Plant morphology share the same basic structure and development as leaves in other plants, and therefore cactus spines are homologous to leaves as well. This aspect of plant morphology overlaps with the study of plant evolution and paleobotany. Secondly, plant morphology observes both the vegetative (somatic) structures of plants, as well as the reproductive structures. The vegetative structures of vascular plants includes the study of the shoot system, composed of stems and leaves, as well as the root system. The reproductive structures are more varied, and are usually specific to a particular group of plants, such as flowers and seeds, fern sori,
Plant matrix metalloproteinase increase of transcript abundance with aging. In the leaves, the MMP gene was expressed in the phloem, developing xylem elements, neighboring mesophyll cell layers, and epidermal cells. The flowers were noted as having the gene in pistils, ovules, and receptacles. It was concluded that the At2-MMP has a physiological role in mature aging tissue and the possibility of being involved in plant senescence. The fungus Chondrostereum purpureum, the causal agent of silver leaf, was grown in liquid culture and agar, which caused it to secrete extracellular proteinases into the medium. The fluid dialysed by the activation of metal ions, which