Enhanced resistance to bacterial and oomycete pathogens by short tandem target mimic RNAs in tomato
Nucleotide binding site leucine-rich repeat (NLR) proteins of the plant innate immune system are negatively regulated by the miR482/2118 family miRNAs that are in a distinct 22-nt class of miRNAs with a double mode of action. First, they cleave the target RNA, as with the canonical 21-nt miRNAs, and...
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Published in | Proceedings of the National Academy of Sciences - PNAS Vol. 116; no. 7; pp. 2755 - 2760 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
National Academy of Sciences
12.02.2019
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Subjects | |
Online Access | Get full text |
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Summary: | Nucleotide binding site leucine-rich repeat (NLR) proteins of the plant innate immune system are negatively regulated by the miR482/2118 family miRNAs that are in a distinct 22-nt class of miRNAs with a double mode of action. First, they cleave the target RNA, as with the canonical 21-nt miRNAs, and second, they trigger secondary siRNA production using the target RNA as a template. Here, we address the extent to which the miR482/2118 family affects expression of NLR mRNAs and disease resistance. We show that structural differences of miR482/2118 family members in tomato (Solanum lycopersicum) are functionally significant. The predicted target of the miR482 subfamily is a conserved motif in multiple NLR mRNAs, whereas for miR2118b, it is a noncoding RNA target formed by rearrangement of several different NLR genes. From RNA sequencing and degradome data in lines expressing short tandem target mimic (STTM) RNAs of miR482/2118, we confirm the different targets of these miRNAs. The effect on NLR mRNA accumulation is slight, but nevertheless, the tomato STTM lines display enhanced resistance to infection with the oomycete and bacterial pathogens. These data implicate an RNA cascade of miRNAs and secondary siRNAs in the regulation of NLR RNAs and show that the encoded NLR proteins have a role in quantitative disease resistance in addition to dominant gene resistance that has been well characterized elsewhere. We also illustrate the use of STTM RNA in a biotechnological approach for enhancing quantitative disease resistance in highly bred cultivars. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 Author contributions: A.C.-P., S.S., and D.C.B. designed research; A.C.-P. and B.A.M.C.S. performed research; A.A.V. and W.S. contributed new reagents/analytic tools; A.C.-P. analyzed data; A.A.V. assisted with writing and analyses; and A.C.-P., S.S., and D.C.B. wrote the paper. 3Present address: Department of Plant Molecular Genetics, Spanish National Center for Biotechnology, Madrid 28049, Spain. 1Present address: Department of Plant Biology and Genome Center, University of California, Davis, CA 95616. Edited by Xuemei Chen, University of California, Riverside, CA, and approved December 20, 2018 (received for review August 22, 2018) 2Present address: Department of Crop Bioinformatics, National Institute of Agricultural Botany, Cambridge CB3 0LE, United Kingdom. |
ISSN: | 0027-8424 1091-6490 |
DOI: | 10.1073/pnas.1814380116 |