Tools - Reference - Detail

Reference Detail

Author Spielmeyer,W., Ellis,M.H. and Chandler,P.M.
Title Semidwarf (sd-1), "green revolution" rice, contains a defective gibberellin 20-oxidase gene.
The introduction of semidwarf rice (Oryza sativa L.) led to record yield increases throughout Asia in the 1960s. The major semidwarfing allele, sd-1, is still extensively used in modern rice cultivars. The phenotype of sd-1 is consistent with dwarfism that results from a deficiency in gibberellin (GA) plant growth hormones. We propose that the semidwarf (sd-1) phenotype is the result of a deficiency of active GAs in the elongating stem arising from a defective 20-oxidase GA biosynthetic enzyme. Sequence data from the rice genome was combined with previous mapping studies to locate a putative GA 20-oxidase gene (Os20ox2) at the predicted map location of sd-1 on chromosome 1. Two independent sd-1 alleles contained alterations within Os20ox2: a deletion of 280 bp within the coding region of Os20ox2 was predicted to encode a nonfunctional protein in an indica type semidwarf (Doongara), whereas a substitution in an amino acid residue (Leu-266) that is highly conserved among dioxygenases could explain loss of function of Os20ox2 in a japonica semidwarf (Calrose76). The quantification of GAs in elongating stems by GC-MS showed that the initial substrate of GA 20-oxidase activity (GA53) accumulated, whereas the content of the major product (GA20) and of bioactive GA1 was lower in semidwarf compared with tall lines. We propose that the Os20ox2 gene corresponds to the sd-1 locus.
Journal Proc. Natl. Acad. Sci. U.S.A.
Country Australia
Volume 99(13)
Pages 9043-9048
Year 2002
PubMed ID 12077303
PubMed Central ID -
Gene SD1
INSD AY114310
Strain Wild Core Collection -
Induced Mutation Lines(NIG Collection) -
Sterile Seed Strain -
Lethal Embryo
Mutantion Strain
Stages in Each Organ
- Muant Lines (Gene)
Cultivated Varieties(NIG Collection) -
Stages in Each Organ -