Popis: |
Silicon was localized in some dicotyledons (Minuartia verna, Silene cucubalus, Thlaspi coerulescens, Viola calaminaria, Nicotiana tabacum, Pisum sativum) by analytical transmission electron microscopy as apoplastic crystalline inclusions of SiO2 in intercellular spaces of the leaf parenchyma, between cell wall and plasma membrane and inside the vacuoles. Ca-silicate, and in some plants Sn-silicate, forms the peripheral parts of the crystalline inclusions. These unstable compounds are converted spontaneously in the plant cells into the more stable SiO2, which forms the central part of all crystalline inclusions. The function of silicon in these plants is discussed. |