| Abstract Detail
Mineral Nutrition Mason, Michael [1], Mathews, Dennis [2], Salt, David [3], Schaller, G. Eric [4]. Cytokinin’s regulation of the nutriome. The plant hormone cytokinin plays a vital role in many plant processes including cell division, chloroplast development, and senescence and has been implicated in regulating various aspects of nutrient acquisition and distribution in plants. Cytokinin signalling begins via a two-component phosphorelay involving histidine kinases, histidine-containing phosphotransfer proteins, and response regulators. Genomic analysis of Arabidopsis thaliana supports the existence of 23 response regulators (ARRs) that can be divided into at least two distinct groups designated type-A and type-B. We have identified T-DNA insertions in 10 of the 11 the type-B ARRs and, from these, have generated higher order mutants. Plants with mutations in a single ARR display only slight or no phenotypes however, progressively greater insensitivity to cytokinin was observed in mutants containing insertions in multiple subfamily I type-B ARRs, with the arr1,10,12 mutant displaying almost complete insensitivity to cytokinin. Analysis of arr mutants with low sensitivity cytokinin by inductively coupled plasma mass spectrometry (ICP-MS) reveals significant alterations in the levels of several plant nutrients. These findings were supported by ICP analysis of plants with mutations in other two-component genes involved in the primary cytokinin response. Our results reveal that cytokinin functions via a two-component signalling pathway to regulate micro-nutrient homeostasis in plants.
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1 - University of Queensland, School of Integrative Biology, St.Lucia, Queensland, 4072, Australia
2 - University of New Hampshire, Department of Plant Biology
3 - Purdue University, Department of Horticulture and Landscape Architecture
4 - Dartmouth College, Biology Department
Keywords:
none specified
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P11012
Abstract ID:1102 |
