How Mangrove Cells Help Plants Survive in Saltwater

Most plants can't survive in saltwater, but mangroves, known for their stilt roots, are an exception. Now, researchers have investigated the cellular secrets that allow these trees and shrubs to thrive in salty environments.

An international team of scientists published a new paper in *Current Biology* detailing the cell traits that distinguish mangroves from other land plants. Their findings reveal how mangroves tolerate saltwater, a crucial adaptation as climate change causes sea levels to rise. The research also suggests ways to develop crops that can withstand salty conditions.

"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, study co-author and assistant professor at New York University's Department of Environmental Studies.

Mangroves have independently evolved to tolerate saltwater environments approximately 30 times over the past 200 million years.

The scientists analyzed 34 mangrove species across 17 plant families. They discovered that, unlike their inland relatives, mangroves don't have smaller or more stomata to boost photosynthetic rates. That said, the reality is a bit more complicated. mangrove leaves possess unusually small epidermal pavement cells and thicker cell walls. This combination provides the mechanical strength needed to withstand low osmotic potentials caused by saltwater.

Different mangrove species employ various mechanisms to manage salt. Some exclude salt using roots with a waxy inner layer.