The food stored in the ripening fruit is derived from

What is the direction of movement of sugars in phloem?

The transport of food in phloem is:

Consider the following statements and choose the correct option from the codes given below:
$I.$ Loading of phloem is related to the increase of sugar in phloem.
$II.$ Active loading of sugar in the sieve tube of phloem is driven by a proton pump.
$III.$ Pressure may be positive or negative in sieve tube cells.
$IV.$ Water and solutes move through the sieve tube against the pressure gradient.
$V.$ Cytoplasmic strands pass through the holes in sieve plates and form continuous filaments.

The improvements so proposed in pressure flow are

Who supported the cytoplasmic flow hypothesis for translocation of food in plants?