OsEIN2 is a positive component in ethylene signaling in rice.
EIN2 is a central signal transducer in the ethylene-signaling pathway, and a unique membrane-anchored protein. By screening a cDNA library, we have isolated a cDNA clone (OsEIN2) that encodes the rice EIN2 homolog. The full-length ORF clone was obtained by reverse transcriptase-polymerase chain reaction. OsEIN2 shares significant amino acid sequence similarity with Arabidopsis EIN2 (57% similarity and 42% identity). Both the numbers and positions of introns and exons in the OsEIN2 and AtEIN2 coding regions are also conserved. To address whether this structural similarity is indicative of functional conservation of the corresponding proteins, we also generated transgenic lines expressing the antisense construct of OsEIN2. Those plants were stunted and shoot elongation was severely inhibited. Their phenotypes were similar to that found with wild-type rice seedlings that were treated with AgNO3, an ethylene signal inhibitor. In the OsEIN2 antisense plants, the expression levels of two ethylene-responsive genes, SC129 and SC255, were decreased compared with the wild types. These results suggest that OsEIN2 is a positive component of the ethylene-signaling pathway in rice, just as AtEIN2 is in Arabidopsis: Our antisense transgenic plants produced approximately 3.5 times more ethylene than the wild-type plants. Expression analysis of rice ACS and ACO genes showed that the transcript levels of OsACS1 and OsACO1 were elevated in the transgenic plants.
Jun
Sung-Hoon
SH
National Research Laboratory of Plant Functional Genomics, Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang, 790-784 Korea.
Han
Min-Jung
MJ
Lee
Shinyoung
S
Seo
Young Sam
YS
Kim
Woo Taek
WT
An
Gynheung
G
D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D016373:DNA, Antisense / Q000235:genetics; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D005030:Ethylenes / Q000096:biosynthesis* / Q000494:pharmacology; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D008969:Molecular Sequence Data; D012275:Oryza / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D010641:Phenotype; D010937:Plant Growth Regulators / Q000096:biosynthesis* / Q000494:pharmacology; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018520:Plant Shoots / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D011956:Receptors, Cell Surface / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics* / Q000502:physiology; D012835:Silver Nitrate / Q000494:pharmacology
D016373:DNA, Antisense; D018076:DNA, Complementary; D005030:Ethylenes; D010937:Plant Growth Regulators; D010940:Plant Proteins; D011956:Receptors, Cell Surface; C036216:ethylene; D012835:Silver Nitrate