title: The effect of mepiquat chloride on elongation of cotton (Gossypium hirsutum L.) internode is associated with low concentration of gibberellic acid.
abstract: The growth regulator mepiquat chloride (MC) is globally used in cotton (Gossypium hirsutum L.) canopy manipulation to avoid excess growth and yield loss. However, little information is available as to whether the modification of plant architecture by MC is related to alterations in gibberellic acid (GA) metabolism and signaling. Here, the role of GA metabolism and signaling was investigated in cotton seedlings treated with MC. The MC significantly decreased endogenous GA3 and GA4 levels in the elongating internode, which inhibited cell elongation by downregulating GhEXP and GhXTH2, and then reducing plant height. Biosynthetic and metabolic genes of GA were markedly suppressed within 2-10d of MC treatment, which also downregulated the expression of DELLA-like genes. A remarkable feedback regulation was observed at the early stage of MC treatment when GA biosynthetic and metabolic genes expression was evidently upregulated. Mepiquat chloride action was controlled by temporal translocation and spatial accumulation which regulated GA biosynthesis and signal expression for maintaining GA homeostasis. The results suggested that MC application could reduce endogenous GA levels in cotton through controlled GA biosynthetic and metabolic genes expression, which might inhibit cell elongation, thereby shortening the internode and reducing plant height.
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China; College of Life Sciences, Henan Normal University, Xinxiang, Henan 453007, China.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
authors.forename: Chun
authors.initials: C
authors.lastname: Mu
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
authors.forename: Mingwei
authors.initials: M
authors.lastname: Du
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
authors.forename: Yin
authors.initials: Y
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Tian
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China. Electronic address: zmc1214@163.com.
authors.forename: Mingcai
authors.initials: M
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China. Electronic address: lizhaohu@cau.edu.cn.
authors.forename: Zhaohu
authors.initials: Z
authors.lastname: Li
mesh_terms: D015536:Down-Regulation; D015870:Gene Expression / Q000187:drug effects*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D005875:Gibberellins / Q000235:genetics* / Q000378:metabolism; D003368:Gossypium / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D010880:Piperidines / Q000494:pharmacology*; D059828:Plant Cells / Q000187:drug effects; D010937:Plant Growth Regulators / Q000378:metabolism / Q000494:pharmacology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018547:Plant Stems / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D005875:Gibberellins; D010880:Piperidines; D010937:Plant Growth Regulators; D010940:Plant Proteins; C007842:gibberellic acid; C049449:mepiquat
keywords: Cell elongation; Cotton; GA; GA biosynthesis; Internode elongation; Mepiquat chloride