Project description:Plant-parasitic cyst nematodes induce the formation of hypermetabolic feeding sites, termed syncytia, as their sole source of nutrients. The formation of the syncytium is orchestrated by the nematode in part by modulation of phytohormone responses, including cytokinin. In response to infection by the nematode H. schachtii, cytokinin signaling is transiently induced at the site of infection and in the developing syncytium. Arabidopsis lines with reduced cytokinin sensitivity show reduced susceptibility to nematode infection, indicating that cytokinin signaling is required for optimal nematode development. Furthermore, lines with increased cytokinin sensitivity also exhibit reduced nematode susceptibility. To ascertain why cytokinin hypersensitivity reduces nematode parasitism, we examined the transcriptomes in wild-type and a cytokinin-hypersensitive type-A arr Arabidopsis mutant in response to H. schachtii infection. Genes involved in the response to biotic stress and defense response were elevated in the type-A arr mutant in the absence of nematodes and were hyper-induced following H. schachtii infection, which suggests that the Arabidopsis type-A arr mutants impede nematode development because they are primed to respond to pathogen infection. These results suggest that cytokinin signaling is required for optimal H. schachtii parasitism of Arabidopsis, but that elevated cytokinin signaling triggers a heightened immune response to nematode infection.

2015-11-18 | GSE72548 | GEO

Arabidopsis thaliana

Project description:Cytokinin treatment on aerial parts of seedlings

| PRJNA99159 | ENA

Trans-Zeatin-N-Glucosides have biological activity in Arabidopsis thaliana

Project description:Cytokinin is an indispensable phytohormone responsible for a number of physiological processes ranging from root development to leaf senescence. The term “cytokinin” refers to several dozen adenine-derived compounds which occur naturally in plants, including the model plant Arabidopsis thaliana. Cytokinins (CKs) can be divided up into various classes and forms; the base forms are generally considered to be active while highly abundant cytokinin-N-glucosides (CKNGs), which are composed of a CK base irreversibly conjugated to a glucose molecule, are considered inactive. However, results from early CK studies suggest CKNGs do not always lack activity despite the perpetuation in the literature that they are inactive. Here we show that exogenous application of CKNGs to Arabidopsis tissue results in a CK response comparable to the application of an active CK base. These results are most apparent in senescence assays in which both a CK base (tZ) and CKNGs (tZ7G, tZ9G) delay senescence in cotyledons. Further physiological experiments involving root growth and shoot regeneration revealed CKNGs do not always have the same effects as CK bases, and these compounds have largely distinct effects on the transcriptome, as well as the proteome. These data are in direct contradiction to previous reports of CKNGs being inactive and raise questions about the function of these compounds as well as their mechanism of action. Because CKNGs make up the majority of CKs in Arabidopsis and other Angiosperms, it is especially important to understand their physiological effects in order to have a more holistic understanding of this essential phytohormone.

2020-05-27 | PXD016087 | Pride

Arabidopsis thaliana

Project description:Time-series transcriptome using VISUAL upon cytokinin application

| PRJDB19045 | ENA

Expression data from Arabidopsis thaliana senescent leaves treated with cytokinins

Project description:Cytokinins are plant hormones with biological functions ranging from coordination of plant growth and development to the regulation of senescence. A series of 2-chloro-N6-(halogenobenzylamino)purine ribosides was prepared and tested for cytokinin activity in selected bioassays. Several compounds showed significant activity, especially in delaying senescence in detached wheat leaves. We used microarrays to gather information about the reprogramming of gene transcription when senescent Arabidopsis leaves were treated with selected C2-substituted aromatic cytokinin ribosides that showed high activity in the senescence bioassay.

2015-12-11 | GSE75875 | GEO

Arabidopsis thaliana strain:Col

Project description:Arabidopsis transcriptome, Analysis of Cytokinin Response

| PRJDB10613 | ENA