Expression of sunflower low-molecular-weight heat-shock proteins during embryogenesis and persistence after germination: localization and possible functional implications
We isolated and sequenced Ha hsp17.9, a DNA complementary (cDNA) of dry-seed stored mRNA that encodes a low-molecular-weight heat-shock protein (LMW HSP). Sequence analysis identified Ha hspl7.9, and the previously reported Ha hspl7.6, as cDNAs encoding proteins (HSP17.6 and H S P 17.9) which belong to different families of cytoplasmic LMW H S Ps. Using specific antibodies we observed differential expression of both proteins during zygotic embryogenesis under controlled environment, and a remarkable persistence of these LMW HSPs during germination. Immuno-blot analysis of HSP17.9 proteins in two-dimensional gels revealed that the polypeptides expressed in embryos were indistinguishable from LMW HSPs expressed in vegetative tissues in response to water deficit; but they appeared different from homologeous proteins expressed in response to thermal-stress. Tissue-print immunolocalization experiments showed that HSP17.9 and HSP17.6 were homogeneously distributed in every tissue of desiccation-tolerant dry seeds and young seedlings under non-stress conditions. These results demonstrate developmental regulation of specific, cytoplasmic, plant LMW HSPs, suggesting also their involvement in water-stress tolerance.
| Main Authors: | , , |
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| Other Authors: | |
| Format: | artículo biblioteca |
| Published: |
Kluwer Academic Publishers
1994
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| Subjects: | Sunflower, Zygotic embryogenesis, Early germination, Cytoplasmic low-molecular weight heat-shock proteins, Desiccation tolerance, Heat-shock proteins, |
| Online Access: | http://hdl.handle.net/10261/32369 http://dx.doi.org/10.13039/501100007273 |
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