IIT Guwahati study explains how plants adapt water transport system during drought

Researchers at the Indian Institute of Technology (IIT) Guwahati have studied how plants adjust their internal water transport systems during drought-induced stress, offering insights that could help develop drought-tolerant crops and improve water-use efficiency.

The findings have been published in the journal Applied Physics Reviews, according to the institute.

Plants transport water from their roots to their leaves through microscopic tubes called xylem, which are interconnected by tiny openings known as pits. These structures help regulate the movement of water within the plant. However, how the xylem network responds to severe water shortages has remained a challenge for researchers, as earlier computational models often treated these vessels as rigid pipes.

To address this gap, Pranab Kumar Mondal, a professor in the Department of Mechanical Engineering at IIT Guwahati, and his research team combined experimental measurements with realistic three-dimensional computer simulations to examine changes in the xylem system during water stress.

The team studied the stems of Indian mustard plants using advanced imaging techniques, microscopic force measurements and chemical tracking. They measured changes in the dimensions, mechanical strength and wall properties of the xylem, as well as changes in the size of the pits.

“These measurements were used to build realistic 3D models. These models showed how plants reorient their xylem to optimise water transport during drought,” Mondal said in a statement.

The study found that during acute water shortages, the xylem tubes become narrower and the pits shrink, increasing resistance to fluid flow. This restricts the movement of water up the stem and helps limit water loss through transpiration from the leaves.

Researchers also found that water can flow sideways through the pits, helping maintain water balance within the plant and preventing the breakdown of the interconnected tube network.

According to the institute, the findings could improve scientific understanding of how plants survive under water-scarce conditions. The insights may also support efforts to develop crop varieties that are more drought-tolerant and use water more efficiently.

The research could have implications for agriculture in regions increasingly affected by water shortages and climate change, potentially helping reduce crop losses and sustain productivity.