Author
MARLA, SAJDEEP - Kansas State University | |
WELTI, RUTH - Kansas State University | |
SHIVA, SUNITHA - Kansas State University | |
LIU, SANZHEN - Kansas State University | |
Burke, John | |
MORRIS, GEOFFRY - Kansas State University |
Submitted to: The Plant Genome
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 6/20/2017 Publication Date: 11/28/2017 Citation: Marla, S.R., Welti, R., Shiva, S., Liu, S., Burke, J.J., Morris, G. 2017. Comparative transcriptome and lipidome analyses reveal molecular systems underlying chilling response in chilling-tolerant sorghums. The Plant Genome. 10:1-16. doi:10.3835/plantgenome2017.03.0025. DOI: https://doi.org/10.3835/plantgenome2017.03.0025 Interpretive Summary: Chilling temperatures are a major constraint for the cereal crop sorghum. Northern Chinese sorghums have adapted to early-season chilling, but molecular mechanisms of chilling tolerance are unknown. We used molecular techniques and lipid analyses to identify what makes the Northern Chinese sorghums cold tolerant. Our findings revealed an increase in protective mechanisms compare to chilling sensitive controls. Changes in gene regulations, lipid types, and protective mechanisms to prevent oxidative damage were identified. Technical Abstract: Chilling temperatures are a major constraint for temperate cultivation of tropical-origin crops, including the cereal crop sorghum (Sorghum bicolor [L.] Moench). Northern Chinese sorghums have adapted to early-season chilling, but molecular mechanisms of chilling tolerance are unknown. We used RNA sequencing to compare the chilling-responsive transcriptomes of a chilling-tolerant Chinese accession to a chilling-sensitive US reference line, and mass spectrometry to compare chilling-responsive lipidomes of four chilling-tolerant Chinese accessions to two US reference lines. Comparative transcriptomics revealed chilling-induced upregulation of cold-response regulator CBF transcription factor and genes involved in reactive oxygen detoxification, jasmonic acid (JA) biosynthesis, and lipid remodeling in the chilling-tolerant line NSZ. Lipidomics revealed conserved chilling-induced increases in unsaturation, as well as lipid remodeling in photosynthetic membranes that is specific to chilling-tolerant Chinese accessions. Our results point to CBF-mediated transcriptional regulation, galactolipid and phospholipid remodeling, and JA as potential molecular mechanisms underlying chilling adaptation in Chinese sorghums. These findings suggest that some molecular systems involved in freezing tolerance of temperate-origin plants may also play a role in chilling tolerance in tropical-origin plants. |