A novel nucleus-targeted protein is expressed in barley leaves during senescence and pathogen infection.
The barley (Hordeum vulgare) cDNA HvS40 represents a gene with enhanced mRNA level during leaf senescence. Biolistic transformation of onion (Allium cepa) epidermal cell layers with a glucuronidase fusion protein construct provided evidence that the 15.4-kD protein encoded by HvS40 is localized to the nucleus. Expression of the gene is induced by jasmonate and salicylic acid; both are known to act as signaling compounds during senescence and defense toward pathogens. Transcript levels of HvS40 were observed to be particularly high in leaf sectors that undergo necrosis and chlorosis after infection with Pyrenophora teres. This pathogen-related expression is, in contrast, clearly reduced in transgenic barley plants expressing a stilbene synthase from grape (Vitis vinifera), whereas the mRNA level of a gene encoding the pathogen-related protein HvPR1 is unaffected. In situ hybridization with HvS40 antisense RNA revealed that during leaf senescence, the HvS40 transcript predominantly accumulates in the mesophyll. Taken together, the findings suggest a connection between the nuclear protein encoded by HvS40 and the degeneration of chloroplasts occurring during senescence and during infection of barley wild-type plants with P. teres.
Krupinska
Karin
K
Institute of Botany, University of Kiel, Olshausenstrasse 40, D-24098 Kiel, Germany. kkrupinska@bot.uni-kiel.de
Haussühl
Kirsten
K
Schäfer
Anke
A
van der Kooij
Tom A W
TA
Leckband
Gunhild
G
Lörz
Horst
H
Falk
Jon
J
D000595:Amino Acid Sequence; D001419:Bacteria / Q000254:growth & development*; D003517:Cyclopentanes / Q000494:pharmacology; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000235:genetics; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism; D001467:Hordeum / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D054883:Oxylipins; D018515:Plant Leaves / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D020156:Salicylic Acid / Q000494:pharmacology; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D003517:Cyclopentanes; D018076:DNA, Complementary; D009687:Nuclear Proteins; D054883:Oxylipins; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; C011006:jasmonic acid; D005966:Glucuronidase; D020156:Salicylic Acid