Comparative Transcriptomics Identifies Differentially Expressed Genes Regulating endoreplication and trichome branching

Purpose:Comparative transcriptome analyses was applied to characterize gene expression after overexpression GaTOP6B in Arabidopsis thaliana. Methods:The fresh leaves were collected from 4-week-old WT plants and transgenic Arabidopsis lines under drought treatments. The total RNA was first extracted using TRIzol Reagent (TaKaRa, Tokyo, Japan), and treated with RNase-free DNase I (TaKaRa), and then followed with mRNA purification using the Magnetic Oligo (dT) Beads (Illumina, San Diego, CA, USA) according to the manufacturer’s protocol. Results: In this study,our RNA-Seq analysis suggested overexpression of GaTOP6B could suppress the downstream signal transduction of jasmonic acid, cytokinin and brassinolide. Furthermore, the transcriptome analysis also confirmed the downregulation of B-type cyclins genes related to cell cycle, and TCP, MYB transcription factors, which subsequently regulate downstream signal cascades to modulate trichome development. Conclusions: Our results provide evidence on the crucial roles of GaTOP6B for improving trichome branch number by enhancing cell ploidy levels and suppressing the expression of related transcription factors. mRNA profiles of the leaves of wild-type plants and transgenic lines