Mn3O4 Nanoparticles Alleviate ROS‐Inhibited Root Apex Mitosis Activities to Improve Maize Drought Tolerance

Abstract

AbstractPoly (acrylic) acid coated Mn3O4 nanoparticles (PAA@Mn3O4 nanoparticles (PMO, 11.02 nm, −28.93 mV)) are synthesized to investigate whether they can help to improve maize drought tolerance and the relevant mechanisms behind this. In planta experimental results show that under drought (15% PEG 6000, polyethylene glycol, mimicking drought stress, 96 h), compared with the control plants, 500 mg L−1 PMO (root application, 96 h) improves maize drought tolerance, showing an increase of root length (21.6%), shoot length (21.2%), fresh weight (7.8%) and total protein (67.2%) content. In addition, PMO significantly decreases the malondialdehyde (MDA) content by 74.7% in maize under drought, compared with the control group. Further, PMO treated maize root apex shows significantly increased mitotic index (MI, 35.5%), and decreased hydrogen peroxide (40.9%). Compared with the control under drought (15% PEG, 96 h), thr root apex of maize plants treated with PMO (500 mg L−1, root application, 96 h) have significantly lower level of H2O2. Overall, the results show that PMO can alleviate drought‐inhibited cell mitosis activities via maintaining ROS (reactive oxygen species) homeostasis. In this study, it is not only shown that PMO can be a good nano‐regulator candidate to improve maize drought tolerance, but also that PMO has potential to modulate plant cell mitosis activities.