OsmiR535, a Potential Genetic Editing Target for Drought and Salinity Stress Tolerance in Oryza sativa.

Bohan Liu,Huan Cao,Erkui Yue

doi:10.3390/plants9101337

Abstract

OsmiR535 belongs to the miR156/miR529/miR535 superfamily, a highly conserved miRNA family in plants. OsmiR535 is involved in regulating the cold-stress response, modulating plant development, and determining panicle architecture and grain length. However, the role that OsmiR535 plays in plant responses to drought and salinity are elusive. In the current study, molecular and genetic engineering techniques were used to elucidate the possible role of OsmiR535 in response to NaCl, PEG(Poly ethylene glycol), ABA(Abscisic acid), and dehydration stresses. Our results showed that OsmiR535 is induced under stressed conditions as compared to control. With transgenic and CRISPR/Cas9 knockout system techniques, our results verified that either inhibition or knockout of OsmiR535 in rice could enhance the tolerance of plants to NaCl, ABA, dehydration and PEG stresses. In addition, the overexpression of OsmiR535 significantly reduced the survival rate of rice seedlings during PEG and dehydration post-stress recovery. Our results demonstrated that OsmiR535 negatively regulates the stress response in rice. Moreover, our practical application of CRISPR/Cas9 mediated genome editing created a homozygous 5 bp deletion in the coding sequence of OsmiR535, demonstrating that OsmiR535 could be a useful genetic editing target for drought and salinity tolerance and a new marker for molecular breeding of Oryza sativa.

Highlights

MicroRNAs are a class of 18–24 nt non-coding RNAs that combine withAGO(ARGONAUTE) proteins to form the miRNA-induced silencing complex, which can recognize and inhibit the expression of target genes at the post-transcription level [1,2]
The OsmiR535 role in abiotic stresses was firstly reported in a microarray study, which demonstrated that OsmiR535 could be induced by cold-stresses [9]
As the sequence shared by miR156/529/535 is highly conserved, seven SPLs were predicted as common target genes of OsmiR535, OsmiR539, and OsmiR156 [13,14]

Summary

Introduction

AGO(ARGONAUTE) proteins to form the miRNA-induced silencing complex (miRISC), which can recognize and inhibit the expression of target genes at the post-transcription level [1,2]. There is growing evidence that miRNAs can influence various biological processes, such as plant growth and development, the stress response, and metabolic processes [3,4,5]. MiR156, miR529, and miR535 share high sequence similarity, belong to the miR156/miR529/miR535 superfamily, and play an essential role in modulating plant growth and development and SPLs(SQUAMOSA promoter-binding protein-like) expression [6,7,8]. The OsmiR535 role in abiotic stresses was firstly reported in a microarray study, which demonstrated that OsmiR535 could be induced by cold-stresses [9]. OsmiR535 modulates plant height, panicle architecture, and grain length by suppressing the expression of OsSPL7/12/16 [6]

Methods

Discussion

Conclusion