ISSN:
1573-5028
Keywords:
late embryogenesis-abundant (lea)
;
thiol-specific antioxidant (TSA)
;
Hordeum vulgare L.
;
desiccation tolerance
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Antioxidants can remove damaging reactive oxygen species produced as by-products of desiccation and respiration during late embryogenesis, imbibition of dormant seeds and germination. We have expressed a protein, PER1, encoded by theBalem (barleyaleurone andembryo) transcript previously called B15C, and show it to reduce oxidative damagein vitro. PER1 shares high similarity to a novel group of thiol-requiring antioxidants, named peroxiredoxins, and represents a subgroup with only one conserved cysteine residue (1-Cys). PER1 is the first antioxidant belonging to the 1-Cys subgroup shown to be functionally active, and the first peroxiredoxin of any kind to be functionally described in plants. The steady state level of the transcript,Per1, homologous to a dormancy-related transcript (pBS128) from bromegrass (Bromus secalinus), increases considerably in imbibed embryos from dormant barley (Hordeum vulgare L.) grains. Our investigations also indicate thatPer1 transcript levels are dormancy-related in the aleurone layer of whole grains. In contrast to most seed-expressed antioxidantsPer1 disappears in germinating embryos, and in the mature aleurone the transcript is down-regulated by the germinating embryo or by gibberellic acid (GA). Our data show that the barley seed peroxiredoxin is encoded by a singlePer1 gene. Possible roles of the PER1 peroxiredoxin in barley grains during desiccation, dormancy and imbibition are discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00040837
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