Differential expression of saporin genes upon wounding, ABA treatment and leaf development.
Saporins are type 1 ribosome-inactivating proteins (RIPs: EC 3.2.2.22) produced in various organs of Saponaria officinalis L. Two distinct saporin types, saporin-L and saporin-S isoforms, were respectively purified from the intra- and extra-cellular fractions of soapwort leaves. The saporin-L isoform was lowly identical, differed for toxicity, molecular mass and amino acid composition from saporin-S proteins forming a new monophyletic group. Genes encoding both L- and S-type isoforms were cloned from leaf-specific cDNA library; the encoded products included the N-terminal diversity observed by protein sequencing and showed compatible weights with those from mass spectra. These genes were intron-less belonging to small gene families. Reverse transcription polymerase chain reaction/quantitative reverse transcription polymerase chain reaction experiments evidenced their differential expression during leaf development, wounding and abscisic acid treatment. These results suggest that the saporin-L and -S proteins may play diversified roles during stress responses.
Tartarini
Andrea
A
Department of Basic and Applied Biology, University of L'Aquila, L'Aquila, Italy. andrea.tartarini@univaq.it
Pittaluga
Eugenia
E
Marcozzi
Giordana
G
Testone
Giulio
G
Rodrigues-Pousada
Renato Alberto
RA
Giannino
Donato
D
Spanò
Laura
L
D000040:Abscisic Acid / Q000494:pharmacology*; D000595:Amino Acid Sequence; D004591:Electrophoresis, Polyacrylamide Gel; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D008969:Molecular Sequence Data; D010802:Phylogeny; D010937:Plant Growth Regulators / Q000494:pharmacology; D018515:Plant Leaves / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D054789:Ribosome Inactivating Proteins, Type 1 / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D029750:Saponaria / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D000076985:Saporins; D017386:Sequence Homology, Amino Acid; D013314:Stress, Mechanical
D010937:Plant Growth Regulators; D010940:Plant Proteins; D020033:Protein Isoforms; D012333:RNA, Messenger; D054789:Ribosome Inactivating Proteins, Type 1; D000040:Abscisic Acid; D000076985:Saporins