title: Expression patterns of an isoflavone reductase-like gene and its possible roles in secondary metabolism in Ginkgo biloba.
abstract: Our results showed that GbIRL1 belongs to the PCBER protein family. Besides, IRL1 gene was a novel gene regulating lignin change and also effecting the accumulation of flavonoids in Ginkgo. A cDNA encoding the IFR-like protein was isolated from the leaves of Ginkgo biloba L., designated as GbIRL1 (Accession no. KC244282). The cDNA of GbIRL1 was 1,203 bp containing a 921 bp open reading frame encoding a polypeptide of 306 amino acids. Comparative and bioinformatic analyses revealed that GbIRL1 showed extensive homology with IFLs from other gymnosperm species. Phylogenetic tree analysis revealed that GbIRL1 shared the same ancestor in evolution with other PCBERs protein and had a further relationship with other gymnosperm species. The recombinant protein was successfully expressed in E. coli strain with pET-28a vector. The vitro enzyme activity assay by HPLC indicated that recombinant GbIRL1 protein could catalyze the formation the TDDC, IDDDC from DDDC, DDC. Tissue expression pattern analysis showed that GbIRL1 was constitutively expressed in stem and roots, especially in the parts of the pest and fungal infection, with the lower expression being found in 1- or 2-year old stem. The increased expression of GbIRL1 was detected when the seedlings were treated with Ultraviole-B, ALA, wounding and ethephon, abscisic acid, salicylic acid. Correlation analysis between GbIRL1 activity and flavonoid accumulation during Ginkgo leaf growth indicated that GbIRL1 might be the rate-limiting enzyme in the biosynthesis pathway of flavonoids in Ginkgo leaves. Results of RT-PCR analysis showed that the transcription level of change in GbIRL1 power correlated with flavonoid contents, suggesting IRL1 gene as a novel gene regulating lignin change and also effecting the accumulation of flavonoids in Ginkgo.
authors: Economic Forest Germplasm Improvement and Comprehensive Utilization of Resources of Hubei Key Laboratories, Hubei Huanggang, 438000, China.
authors: Cheng
authors: C
authors: Hua
authors: Li
authors: L
authors: Linling
authors: Xu
authors: X
authors: Feng
authors: Wang
authors: W
authors: Yan
authors: Yuan
authors: Y
authors: Honghui
authors: Wu
authors: W
authors: Conghua
authors: Wang
authors: W
authors: Shaobing
authors: Liao
authors: L
authors: Zhiqin
authors: Hua
authors: H
authors: Juan
authors: Wang
authors: W
authors: Yuping
authors: Cheng
authors: C
authors: Shuiyuan
authors: Cao
authors: C
authors: Fuliang
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D003001:Cloning, Molecular; D005419:Flavonoids / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D020441:Ginkgo biloba / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism*; D008031:Lignin / Q000378:metabolism; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D009943:Organophosphorus Compounds / Q000494:pharmacology; D044925:Oxidoreductases Acting on CH-CH Group Donors / Q000235:genetics* / Q000378:metabolism*; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000201:enzymology / Q000235:genetics; D018547:Plant Stems / Q000201:enzymology / Q000235:genetics; D020156:Salicylic Acid / Q000494:pharmacology; D036226:Seedlings / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D005419:Flavonoids; D009943:Organophosphorus Compounds; D010940:Plant Proteins; D000040:Abscisic Acid; D008031:Lignin; C071072:vestitone reductase; D044925:Oxidoreductases Acting on CH-CH Group Donors; D020156:Salicylic Acid; C005073:ethephon