Molecular Targeted Suppression of Male Fertility in Amaranthus palmeri S. Watson: Function and Layered Double Hydroxide Nanosheets-Based Delivery System of ApmiR319

Amaranthus palmeri is one of the most troublesome invasive agricultural weeds worldwide, exhibiting super invasiveness and high resistance to conventional management strategies. Artificial microRNA-mediated silencing technology, coupled with a nanoparticle-mediated delivery system, represents an attractive approach for fertility control in A. palmeri . In this study, we first characterised the biological function of ApMIR319 via ectopic overexpression in Arabidopsis , identifying it as a crucial candidate molecular target for fertility regulation in A. palmeri . Subsequently, we prepared layered double hydroxide (LDH) nanosheets using the co-precipitation-hydrothermal method. Employing the LDH nanosheets as nanocarriers, we implemented nearly complete encapsulation of the ApmiR319 mimic at a mass ratio of 1:100. The LDH-ApmiR319 mimic complex exhibited stable loading capacity in neutral and alkaline solutions. Furthermore, the LDH-ApmiR319 mimic complex demonstrated robust adhesion to leaf surfaces and enhanced resistance to enzymatic degradation. Spraying treatments with the LDH-ApmiR319 mimic complex significantly elevated ApmiR319 expression levels in male florets, while concurrently down-regulating its target genes ( ApTCP4 , ApTCP10 and ApMYB33 ), thereby inhibiting pollen development in A. palmeri . In conclusion, this study successfully established an LDH nanosheet-mediated delivery system of ApmiR319 mimic for male fertility control in A. palmeri . It represents a novel strategy and direction for achieving sustainable management of this weed.