Tetrapyrrole Biosynthesis

Mrna Biosynthesis Plants

The light-induced expression of Lhc proteins was found to coincide with the greening and maturation process of chloroplasts implying the action of a plastid signal. One potential signal could be attributed to the chlorophyll precursor Mg-Proto-Porphyrin-IX (Mg-Proto-IX). Feeding experiments with the iron chelator dipyridyl led to decreased Lhcb mRNA levels in Chlamydomonas reinhardtii (Johanningmeier and Howell 1984). The chelation of iron leads to an interruption of the heme feedback...

Plastid Stay GreenProtein SGR Ensures Adequate Plastid Reconversion

Photosynthetic organisms have evolved pathways to ensure the destruction of chlorophylls and the disposal of its byproducts throughout the life cycle. Chlorophyll breakdown inplanta is tightly connected to the extensive dismantling of thylakoid proteins and ultrastructural changes of plastid membranes. A characteristic aspect of this cata-bolic process occurs in senescing plant tissues when chloroplasts transform into gerontoplasts (Parthier 1988), and during flower development and fruit...