Drought and powerful storms have affected plant communities. Now,
scientists at the National University of Singapore (NUS) have discovered
how plants control the development of stomata to reduce water loss under
During water shortage, plants have two stomatal reactions. They restrict
the growth of new stomata and seal the pores of existing ones. The
phytohormone abscisic acid regulates these reactions (ABA), is essential
for plant drought adaptation, and is especially pertinent for
maintaining agriculture in the face ofclimate change. However, it has
remained unclear how ABA reduces stomatal output.
The research group from the Department of Biological Sciences at NUS
under the direction of Assistant Professor LAU On Sun, discovered that
the critical stomatal regulator SPEECHLESS (SPCH) is directly
phosphorylated by the core kinases of ABA signaling, which are active
during drought. ABA phosphorylates the SPCH protein at two different
locations, and this phosphorylation causes SPCH to degrade.
Prof. Lau said, "Our results demonstrate that a specific 'code'
underlies a key plant water conservation response. This is exciting
because it suggests that by manipulating the code, we could optimize
crop plants for various growing conditions, from conventional to urban
farming, and fine-tune their drought tolerance."