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

Where is the bidirectional transport of minerals observed?

During translocation,the carbohydrates are relatively richer in:

Explain the pressure flow hypothesis of translocation of sugar in plants.

Arrange the following events of mass flow of organic material in sequence:
$I$. Sugars are transported from cell to cell in the leaf
$II$. Food is synthesized in form of glucose by leaf cells
$III$. Movement of water takes place into sieve tube elements
$IV$. Downward movement of sugar occurs in the stem
$V$. Solutes are actively transported into the sieve elements

Food is transported to various parts of the plant through