Abstract

The phytochrome-interacting factors (PIFs) proteins belong to the subfamily of basic helix–loop–helix (bHLH) transcription factors and play important roles in chloroplast development and chlorophyll biosynthesis. Currently, knowledge about the PIF gene family in Camellia sinensis remains very limited. In this study, seven PIF members were identified in the C. sinensis genome and named based on homology with AtPIF genes in Arabidopsis thaliana. All C. sinensis PIF (CsPIF) proteins have both the conserved active PHYB binding (APB) and bHLH domains. Phylogenetic analysis revealed that CsPIFs were clustered into four groups—PIF1, PIF3, PIF7, and PIF8—and most CsPIFs were clustered in pairs with their corresponding orthologs in Populus tremula. CsPIF members in the same group tended to display uniform or similar exon–intron distribution patterns and motif compositions. CsPIF genes were differentially expressed in C. sinensis with various leaf colors and strongly correlated with the expression of genes involved in the chlorophyll metabolism pathway. Promoter analysis of structural genes related to chlorophyll metabolism found DNA-binding sites of PIFs were abundant in the promoter regions. Protein–protein interaction networks of CsPIFs demonstrated a close association with phytochrome, PIF4, HY5, TOC1, COP1, and PTAC12 proteins. Additionally, subcellular localization and transcriptional activity analysis suggested that CsPIF3b was nuclear localized protein and possessed transcriptional activity. We also found that CsPIF3b could activate the transcription of CsHEMA and CsPOR in Nicotiana benthamiana leaves. This work provides comprehensive research of CsPIFs and would be helpful to further promote the regulation mechanism of PIF on chlorophyll metabolism in C. sinensis.

Highlights

  • IntroductionLeaf color is an important trait that can be identified in the breeding process of plants

  • The molecular weight of proteins ranges from 44.84 kDa (CsPIF8a) to 77.34 kDa (CsPIF3a), and their isoelectric points are between 5.88 (CsPIF3a) and 9.26 (CsPIF7b)

  • Cells transformed with pGBKT7-CsPIF3b and the positive and CsPOR pro-LUC, compared with the co-transfection of the reporters with the empty grew well and showed X-α-Gal activity in the synthetic defined (SD)/-Tr vector. These results suggested that CsPIF3b could activate the expression of chlorophyll

Read more

Summary

Introduction

Leaf color is an important trait that can be identified in the breeding process of plants. High-theanine-content tea cultivars with different leaf colors are attracting increasing attention due to the unique color and multiple health benefits. According to the color of leaves, high-theanine tea cultivars can be divided into three types: green, white and yellow [4]. Numerous studies have demonstrated that tea cultivars with white or yellow leaves are mainly caused by the decrease of chlorophyll content, which is related to the abnormal chloroplast development, including changes of chloroplast structure, decreased the number of chloroplasts and granular layer, disintegration of the matrix lamella [5,6]

Methods
Results
Discussion
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call