De Novo Assembly and Analysis of Tartary Buckwheat (Fagopyrum tataricum Garetn.) Transcriptome Discloses Key Regulators Involved in Salt-Stress Response.

Qi Wu,Yan Wan,Xue Bai,Jun Yan,Wei Zhao,Liang Zou,Gang Zhao,Dabing Xiang

doi:10.3390/genes8100255

Abstract

Soil salinization has been a tremendous obstacle for agriculture production. The regulatory networks underlying salinity adaption in model plants have been extensively explored. However, limited understanding of the salt response mechanisms has hindered the planting and production in Fagopyrum tataricum, an economic and health-beneficial plant mainly distributing in southwest China. In this study, we performed physiological analysis and found that salt stress of 200 mM NaCl solution significantly affected the relative water content (RWC), electrolyte leakage (EL), malondialdehyde (MDA) content, peroxidase (POD) and superoxide dismutase (SOD) activities in tartary buckwheat seedlings. Further, we conducted transcriptome comparison between control and salt treatment to identify potential regulatory components involved in F. tataricum salt responses. A total of 53.15 million clean reads from control and salt-treated libraries were produced via an Illumina sequencing approach. Then we de novo assembled these reads into a transcriptome dataset containing 57,921 unigenes with N50 length of 1400 bp and total length of 44.5 Mb. A total of 36,688 unigenes could find matches in public databases. GO, KEGG and KOG classification suggested the enrichment of these unigenes in 56 sub-categories, 25 KOG, and 273 pathways, respectively. Comparison of the transcriptome expression patterns between control and salt treatment unveiled 455 differentially expressed genes (DEGs). Further, we found the genes encoding for protein kinases, phosphatases, heat shock proteins (HSPs), ATP-binding cassette (ABC) transporters, glutathione S-transferases (GSTs), abiotic-related transcription factors and circadian clock might be relevant to the salinity adaption of this species. Thus, this study offers an insight into salt tolerance mechanisms, and will serve as useful genetic information for tolerant elite breeding programs in future.

Highlights

Soil salinization has been an afflicting factor for plant agriculture [1]
In order to evaluate the effects of salt on physiological activities in F. tataricum seedlings, we measured a series of key physiological indices including relative water content (RWC), electrolyte leakage (EL), malondialdehyde (MDA) content, superoxide dismutase (SOD) and peroxidase (POD)
Two-week-old Chuan Qiao No.1 seedlings were treated with 200 mM NaCl solution, and the aerial parts of seedling plants were collected at 0 h and 24 h after salt treatment

Summary

Introduction

Soil salinization has been an afflicting factor for plant agriculture [1]. Breeding and application of salt-tolerant elites for each food crop is becoming extremely urgent to feed the global population in future decades. Prior to achieving this goal there should be a good knowledge of the fundamental. Plants have generated a complex of strategies mainly containing osmotic tolerance, detoxification of ions, and tolerance of tissue to accumulated ions [2]. A series of signal perception, signal transduction, transcriptional regulation and biochemical reactions are employed to achieve the responses [3]. Protein kinases (e.g., calcium-dependent protein kinases (CDPKs) and CBL-interacting protein kinases (CIPKs)) are very important for hyperosmotic signal transduction to downstream gene transcription regulation [3,4]

Methods

Results

Conclusion