Phloem Delivery of Fludioxonil by Plant Amino Acid Transporter-Mediated Polysuccinimide Nanocarriers for Controlling Fusarium Wilt in Banana

Abstract

Fusarium wilt disease poses a serious threat to the global production of bananas. The targeted delivery of fungicides to banana phloem tissues may offer new hope for controlling this hard-to-treat vascular disease. In this study, fludioxonil (FLU)-loaded glycine methyl ester-conjugated polysuccinimide nanoparticles (PGA) were prepared with a loading efficiency (LE) of 27.9%. The obtained nanoparticles (FLU@PGA) exhibited pH-sensitive controlled release, specifically under an alkaline pH in plant phloem. In vivo experiments in potted bananas demonstrated that FLU@PGA can achieve the downward delivery of FLU to banana rhizomes and roots after foliar application, reducing disease severity by 50.4%. The phloem transport studies showed that the phloem loading of FLU@PGA was involved in an active transport mechanism at the organ level (castor bean seedlings). The observation of fluorescein-5-isothiocyanate cadaverine-labeled PGA nanocarriers showed that they could be absorbed by mesophyll cells and loaded into vascular tissues through the symplastic pathway. Furthermore, the interaction of FLU@PGA with the plant amino acid transporter AtLHT1 was observed to enhance transmembrane uptake at the cellular level (Xenopus oocytes). These results suggested that the phloem-targeted delivery of fungicide by transporter-mediated nanocarriers could be a promising new strategy for the management of Fusarium wilt in bananas.

From mouse to mouse‐ear cress: Nanomaterials as vehicles in plant biotechnology

“…Much of our knowledge derives from studies in environmental sciences relating to the uptake and translocation tracing of solid nanoparticles, [ 37,38 ] but some studies have used polymeric carriers similar to those used in biomedicine [ 31 ] and peptide‐based nanocarriers. [ 39 ]…”

“…[ 31 ] Phloem loading of labeled glycine methyl ester‐conjugated polysuccinimide nanoparticles was observed in banana plants. [ 39 ] In the case of liposomes, bidirectional phloem transport was reported for both leaves and roots. [ 35 ] One of the few papers addressing the anatomy of phloem transport suggested that, following foliar application, AuNPs moved symplasmically from mesophyll cells to the phloem (Figure 3).…”

“…Just like the special microenvironment of cancer‐tissue‐inspired designs of tumor‐specific release stimuli, all current approaches will require careful scrutiny when adapting nanocarriers for use in plants. Some approaches that have been considered to date include those based on pH gradients in cells, [ 39 ] light, [ 92 ] ROS, [ 93 ] and temperature [ 31 ] as triggering mechanisms.…”

“…Much of our knowledge derives from studies in environmental sciences relating to the uptake and translocation tracing of solid nanoparticles, [37,38] but some studies have used polymeric carriers similar to those used in biomedicine [31] and peptide-based nanocarriers. [39] Delivering nanomaterials into plant cells and targeting them to specific organelles such as chloroplasts is challenging. Routes of entry are generally limited to either root uptake from soil or through either cuticular or stomatal uptake pathways after foliar application.…”

A Light-Triggered pH-Responsive Metal–Organic Framework for Smart Delivery of Fungicide to Control Sclerotinia Diseases of Oilseed Rape

“…Currently, controlled release formulations of pesticides, which may involve on-demand or site-specific responsive release to biotic (glutathione and enzymes) , or abiotic stimuli (pH, temperature, light, and water) − could minimize or completely avoid the repeated application of pesticides . Fischer et al .…”