Vectorisation of agrochemicals via amino acid carriers: influence of the spacer arm structure on the phloem mobility of phenylpyrrole conjugates in the Ricinus system.
BACKGROUND
Excessive agrochemical use poses significant threats to environmental safety and human health. Reducing pesticide use without reducing yield is necessary for sustainable agriculture. Therefore, we developed a vectorisation strategy to enhance agrochemical delivery through plant amino acid carriers.


RESULTS
In addition to a fenpiclonil conjugate recently described, three new amino acid conjugates were synthesised by coupling fenpiclonil to an l-α-amino acid. Phloem mobility of these conjugates, which exhibit different structures of the spacer arm introduced between fenpiclonil and the α-amino acid function, was studied using the Ricinus model. Conjugate L-14, which contains a triazole ring with the shortest amino acid chain, showed the best phloem systemicity among the four conjugates. By contrast, removing the triazole ring in the spacer arm did not improve systemicity. L-14 exhibited phloem systemicity at all reported pH values (pH values from 5.0 to 6.5) of the foliar apoplast, while acidic derivatives of fenpiclonil were translocated only at pH values near 5.0.


CONCLUSIONS
The conjugates were recognised by a pH-dependent transporter system and translocated at distance in the phloem. They exhibited a broader phloem systemicity than fenpiclonil acidic derivatives within the pH value range of the foliar apoplast. © 2017 Society of Chemical Industry.
Institut de Chimie des Milieux et des Matériaux de Poitiers, Université de Poitiers, Poitiers, France.
Sophie
S
Marhadour
Institut de Chimie des Milieux et des Matériaux de Poitiers, Université de Poitiers, Poitiers, France.|Laboratoire Écologie et Biologie des Interactions, Université de Poitiers, Poitiers, France.
Hanxiang
H
Wu
Guizhou Tea Reasearch Institute, Guizhou Academy of Agricultural Science, Guiyang, Guizhou, China.
Wen
W
Yang
Institut de Chimie des Milieux et des Matériaux de Poitiers, Université de Poitiers, Poitiers, France.
Cécile
C
Marivingt-Mounir
Laboratoire Écologie et Biologie des Interactions, Université de Poitiers, Poitiers, France.
Jean-Louis
JL
Bonnemain
Institut de Chimie des Milieux et des Matériaux de Poitiers, Université de Poitiers, Poitiers, France.
Jean-François
http://orcid.org/0000-0001-7840-0619
JF
Chollet
D016573:Agrochemicals / Q000737:chemistry* / Q000378:metabolism*; D000596:Amino Acids / Q000378:metabolism*; D001692:Biological Transport; D009068:Movement; D052585:Phloem / Q000378:metabolism*; D011758:Pyrroles / Q000737:chemistry* / Q000378:metabolism*; D012278:Ricinus / Q000378:metabolism*
D016573:Agrochemicals; D000596:Amino Acids; D011758:Pyrroles
amino acid carrier; conjugate systemicity; fungicide; phenylpyrroles; phloem transport; sustainable agriculture