Transcriptome analysis uncovers the gene expression profile of salt-stressed potato (Solanum tuberosum L.)

Qing Li,Yuzhi Qin,Guangcun Li,Xingyao Xiong,Wanxing Wang,Xinxi Hu,Hongying Ding

doi:10.1038/s41598-020-62057-0

Abstract

Potato (Solanum tuberosum L.) is an important staple food worldwide. However, its growth has been heavily suppressed by salt stress. The molecular mechanisms of salt tolerance in potato remain unclear. It has been shown that the tetraploid potato Longshu No. 5 is a salt-tolerant genotype. Therefore, in this study we conducted research to identify salt stress response genes in Longshu No. 5 using a NaCl treatment and time-course RNA sequencing. The total number of differentially expressed genes (DEGs) in response to salt stress was 5508. Based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, it was found that DEGs were significantly enriched in the categories of nucleic acid binding, transporter activity, ion or molecule transport, ion binding, kinase activity and oxidative phosphorylation. Particularly, the significant differential expression of encoding ion transport signaling genes suggests that this signaling pathway plays a vital role in salt stress response in potato. Finally, the DEGs in the salt response pathway were verified by Quantitative real-time PCR (qRT-PCR). These results provide valuable information on the salt tolerance of molecular mechanisms in potatoes, and establish a basis for breeding salt-tolerant cultivars.

Highlights

Potato (Solanum tuberosum L.) is an important staple food worldwide
When Ca2+ reaches a certain concentration, Ca2+ binds to 14-3-3 and ScaBP5/8, which causes 14-3-3 to dissociate from SOS210 and bind to protein kinase 5 (PKS5)/24, inhibiting its kinase activity with the help of J3 (DnaJ homolog3) and eliminating the inhibition of serine/threonine-protein kinase 24 (SOS2) and ATPase[15]
Except for slight leaf rolling, which was observed after 48 h of NaCl stress, Longshu No 5 looked similar to control seedlings grown without NaCl, while severe lodging and wilting were observed in the salt-sensitive genotype Qingshu No 9 after 24 h (Fig. 1a)

Summary

Introduction

Potato (Solanum tuberosum L.) is an important staple food worldwide. its growth has been heavily suppressed by salt stress. The significant differential expression of encoding ion transport signaling genes suggests that this signaling pathway plays a vital role in salt stress response in potato. Plant membrane receptors sense extracellular salt stress stimuli, and these stimuli signals are translated into intracellular signals through the generation of second messengers such as calcium, reactive oxygen species (ROS) and inositol phosphates These second messengers activate transcription factors (TFs) or protein kinases (PKs), inducing specific genes to be differentially expressed[7]. The complex gene expression cascades activated during the response to salt stress involve signaling pathways related to Na+ efflux and Na+ localization[9], which are regulated by calcium-activated 14-3-3 proteins that act as molecular switches[10]. In addition to the well characterized ANN–14-3-3–PKS5/24/J3–SCaBP5/8–SOS2–SOS1 signaling pathway and ANN–14-3-3–PKS5/24/J3–SCaBP5/8– SOS2–NHXs signaling pathway, there are still networks that are as yet uncharacterized

Methods

Results

Conclusion