Pollen tube growth, which is important in species-specific barrier
mechanism, is once thought to be promoted by sugars. This belief is
disproved by a study by Ruth Stadler and colleagues from the University of
Erlagen in Germany.

The team finds the inhibitory effect of glucose on pollen tube elongation
through in vitro assays of plants with CRISPR-Cas9-knocked out SUGAR
TRANSPORT PROTEIN (STP) genes. These plants had a weak response to glucose,
indicating that glucose uptake is mainly mediated by these knocked out
genes. They also reported that glucose can be detected by HEXOKINASE, and
its effect can be countered by supplying the plant with equal amounts of
fructose.



[www.plantcell.org]