Scientists at the University of California, Los Angeles, working with a botanical garden in Yunnan, China, have come up with a new method to quickly predict the drought tolerance of plants. According to a UCLA press release:

It is based on an important trait known as “turgor loss point.” During drought, the leaf cells’ water becomes harder to replace. The turgor loss point is reached when leaf cells become so dehydrated their walls become flaccid. This cell-level loss of turgor — or swollenness — causes the leaf to become limp and wilted, and the plant cannot grow, UCLA professor Lawren Sack said. The new method, based on a technique called “osmometry,” requires only about 10 minutes per leaf, sufficient to make a fast estimate for a given species.

The scientists found that plants with greater saltiness tend to be more drought-resistant, because they are better at retaining water. “Drought-tolerant plants typically have low turgor loss points and saltier sap,” said lead author Megan Bartlett, a UCLA graduate student in the Department of Ecology and Evolutionary Biology. “Some plant species even load more salt into their cells when they experience a drought to lower their turgor loss point and improve their drought tolerance.”

The study recently was published in Methods in Ecology and Evolution, a scientific journal. The full text can be accessed here, but it requires an institutional membership or paid access.