Transcriptome-Wide Identification and Characterization of MYB Transcription Factor Genes in the Laticifer Cells of Hevea brasiliensis.

Ying Wang,Dong Guo,Jia-Hong Zhu,Shi-Qing Peng,Di-Feng Zhan,Hui-Liang Li

doi:10.3389/fpls.2017.01974

Abstract

MYB transcription factors hold vital roles in the regulation of plant secondary metabolic pathways. Laticifers in rubber trees (Hevea brasiliensis) are of primary importance in natural rubber production because natural rubber is formed and stored within these structures. To understand the role of MYB transcription factors in the specialized cells, we identified 44 MYB genes (named HblMYB1 to HblMYB44) by using our previously obtained transcriptome database of rubber tree laticifer cells and the public rubber tree genome database. Expression profiles showed that five MYB genes were highly expressed in the laticifers. HblMYB19 and HblMYB44 were selected for further study. HblMYB19 and HblMYB44 bound the promoters of HbFDPS1, HbSRPP, and HRT1 in yeast. Furthermore, the transient overexpression of HblMYB19 and HblMYB44 in tobacco plants significantly increased the activity of the promoters of HbFDPS1, HbSRPP, and HRT1. Basing on this information, we proposed that HblMYB19 and HblMYB44 are the regulators of HbFDPS1, HbSRPP, and HRT1, which are involved in the biosynthesis pathway of natural rubber.

Highlights

MYB transcription factors (TFs) comprise a TF family highly rich in plants (Dubos et al, 2010)
Given the interaction between yeast HblMyb19 and HblMyb44 and the promoters of HRT1, HbSRPP, and HbFDPS1, we investigated whether HblMyb19 and HblMyb44 participate in the regulation of the promoters of HbHRT, HbSRPP, and HbFDPS1 in plants
These results strongly indicated that HRT1, HbSRPP, and HbFDPS1 are the target genes of HblMyb19 and HblMyb44, and HblMyb19 and HblMyb44 are transcriptional activators of HRT1, HbSRPP, and HbFDPS1

Summary

Introduction

MYB transcription factors (TFs) comprise a TF family highly rich in plants (Dubos et al, 2010). Plant MYB TFs contain highly conserved MYB domains involved in DNA binding (Rosinski and Atchley, 1998; Jin and Martin, 1999). MYB TFs are involved in plant growth and development (Cominelli and Tonelli, 2009; Oh et al, 2011; Huang et al, 2013; Cai et al, 2015), hormone signal transduction (Shin et al, 2007; Zhao et al, 2014), secondary metabolism (Chezem and Clay, 2016; Chezem et al, 2016; Zhai et al, 2016), abiotic stress responses (Dai et al, 2007; Oh et al, 2011; Peng et al, 2011), and disease resistance (Liu et al, 2013; Zhang et al, 2015)

Methods

Results

Discussion

Conclusion