Ectopic Expression of JcCPL1, 2, and 4 Affects Epidermal Cell Differentiation, Anthocyanin Biosynthesis and Leaf Senescence in Arabidopsis thaliana.

Yanbo Chen,Yaping Chen,Bingbing Liao,Yali Guo,Meiru Li,Yaqin Wang,Pingzhi Wu,Guojiang Wu,Chao Zhang,Huawu Jiang

doi:10.3390/ijms23041924

Abstract

The CAPRICE (CPC)-like (CPL) genes belong to a single-repeat R3 MYB family, whose roles in physic nut (Jatropha curcas L.), an important energy plant, remain unclear. In this study, we identified a total of six CPL genes (JcCPL1–6) in physic nut. The JcCPL3, 4, and 6 proteins were localized mainly in the nucleus, while proteins JcCPL1, 2, and 5 were localized in both the nucleus and the cytoplasm. Ectopic overexpression of JcCPL1, 2, and 4 in Arabidopsis thaliana resulted in an increase in root hair number and decrease in trichome number. Consistent with the phenotype of reduced anthocyanin in shoots, the expression levels of anthocyanin biosynthesis genes were down-regulated in the shoots of these three transgenic A. thaliana lines. Moreover, we observed that OeJcCPL1, 2, 4 plants attained earlier leaf senescence, especially at the late developmental stage. Consistent with this, the expression levels of several senescence-associated and photosynthesis-related genes were, respectively, up-regulated and down-regulated in leaves. Taken together, our results indicate functional divergence of the six CPL proteins in physic nut. These findings also provide insight into the underlying roles of CPL transcription factors in leaf senescence.

Highlights

Introduction published maps and institutional affilMYB transcription factors constitute one of the largest families of plant transcription factors
The results show that the expression levels of chalcone isomerase (CHI), chalcone synthase (CHS), flavanone 3-hydroxylase (F3H), FLS1 and BAN gene in OeJcCPL1, OeJcCPL2 and OeJcCPL4 shoots were not significantly changed when compared with wild type A. thaliana (WT) shoots (Figure 7)
Analysis of the structure of these revealed that the genes encoding the single repeat R3 MYB region of the six physic nut CPLs have the same exon-intron arrangement and the proteins they encode have high sequence similarity at the amino acid level in the MYB domain region

Summary

Introduction

Introduction published maps and institutional affilMYB transcription factors constitute one of the largest families of plant transcription factors. A protein encoded by an MYB gene usually includes one to four incompletely repeated MYB domains, which are named R1, R2 and R3 according to their sequence similarity with the c-MYB protein [1,2]. A MYB domain generally contains 52 amino acid residues which form three a-helices, of which the second and third make up a structure that interacts with the major groove of DNA [1,2]. According to the number of MYB domains, the MYB transcription factor superfamily can be divided into four families: R2R3-MYB, 3R-MYB, 4R-MYB and MYB-related [3]. MYB-related proteins usually contain a single MYB domain, but sometimes there are two MYB domains, and they have been classified into five subfamilies: CCA1-like, CAPRICE (CPC)-like (CPL), TBP-like, I-box-binding-like and R-R-type [4]. MYB-related proteins usually contain a single MYB domain, but sometimes there are two MYB domains, and they have been classified into five subfamilies: CCA1-like, CAPRICE (CPC)-like (CPL), TBP-like, I-box-binding-like and R-R-type [4]. iations.

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Results

Conclusion