Transcriptome Analysis Reveals Regulatory Framework for Salt and Drought Tolerance in Hibiscus hamabo Siebold & Zuccarini

Abstract

Hibiscus hamabo Siebold & Zuccarini (H. hamabo) is tolerant to salt and drought conditions, but the molecular mechanisms that underlie this stress tolerance remain unclear. In this study, the transcriptome of H. hamabo roots was investigated under NaCl or PEG treatment. A total of 20,513 and 27,516 significantly changed known genes at 6 h and 24 h, respectively, were detected between the salt or drought treatments and the control libraries. Among these, there were 3845 and 7430 overlapping genes under the two stresses at 6 h and 24 h, respectively. Based on the analysis of enriched KEGG pathways and clustering of expression patterns, the DEGs that were continuously up- or down-regulated under both salt and drought treatments were mainly enriched in MAPK signaling pathway, transcription factors, transporters and other pathways. The transcriptome expression profiles of H. hamabo provide a genetic resource for identifying common regulatory factors involved in responses to different abiotic stresses. In addition, the identified factors may be useful to developing genetic breeding strategies for the Malvaceae.

Transcriptome Analysis of Salt Stress in Hibiscus hamabo Sieb. et Zucc Based on Pacbio Full-Length Transcriptome Sequencing

“…In this study, 522 transcription factors were found among the DEGs; the most abundant transcription factor family was MYB, followed by SNF2, bHLH, WRKY, and other families. These results are consistent with previous reports on the transcription factors involved in plant responses to salt stress, indicating that transcription factors play a key role in the response of H. hamabo to salt stress [ 20 ]. In addition, the expression patterns of different transcription factor families have temporal and spatial specificity, indicating that transcription factors have very complex regulatory mechanisms.…”

“…J. L. Yang, B. R. Baum et C. Yen (78.01%) [ 25 ], Vicia sativa L. (66.10%) [ 26 ], and Elymus sibiricus L. (79.81%) [ 27 ]. Previously, our team used second-generation sequencing to acquire 75,257 unigene in H. hamabo [ 20 ]. We obtained a larger number of unigenes in our study by sequencing the entire transcriptome, and the unigenes are longer and more complete (4917 bp).…”

“…The genome and transcriptome sequencing of mangrove plants and halophytes is crucial to understanding plant salt tolerance mechanisms [ 17 , 18 , 19 ]. The regulatory mechanism of H. hamabo under salt stress was discovered using next-generation sequencing (NGS) technology [ 20 ]. However, the accuracy of transcriptome is greatly reduced due to the evident shortcomings of second-generation sequencing, such as the short length of sequencing runs and poor assembly findings.…”

“…According to the RNA-sequencing (RNA-seq) data obtained by the Illumina sequencing platform, the transcriptional expression level under NaCl stress was corrected, compared, and analyzed. As the long-term treatments resembled the condition of real habitat of H. hamabo , longer times (48 h and 72 h), compared with previous work, treated samples were selected to predict resistance-forming of H. hamabo in response to salt stress in this study [ 20 ]. HhWRKY79 was discovered based on the level of expression, and the function of HhWRKY 79 in regulating salt stress tolerance was preliminarily verified using transgenic Arabidopsis thaliana (L.) Heynh.…”

Genome-wide Analysis of Basic Helix-Loop-Helix Family Genes and Expression Analysis in Response to Drought and Salt Stresses in Hibiscus hamabo Sieb. et Zucc

“…Tbtools were used to draw a heat map of log 2 (1 + 2 −∆∆CT ) values. HhbHLH gene expression was analyzed according to the FPKM value of the transcriptome data of the H. hamabo under drought and salt stresses [40], and Tbtools was used to draw a heat map of the log 2 (1+FPKM) value.…”