Specific delivery of agrochemicals

Abstract

Described is the specific delivery of agrochemicals to plants. More specifically, described is a composition having a targeting agent comprising at least one binding domain that specifically binds to a binding site on an intact living plant and an agrochemical or a combination of agrochemicals. Also described is a binding domain that specifically binds the binding site on an intact living plant. More specifically, described are binding domains comprising a peptide sequence that comprises four framework regions and three complementary-determining regions, or any suitable fragment thereof, so that the binding domains are able to bind or retain a carrier onto a plant. Described are binding domains that specifically bind trichomes, stomata, cuticle, lenticels, thorns, spines, root hairs, or wax layer. Described is a method for delivery of agrochemicals to a plant, for improving the deposition of agrochemicals on a plant, and for retaining the agrochemicals on a plant, using targeting agents comprising the binding domains, and to a method for protecting a plant against biotic or abiotic stress or controlling plant growth using the same. Also, described is a method for manufacturing a specifically targeting agrochemical carrier.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S)[0001]This application is a continuation-in-part of co-pending U.S. patent application Ser. No. 13 / 081,435, filed Apr. 6, 2011, which is a utility conversion of U.S. Provisional Patent Application Ser. No. 61 / 341,930, filed Apr. 6, 2010, and claims priority to European Patent Application Serial No. EP 10159100.6, filed Apr. 6, 2010, the disclosure of each of which is hereby incorporated herein by this reference in its entirety.STATEMENT ACCORDING TO 37 C.F.R. §1.821(c) or (e) SEQUENCE LISTING SUBMITTED AS PDF FILE WITH A REQUEST TO TRANSFER CRF FROM PARENT APPLICATION[0002]Pursuant to 37 C.F.R. §1.821(c) or (e), a file containing a PDF version of the Sequence Listing has been submitted concomitant with this application, the contents of which are hereby incorporated by reference. The transmittal documents of this application include a Request to Transfer CRF from the parent application.TECHNICAL FIELD[0003]The disclosure relates to specific de...

AI Technical Summary

Benefits of technology

[0015]Targeting agents comprising these binding domains, can retain agrochemicals specifically to binding sites on the plant or plant parts and can be used to deliver and retain agrochemicals to the plant, preferably to the intact living plant, so that the binding domains comprised in such targeting agents specifically bind to binding sites on the plant, where the agrochemicals can exert their activity. Agrochemical compositions comprising at least one targeting agent and an agrochemical, preferably bound on or comprised in a carrier, may be suitable to allow the use of a reduced dose of the agrochemical and / or reduction of the frequency of application of the agrochemical, comprised in such composition whilst maintaining its overall efficacy.

[0016]Moreover, when comprised in a composition disclosed herein, the agrochemical may exert its activity over a longer period of time, eventually resulting in less agrochemical being lost and contaminating the environment; also, by applying an agrochemical in a composition hereof, it is possible to introduce specificity into the activity of the agrochemical that is otherwise not present.

Problems solved by technology

Apart from giving rise to reduced efficacy of the chemical, losses of chemicals into the soil due to dripping off the plant while spraying or due to wash-out during rainfall may result in groundwater contamination, environmental damage, loss of biodiversity, and human and animal health consequences.

Although this may have advantages compared with the normal spraying, the efficacy of such delivery method is limited, and the particles may be non-optimally distributed over the leaf, or washed away under naturally variable climatological conditions, before the release of the compound is completed.

First, although cellulose is a major component of plant cell walls and about 33% of all plant matter consists of cellulose, cellulose is, in intact living plants, shielded off from the outside environment by the plant cuticle, formed by cutin and waxes, which is an impermeable barrier with which plant cell walls are covered, making cellulose poorly accessible for binding by CBDs.

Second, effective delivery of an encapsulated benefit agent to the plant requires simultaneous binding of the first binding domain to the plant and the second binding domain to the microparticle. As the likelihood of both binding events occurring is determined by a delicate equilibrium between the molar concentrations of the binding domains and their target molecules and the molar concentration of the bound complex, it is highly unlikely that sufficient multifunctional fusion proteins are present in solution to enable such simultaneous binding. Moreover, the equilibrium of a binding event is strongly influenced by environmental parameters such as temperature and pH, for which the optimal conditions may be considerably different for each of the binding domains. Therefore, it is highly unlikely that such simultaneous binding of two binding domains of such multifunctional fusion protein would result in a sufficiently strong binding that would retain an encapsulated benefit agent to a plant.

Third, although binding of a CBD is to a certain extent specific for cellulose, using a multifunctional fusion protein in which CBD should bind to the plant is to be considered as a generic binding approach, as all plants contain cellulose, and is therefore similar to aspecific sticking with tackifiers or stickers. A targeted approach in which specific binding of a binding domain would allow discrimination between binding to one plant species versus another would be of considerably higher value. WO03031477 also suggests, without further exemplification, that other binders to carbohydrates or polysaccharides can be used to generate fusion proteins to deposit microparticles onto living organisms. However, neither binding domains other than CBDs, nor binding domains binding to intact living plants were disclosed in WO03031477.

However, it is unclear whether any of the plant cell wall constituents to which the antibodies have been generated, would be directly accessible for an antibody from the outside environment.

However, so far, no plant-binding VHH have been described.

Images