Aromatic Cytokinin Arabinosides Promote PAMP-like Responses and Positively Regulate Leaf Longevity
Language English Country United States Media print-electronic
Document type Journal Article, Research Support, Non-U.S. Gov't
- MeSH
- Arabidopsis chemistry metabolism MeSH
- Arabinonucleosides chemistry pharmacology MeSH
- Cytokinins chemistry pharmacology MeSH
- Plant Immunity drug effects MeSH
- Plant Leaves drug effects MeSH
- MAP Kinase Signaling System drug effects MeSH
- Mitogen-Activated Protein Kinases genetics metabolism MeSH
- Molecular Structure MeSH
- Pathogen-Associated Molecular Pattern Molecules pharmacology MeSH
- Arabidopsis Proteins genetics metabolism MeSH
- Gene Expression Regulation, Plant drug effects MeSH
- Structure-Activity Relationship MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Arabinonucleosides MeSH
- Cytokinins MeSH
- Mitogen-Activated Protein Kinases MeSH
- Pathogen-Associated Molecular Pattern Molecules MeSH
- Arabidopsis Proteins MeSH
Cytokinins are plant hormones with biological functions ranging from coordination of plant growth to the regulation of biotic and abiotic stress-related responses and senescence. The components of the plant immune system can learn from past elicitations by microbial pathogens and herbivores and adapt to new threats. It is known that plants can enter the primed state of enhanced defense induced by either natural or synthetic compounds. While the involvement of cytokinins in defense priming has been documented, no comprehensive model of their action has been provided to date. Here, we report the functional characterization of two aromatic cytokinin derivatives, 6-benzylaminopurine-9-arabinosides (BAPAs), 3-methoxy-BAPA and 3-hydroxy-BAPA, that proved to be effective in delaying senescence in detached leaves while having low interactions with the cytokinin pathway. An RNA-seq profiling study on Arabidopsis leaves treated with 3-methoxy-BAPA revealed that short and extended treatments with this compound shifted the transcriptional response markedly toward defense. Both treatments revealed upregulation of genes involved in processes associated with plant innate immunity such as cell wall remodeling and upregulation of specific MAP kinases, most importantly MPK11, which is a MAPK module involved in stress-related signaling during the pathogen-associated molecular patterns (PAMPs) response. In addition, elevated levels of JA and its metabolites, jasmonate/ethylene-driven upregulation of PLANT DEFENSIN 1.2 (PDF1.2) and other defensins, and also temporarily elevated levels of reactive oxygen species marked the plant response to 3-methoxy-BAPA treatment. Synergistic interactions were observed when plants were cotreated with 3-hydroxy-BAPA and the flagellin-derived bacterial PAMP peptide (flg22), leading to the enhanced expression of the PAMP-triggered immunity (PTI) marker gene FRK1. Our data collectively show that some BAPAs can sensitively prime the PTI responses in a low micromolar range of concentrations while having no observable negative effects on the overall fitness of the plant.
References provided by Crossref.org
Chemical priming of plant defense responses to pathogen attacks
The Role of a Cytokinin Antagonist in the Progression of Clubroot Disease
Plant hormone cytokinin at the crossroads of stress priming and control of photosynthesis
