What is the reason for the appearance of tissues and organs in plants?

Plants received tissues and organs through evolution. Leaves, stem, root, flowers and buds are formed as plants adapt to their environment. The presence of chloroplasts and the multicellular structure of plants required the presence of pathways for supplying water to the cells. This is how the root and the conducting cells appeared. The flowers appeared after the insects appeared. They were needed to attract insects. The pigments that color the petals help the flower stand out from the foliage and soil. This increases the chance of insect pollination of the flower.