<Li> The sucrose diffuses through the plasmodesmata from the companion cells to the sieve tube elements . As a result, concentration of sucrose increases in the sieve tube elements . </Li> <Li> Water moves by osmosis from the nearby xylem in the same leaf vein . This increases the hydrostatic pressure of the sieve tube elements . </Li> <Li> Hydrostatic pressure moves the sucrose and other substances through the sieve tube cells, towards a sink . </Li> <Li> In the storage sinks, such as sugar beet root and sugar cane stem, sucrose is removed into apoplast prior to entering the symplast of the sink . </Li>

What is the first step in the pressure flow mechanism of translocation