Exploring Flowering Genes in Isabgol (Plantago ovata Forsk.) Through Transcriptome Analysis

Abstract

Flowering is one of the major developmental processes that govern the economic yield of crop plants. However, little is known about the molecular mechanisms underlying flowering in Isabgol, an important high-value medicinal crop. Here, we analyzed the leaf transcriptome of early and late flowering genotypes by high throughput next-generation sequencing to uncover the genes and pathways involved in flowering time and flower development. Illumina paired-end sequencing of Isabgol leaves at the stem elongation stage, generated 8,976,119 and 4,282,684 reads respectively in DPO-14 (early flowering) and DPO-185 (late flowering) genotypes. The sequence assembly resulted in 40,175 and 39,533 transcripts respectively in early and late genotypes. A total of 17,768 (95.50) in DPO-14 and 21,255 (94.10) in DPO-185 CDS were annotated. There were 8981CDS were differentially expressed of which 1220 (13.58%) were significantly upregulated while 1485 (16.53%) CDS were significantly downregulated in DPO-185 compared with DPO-14. In total, 229 genes were identified belongs to distinct flowering pathways in Isabgol. A putative schematic network of flowering pathway regulation in Isabgol was proposed. Significant DEGs (60 genes) related to flowering time and flower development were detected between the early and late flowering genotypes. Significant differences in fold change expression of 17 genes were observed in early and late flowering genotypes. Many differentially expressed genes (DEGs) involved in flowering time and flower development were identified. The expression data will serve as a resource for unraveling the functions of specific genes involved in flower development in Isabgol and other plants. These findings are significant for further understanding of the molecular basis for flowering time regulation, breeding, and molecular biology in Isabgol as well as other crop plants.