Plants' Drought Response Now Uncovered

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 dry conditions.

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 of climate 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."

For more details, read the article in Nature World News.