piperidines and gibberellic-acid

The use of gibberellic acid (GA3) and N, N-dimethyl piperidinium chloride (DPC) in combination with prometryn would likely increase the control of black nightshade in cotton fields. Experiments were designed to investigate the physiological and biochemical responses of black nightshade at the three- to four-leaf stage to prometryn applied at different rates, either alone or in combination with GA3 or DPC, in a greenhouse environment. These studies demonstrated that prometryn applied in combination with DPC at low rates (7.2 g ai ha(-1)) led to increased fresh weight and visible injury of black nightshade compared with prometryn applied alone or in combination with GA3; however, at rates of 36, 180, and 900 g ai ha(-1), prometryn in combination with DPC caused the least visible injury among all treatments and prometryn in combination with GA3 caused the greatest visible injury. These results suggest that black nightshade suffered more severe damage when prometryn was applied in combination with GA3, which is supported by the reduced soluble protein content, lower antioxidant enzyme activities, and higher malondialdehyde (MDA) content in the plants treated with prometryn plus GA3. These results indicate that the application of GA3 in combination with prometryn to black nightshade may have the potential to lower the levels of prometryn tolerance in these plants.

Topics: Dose-Response Relationship, Drug; Gibberellins; Piperidines; Plant Growth Regulators; Plant Proteins; Prometryne; Solanum nigrum

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.

Topics: Down-Regulation; Gene Expression; Gene Expression Regulation, Plant; Genes, Plant; Gibberellins; Gossypium; Piperidines; Plant Cells; Plant Growth Regulators; Plant Proteins; Plant Stems; Seedlings; Signal Transduction

To investigate the effect of plant growth regulators on the growth and quality of Angelica dahurica var. formosana.. Five plant growth regulators: chlormequat chloride (CCC), Mepiquat chloride (PIX), Gibberellic acid (GA3), Paclobutrazol (PP333) and Maleic Hydrazide (MH) were sprayed in rosette stage, the effects of these plant growth regulators (PGRs) on the growth, yield and quality of A. dahurica var. formosanaw were observed. The biological traits were first measured and then imperatorin and isoimperatorin contents in roots were determined by HPLC.. Low concentration GA3 increased the yield while not influenced the premature bolting rate and the coumarin content.. Spraying of GA3 (30 mg x L(-1)) could guarantee the growth and development of A. dahurica var. formosana to have a higher yield and maintain the active ingredients content in the root as well.

Topics: Angelica; Chlormequat; Gibberellins; Maleic Hydrazide; Piperidines; Plant Growth Regulators; Triazoles