cDNA Cloning and Characterization of Gibberellin-responsive Genes in Photoblastic Lettuce Seeds

Two cDNA clones, cLRG5 and cLRG11, that respond to gibberellin (GA) were isolated from seeds of photo blastic lettuce (Lectuca sativa L. cv. Grand Rapids) by differential screening. Northern blot analysis indicated that the levels of LRG5 and LRG11 mRNAs were raised to slightly higher levels 10h after the start of GA treatment and the levels were maintained at least for further 8h, while those in the control seeds gradually decreased. Red light irradiation had effects similar to GA treatment. The cLRG5 insert encodes a putative polypeptide of 380 amino acids that is highly homologous to alcohol dehydrogenases from several higher plants. With regard to the cLRG11 insert, no homologous gene has been reported.