Synthesis and phloem mobility of acidic derivatives of the fungicide fenpiclonil

Chollet, Jean-François; Rocher, Françoise; Jousse, Cyril; Delétage-Grandon, Céline; Bashiardes, Georges; Bonnemain, Jean‐Louis

doi:10.1002/ps.906

Cited by 48 publications

(81 citation statements)

References 22 publications

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“…6A). These values were lower than those noted (21-or 22-fold) for Suc and Phe, which are taken up by specific carrier systems (Lemoine, 2000;Chen et al, 2001), much higher than those reported (0.2-or 0.3-fold) for glyphosate (Delétage-Grandon et al, 2001) and acidic derivatives of fenpiclonil (Chollet et al, 2004(Chollet et al, , 2005, but close to that noted for 2,4-D, which is less ionized than SA at apoplastic pH (Fig. 6B) but larger in size (Fig.…”

Section: Measurement Of Sa Accumulation In the Phloem Sap And Comparisupporting

confidence: 49%

“…The discrepancy between SA uptake and percentage of the undissociated form of the molecule at biological pH is still more marked when a homogeneous aqueous medium is taken into consideration (pK a 3.0). By contrast, data from systemicity tests using the Ricinus system indicate that acidic derivatives of the fungicide fenpiclonil (compounds 2a and 2b) are taken up only in their undissociated form in accordance with the iontrap mechanism (Chollet et al, 2004(Chollet et al, , 2005.…”

Section: Time-course Experimentsmentioning

confidence: 88%

“…These values are practically identical to those calculated using ACD LogD version 9.0 software (pK a 5 3.01; log K ow 5 2.06). According to the calculations made by this software, two acidic derivatives of fenpiclonil (compounds 2a and 2b) recently synthesized (Chollet et al, 2004(Chollet et al, , 2005 and 2,4-dichlorophenoxyacetic acid (2,4-D) exhibited a phloem mobility ability near to that of SA (Fig. 2, A and B).…”

Section: Predicting Phloem Mobility Of Sa In Comparison With Other Momentioning

confidence: 99%

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Salicylic Acid, an Ambimobile Molecule Exhibiting a High Ability to Accumulate in the Phloem

et al. 2006

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The ability of exogenous salicylic acid (SA) to accumulate in castor bean (Ricinus communis) phloem was evaluated by HPLC and liquid scintillation spectrometry analyses of phloem sap collected from the severed apical part of seedlings. Time-course experiments indicated that SA was transported to the root system via the phloem and redistributed upward in small amounts via the xylem. This helps to explain the peculiarities of SA distribution within the plant in response to biotic stress and exogenous SA application. Phloem loading of SA at 1, 10, or 100 mM was dependent on the pH of the cotyledon incubating solution, and accumulation in the phloem sap was the highest (about 10-fold) at the most acidic pH values tested (pH 4.6 and 5.0). As in animal cells, SA uptake still occurred at pH values close to neutrality (i.e. when SA is only in its dissociated form according to the calculations made by ACD LogD suite software). The analog 3,5-dichlorosalicylic acid, which is predicted to be nonmobile according to the models of Bromilow and Kleier, also moved in the sieve tubes. These discrepancies and other data may give rise to the hypothesis of a possible involvement of a pH-dependent carrier system translocating aromatic monocarboxylic acids in addition to the ion-trap mechanism.

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Section: Measurement Of Sa Accumulation In the Phloem Sap And Comparisupporting

confidence: 49%

Section: Time-course Experimentsmentioning

confidence: 88%

Section: Predicting Phloem Mobility Of Sa In Comparison With Other Momentioning

confidence: 99%

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Salicylic Acid, an Ambimobile Molecule Exhibiting a High Ability to Accumulate in the Phloem

et al. 2006

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“…A residual uptake of BA and SA at pH values close to neutrality was also noted in intestinal cells Tsuji et al, 1994). By contrast, phloem uptake of acid derivatives of fenpiclonil in Ricinus occurred only in their permeant undissociated form (Chollet et al, 2004(Chollet et al, , 2005.…”

Section: Structure-phloem Mobility Relationshipsmentioning

confidence: 82%

“…The algorithms for the predictions are based on contributions of separate atoms, structural fragments, and intramolecular interactions between different fragments. LogD is a very important parameter for bioavailability and absorption studies of drugs (van de Waterbeemd et al, 2003) and agrochemicals (Chollet et al, 2004(Chollet et al, , 2005. The calculation of confidence limits for LogD (d LogD) is not implemented into ACD software but can be evaluated for a monoacid with the following formula: where logP is the octanol-water partition coefficient for uncharged species and logPion is the octanol-water partition coefficient for negatively charged species.…”

Section: Physicochemical Propertiesmentioning

confidence: 99%

Salicylic Acid Transport in Ricinus communis Involves a pH-Dependent Carrier System in Addition to Diffusion

et al. 2009

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Despite its important functions in plant physiology and defense, the membrane transport mechanism of salicylic acid (SA) is poorly documented due to the general assumption that SA is taken up by plant cells via the ion trap mechanism. Using Ricinus communis seedlings and modeling tools (ACD LogD and Vega ZZ softwares), we show that phloem accumulation of SA and hydroxylated analogs is completely uncorrelated with the physicochemical parameters suitable for diffusion (number of hydrogen bond donors, polar surface area, and, especially, LogD values at apoplastic pHs and D LogD between apoplast and phloem sap pH values). These and other data (such as accumulation in phloem sap of the poorly permeant dissociated form of monohalogen derivatives from apoplast and inhibition of SA transport by the thiol reagent p-chloromercuribenzenesulfonic acid [pCMBS]) lead to the following conclusions. As in intestinal cells, SA transport in Ricinus involves a pH-dependent carrier system sensitive to pCMBS; this carrier can translocate monohalogen analogs in the anionic form; the efficiency of phloem transport of hydroxylated benzoic acid derivatives is tightly dependent on the position of the hydroxyl group on the aromatic ring (SA corresponds to the optimal position) but moderately affected by halogen addition in position 5, which is known to increase plant defense. Furthermore, combining time-course experiments and pCMBS used as a tool, we give information about the localization of the SA carrier. SA uptake by epidermal cells (i.e. the step preceding the symplastic transport to veins) insensitive to pCMBS occurs via the ion-trap mechanism, whereas apoplastic vein loading involves a carrier-mediated mechanism (which is targeted by pCMBS) in addition to diffusion.

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Systemic properties of myclobutanil in soybean plants, affecting control of Asian soybean rust (Phakopsora pachyrhizi)

Kemmitt¹,

deBoer²,

Ouimette³

et al. 2008

Pest Management Science

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Synthesis and phloem mobility of acidic derivatives of the fungicide fenpiclonil

Cited by 48 publications

References 22 publications

Salicylic Acid, an Ambimobile Molecule Exhibiting a High Ability to Accumulate in the Phloem

Salicylic Acid, an Ambimobile Molecule Exhibiting a High Ability to Accumulate in the Phloem

Salicylic Acid Transport in Ricinus communis Involves a pH-Dependent Carrier System in Addition to Diffusion

Systemic properties of myclobutanil in soybean plants, affecting control of Asian soybean rust (Phakopsora pachyrhizi)

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