Mepiquat chloride promotes cotton lateral root formation by modulating plant hormone homeostasis

• Published in: BMC plant biology Vol. 19; no. 1; p. 573
• Main Authors: Wu, Qian, Du, Mingwei, Wu, Jie, Wang, Ning, Wang, Baomin, Li, Fangjun, Tian, Xiaoli, Li, Zhaohu
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 21.12.2019; BioMed Central; BMC
• Subjects: Abscisic acid; Acetic acid; Agricultural chemicals; Analysis; Biosynthesis; Cell cycle; Cell division; Chlorides; Cotton; Cultivars; Gene expression; Gene Expression Profiling; Gene Expression Regulation, Plant - drug effects; Genes; Gibberellins; Gossypium - drug effects; Gossypium - genetics; Gossypium - growth & development; Gossypium hirsutum; Growth regulators; Homeostasis; Hormones; indole acetic acid; Indoleacetic acid; Kinases; Lateral root; lateral roots; mepiquat; Mepiquat chloride (MC); Metabolism; Molecular modelling; Organic acids; Organogenesis, Plant - drug effects; Physiological aspects; Phytohormone; Phytohormones; Piperidines - pharmacology; Plant growth; Plant Growth Regulators - pharmacology; Plant hormones; Plant Roots - drug effects; Plant Roots - genetics; Plant Roots - growth & development; Principal components analysis; Root development; root growth; seed treatment; Seed treatments; Seeds; Signal transduction; Signaling; Transcriptome; transcriptomics; Transport; Lateral root; Mepiquat chloride (MC); Phytohormone; Cotton; Transcriptome
• ISSN: 1471-2229; 1471-2229
• DOI: 10.1186/s12870-019-2176-1

Mepiquat chloride (MC), a plant growth regulator, enhances root growth by promoting lateral root formation in cotton. However, the underlying molecular mechanisms of this phenomenon is still unknown. In this study, we used 10 cotton (Gossypium hirsutum Linn.) cultivars to perform a seed treatment with MC to investigate lateral root formation, and selected a MC sensitive cotton cultivar for dynamic monitor of root growth and transcriptome analysis during lateral root development upon MC seed treatment. The results showed that MC treated seeds promotes the lateral root formation in a dosage-depended manner and the effective promotion region is within 5 cm from the base of primary root. MC treated seeds induce endogenous auxin level by altering gene expression of both gibberellin (GA) biosynthesis and signaling and abscisic acid (ABA) signaling. Meanwhile, MC treated seeds differentially express genes involved in indole acetic acid (IAA) synthesis and transport. Furthermore, MC-induced IAA regulates the expression of genes related to cell cycle and division for lateral root development. Our data suggest that MC orchestrates GA and ABA metabolism and signaling, which further regulates auxin biosynthesis, transport, and signaling to promote the cell division responsible for lateral root formation.