Isolation and identification of GID1 orthologous gene in conifers and its function prediction.

GID1 as the gibberellins (GA) receptor is an essential component of GA signaling pathway.The GID1 genes have been cloned widely from angiosperms,but researches on them in conifers are scarcely documented.We obtained and identified the orthologous gene of GID1 from Pinus tabuliformis transcriptome with AtGID1s probe sequence.Based on this sequence,the GID1 genes were cloned from P.sylvestris var. mongolica,P.bungeana and P.densiflora and the GID1-like genes in P.taeda,Picea glauca,P.abies and Larix kaempferi were also obtained from public database.The conservation of amino acid sequences,protein structures and expression levels of coniferous GID1s were analyzed.The result showed that there probably is only one GID1 with highly conserved sequence in conifers.Although the identity of GID1s is low between conifers and angiosperms,they have highly similar amino acids which are essential for binding affinity to GA and quite conserved functional domains which can interact with DELLA protein.Thus, these orthologous GID1 genes may have functions of receptor.Expression analysis showed that the GID1 had stable expressions in different organs in P.abies and in different developmental stages of male and female cones in Pinus tabuliformis, indicating that GID1 may widely participate in developmental process of these tissues,and the transcriptional regulation of GID1 might not be the key regulatory mechanism in GA signaling pathway.Our study lays a foundation for the research of molecular mechanism of GID1 in the growth and development of conifers.