Journal Article

Cloning and functional characterization of PjPORB, a member of the POR gene family in Pseudosasa japonica cv. Akebonosuji

Jiang, Keyi, Zhou, Mingbing

2016

Overview

In angiosperms, NADPH: protochlorophyllide oxidoreductase (POR) catalyzes the photoreduction of protochlorophyllide (Pchlide) to chlorophyllide (Chlide), the only light-dependent step in chlorophyll biosynthesis. There is a wide variety of gene organization and light- and development-dependent regulatory mechanisms for the POR genes. In this study, a POR homologue, designated PjPORB , was isolated from Pseudosasa japonica cv. Akebonosuji, which is a cultivar of high ornamental value in landscape due to its unique green-white striped leaf phenotype. The full-length PjPORB cDNA was 1567 bp long with a 1185 bp ORF that encoded 394 amino acids. Multiple amino acid sequence alignment showed that the putative PjPORB shared a high similarity to POR homologues from other plant species, and that the cofactor (NADPH)-binding motif and active site motif in particular were highly conserved among all the PORs. Further, PjPORB was overexpressed in Arabidopsis thaliana ; and the Pchlide contents of the genetically modified plants were reduced to a larger extent than that of wild type plants, thereby indicating its important role in Pchlide photoreduction. In real-time quantitative RT-PCR analysis, PjPORB was expressed at higher levels in leaf samples than in culms and roots, and showed a first increasing-then decreasing expression pattern during the development of white, stripe, and green leaf samples, thus indicating its essential role in leaf development. Although the mRNA levels for PjPORB did not differ considerably among white, stripe, and green leaf samples within the two almost same earlier developmental stages, its expression levels in the late leaf developmental stage fell into two distinct classes: high expression levels in strip and green leaf samples, and low expression levels in white leaf. Collectively, these expression data suggested that PjPORB may be involved in the leaf color variation for P. japonica cv. Akebonosuji.

• Publisher: Springer Netherlands,Springer Nature B.V
• Subject: active sites / Agriculture / amino acid sequences / Amino acids / Arabidopsis thaliana / Biomedical and Life Sciences / Biosynthesis / chlorophyll / Cloning / color / complementary DNA / culms / Cultivars / Developmental stages / genes / Genetically modified organisms / genetically modified plants / landscapes / leaf development / Leaves / Life Sciences / messenger RNA / NADP (coenzyme) / open reading frames / Original Paper / ornamental value / phenotype / Plant Anatomy/Development / Plant Physiology / Plant Sciences / Plant species / Pseudosasa / reverse transcriptase polymerase chain reaction / roots / sequence alignment