Given so much of the world’s population lives along coasts, mangroves’ functions directly benefit many people.
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Saltwater would kill most plants, but it cannot fell the ancient mangroves species distinct for their giant stilt roots. So how do they survive on brine? International researchers and authors of a new paper in Current Biologyhave delved into their cells and discovered what makes mangrove shrubs and trees so different from all other terrestrial plants.
The scientists identified cell traits that are critical to tolerating a surge in saltwater as climate change raises sea levels. And this could also help create plants, especially agricultural crops, to survive in salty water.
“This work reveals that just a few simple cell traits are critical to tolerating the extreme conditions experienced by some of the most distinctive and resilient plants in the world,” said Adam Roddy, a co-author and assistant professor in New York University’s department of environmental studies.
Mangroves have evolved 30 times over the last 200 million years as they adapted to saltwater.
The scientists analysed 34 mangroves species and across 17 plant families and found that, compared to their inland relatives, mangroves do not exhibit smaller or more stomata to enable higher photosynthetic rates. Mangroves however have unusually small leaf epidermal pavement cells and thicker cell walls, which together give them more mechanical strength to tolerate low osmotic potentials.
Different groups of mangroves use a variety of mechanisms. To exclude salt, some species have roots with a waxy layer inside that’s able to filter out most of the salt, Dr. Roddy told The Hindu. “This requires them to create a lot of tension to essentially ‘pull’ the water out of solution and into their bodies. Other species will take up a lot of salt, but then they concentrate the saltwater and secrete it out of their leaves through specialised tissues.”
Mangroves are special as they’re able to tolerate high amounts of salt and live along coasts, also protecting them against erosion, and they provide habitats for both sea animals and birds. Given so much of the world’s population lives along coasts, these functions directly benefit humans, Dr. Roddy said.
The study offers strategies to engineer salt-tolerant plants by manipulating cell size and cell wall properties. “If we want to manipulate plants,” Dr. Roddy said, “then focusing on ones of particular economic importance that would also be threatened by increasing salinity would be the way to start.”
Published – December 14, 2025 06:16 am IST
