Comparative Transcriptome Analysis of Close Wild Relatives of Sweet Potato Reveals Important Salt Adaptation Mechanisms for Crop Improvement. Plant and Animal Genome XXIV Conference, January 2016. Daniella J. Freese 1, Robert Reid 1, Huazhong Shi 2, Hengyou Zhang 1, Ann Loraine 1, Bao-Hua Song 1.
1 University of North Carolina at Charlotte, Charlotte, NC
2 Texas Tech University, Lubbock, TX
Soil salinity is one of the major environmental factors causing crop loss worldwide. Here we conducted a comparative transcriptome analysis of two diploid wild relatives of sweet potato, beach morning glory (halophyte) and white star (glycophyte) following salt treatment. Our objective was to discern novel genes and pathways that confer salt tolerance in the halophyte. Overall, our results highlighted the lineage-specific mechanisms in conferring salt tolerance and importance of applying crop wild relatives in crop improvement. Specifically, our results showed that the glycophyte exhibited more differentially expressed genes (DEGs) than the halophyte relative, suggesting the role of constitutive vs induced gene expression in evolutionarily adapted and non-adapted species. Meanwhile, the root tissue in both species exhibited more differentially expressed genes than the leaves. This highlights the role of the root tissue in conferring salt tolerance. Hierarchical clustering analysis of the root tissue revealed 53.6 % of halophyte-specific up regulated DEGs under salt stress. Lastly, 102 and 23 putative orphan genes were found up regulated in the roots of the halophyte and glycophyte respectively. This could be an unexplored pool of novel genes with potential roles in salt tolerance.