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. Overall design: mRNA profiles of the leaves of wild-type plants and transgenic lines