Fig. 1. Identification of sucrose transporters. (A and B) HEK293T cell–FRET sensor uptake assay. (A) Of ~50 membrane protein genes tested, AtSWEET10 to 15 showed sucrose influx as measured with the sucrose sensor FLIPsuc90m∆1V;
(B) Representative trace of sucrose uptake by AtSWEET11 (blue) compared to control (black). (C) Sucrose uptake by AtSWEET11 in the presence of inhibitors (NPG, PCMBS). (D) Sucrose uptake by AtSWEET11 in the presence of different concentrations of sucrose. (E) Sucrose uptake by AtSWEET11 in the presence of different concentrations of glucose. (F and G) Rice protoplast assay. (F) Representative images of rice protoplasts expressing GFP alone or GFP-tagged OsSWEET11. (G) Fluorescence intensity of GFP alone or GFP-OsSWEET11 expressed in rice protoplasts. (H and I) Yeast complementation assay. (H) Growth of yeast mutant strain EBY.VW4000 expressing SUC2 (positive control) or empty vector (negative control) on medium with sucrose or glucose as the sole carbon source. (I) Growth of yeast mutant strain EBY.VW4000 expressing OsSWEET11 or empty vector on medium with sucrose or glucose as the sole carbon source. Data are means ± SEM (A) or means ± SD (B to I) of three independent experiments. Asterisks indicate significant difference from control (*P < 0.05, ***P < 0.001, Student’s t test). Scale bar, 20 μm (F).
Interpret SWEET 11 AND 12 Proteins in the phloem transport and why is important
SWEET 11 and 12 proteins are sucrose transporters that play a crucial role in phloem transport, which is the movement of sugars and other nutrients through the phloem tissue of plants. Phloem transport is essential for long-distance transport of photosynthates (sugars produced during photosynthesis) from source tissues, such as leaves, to sink tissues, such as roots, fruits, and developing seeds.
The SWEET proteins, including SWEET11 and 12, are responsible for the loading of sucrose into the phloem sieve elements, which are specialized cells involved in sugar transport. These transporters facilitate the movement of sucrose from the source tissues into the phloem sieve elements, where it is transported to the sink tissues for utilization or storage.
The importance of SWEET 11 and 12 proteins in phloem transport is highlighted by their role in regulating sugar distribution and partitioning within the plant. Efficient phloem loading and transport are essential for maintaining plant growth, development, and reproductive success. Disruptions in phloem transport can result in impaired growth, reduced yield, and overall plant stress.
Furthermore, understanding the mechanisms and regulation of SWEET 11 and 12 proteins in phloem transport is important for crop improvement. Manipulating the expression or activity of these transporters can potentially enhance the efficiency of sugar transport and partitioning, leading to increased crop yield and improved nutritional qualities.
Overall, SWEET 11 and 12 proteins have a significant role in phloem transport, contributing to the proper distribution of sugars throughout the plant and impacting plant growth, development, and crop productivity.
Step 1: In this experiment, the researchers used a HEK293T cell-FRET sensor uptake assay to identify sucrose transporters.
Step 2: The assay involved testing approximately 50 membrane protein genes.
Step 3: Among the tested genes, the genes AtSWEET10 to 15 exhibited sucrose influx.
Step 4: Sucrose influx was measured using a sucrose sensor called FLIPsuc90m∆1V.