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Involvement of K+ in Leaf Movements During Suntracking Introduction Many plants orient their leaves in response to directional light signals. Heliotropic movements, or movements that are affected by the sun, are common among plants belonging to the families Malvac ....

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.... Many plants that exhibit diaheliotropic movements also show paraheliotropic response as well. Paraheliotropism minimizes water loss by reducing the amount of light absorbed by the leaves; the leaves orient themselves parallel to the sun’s rays. Plants that exhibit paraheliotropic behavior usually do so at midday, when the sun’s rays are perpendicular to the ground. This reorientation takes place only in leaves of plants that are capable of nastic light-driven movements, such as the trifoliate leaf of Erythrina spp. (Herbert 1984). However, this phenomenon has been observed in other legume species that exhibit diaheliotropic leaf movement as w ....