Molecular\nMechanisms of Early Flowering in Tomatoes\nInduced by Manganese Ferrite (MnFe2O4) Nanomaterials

Nanomaterials\n(NMs) have demonstrated enormous potential to improve\nagricultural production. Ten mg L–1 of customized\nmanganese ferrite (MnFe2O4) NMs was selected\nas the optimal dose based on its outstanding effects on promoting\ntomato flowering and production. After the foliar application before\nflowering, MnFe2O4 NMs increased the leaf chlorophyll\ncontent by 20 percent, and significantly upregulated the expressions\nof ferredoxin, PsaA, and PsbA in leaves, likely by serving as an electron donor,\nleading to a significant increase in photosynthesis efficiency by\n13.3%. Long distance transport of sucrose was then confirmed by the\nupregulation of sucrose transporter SUT1 and SUT2 in NM-treated leaves and meristems. The genes associated\nwith gibberellin biosynthesis, including GA20ox2, GA20ox3, and SIGAST, and a flowering induction\ngene SFT, were also significantly upregulated. Importantly,\nthe flowering time was 13 days earlier by MnFe2O4 NMs over the control. At the reproductive stage, MnFe2O4 NMs increased pollen activity and ovule size, leading\nto the significant increase in fruit number per plant, single fruit\nweight, and fruit weight per plant by 50%, 30%, and 75%, respectively.\nMetabolically, a significant increase of glucose-6-phosphate, phenylalanine,\nrutin, and ascorbic acid (vitamin C), as well as a significant decrease\nof tomatine and methionine, demonstrates an increased nutritional\nvalue of the tomato fruits. A verified companion field experiment\nshowed an increase of 84.1% in total tomato production with the MnFe2O4 NM amendment. These findings provide support\nfor the early flowering and yield improvement in nano-enabled agricultural\nsystems.