Identification of Fe-excess-induced genes in rice shoots reveals a WRKY transcription factor responsive to Fe, drought and senescence.
Fe participates in several important reactions in plant metabolism. However, Fe homeostasis in plants is not completely understood, and molecular studies on Fe-excess stress are scarce. Rice (Oryza sativa L. ssp. indica) is largely cultivated in submerged conditions, where the extremely reductive environment can lead to severe Fe overload. In this work, we used representational difference analysis (RDA) to isolate sequences up-regulated in rice shoots after exposure to Fe-excess. We isolated 24 sequences which have putative functions in distinct cellular processes, such as transcription regulation (OsWRKY80), stress response (OsGAP1, DEAD-BOX RNA helicase), proteolysis (oryzain-α, rhomboid protein), photosynthesis (chlorophyll a/b binding protein), sugar metabolism (β glucosidase) and electron transport (NADH ubiquinone oxireductase). We show that the putative WRKY transcription factor OsWRKY80 is up-regulated in rice leaves, stems and roots after Fe-excess treatment. This up-regulation is also observed after dark-induced senescence and drought stress, indicating that OsWRKY80 could be a general stress-responsive gene. To our knowledge, this is the first report of an Fe-excess-induced transcription factor in plants.
Ricachenevsky
Felipe Klein
FK
Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, P.O. Box 15005, Porto Alegre, RS, 91501-970, Brazil.
Sperotto
Raul Antonio
RA
Menguer
Paloma Koprovski
PK
Fett
Janette Palma
JP
D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D003624:Darkness; D055864:Droughts; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D017343:Genes, Plant / Q000235:genetics; D007501:Iron / Q000494:pharmacology*; D009928:Organ Specificity / Q000187:drug effects / Q000235:genetics; D012275:Oryza / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018520:Plant Shoots / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects
D018076:DNA, Complementary; D010940:Plant Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; D007501:Iron