Guwahati: Researchers at the Indian Institute of Technology, Guwahati (IIT-Guwahati) have found how plants adjust their internal water transport system during drought. This discovery could help develop drought-tolerant crop varieties and reduce agricultural losses.
The study, published in Applied Physics Reviews, examined how drought-induced water stress changes the structure and functioning of xylem, the microscopic tubes in plant stems that carry water from roots to leaves.
Led by Prof. Pranab Kumar Mondal of the Department of Mechanical Engineering, the research team combined experimental measurements with realistic three-dimensional computer simulations to investigate how plants regulate water movement under stress.
The researchers studied Indian mustard plants using advanced imaging, microscopic force measurements and chemical tracking. They measured changes in xylem dimensions, mechanical strength, and wall characteristics, as well as the tiny openings called pits that connect the vessels.
“We studied the stems of the Indian mustard plant using advanced imaging, microscopic force measurements, and chemical tracking. We then precisely mapped how drought alters the xylem in terms of wall elasticity and fluid movement. These measurements were used to build realistic 3D models. These models showed how plants reorient their xylem to optimise water transport during drought,” Prof. Mondal said.
The study found that during acute water shortages, the xylem tubes narrow and the connecting pits become smaller, increasing resistance to water flow. This restricts the upward movement of water and helps limit water loss through transpiration from the plant’s upper parts.
The researchers also found that water begins to flow sideways through the pits, helping maintain water balance within the plant and preventing the breakdown of its interconnected water transport network.
Earlier computational studies treated xylem vessels as rigid pipes, limiting their ability to capture how plants alter their internal transport systems under drought conditions. The IIT Guwahati team addressed this gap by incorporating experimentally measured structural and mechanical changes into its three-dimensional models.
“This research will help us better understand how plants survive under water-scarce conditions. In the future, these insights may help scientists develop crop varieties that are more drought-tolerant and can use water more efficiently. Such knowledge could contribute to more sustainable agriculture and help maintain crop productivity in the face of climate change,” Prof. Mondal said.
The findings could help scientists identify traits for breeding drought-resistant crops, improve water-use efficiency and reduce crop losses in regions increasingly affected by water shortages.
The paper was co-authored by Prof. Mondal and Jinmay Kalita, a research scholar in the Department of Mechanical Engineering at IIT Guwahati; Sumit Kumar Mehta, ANRF-National Post-Doctoral Fellow who worked in the department; and Suraj Panja, Post-Doctoral Fellow at IIT Guwahati.