Chinese scientists' new research provides insights on controlling 'mile-a-minute' weed

BEIJING -- New research conducted by Chinese scientists has revealed the molecular mechanism of the environmental adaptation and rapid growth of a weed, Mikania micrantha, providing insights on how to prevent its invasion.

Mikania micrantha, nicknamed the "mile-a-minute" weed, is an extremely fast-growing, sprawling, perennial vine belonging to the family Asteraceae and native to tropical America. The vine is listed as one of the 100 worst invasive species by the International Union for Conservation of Nature.

The invasion of the weed has caused economic losses related to forests and crop production by climbing plants to the canopy and blocking sunlight, and has led to a loss of genetic and species diversity, a decline in soil and food web stability, and altered nutrient cycling, scientists say.

It is problematic in tropical Asia, in parts of Papua New Guinea, on Indian Ocean islands and Pacific Ocean islands, and in Florida in the United States.

The weed has also spread to Guangdong, Guangxi, Yunnan, Hainan and other regions in China. It is one of the most harmful invasive plants in south China. In the Pearl River Delta alone, it causes ecological and economic losses of nearly one billion yuan (about $146 million) annually.

Previously, the molecular mechanism underlying the fast growth of the weed was not clear.

Scientists from the Agricultural Genomics Institute at Shenzhen under the Chinese Academy of Agricultural Sciences, South China Normal University and the South China Agricultural University aimed to explore the possible reasons behind its rapid growth.

The research shows that Mikania micrantha achieves higher photosynthetic capacity by CO2 absorption at night to supplement its carbon fixation during the day, as well as enhanced stem photosynthesis efficiency. Furthermore, the metabolites of the plant can increase the availability of nitrogen by enriching the microbes that participate in nitrogen cycling pathways.

This suggests that Mikania micrantha may develop a special mechanism allowing it to achieve a higher photosynthetic rate that enables fast growth, and the details of the photosynthesis mechanism need further research, scientists say.

The study provides a theoretical basis for precise prevention and control of the weed at the molecular level.

The research was recently published in the academic journal Nature Communication.