Genome-wide identification and comparative analysis of drought-related microRNAs in two maize inbred lines with contrasting drought tolerance by deep sequencing.

Xuyang Liu,Yu Li,Chunhui Li,Yunsu Shi,Luyang Hao,Xiaojing Zhang,Cheng Liu,Dengfeng Zhang,Yanchun Song,Tianyu Wang,Xiaoqing Xie,Baocheng Sun,Yongxiang Li,Huaijun Tang,Keqiang Wu

doi:10.1371/journal.pone.0219176

Abstract

Drought has become one of the most serious abiotic stresses influencing crop production worldwide. Understanding the molecular regulatory networks underlying drought adaption and tolerance in crops is of great importance for future breeding. microRNAs (miRNAs), as important components of post-transcriptional regulation, play crucial roles in drought response and adaptation in plants. Here, we report a miRNome analysis of two maize inbred lines with contrasting levels of drought tolerance under soil drought in the field. Differential expression analysis showed 11 and 34 miRNAs were uniquely responded to drought in H082183 (drought tolerant) and Lv28 (drought sensitive), respectively, in leaves. In roots, 19 and 23 miRNAs uniquely responded to drought in H082183 and Lv28, respectively. Expression analysis of these drought-responsive miRNA-mRNA modules revealed miR164-MYB, miR164-NAC, miR159-MYB, miR156-SPL and miR160-ARF showed a negative regulatory relationship. Further analysis showed that the miR164-MYB and miR164-NAC modules in the tolerant line modulated the stress response in an ABA (abscisic acid)-dependent manner, while the miR156-SPL and miR160-ARF modules in the sensitive line participated in the inhibition of metabolism in drought-exposed leaves. Together, our results provide new insight into not only drought-tolerance-related miRNA regulation networks in maize but also key miRNAs for further characterization and improvement of maize drought tolerance.

Highlights

To meet the rising demand resulting from population growth and economic development, crop production should maintain a sustainable increase [1]
The results showed that the leaf relative water content (RWC) of both genotypes under drought were significantly (P < 0.001) lower than those of their well-watered controls at 27 and 46 days after drought (Fig 1A)
The leaf RWCs of both H082183 and Lv28 decreased to approximately 82%, and showed no significant difference at 46 days after drought

Summary

Introduction

To meet the rising demand resulting from population growth and economic development, crop production should maintain a sustainable increase [1]. The increasing environmental stresses resulting from global climate change, such as drought, have become major threats to crop production [2]. Genome-wide identification of drought-related microRNAs in maize

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