In times of a constantly
growing world population and increasing
demand for food, sustainable agriculture is crucial. The rainfastness
of plant protection agents is of pivotal importance to reduce the
amount of applied nutrients, herbicides, and fungicides. As a result
of protective agent wash-off, plant protection is lost, and soils
and groundwater are severely polluted. To date, rainfastness of plant
protection products has been achieved by adding polymeric adjuvants
to the agrochemicals. However, polymeric adjuvants will be regarded
as microplastics in the future, and environmentally friendly alternatives
are needed. Anchor peptides (APs) are promising biobased and biodegradable
adhesion promoters. Although the adhesion of anchor peptides to artificial
surfaces, such as polymers, has already been investigated in theory
and experimentally, exploiting the adhesion to biological surfaces
remains challenging. The complex nature and composition of biological
surfaces such as plant leaves and fruit surfaces complicate the generation
of accurate models. Here, we present the first detailed three-layered
atomistic model of the surface of apple leaves and use it to compute
free energy profiles of the adhesion and desorption of APs to and
from that surface. Our model is validated by a novel fluorescence-based
microtiter plate (MTP) assay that mimics these complex processes and
allows for quantifying them. For the AP Macaque Histatin, we demonstrate
that aromatic and positively charged amino acids are essential for
binding to the waxy apple leaf surface. The established protocols
should generally be applicable for tailoring the binding properties
of APs to biological interfaces.