Genome-Wide Identification, Characterization and Expression Analysis of TCP Transcription Factors in Petunia.

Shuting Zhang,Qin Zhou,Fei Li,Guofeng Liu,Baojun Liu,Manzhu Bao,Jiaqi Zhang,Lan Wu,Feng Chen

doi:10.3390/ijms21186594

Shuting Zhang, Qin Zhou + Show 7 more

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https://doi.org/10.3390/ijms21186594

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Abstract

The plant-specific TCP transcription factors are well-characterized in both monocots and dicots, which have been implicated in multiple aspects of plant biological processes such as leaf morphogenesis and senescence, lateral branching, flower development and hormone crosstalk. However, no systematic analysis of the petunia TCP gene family has been described. In this work, a total of 66 petunia TCP genes (32 PaTCP genes in P. axillaris and 34 PiTCP genes in P. inflata) were identified. Subsequently, a systematic analysis of 32 PaTCP genes was performed. The phylogenetic analysis combined with structural analysis clearly distinguished the 32 PaTCP proteins into two classes—class Ι and class Ⅱ. Class Ⅱ was further divided into two subclades, namely, the CIN-TCP subclade and the CYC/TB1 subclade. Plenty of cis-acting elements responsible for plant growth and development, phytohormone and/or stress responses were identified in the promoter of PaTCPs. Distinct spatial expression patterns were determined among PaTCP genes, suggesting that these genes may have diverse regulatory roles in plant growth development. Furthermore, differential temporal expression patterns were observed between the large- and small-flowered petunia lines for most PaTCP genes, suggesting that these genes are likely to be related to petal development and/or petal size in petunia. The spatiotemporal expression profiles and promoter analysis of PaTCPs indicated that these genes play important roles in petunia diverse developmental processes that may work via multiple hormone pathways. Moreover, three PaTCP-YFP fusion proteins were detected in nuclei through subcellular localization analysis. This is the first comprehensive analysis of the petunia TCP gene family on a genome-wide scale, which provides the basis for further functional characterization of this gene family in petunia.

Highlights

The final shape and size of lateral organs such as leaves and flowers are established mainly by the elaborate coordination of cell proliferation and cell expansion in response to internal developmental and external environmental cues
Based on the differential features within the conserved TCP domain, TCP proteins can be categorized into two classes: class I and class II, and the latter can be further divided into the ubiquitous CINCINNATA (CIN-TCP subclade) and the angiosperm-specific CYC/Teosinte Branched 1 (TB1) subclade [3,4]
32 PaTCP genes were identified in P. axillaris (Table 1, Table S1) and 34 PiTCP genes were identified in P. inflata (Table S2)

Summary

Introduction

The final shape and size of lateral organs such as leaves and flowers are established mainly by the elaborate coordination of cell proliferation and cell expansion in response to internal developmental and external environmental cues. This coordination relies on the complex regulatory circuits in which many microRNAs (miRNAs) and transcription factors are recruited [1]. Based on the differential features within the conserved TCP domain, TCP proteins can be categorized into two classes: class I (or TCP-P clade) and class II (or TCP-C clade), and the latter can be further divided into the ubiquitous CINCINNATA (CIN-TCP subclade) and the angiosperm-specific CYC/TB1 subclade [3,4]. Besides the conserved TCP domain, some class II members contain an arginine-rich R domain with unknown biological function, and the majority of the CYC/TB1 subclade members have a conserved ECE motif (a glutamic acid-cysteine-glutamic acid stretch) that remains functionally uncharacterized [3,5]

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