Nanoparticle Delivery of Antisense miR162 Inhibits Invasive Habitat Adaption of Alternanthera Philoxeroides.

Phenotypic flexibility in adaptive traits is crucial for organisms to thrive in changing environments. Alternanthera philoxeroides, native to South America, has become an invasive weed in Asia. The mechanism by which invasive capacity is achieved remains unknown. Here, it is demonstrated that miR162 plays a crucial role in submergence survival for A. philoxeroides. These results highlight that the level of miR162 significantly increases in stems from 3 to 48 h upon water submergence, and knockdown of miR162 via TRV-based VIGS system significantly disrupts stem elongation upon water submergence, ultimately resulting in a failure of plants protruding from the water surface. Interestingly, miR162 is not up-regulated in the noninvasive congeneric alien species Alternanthera pungens, which is also native to South America but has retained its original habitats in Asia. The presence of anaerobic responsive elements (AREs) in the promoter sequences of MIR162 from A. philoxeroides rather than A. pungens may contribute to its invasion capacity. Importantly, nanoparticle delivery of antisense RNA oligonucleotides of miR162 significantly impairs stem elongation during water submergence. Thus, our findings reveal that the achievement of specific miRNA activity can drive rapid phenotypic variation, and miR162 has the potential as a bio-pesticide for controlling the invasive growth of A. philoxeroides.