Narrow leaf 1 (NAL1) plays an important role in plant branching, while little is known about the roles of this gene in petunias. In this study, PhNAL1b was cloned from Petunia×hybrida cv. Mitchell Diploid, with a total length of 1 767 bp, encoding a protein composed of 588 amino acid residues and containing the peptidase S64 domain. The PhNAL1b promoter region contained several elements involved in the responses to auxin, jasmonic acid, abscisic acid, and light. The expression analysis showed that PhNAL1b had the highest expression level in roots and the lowest expression level in flowers, and its transcription could be inhibited by decapitation and cytokinin. The subcellular localization analysis showed that PhNAL1b was located in the nucleus and was a nuclear protein. Virus-induced gene silencing was employed to downregulate the expression of PhNAL1b, which resulted in significant increases in branch number and plant height. The results indicated that PhNAL1b played an important role in regulating the branching of petunias. This study lays a foundation for revealing the mechanism of NAL1 in regulating branch development and provides genetic resources for plant architecture improvement.
Petunia/growth & development* ; Plant Proteins/metabolism* ; Diploidy ; Gene Expression Regulation, Plant ; Cloning, Molecular ; Promoter Regions, Genetic

ERF family transcription factor (TF) represented ethylene-responsive protein which harbored a conserved AP2 domain. After searching the plant transcription factor database, a total of 75 unigenes was found which contained AP2 domain from the transcriptome dataset of Panax quinquefolius L. One unique sequence of ERF transcript, named as PqERF1, was cloned with entire open reading frame of 933 base pairs (bp). Protein prediction result indicated that the gene was localized in nucleus and had a conserved AP2 domain. PqERF1 gene could be induced by methyl jasmonate (MeJA) which was consistent to the inducing profile of triterpene ginsenosides. InterproScan prediction indicated that PqERF1 was probably a pathogenesis-related gene. Sequence alignment and phylogenetic analysis demonstrated PqERF1 was with high identity and had relative close relationship to the NtERF4 (Nicotiana tabacum), PhERF12 (Petunia x hybrida) and DcERF1 (Daucus carota) which was related to plant defense, regulation of secondary metabolism and the flower senescence respectively. Therefore, the gene was likely involved in regulation of secondary metabolism, plant defense and physical processes which would provide gene resource for further study on secondary metabolite synthesis and molecular breeding of P. quinquefolius.
Amino Acid Sequence ; Computational Biology ; Daucus carota ; genetics ; metabolism ; Gene Expression Regulation, Plant ; Open Reading Frames ; Panax ; genetics ; metabolism ; Petunia ; genetics ; metabolism ; Phylogeny ; Plant Proteins ; genetics ; metabolism ; Protein Structure, Secondary ; RNA, Plant ; genetics ; Sequence Alignment ; Tobacco ; genetics ; metabolism ; Transcription Factor AP-2 ; genetics ; metabolism