#Question id: 13204
#Unit 6. System Physiology – Plant
Many of the carriers of Sucrose–H+ symporters in the phloem play various role in transport, most of the transporters are found in source, path, and sink tissues. Some carriers are characterized such as;
a) SUT1, has high-affinity / low-capacity transporter found in the minor veins of source tissues, appears to be important in phloem loading.
b) Important role of SUT1 in phloem loading appears to be complemented by SUT4, which is low-affinity/high-capacity carrier
c) SUT2, appears to function as a sucrose sensor. This is indicated by findings showing that SUT2 is more highly expressed in sink and path tissues than in source leaves.
d) The major sucrose transporters in phloem loading into the companion cells and final uptake into companion cells appears to be the function of SUT4
Which of the following combination is correct?