The conductive tissues of the angiosperms are the xylem which drives the raw sap and the phloem which conducts the elaborate sap.The phloem, or liber, drives the elaborate sap, solution of organic substances rich in carbohydrates, from the leaves to the other organs.
The elaborate sap (which contains organic substances produces by photosynthesis) is produced in the leaves, where the majority of the chlorophyll subsist, so if the leave die off, the production of organic substances and the elaborate sap are reduced, so its transport by the phloem will be reduced, and this is how the phloem will be affected by the dying of the leaves.
