Elicitor-dependent expression of the ribosome-inactivating protein beetin is developmentally regulated.
BE27 and BE29 are two forms of beetin, a virus-inducible type 1 ribosome-inactivating protein isolated from leaves of Beta vulgaris L. Western blot analysis revealed the presence of beetin forms in adult plants but not in germ or young plants, indicating that the expression of these proteins is developmentally regulated. While beetins are expressed only in adult plants, their transcripts are present through all stages of development. In addition, the treatment of B. vulgaris leaves with mediators of plant-acquired resistance such as salicylic acid and hydrogen peroxide promoted the expression of beetin by induction of its transcript, but only in adult plants. The plant expresses three mRNAs which differ only in their 3' untranslated region. All these observations suggest a dual regulation of beetin expression, i.e. at the post-transcriptional and transcriptional levels. Additionally, total RNA isolated from leaves treated with hydrogen peroxide, which express high levels of active beetin, is not de-adenylated by endogenous beetin, nor in vitro by the addition of BE27, thus suggesting that sugar beet ribosomes are resistant to beetin.
Iglesias
Rosario
R
Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Valladolid, E-47005 Valladolid, Spain.
Pérez
Yolanda
Y
Citores
Lucía
L
Ferreras
José M
JM
Méndez
Enrique
E
Girbés
Tomás
T
D020413:3' Untranslated Regions / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D001483:Base Sequence; D027461:Beta vulgaris / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects*; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D018515:Plant Leaves / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D026721:RNA 3' End Processing; D012333:RNA, Messenger / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D018749:RNA, Plant / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D054788:Ribosome Inactivating Proteins / Q000235:genetics* / Q000378:metabolism; D020156:Salicylic Acid / Q000494:pharmacology*; D012689:Sequence Homology, Nucleic Acid; D015533:Transcriptional Activation / Q000187:drug effects*
D020413:3' Untranslated Regions; D010940:Plant Proteins; D012333:RNA, Messenger; D018749:RNA, Plant; D006861:Hydrogen Peroxide; D054788:Ribosome Inactivating Proteins; D020156:Salicylic Acid