An Arabidopsis Histidine Kinase Is Essential for Megagametogenesis

Cytokinin-Independent 1 (CKI1) belongs to a group of putative plant histidine kinases whose members do not appear to act as ethylene receptors. The deduced protein structure, combined with the observation that Arabidopsis callus cultures overexpressing CKI1 exhibit a "cytokinin-independent"...

Full description

Saved in:
Bibliographic Details
Published in:Proceedings of the National Academy of Sciences - PNAS 2002-11, Vol.99 (24), p.15800-15805
Main Authors: Pischke, Melissa S., Jones, Linda G., Otsuga, Denichiro, Fernandez, Donna E., Drews, Gary N., Sussman, Michael R.
Format: Article
Language:English
Subjects:
Alleles
Arabidopsis - enzymology
Arabidopsis - physiology
Arabidopsis Proteins - genetics
Arabidopsis Proteins - physiology
Biological Sciences
Botany
Cell Division
Cell nucleus
Cytokines
Cytokinins
DNA, Bacterial - genetics
Embryo sac
Female animals
Gametogenesis - physiology
Gametophytes
Gene Expression Profiling
Genes
Microscopy, Confocal
Mother cells
Mutagenesis, Insertional
Mutation
Organ Culture Techniques
Phenotype
Phenotypes
Phosphorylation
Plants
Polymerase chain reaction
Protein Kinases - genetics
Protein Kinases - physiology
Protein Processing, Post-Translational
RNA, Messenger - biosynthesis
RNA, Plant - biosynthesis
Signal Transduction
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Cytokinin-Independent 1 (CKI1) belongs to a group of putative plant histidine kinases whose members do not appear to act as ethylene receptors. The deduced protein structure, combined with the observation that Arabidopsis callus cultures overexpressing CKI1 exhibit a "cytokinin-independent" cell division and greening phenotype, led to the hypothesis that CKI1 is involved in cytokinin signaling, perhaps acting as a cytokinin receptor. To test the function of CKI1, we used a reverse-genetic approach to identify plants carrying T-DNA insertions in CKI1. Two independent alleles were identified, which produce the same developmental phenotype. Analyses of populations segregating for the cki1-5 or cki1-6 T-DNA insertion alleles failed to reveal any homozygous cki1 plants, indicating that the homozygous mutant condition was lethal. Based on segregation distortion, transmission studies, a microscopy-based examination of developing female gametophytes, and mRNA expression data, we suggest that CKI1 function is required for megagametophyte development. Our work with CKI1 mutants indicates that signal transduction by means of a His/Asp phosphorelay system may play an important and previously unsuspected role in female gametophyte development in Arabidopsis.
ISSN:0027-8424
1091-6490
DOI:10.1073/pnas.232580499