Chinese researchers recently concluded that the accumulations of flavonoids in sand rice were more likely as a result of local adaption to environmental heterogeneity combined with precipitation and temperature other than high altitude. 

As a pioneer plant endemic to the temperate deserts in Asia, sand rice could be domesticated into an ideal crop with outstanding ecological and medicinal characteristics because it is rich in flavonoids. 

To verify whether flavonoid accumulation was determined by environmental or genetic factors, researchers from the Northwest Institute of Eco-Environment and Resources of the Chinese Academy of Sciences (CAS) conducted flavonoid-targeted metabolic profiling among 14 populations of sand rice collected from regions with different altitudes based on a common garden experiment. 

They found that contents of some flavonoids such as quercetin, tricin, and rutin were significantly enriched in low-altitude populations than in middle-and high-altitude, which were positively correlated to precipitation of the in situ habitat. This phenomenon indicated that the accumulation of flavonoids was not a result of local adaptation to high altitude.  

Furthermore, association analysis with in situ environmental variables showed that the contents of quercetin, tricin, and rutin were strongly positively correlated with latitude, longitude, and precipitation gradients and negatively correlated with temperature gradients. 

Thus, the researchers concluded that the accumulations of flavonoids in sand rice were more likely as a result of local adaption to environmental heterogeneity combined with precipitation and temperature other than high altitude. 

This study not only sheds light on the molecular ecological basis for sand rice adapted to the desert heterogeneity, but also provides instructive guidelines for the development and utilization of the wild plant in food, pharmaceutical, and cosmetic industries under global climate change. 

This study has been published on Frontiers in Plant Science entitled "Variations in Flavonoid Metabolites along Altitudinal Gradient in a Desert Medicinal Plant Agriophyllum squarrosum."