Stockholm, 22 September 2022
A new study shows that we can create and select plants that can better recover from drought without affecting the size of the plant or seed yield, by genetically modifying their lignin chemistry. These results could be used in both agriculture and forestry to tackle future climatic challenges.
Lignin, the second most abundant biopolymer on Earth, represents about 30 percent of the total carbon on the planet. It allows plants to conduct water and stand up right; without lignin, plants cannot grow nor survive.
For long, scientists did not consider that lignin had a “code” like in DNA or proteins. Researchers led by Stockholm University, Department of Ecology, Environment and Plant Sciences (DEEP), in collaboration with Stockholm University Department of Material Sciences (MMK) and Tokyo University of Agriculture and Technology (TUAT); have now challenged this old paradigm by demonstrating the existence of a lignin chemical "code”.
They showed that each cell uses this code to adjust their lignin to function at its optimum and resist stresses. These results are published in the high-ranking scientific journal The Plant Cell and could be used in both agriculture and forestry to tackle future climatic challenges.
“It takes only one simple chemical change, just one hydrogen atom apart from alcohol to aldehyde to make plants highly resilient to drought in conditions where alcohol-rich plants would all die”, explained Edouard Pesquet, associated professor in molecular plant physiology and senior author of the study.
Interestingly, professor Shinya Kajita from TUAT showed that such large increases of lignin aldehydes can occur naturally in the wild. In the Japanese silk industry for example, mulberry with high lignin aldehyde levels have long been used and loved by silk caterpillars.
“These results [not only] revise our understanding of lignin and plant water conduction, but also open great possibilities to use the lignin 'code' to improve crops and trees to face water availability problems. The modification of lignin chemistry at the single cell level, is ultimately the mechanism enabling plants to grow, hydrate and resist climate change stresses”, Pesquet said.
Plant biomechanics and resilience to environmental changes are controlled by specific lignin chemistries in each vascular cell type and morphotype, by Ménard, Blaschek et al. is published in the journal The Plant Cell September 2022.