Q.List out the non-photosynthetic parts of a plant that need a supply of Sucrose.

Any plant part that cannot photosynthesise for itself — roots, developing fruits/seeds, storage tubers, non-green stem tissue, etc. — must receive sucrose transported to it from the leaves.

In the source-to-sink model of translocation, mature, green, photosynthesising leaves act as the 'source,' making sugar (largely as sucrose) in excess of their own immediate needs. This sucrose is loaded into the phloem sieve tubes and transported (by the pressure-flow/mass-flow mechanism) to 'sink' regions of the plant — any part that consumes or stores sugar but does not itself produce enough (or any) sugar by photosynthesis. Such non-photosynthetic parts that require this imported sucrose supply include:

• Roots: entirely non-green (underground), so they depend completely on sucrose from the shoot for respiration and growth.
• Developing fruits and seeds: these are sinks that accumulate large amounts of sugar (and convert it to starch, oils, or other storage forms) received from the parent plant's leaves. …