MYC cis-Elements in PsMPT Promoter Is Involved in Chilling Response of Paeonia suffruticosa.

Yuxi Zhang,Shupeng Gai,Wenwen Song,Lei Dong,Jingjing Liu,Tingzhao Sun,Chunying Liu,Shaoqing Liu,Keqiang Wu

doi:10.1371/journal.pone.0155780

Abstract

The MPT transports Pi to synthesize ATP. PsMPT, a chilling-induced gene, was previously reported to promote energy metabolism during bud dormancy release in tree peony. In this study, the regulatory elements of PsMPT promoter involved in chilling response were further analyzed. The PsMPT transcript was detected in different tree peony tissues and was highly expressed in the flower organs, including petal, stigma and stamen. An 1174 bp of the PsMPT promoter was isolated by TAIL-PCR, and the PsMPT promoter::GUS transgenic Arabidopsis was generated and analyzed. GUS staining and qPCR showed that the promoter was active in mainly the flower stigma and stamen. Moreover, it was found that the promoter activity was enhanced by chilling, NaCl, GA, ACC and NAA, but inhibited by ABA, mannitol and PEG. In transgenic plants harboring 421 bp of the PsMPT promoter, the GUS gene expression and the activity were significantly increased by chilling treatment. When the fragment from -421 to -408 containing a MYC cis-element was deleted, the chilling response could not be observed. Further mutation analysis confirmed that the MYC element was one of the key motifs responding to chilling in the PsMPT promoter. The present study provides useful information for further investigation of the regulatory mechanism of PsMPT during the endo-dormancy release.

Highlights

The mitochondrial phosphate transporter (MPT) shuttles inorganic phosphate (Pi) into the mitochondrial matrix, where Pi is utilized for oxidative phosphorylation to synthesize ATP from ADP
The results of Quantitative real-time PCR (qPCR) indicated that the transcription of PsMPT was detected in all tree peony tissues; the PsMPT transcript was very low in root, stem, leaf and calyx, but high in flower organs, including petal, stamen and stigma (Fig 1A)
The results indicated that PsMPT was expressed preferentially in flower organs of tree peony

Summary

Introduction

The mitochondrial phosphate transporter (MPT) shuttles inorganic phosphate (Pi) into the mitochondrial matrix, where Pi is utilized for oxidative phosphorylation to synthesize ATP from ADP. MPT encoding genes have been cloned from mammals [1,2,3], yeast [4], and wood frogs [5] with most studies focusing mainly on the structure and catalytic function of the transporters. Plant MPT genes were identified to be involved in abiotic stress responses, and their expression. The sequences and structures of 26 potential PT family genes in rice were analyzed, and six MPTs showed tissue preferential expression profiles, among which OsPT17 and OsPT19 were differently regulated under hormone treatment conditions. Six putative cis-elements were found in all of the OsPT genes including ARR1AT, CAATBOX1, CACTFTPPCAL, GATABOX, GT1CONSENSUS and GTGANTG10. GATABOX and GT1CONSENSUS are light-responsive cis-elements, and CACTFTPPCAL is necessary for carbon metabolism [11]. Current knowledge of MPT regulation and the molecular mechanisms mediating its biological functions in plants is still incomplete

Methods

Results

Conclusion