Expressional regulation of CKI1 provides molecular evidence for hormone interplay during Arabidopsis root development
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| Year of publication | 2005 |
| Type | Conference abstract |
| MU Faculty or unit | |
| Citation | |
| Description | Gametophytic expression of sensor histidine kinase CKI1, originally implicated in cytokinin signaling, was shown to be essential for megagametogenesis in Arabidopsis. Using CKI1 promoter::uidA lines and CKI1 mRNA and protein in situ localization, we have identified the activity of CKI1 in both root (root tip, vascular tissue and lateral root primordia) and shoot (shoot apical meristem, vascular tissue of cotyledons, floral organs, flower pedicels and inflorescence stem). We have found that the activity of CKI1 promoter in the root (but not the shoot) of young seedlings could be manipulated by exogenous application of cytokinin, auxin and auxin transport inhibitors. The ectopic expression domain of CKI1 after application of both hormones overlaps with auxin intracellular local maxima as identified by the auxin responsive promoter DR5. Cytokinin induced changes of the auxin pattern might explain the observed dependence of CKI1 transcription activity on both hormones, thus providing molecular evidence for the long known interplay between the two principal plant growth regulators. The role of ethylene in the CKI1 response to both cytokinin and auxin will be discussed. Supported by LN00A081, MSM0021622415, AVOZ50040507 and IAA600380507. |
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