Mitogen-Activated Protein Kinase Expression Profiling Revealed Its Role in Regulating Stress Responses in Potato (Solanum tuberosum).

Madiha Zaynab,Mateen Sajid,Xuewei Yang,Mahpara Fatima,Yasir Sharif,Nazia Rehman,Hamed A Ghramh,Shuangfei Li,Khalid Ali Khan,Athar Hussain

doi:10.3390/plants10071371

Abstract

Mitogen-activated protein kinase (MAPK) cascades are the universal signal transduction networks that regulate cell growth and development, hormone signaling, and other environmental stresses. However, their essential contribution to plant tolerance is very little known in the potato (Solanum tuberosum) plant. The current study carried out a genome-wide study of StMAPK and provided a deep insight using bioinformatics tools. In addition, the relative expression of StMAPKs was also assessed in different plant tissues. The similarity search results identified a total of 22 StMAPK genes in the potato genome. The sequence alignment also showed conserved motif TEY/TDY in most StMAPKs with conserved docking LHDXXEP sites. The phylogenetic analysis divided all 22 StMAPK genes into five groups, i.e., A, B, C, D, and E, showing some common structural motifs. In addition, most of the StMAPKs were found in a cluster form at the terminal of chromosomes. The promoter analysis predicted several stress-responsive Cis-acting regulatory elements in StMAPK genes. Gene duplication under selection pressure also indicated several purifying and positive selections in StMAPK genes. In potato, StMAPK2, StMAPK6, and StMAPK19 showed a high expression in response to heat stress. Under ABA and IAA treatment, the expression of the total 20 StMAPK genes revealed that ABA and IAA played an essential role in this defense process. The expression profiling and real-time qPCR (RT-qPCR) exhibited their high expression in roots and stems compared to leaves. These results deliver primary data for functional analysis and provide reference data for other important crops.

Highlights

Plants often experience various environmental stresses, including biotic and abiotic stresses [1,2]
The current study reported higher transcript abundances of StMAPKs in the roots; such evidence was observed in previous studies [50,52] and supported our results where StMAPKs19, StMAPKs5, and StMAPKs6 show a high expression in root tissues
Under abscisic acid (ABA) and Indole acetic acidpart (IAA) treatment, the upregulation of 20 StMAPK genes revealed that ABA and IAA played an essential role in this defense process, similar to Zhou et al.’s (2017) results [57]

Summary

Introduction

Plants often experience various environmental stresses, including biotic (diseases, insect pests, weeds, etc.) and abiotic stresses (drought, low and high temperature, salinity, etc.) [1,2]. These factors attenuate plant development and growth, which can badly affect plant productivity and yield quality [2]. The MAPK cascade is one of the major signal transduction pathways that control several mechanisms, including cell differentiation [7,8], hormonal and maturation transduction [9], development [10], immunization [11], and various biotic and abiotic stresses in plants [12,13]. The activated MAPK influences the phosphorylation of transcriptional factors and stimulates the signaling components to regulate the downstream target gene expression [16]

Methods

Results

Discussion

Conclusion