Transcriptome profiling of the elongating internode of cotton (Gossypium hirsutum L.) seedlings in response to mepiquat chloride

• DOI: 10.21203/rs.2.12849/v1
• Publication Date: 2019-08-14T21:38:04Z
• Authors: Li Wang; Ying Yin; Li-Feng Wang; Menglei Wang; Miao Zhao; Ye Tian; Yong-Fang Li
• Keywords: Brassinosteroid; Plant stem; Gossypium; MYB; Flavonoid Biosynthesis

Abstract Background The plant growth retardant mepiquat chloride (MC) has been extensively used to produce compact canopies and increase yield in cotton (Gossypium hirsutum L.). Previous studies mainly focused on the role of gibberellins (GA) MC-induced inhibition cotton. However, molecular mechanism underlying retardation remained largely unknown. Results In present study, we conducted histological, transcriptomic, phytohormone analyses second elongating internodes seedlings treated with MC. Histological analysis revealed that MC-mediated shortening was caused by suppression cell division decrease length; this phenotype confirmed transcriptome profiling. Many genes related were significantly downregulated MC-treated internodes, such as cycle, wall biosynthesis modification, transport protein aquaporins. Furthermore, expression secondary metabolism, especially lignin flavonoid, down-regulated MC treatment. GA, auxin, brassinosteroid (BR), ethylene metabolism signaling remarkably suppressed, whereas cytokinin (CK) abscisic acid (ABA) induced Consistent RNA-Seq analysis, significant endogenous BR content, but an CK observed after addition, many transcription factors (TFs) bHLH, AP2-EREBP, Orphans, MYB, GRF, TCP differentially regulated MC; these TFs are associated expansion, signaling, circadian rhythm. Conclusions This study provides novel insights into internode elongation seedlings. reduces suppressing downstream cascades BR; altering TFs; further reducing expansion.