The Expression of Small Heat Shock Proteins in Seeds Responds to Discrete Developmental Signals and Suggests a General Protective Role in Desiccation Tolerance1
AUTOR(ES)
Wehmeyer, Nadja
FONTE
American Society of Plant Physiologists
RESUMO
To learn more about the function and regulation of small heat shock proteins (sHSPs) during seed development, we studied sHSP expression in wild-type and seed maturation mutants of Arabidopsis by western analysis and using an HSP17.4 promoter-driven β-glucuronidase (GUS) reporter gene in transgenic plants. In the absence of stress, GUS activity increases during development until the entire embryo is stained before desiccation. Heat-stressed embryos stained for GUS at all stages, including early stages that showed no detectable HSP17.4::GUS activity without heat. Examination of HSP17.4 expression in seeds of the transcriptional activator mutants abi3-6, fus3-3 (AIMS no. CS8014/N8014), and lec1-2 (AIMS no. CS2922/N2922) showed that protein and HSP17.4::GUS activity were highly reduced in fus3-3 and lec1-2 and undetectable in abi3-6 seeds. In contrast, heat-stressed abi3-6, fus3-3, and lec1-2 seeds stained for GUS activity throughout the embryo. These data indicate that there is distinct developmental and stress regulation of HSP17.4, and imply that ABI3 activates HSP17.4 transcription during development. Quantitation of sHSP protein in desiccation-intolerant seeds of abi3-6, fus3-3, lec1-2, and line24 showed that all had <2% of wild-type HSP17.4 levels. In contrast, the desiccation-tolerant but embryo-defective mutants emb266 (AIMS no. CS3049/N3049) and lec2-1 (AIMS no. CS2728/N2728) had wild-type levels of HSP17.4. These data correlate a reduction in sHSPs with desiccation intolerance and suggest that sHSPs have a general protective role throughout the seed.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=58944Documentos Relacionados
- Heat Sensitivity in a Bentgrass Variant. Failure to Accumulate a Chloroplast Heat Shock Protein Isoform Implicated in Heat Tolerance1
- The Responses of Cytochrome Redox State and Energy Metabolism to Dehydration Support a Role for Cytoplasmic Viscosity in Desiccation Tolerance1
- Sugars and Desiccation Tolerance in Seeds 1
- Expression of Small Heat-Shock Proteins at Low Temperatures1 : A Possible Role in Protecting against Chilling Injuries
- Synthesis of small heat-shock proteins is part of the developmental program of late seed maturation.