL and JL carried out under controlled environment conditions, with sampling at 1, 3, 10, and 25 days post inoculation in infected and control plants. <br><strong> Results<br></strong> All of the inoculated trees rapidly developed lesions but no statistically significant differences were found in lesion lengths between EL and JL. RNA-Sequencing comparing control and inoculate saplings identified key differences in differentially expressed genes (DEGs) between the two larch species. European larch had rapid induction of defence genes within 24 hours of infection followed by sustained expression until 25 days after inoculation. Results in JL were more varied; upregulation was stronger but more transient and represented fewer defence pathways. Gene enrichment analyses highlighted differences in jasmonate signalling and regulation including NPR1 upregulation in EL only, and specific aspects of secondary metabolism. Some DEGs were represented by multiple responsive copies including lipoxygenase, chalcone synthase and nucleotide-binding, leucine-rich-repeat genes. <br><strong> Conclusion<br></strong> The variations between EL and JL in responsive DEGs of interest as potentially related to differences seen in the field and should be considered in the selection of trees for planting and future breeding.
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spelling oxford-uuid:05e6100d-fc48-41f2-929f-8885937e23dd2022-10-13T17:01:48ZComparative transcriptomic responses of European and Japanese larches to infection by Phytophthora ramorumJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:05e6100d-fc48-41f2-929f-8885937e23ddEnglishSymplectic ElementsBioMed Central2022Dun F, HHung, TINGreen, SMackay, JJ<strong>Background and objectives<br></strong> Phytophthora ramorum severely affects both European larch (EL) and Japanese larch (JL) trees as indicated by high levels of mortality particularly in the UK. Field observations suggested that EL is less severely affected and so may be less susceptible to P. ramorum than JL; however, controlled inoculations have produced inconsistent or non-statistically significant differences. The present study aimed to compare RNA transcript accumulation profiles in EL and JL in response to inoculation with P. ramorum to improve our understanding of their defence responses. <br><strong> Methodology<br></strong> RNA-sequencing was carried out on bark tissues following the inoculation with P. ramorum of potted saplings in both EL and JL carried out under controlled environment conditions, with sampling at 1, 3, 10, and 25 days post inoculation in infected and control plants. <br><strong> Results<br></strong> All of the inoculated trees rapidly developed lesions but no statistically significant differences were found in lesion lengths between EL and JL. RNA-Sequencing comparing control and inoculate saplings identified key differences in differentially expressed genes (DEGs) between the two larch species. European larch had rapid induction of defence genes within 24 hours of infection followed by sustained expression until 25 days after inoculation. Results in JL were more varied; upregulation was stronger but more transient and represented fewer defence pathways. Gene enrichment analyses highlighted differences in jasmonate signalling and regulation including NPR1 upregulation in EL only, and specific aspects of secondary metabolism. Some DEGs were represented by multiple responsive copies including lipoxygenase, chalcone synthase and nucleotide-binding, leucine-rich-repeat genes. <br><strong> Conclusion<br></strong> The variations between EL and JL in responsive DEGs of interest as potentially related to differences seen in the field and should be considered in the selection of trees for planting and future breeding.
spellingShingle Dun F, H
Hung, TIN
Green, S
Mackay, JJ
Comparative transcriptomic responses of European and Japanese larches to infection by Phytophthora ramorum
title Comparative transcriptomic responses of European and Japanese larches to infection by Phytophthora ramorum
title_full Comparative transcriptomic responses of European and Japanese larches to infection by Phytophthora ramorum
title_fullStr Comparative transcriptomic responses of European and Japanese larches to infection by Phytophthora ramorum
title_full_unstemmed Comparative transcriptomic responses of European and Japanese larches to infection by Phytophthora ramorum
title_short Comparative transcriptomic responses of European and Japanese larches to infection by Phytophthora ramorum
title_sort comparative transcriptomic responses of european and japanese larches to infection by phytophthora ramorum
work_keys_str_mv AT dunfh comparativetranscriptomicresponsesofeuropeanandjapaneselarchestoinfectionbyphytophthoraramorum
AT hungtin comparativetranscriptomicresponsesofeuropeanandjapaneselarchestoinfectionbyphytophthoraramorum
AT greens comparativetranscriptomicresponsesofeuropeanandjapaneselarchestoinfectionbyphytophthoraramorum
AT mackayjj comparativetranscriptomicresponsesofeuropeanandjapaneselarchestoinfectionbyphytophthoraramorum