Genome-wide Identification of TCP Family Transcription Factors from Populus euphratica and Their Involvement in Leaf Shape Regulation.

Xiaodong Ma,Yuanzhong Jiang,Jianchao Ma,Keming Luo,Chaofeng Li,Di Fan

doi:10.1038/srep32795

Abstract

Higher plants have been shown to experience a juvenile vegetative phase, an adult vegetative phase, and a reproductive phase during its postembryonic development and distinct lateral organ morphologies have been observed at the different development stages. Populus euphratica, commonly known as a desert poplar, has developed heteromorphic leaves during its development. The TCP family genes encode a group of plant-specific transcription factors involved in several aspects of plant development. In particular, TCPs have been shown to influence leaf size and shape in many herbaceous plants. However, whether these functions are conserved in woody plants remains unknown. In the present study, we carried out genome-wide identification of TCP genes in P. euphratica and P. trichocarpa, and 33 and 36 genes encoding putative TCP proteins were found, respectively. Phylogenetic analysis of the poplar TCPs together with Arabidopsis TCPs indicated a biased expansion of the TCP gene family via segmental duplications. In addition, our results have also shown a correlation between different expression patterns of several P. euphratica TCP genes and leaf shape variations, indicating their involvement in the regulation of leaf shape development.

Highlights

The process of leaf development is composed of primordia initiation, establishment of polarity in three axes, lamina expansion, and formation of leaf margin[16,17,18], and involves coordinated regulation among transcription factors, small RNAs and hormones[19]
Class I is formed by a group of relatively closely related proteins exemplified by rice PCF1 and PCF2, whereas class II is further subdivided into two clades according to differences within the TCP domain: the CIN clade exemplified by CINCINNATA (CIN) of Antirrhinum[41] and the CYC/TB1 clade including CYC and tb[142]
In this study, we firstly carried out genome-wide identification of TCP transcription factors in P. trichocarpa and P. euphratica, and we conducted expression analysis of TCP genes in various leaf types of P. euphratica to establish a correlation between their expression and various leaf morphologies

Summary

Introduction

The process of leaf development is composed of primordia initiation, establishment of polarity in three axes, lamina expansion, and formation of leaf margin[16,17,18], and involves coordinated regulation among transcription factors, small RNAs and hormones[19]. Many members of the TCP family from both Class I and Class II have been demonstrated to participate in leaf development control in Antirrhinum[41], Arabidopsis[43,44,45,46,47,48,49], and tomato[50] They have been shown to physically interact with several proteins involved in leaf development regulation, including ASYMMETRIC LEAVES1 (AS1), AS2 and NGATHA (NGA)[46,51,52]. SPL9, a target of MiR156, has been reported to interact with TCP4 and this complex promoted CUC-controlled acquisition of leaf complexity in Arabidopsis[53], indicating that TCPs may play important roles in the regulatory cascade of leaf shape control centered by the MiR156 module It remains unknown whether TCPs are involved in leaf morphology regulation in woody plants. In this study, we firstly carried out genome-wide identification of TCP transcription factors in P. trichocarpa and P. euphratica, and we conducted expression analysis of TCP genes in various leaf types of P. euphratica to establish a correlation between their expression and various leaf morphologies

Methods

Results

Conclusion