Compositions and methods are provided where a plant comprising an avenic acid transporter is planted in a field with a target plant in need of increased iron uptake. The plant comprising the avenic acid transporter in an embodiment further comprises one or more constructs comprising nucleic acid molecules expressing heavy and light chains forming an antibody specific to the avenic acid transporter or functional small peptide and may also include a sequence targeting the apoplast. The antibody or functional small peptide is operably linked to a floral promoter or inducible natural or synthetic promoter. Upon expression regulated by the floral promoter or exposure to the inducing conditions, or both, the plant increases its production of avenic acid transporter antibodies, enters senescence and eventually dies. As a result, the plant is not harvested with the target plant, provides a cover crop, and does not continue to use nutrients, and other resources that benefit the targeted plant. Increased avenic acid is produced by the plant prior to dying in response to Fe3+ starvation induced by inactivation of the Fe+3/phytosiderophore transporter.
