Transcriptome analysis of scions grafted to potato rootstock for improving late blight resistance

Mapping Intimacies ◽

10.21203/rs.3.rs-58639/v2 ◽

2020 ◽

Author(s):

Yuexin Li ◽

Degang Zhao

Keyword(s):

Disease Resistance ◽

Late Blight ◽

Protein Kinases ◽

Molecular Mechanisms ◽

Late Blight Resistance ◽

Potato Late Blight ◽

Susceptible Variety ◽

Resistant Variety ◽

Blight Resistance ◽

Expression Levels

Abstract Background: Late blight seriously threatens potato cultivation worldwide. The severe and widespread damage caused by the fungal pathogen can lead to drastic decreases in potato yield. Although grafting technology has been widely used to improve crop resistance, the effects of grafting on potato late blight resistance as well as the associated molecular mechanisms remain unclear. Therefore, we performed RNA transcriptome sequencing analysis and the late blight resistance testing of the scion when the potato late blight-resistant variety Qingshu 9 and the susceptible variety Favorita were used as the rootstock and scion, respectively, and vice versa. The objective of this study was to evaluate the influence of the rootstock on scion disease resistance and to clarify the related molecular mechanisms.Results: A Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis revealed that the expression levels of genes related to plant–pathogen interactions, plant mitogen-activated protein kinase (MAPK) signaling pathways, and plant hormone signal transduction pathways were significantly up-regulated in the scion when Qingshu 9 was used as the rootstock. These genes included late blight response genes encoding calcium-dependent protein kinases (CDPKs), chitin elicitor receptor kinases (CERKs), LRR receptor serine/threonine protein kinases (LRR-LRKs), NPR family proteins in the salicylic acid synthesis pathway, and MAPKs. When Favorita was used as the rootstock, the expression levels of the late blight response genes were not up-regulated in the Qingshu 9 scion, but the expression levels of the genes related to proline metabolism, fatty acid chain elongation, and diterpenoid biosynthesis pathways were down-regulated. Resistance results showed that self-grafting of the susceptible variety and grafting with the resistant variety as the rootstock increased the resistance of the susceptible scion to late blight. However, the resistance was stronger after grafting with the resistant variety as the rootstock. Using the susceptible variety as the rootstock decreased the late blight resistance of the resistant scion.Conclusions: Our results showed that changes to the expression of disease resistance genes in the scion after grafting are associated with late blight resistance. The results provide the basis for exploring the molecular mechanism underlying the effects of rootstocks on scion disease resistance.

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Transcriptome analysis of scions grafted to potato rootstock for improving late blight resistance

BMC Plant Biology ◽

10.1186/s12870-021-03039-w ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Yuexin Li ◽

Degang Zhao

Keyword(s):

Disease Resistance ◽

Late Blight ◽

Protein Kinases ◽

Molecular Mechanisms ◽

Late Blight Resistance ◽

Potato Late Blight ◽

Lesion Size ◽

Susceptible Variety ◽

Resistant Variety ◽

Blight Resistance

Abstract Background Late blight seriously threatens potato cultivation worldwide. The severe and widespread damage caused by the fungal pathogen can lead to drastic decreases in potato yield. Although grafting technology has been widely used to improve crop resistance, the effects of grafting on potato late blight resistance as well as the associated molecular mechanisms remain unclear. Therefore, we performed RNA transcriptome sequencing analysis and the late blight resistance testing of the scion when the potato late blight-resistant variety Qingshu 9 and the susceptible variety Favorita were used as the rootstock and scion, respectively, and vice versa. The objective of this study was to evaluate the influence of the rootstock on scion disease resistance and to clarify the related molecular mechanisms. Results A Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis revealed that the expression levels of genes related to plant–pathogen interactions, plant mitogen-activated protein kinase (MAPK) signaling pathways, and plant hormone signal transduction pathways were significantly up-regulated in the scion when Qingshu 9 was used as the rootstock. Some of these genes encoded calcium-dependent protein kinases (CDPKs), chitin elicitor receptor kinases (CERKs), LRR receptor serine/threonine protein kinases (LRR-LRKs), NPR family proteins in the salicylic acid synthesis pathway, and MAPKs which were potato late blight response proteins. When Favorita was used as the rootstock, only a few genes of late blight response genes were upregulated in the scion of Qingshu 9. Grafted plants using resistant variety as rootstocks inoculated with P. infestans spores showed significant reductions in lesion size while no significant difference in lesion size was observed when susceptible variety was used as the rootstock. We also showed that this induction of disease resistance in scions, especially scions derived from susceptible potato varieties was mediated by the up-regulation of expression of genes involved in plant disease resistance in scions. Conclusions Our results showed that potato grafting using late blight resistant varieties as rootstocks could render or enhance resistance to late blight in scions derived from susceptible varieties via up-regulating the expression of disease resistant genes in scions. The results provide the basis for exploring the molecular mechanism underlying the effects of rootstocks on scion disease resistance.

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Transcriptome Analysis of Grafted Potato Rootstock for Improvement of Scion Late-Blight Resistance

10.21203/rs.3.rs-58639/v1 ◽

2020 ◽

Author(s):

Yuexin Li ◽

Degang Zhao

Keyword(s):

Late Blight ◽

Molecular Mechanisms ◽

Enrichment Analysis ◽

Late Blight Resistance ◽

Potato Late Blight ◽

Mapk Signaling ◽

Susceptible Variety ◽

Resistant Variety ◽

Blight Resistance

Abstract Late blight seriously threatens potato cultivation worldwide. Damage caused by the fungus, which is severe and widespread, can lead to drastic reductions in potato yield and even total loss. Although grafting technology has been widely used to improve crop resistance, the effects and associated molecular mechanisms of grafting on resistance to potato late blight are unclear. In this study, we therefore performed RNA transcriptome sequencing of the scion when potato late blight-resistant variety Qingshu 9 and susceptible variety Favorita were used as the rootstock and scion, respectively, and vice versa. Using the sequencing results, we analyzed the influence of the rootstock on scion resistance and related molecular mechanisms. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that plant–pathogen interactions, the plant MAPK signaling pathway, and genes on the SA pathway were significantly up-regulated in the scion when Qingshu 9 was used as the rootstock. When Favorita was used as the rootstock, β-ketoacyl-CoA synthase-related genes in the scion, Qingshu 9, were significantly down-regulated. Resistance to late blight on scion leaves were also tested in vitro, which results consistent with those obtained by sequencing. All the generated evidence indicates that the use of resistant and susceptible varieties as rootstocks can respectively increase and reduce resistance to late blight. Our sequencing results further elucidate the molecular mechanism underlying the post-grafting effects of rootstocks on late blight resistance and provide a theoretical basis for the transfer of resistance genes between scions and rootstocks after grafting.

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Faculty Opinions recommendation of Accelerated cloning of a potato late blight-resistance gene using RenSeq and SMRT sequencing.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.726310370.793518186 ◽

2016 ◽

Author(s):

Jiming Jiang

Keyword(s):

Late Blight ◽

Resistance Gene ◽

Late Blight Resistance ◽

Potato Late Blight ◽

Blight Resistance ◽

Smrt Sequencing

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Higher Copy Numbers of the Potato RB Transgene Correspond to Enhanced Transcript and Late Blight Resistance Levels

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-22-4-0437 ◽

2009 ◽

Vol 22 (4) ◽

pp. 437-446 ◽

Cited By ~ 72

Author(s):

James M. Bradeen ◽

Massimo Iorizzo ◽

Dimitre S. Mollov ◽

John Raasch ◽

Lara Colton Kramer ◽

...

Keyword(s):

Disease Resistance ◽

Late Blight ◽

Resistance Gene ◽

Resistance Genes ◽

Rna Silencing ◽

Late Blight Resistance ◽

Blight Resistance ◽

Transcript Levels ◽

Cultivated Potato ◽

Copy Numbers

Late blight of potato ranks among the costliest of crop diseases worldwide. Host resistance offers the best means for controlling late blight, but previously deployed single resistance genes have been short-lived in their effectiveness. The foliar blight resistance gene RB, previously cloned from the wild potato Solanum bulbocastanum, has proven effective in greenhouse tests of transgenic cultivated potato. In this study, we examined the effects of the RB transgene on foliar late blight resistance in transgenic cultivated potato under field production conditions. In a two-year replicated trial, the RB transgene, under the control of its endogenous promoter, provided effective disease resistance in various genetic backgrounds, including commercially prominent potato cultivars, without fungicides. RB copy numbers and transcript levels were estimated with transgene-specific assays. Disease resistance was enhanced as copy numbers and transcript levels increased. The RB gene, like many other disease resistance genes, is constitutively transcribed at low levels. Transgenic potato lines with an estimated 15 copies of the RB transgene maintain high RB transcript levels and were ranked among the most resistant of 57 lines tested. We conclude that even in these ultra–high copy number lines, innate RNA silencing mechanisms have not been fully activated. Our findings suggest resistance-gene transcript levels may have to surpass a threshold before triggering RNA silencing. Strategies for the deployment of RB are discussed in light of the current research.

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