Genome-Wide Analysis of TCP Family Genes in Zea mays L. Identified a Role for ZmTCP42 in Drought Tolerance.

Shuangcheng Ding,Zhenzhen Cai,Hewei Du,Hongwei Wang

doi:10.3390/ijms20112762

Shuangcheng Ding, Zhenzhen Cai + Show 2 more

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https://doi.org/10.3390/ijms20112762

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Abstract

The Teosinte-branched 1/Cycloidea/Proliferating (TCP) plant-specific transcription factors (TFs) have been demonstrated to play a fundamental role in plant development and organ patterning. However, it remains unknown whether or not the TCP gene family plays a role in conferring a tolerance to drought stress in maize, which is a major constraint to maize production. In this study, we identified 46 ZmTCP genes in the maize genome and systematically analyzed their phylogenetic relationships and synteny with rice, sorghum, and Arabidopsis TCP genes. Expression analysis of the 46 ZmTCP genes in different tissues and under drought conditions, suggests their involvement in maize response to drought stress. Importantly, genetic variations in ZmTCP32 and ZmTCP42 are significantly associated with drought tolerance at the seedling stage. RT-qPCR results suggest that ZmTCP32 and ZmTCP42 RNA levels are both induced by ABA, drought, and polyethylene glycol treatments. Based on the significant association between the genetic variation of ZmTCP42 and drought tolerance, and the inducible expression of ZmTCP42 by drought stress, we selected ZmTCP42, to investigate its function in drought response. We found that overexpression of ZmTCP42 in Arabidopsis led to a hypersensitivity to ABA in seed germination and enhanced drought tolerance, validating its function in drought tolerance. These results suggested that ZmTCP42 functions as an important TCP TF in maize, which plays a positive role in drought tolerance.

Highlights

Severe drought causes a grievous decline in crop yield by negatively affecting plant growth and reproduction [1,2]
The protein sequences of the putative maize Teosinte branched 1/Cycloidea/Proliferating (TCP) transcription factors (TFs) were retrieved from the Plant Transcription Factor
A BLASTP analysis was performed in Phytozome V10, using all of the Arabidopsis and rice TCP protein sequences as queries, and the predicted protein sequences without a TCP domain (Pfam: PF03634) were excluded from the results

Summary

Introduction

Severe drought causes a grievous decline in crop yield by negatively affecting plant growth and reproduction [1,2]. Teosinte branched 1/Cycloidea/Proliferating (TCP) genes encode plant-specific TFs and are named after the first three functionally characterized members of this TF family—Teosinte Branched 1 (TB1)in maize (Zea mays L.), Cycloidea (CYC)in snapdragon (Antirrhinum majus), and Proliferating Cell nuclear antigen Factor (PCF)in rice (Oryza sativa) [8]. This class of TFs share a highly conserved TCP domain, which contains a 59-amino acid, non-canonical basic-Helix-Loop-Helix (bHLH)structural motif that allows DNA binding, protein–protein interaction, and protein nuclear localization [8,9,10].

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