Synthesis of plant growth

Dioxin vinylogous esters derived from cyclic 1,3-diketones (e.g., 4) are valuable building blocks for the construction of natural and unnatural carbocyclic products.2 In connection with a synthesis of plant-growth regulators, Crow and... 

Benzothiazolones are useful intermediates in the synthesis of plant growth regulators, and may be synthesized from substituted anilines by first converting the latter (with formaldehyde) into l,3,5-(triaminoaryl)-l,3,5-triazines which then break down on stirring successively with chlorocarbonylsulphenyl chloride and aluminium chloride. 

Synthesis and Screening. One of the key problems for industry is the question "How does one screen for new plant growth regulants " (8). In the case of herbicides and insecticides, they either work or they don t. The field effects of plant growth regulators are harder to see, predict or test for. 

Fasciculol G (13) is a further member of the series of plant growth inhibitors from Neamatoloma fasciculare (see Vol. 9, p. 188). Structure (14) has been proposed for fasciculatol from Veronia fasciculata Extraction of a fossil plant from the Ningyo-Toge uranium deposit afforded the nortriterpenoid ketones (15) and (16). The structure (17) of a new tetracyclic triterpenoid from Pertya robusta was confirmed by partial synthesis of its dihydro-derivative from 24-methyl-enecycloartenol. "... 

Pincon, G., Maury, S., Hoffmann, L., Geoffroy, P, Lapierre, C., Pollet, B. and Legrand, M. (2001) Repression of O-methyltransferase genes in transgenic tobacco affects lignin synthesis and plant growth. Phytochemistry, 57,1167-76. 

Nomura, T. Kitasaka, Y. Tokatsuto, S. Reid, J.B. Fukami, M. Yoko, T. Brassinosteroid/sterol synthesis and plant growth affected by Ika and Ikb mutation of pea. Plant Physiol. 1999, 119, 1517-1526. 

The discovery of brassinolide by scientists at USDA led to the development of a new group of plant growth substances, termed brassinosteroids, which have the potential for increasing crop yields and biomass. The chapter summarizes the USDA s contributions to brassinosteroids, which include isolation and identification of brassinolide, synthesis of brassinolide and its analogs, and limited biological and field studies on brassinosteroids. An overview of the current data requirements for the registration of brassinosteroids as biochemical pesticides under the Federal Insecticide, Fungicide, and Rodenticide Act is presented. 

Nonetheless unanswered questions remain. What are the relative contributions of branched chain amino acid deficiency and AKB overabundance to the cytotoxic effects of the sulfonylurea and Imldazollnone herbicides Will the delineation of the cytotoxicity of AKB towards typhimurium, the only system in which it has been approached, provide relevant information towards the roles of this molecule in the Inhibition of plant growth Can herbicide-resistant alleles of ALS structural genes be used as dominant selectable markers In the transformation of a wide variety of sensitive cell lines What are the structural details of the interaction of ALS with the sulfonylurea and imldazollnone herbicides Are eukaryotic ALS Isozymes composed of nonldentlcal subunits How does SM cause cessation of DNA synthesis in plants In the next few years answers to some of these questions may emerge. 

Nitrogen is the one element above all others that we associate with growth. As pointed out in Chapter 14, it is a constituent of proteins, enzymes, chlorophyll, deoxyribonucleic acids that make up the genetic code, amino acids and many intermediates invplved in the synthesis of plant substances. It is characteristically present in comparatively large amounts in the growing tips of plants, hut it can move about readily from one part of the plant to another to meet the primary needs at the time. 

Scheme 17.9). The synthesis and plant growth regulatory activity of each enantiomer has recently been shown by Cheminova [50a]. A patent describing the synthesis of the trans epoxiconazole has recently been published [50b]. 

EC.4.1.1.39] is a major determitant of plant growth and yield. In plant, RuBisco has the structure of LgSg. To facilitate the study on structure-function relationship of rbcS by site-specific mutagenesis, we report here the total synthesis of a gene (Fig. 1) for the mature rbcS from tobacco. 

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