Location: Crop Improvement and Protection ResearchTitle: Transcriptomic and gene co-expression network analysis of cultivated lettuce (Lactuca sativa L) and its wild progenitor (L. serriola) under contrasting nitrogen conditions
Submitted to: American Society of Horticulture Science Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 3/8/2021
Publication Date: 8/7/2021
Citation: Kumar, P., Eriksen, R.L., Simko, I., Mou, B. 2021. Transcriptomic and gene co-expression network analysis of cultivated lettuce (Lactuca sativa L) and its wild progenitor (L. serriola) under contrasting nitrogen conditions. American Society for Horticultural Science Annual Conference, August 5-9, 2021, Denver, Colorado.
Technical Abstract: Large amounts of nitrogen fertilizers applied during lettuce production are lost due to leaching or volatilization causing severe environmental pollution and increasing cost of production. Developing lettuce varieties with high nitrogen use efficiency (NUE) is the eco-friendly solution to reduce nitrogen pollution. We performed comparative transcriptomic analysis of the cultivated lettuce (Lactuca sativa L.) and its wild progenitor (L. serriola) under high and low nitrogen conditions. A total of 2,704 differentially expressing genes (DEGs) were identified. Key enriched biological processes included photosynthesis, oxidation-reduction process, chlorophyll biosynthetic process, and cell redox homeostasis. The transcription factors (TFs) belonging to ethylene responsive factor (ERF) family and bHLH family were top differentially expressing TFs. Using pairwise comparisons and weighted gene co-expression network analysis (WGCNA) we constructed nine co-expression modules. Among these, light-green and blue modules were further investigated because of their significant association with total nitrogen content and photosynthetic efficiency of photosystem II (PSII). Three highly correlated clusters were identified which included hub genes for nitrogen metabolism, secondary metabolites, and carbon assimilation and were regulated by cluster specific TFs. The expression of nitrogen transportation and assimilation genes varied significantly between the two lettuce species and thereby provides the opportunity of introgression of wild alleles into the cultivated germplasm for developing high NUE lettuce cultivars.