Gene expression patterns reveal tissue-specific signaling networks controlling programmed cell death and ABA- regulated maturation in developing barley seeds.
Gene expression patterns covering over 10,000 seed-expressed sequences were analyzed by macroarray technology in maternal tissue (mainly pericarp) and filial endosperm and embryo during barley seed development from anthesis until late maturation. Defined sets of genes showing distinct expression patterns characterized both tissue type and major developmental phases. The analysis focused on regulatory networks involved in programmed cell death (PCD) and abscisic acid (ABA)-mediated maturation. These processes were similar in the different tissues, but typically involved the expression of alternative members of a common gene family. The analysis of co-expressed gene sets and the identification of cis regulatory elements in orthologous rice gene 'promoter' regions suggest that PCD in the pericarp is mediated by distinct classes of proteases and is under the hormonal control of both jasmonic acid (JA) and ethylene via ethylene-responsive element binding protein (EREBP) transcription factors (TFs). On the other hand, PCD in endosperm apparently involves only the ethylene pathway, but employs distinct gene family members from those active in the pericarp, and a different set of proteases and TFs. JA biosynthetic genes are hardly activated. Accordingly, JA levels are high in the pericarp but low in the endosperm during middle and late developmental stages. Similarly, genes acting in the deduced ABA biosynthetic pathway and signaling network differ between endosperm and embryo. ABA in the endosperm appears to exert an influence over storage product synthesis via SNF1 kinase. In the embryo, ABA seems to influence the acquisition of desiccation tolerance via ABA response element binding factors, but the data also suggest the existence of an ABA-independent but interactive pathway acting via the dehydration-responsive element binding (DREB) 2A TF.
Sreenivasulu
Nese
N
Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, D-06466, Germany.
Radchuk
Volodymyr
V
Strickert
Marc
M
Miersch
Otto
O
Weschke
Winfriede
W
Wobus
Ulrich
U
D000040:Abscisic Acid / Q000378:metabolism*; D020816:Amino Acid Motifs; D017209:Apoptosis / Q000235:genetics / Q000502:physiology*; D002118:Calcium / Q000378:metabolism; D016000:Cluster Analysis; D003517:Cyclopentanes / Q000378:metabolism; D005030:Ethylenes / Q000378:metabolism; D020869:Gene Expression Profiling; D001467:Hordeum / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D050356:Lipid Metabolism; D026161:MADS Domain Proteins / Q000502:physiology; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D054883:Oxylipins; D010447:Peptide Hydrolases / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D011494:Protein Kinases / Q000502:physiology; D012639:Seeds / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D003517:Cyclopentanes; D005030:Ethylenes; D026161:MADS Domain Proteins; D008565:Membrane Proteins; D054883:Oxylipins; D010940:Plant Proteins; D014157:Transcription Factors; C092149:oleosin protein, Hordeum vulgare; C011006:jasmonic acid; D000040:Abscisic Acid; C036216:ethylene; D011494:Protein Kinases; D010447:Peptide Hydrolases; D002118:Calcium