The mechanisms that regulate the loading of sucrose from the apoplast to the sieve-tube members by sucrose-H⁺ symporters are not well understood.Of the following possible regulatory factors,which is least likely to be of direct importance?

Question

Quizplus · Accepted Answer

The density of direct cytoplasmic connections between companion cells and sieve-tube members is not directly involved in the loading of sucrose into sieve-tube members. Sucrose is loaded into sieve-tube members by sucrose-H+ symporters located in the plasma membrane of sieve-tube members. The turgor pressure of sieve-tube members, the sucrose concentration in the apoplast, and the number of available symporter protein molecules in the plasma membranes of sieve-tube members are all factors that can affect the rate of sucrose loading.

The Mechanisms That Regulate the Loading of Sucrose from the Apoplast