Alteration of Leaf Movement of Abutilon theophrasti (Malvaceae) by Mycorrhizal Infection

Abutilon theophrasti (Malvaceae) plants orient their leaves in a downward folded position at night but display them more horizontally during the light period. The absence of vesicular-arbuscular mycorrhizal infection of Abutilon resulted in an alteration in the range of leaf movement. Mycorrhizal plants held their leaves nearly horizontal during the middle portion of the day. Uninfected plants, however, reoriented their leaves less during the night/day transition and held them several degrees below horizontal during midday. This modification of leaf angle caused by the absence of mycorrhizal infection was associated with lower leaf P concentration, lower stomatal conductance and higher leaf temperature