Effect of Ring Substituents on Phloem Transport and Metabolism of Phenoxyacetic Acid and Six Analogues in Soybean [Glycine Max]

Crisp, Carl E.; Larson, John E.

doi:10.1016/b978-0-08-029222-9.50033-0

Cited by 4 publications

(3 citation statements)

References 22 publications

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“…Phloem translocation is an important requirement for the activity of many herbicides and, as such, is a process that has been investigated in considerable detail in recent years. Areas of study include the physicochemical properties that confer phloem mobility on herbicides (6,7,9,10,32), the relationship between behavior in excised tissues and whole Plant translocation (30), and the effects of herbicides on assimilate transport (17,20,34).…”

Section: Introductionmentioning

confidence: 99%

Physiological Basis for the Different Phloem Mobilities of Chlorsulfuron and Clopyralid

1990

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Foliar-applied clopyralid was translocated much more readily than chlorsulfuron in the phloem of Tartary buckwheat plants. This result was not due to greater penetration of clopyralid into the treated leaf or to greater retention of chlorsulfuron in the cuticle. Experiments with excised leaf disks indicated that chlorsulfuron was taken up more readily by the leaf tissue and accumulated in the tissue to a higher concentration than clopyralid. Both herbicides effluxed readily from the tissue after transfer to herbicide-free medium, indicating that the accumulation was not due to irreversible binding within the tissue. Chlorsulfuron (2.8 nmol) applied with14C-sucrose reduced14C export from the treated leaf. Chlorsulfuron also reduced export of14C following exposure of the treated leaf to14CO2at 6, 12, or 24 h after herbicide application. This effect of chlorsulfuron could be partially reversed by pretreating the plants with a combination of 1 mM valine, leucine, and isoleucine. In similar experiments clopyralid had no effect on assimilate transport. It is concluded that phloem translocation of chlorsulfuron in sensitive species is limited by a rapid, indirect effect on phloem transport that reduces both its own translocation and that of assimilate.

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Section: Introductionmentioning

confidence: 99%

Physiological Basis for the Different Phloem Mobilities of Chlorsulfuron and Clopyralid

1990

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“…In this connection, Cleland ( I 983) cites the role of (i) auxin, produced in the apical bud and young leaves for xylem differentiation (Jacobs & Morrow, 1957); In agreement with Section 111, however, each plant-growth substance influences both the generating and the distal cells and, for example, in withering flowers ethylene accelerates the ageing both of the synthesizing cells and of the adjacent ones (Kende & Hanson, 1976. It might be said by way of explanation that, although present understanding of the translocation of substances in plants is fragmentary (Hathway, 1989), progress with model substances (Crisp & Look, 1979;Crisp & Larson, 1983) implies that, for example, auxin, the gibberellins, abscisic acid and the synthetic plantgrowth regulators have favourable molecular characteristics both for xylem and for active phloem translocations. In the case of ethylene, which lacks a solubilizing carboxyl group, transport would probably be confined to the xylem.…”

Section: ( I ) Hormonal Statusmentioning

confidence: 63%

Plant Growth and Development in Molecular Perspective

Hathway¹

1990

Biological Reviews

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Summary After some false starts in which inactive plant substances were isolated, the isolation and identification of auxin as the growth substance at the meristems and of ethylene as the ripening agent in climacteric fruits represented outstanding achievements. In early work, the non‐localized origin of auxin at the meristem and its possible transport for coleoptile development were obscured by the superimposition on the results of physiological experiments of the idea of a close parallelism between the plant‐growth substances and mammalian hormones. At that time, an absence of chemical instrumentation, suitable for measurement of the tissue levels, compounded the difficulty in interpreting available physiological evidence. Member(s) of each of the five groups of naturally occurring plant‐growth substances, namely the auxins, cytokinins, gibberellins, ethylene and the growth inhibitors, including abscisic acid, are biologically active at a concentration of 10 μm or less, however, and in this respect they would appear to qualify as candidate phytohormones. The sensitivity of plant cells to phytohormones contributes to plant growth and development, and both the variations in sensitivity, for example, of wheat coleoptiles towards growth and the growth of the coleoptiles per se give parallel unimodal relationships with regard to time; the curve representing sensitivity precedes that for growth. A new graphical analysis implies that the growth sensitivity and growth rate functions are mutually interdependent. The assumption is made in point 4 that growth substance complexes with receptor protein in growth‐sensitive cells, and the concept of receptors would provide explanation for the obvious amplification of effects induced by growth substances. Numerous biological situations occur in which the presence of significant amounts of plant hormone controls growth and development. In gravitropism and phototropism, tropistic curvature depends on the difference in physiological concentration of auxin on the two sides of the organ concerned. In infected tobacco plants, the cytokinin to auxin ratios for the tumours determine the kind of development (tumours and shoots, tumours only or tumours plus roots), which takes place. Auxin‐binding protein has been identified immunologically, and isolated. Work with hormone receptors for gibberellin does not afford unequivocal evidence for more than one primary site of action. Hitherto, no specific receptor protein is known for cytokinins. Clear evidence derives, both from structure–activity relationships and from unimodal concentration–response curves, for receptor specificity to auxin action. There is also evidence for a structure–activity relationship in respect of the cytokinin series of compounds. From the evidence (points 1–8), there emerges a picture of hormone‐induced growth and development of plant cells, which have been made sensitive to hormone through the presence of specific receptor proteins. That plant growth and developmental processes involve changes in gene expression...

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“…), and the environment in which both are found. Although much of the physiological and morphological effects of the plant on herbicides are understood (Devine et al, 1993a), it has been far easier to modify the chemical properties of the herbicide (Crisp and Look, 1978;Crisp and Larson, 1983;Lichtner, 1986) for resistance than it has been to alter the translocation factors in the plant. Additionally, differential translocation of herbicides within different plant species is intimately related to concurrent herbicide metabolism, a confounding factor when studying translocation resistance mechanisms.…”

Section: Translocationmentioning

confidence: 99%

Herbicide-Resistant Field Crops

Dekker

Duke

1995

Advances in Agronomy

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This chapter reviews information about how crop plants resist herbicides and how resistance is selected for in plants and surveys specific herbicide-resistant crops by chemical family. The discussion in the chapter includes HRCs derived from both traditional and biotechnological selection methodologies. Plants avoid the effects of herbicides they encounter by several different mechanisms. These mechanisms can be grouped into two categories: those that exclude the herbicide molecule from the site in the plant where they induce the toxic response and those that render the specific site of herbicide action resistant to the chemical. The chapter presents herbicide-resistant crops by the herbicide chemical family-such as, triazine, acetolactate synthatase, acetyl-CoA carboxylase, glyphosate, bromoxynil, phenoxycarboxylic acids, and glufosinate. Resistant crops are listed in the chapter regardless of whether they have been commercialized or were developed for experimental purposes only, and are provided regardless of their "success" as resistant plants. DisciplinesAgricultural Science | Agriculture | Agronomy and Crop Sciences | Weed Science CommentsThis article is

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Effect of Ring Substituents on Phloem Transport and Metabolism of Phenoxyacetic Acid and Six Analogues in Soybean [Glycine Max]

Cited by 4 publications

References 22 publications

Physiological Basis for the Different Phloem Mobilities of Chlorsulfuron and Clopyralid

Physiological Basis for the Different Phloem Mobilities of Chlorsulfuron and Clopyralid

Plant Growth and Development in Molecular Perspective

Herbicide-Resistant Field Crops

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