Abstract
Linker histones are ubiquitous structural components of chromatin that have been shown to influence the expression of a subset of genes in diverse organisms. Plants contain a minor linker histone variant that is expressed in most tissues of all organs, and is induced during drought stress. Based on reporter gene analysis in roots, His1-3 is expressed almost exclusively in emerging secondary roots in unstressed plants, but is primarily expressed in the root meristem and elongation zone of stressed plants. In shoots, expression is higher in younger tissues than older tissues. In order to investigate the function of H1-3, we have generated lines with altered levels of H1-3. Plants expressing an antisense His1-3 transcript exhibit a greatly impaired induction (5% of wild-type RNA levels during stress) of His1-3 transcripts in shoots during drought and contain decreased protein relative to wild-type control plants. In plants overexpressing His1-3, more H1-3 is bound to chromatin than in unstressed wild-type plants. None of the plants containing these transgenes display phenotypic aberrations or differences in water content during drought stress. Additionally, the expression of several drought-responsive genes is not significantly altered in lines misexpressing His1-3.
Original language | English (US) |
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Pages (from-to) | 159-169 |
Number of pages | 11 |
Journal | Plant molecular biology |
Volume | 41 |
Issue number | 2 |
DOIs | |
State | Published - Sep 1999 |
Bibliographical note
Funding Information:We thank the Arabidopsis Biological Resources Center for providing us with several cDNAs used as probes in this research, and the laboratory of Peter Snustad, Department of Genetics and Cell Biology, University of Minnesota, St. Paul, for the TUB1 cDNA. Bud Markhardt, Department of Horticulture, University of Minnesota, provided much useful advice on the assessment of plant water status. We especially thank Colleen Jacks, Department of Biology, Gustavus Adolphus College, St. Peter, MN, who generated the constructs used in this study. This work was largely funded by a grant from the USDA (95-37301-1800).
Keywords
- Antisense
- Arabidopsis
- Chromatin
- Environmental stress
- Linker histone variants