Transcriptome profile analysis of two Vicia faba cultivars with contrasting salinity tolerance during seed germination

Abstract

Faba bean (Vicia faba L.) is an important food legume crop. Salinity soils severely constrain the production of faba bean, however, the seed germination of faba bean, which is a vital plant growth stage, is sensitive to salinity. Planting improved varieties of faba bean, which exhibit salt tolerance in seed germination stage, is an optimal strategy for faba bean product. To investigate the genes dynamics during the seed germination stage under salinity, RNA-seq method was used to investigate genome-wide transcription profiles of two faba bean varieties with contrast salt-tolerance during the seed germination. A total of 4,486 differentially expressed genes (DEGs) were identified among the comparison of salt-tolerant variety Y134 and salt-sensitive variety Y078 treated with salinity or not. Of these, 1,410 candidate DEGs were identified as salt-stress response genes. Furthermore, 623 DEGs were identified as variety-specific response gene during seed germination at 16 h or 24 h with salt treatment. Based on the pathway enrichment according to the Kyoto Encyclopedia of Genes and Genomes database (KEGG), these DEGs involving in cell wall loosening (e.g., xyloglucan endotransglucosylase/hydrolase, chitinase, and expansin), hormone metabolism (e.g., LEA genes, genes associated with ABA or ethylene signal pathway), chromatin remodeling (e.g., chromatin structure proteins, LHP1), small interfering RNA pathway, etc., were significantly up-regulated in salt-tolerance variety with salt treatment, indicating that they play critical roles in regulation of seed germination. The results indicated that a clearer mechanism of gene regulation that regulates the seed germination responding to salinity in faba bean. These findings are helpful to increase the understanding of the salt tolerance mechanism of crops during seed germination, and provide valuable genetic resource for the breeding of salt-tolerant faba bean varieties in future.

Ethylene: A Master Regulator of Salinity Stress Tolerance in Plants

“…Notwithstanding, Chang et al [95] reported that salinity interferes with the ethylene signaling pathway and decreases ethylene production in seeds of C. sativus, which was associated with the inhibition of germination. In Faba beans (Vicia faba), seed germination in salinity-tolerant Y134 is not inhibited during salinity stress as compared to the salinity-sensitive Y078 probably because of the downregulation of genes related to ABA and ethylene signaling pathways and upregulation of late embryogenesis abundant (LEA) genes [106]. Seeds of Capsicum annuum primed with SA showed higher a germination rate due to suppression of the ethylene level as well as elevation of total soluble sugar contents and SOD activity [107].…”

Defining the Cell Wall, Cell Cycle and Chromatin Landmarks in the Responses of Brachypodium distachyon to Salinity

“…Salinity can affect seed germination by creating the osmotic potential to prevent water uptake and/or by providing conditions for the entry of ions that may be toxic to the embryo or developing seedling. At the seed germination stage, salt stress restricts water absorption, inhibits the growth of the embryo axis and leads to secondary seed dormancy [ 41 ]. Brachypodium had a decreased germination efficiency under saline conditions.…”

Transcriptome-based analysis of salt-related genes during the sprout stage of common bean (Phaseolus vulgaris) under salt stress conditions

“…A previous RNA-seq study detected six DEGs between two asparagus bean (Vigna unguiculata) cultivars with contrasting salt-induced phenotypes that were grown under saline and control conditions [55]. In another study, two faba bean varieties with contrasting salt tolerance during the germination stage underwent salt and control treatments to investigate the genome-wide transcription profiles via RNA-seq [56]. Moreover, 13 genes responsive to salinity during the germination stage were revealed by a genome-wide association analysis and the RNA sequencing of 196 upland cotton genotypes [57].…”