In cooperation with international colleagues, Prof. Feng Yulong’ s research team has studied the mechanism of nitrogen allocation in Ageratina adenophora, a noxious invasive plant throughout the subtropics. The research result entitled “Evolutionary tradeoffs for nitrogen allocation to photosynthesis versus cell walls in an invasive plant” has been published online in PNAS (Proceedings of the National Academy of Sciences of the United States of America).

    An anonymous expert reviewer said in the written comment about the research that “…the research reported in this manuscript takes the investigation of mechanistic causes for invasiveness to a new level…”

    PNAS is one of the world's most-cited multidisciplinary scientific serials. Since its establishment in 1914, it continues to publish cutting-edge research reports, commentaries, reviews, perspectives, colloquium papers, and actions of the Academy. Coverage in PNAS spans the biological, physical, and social sciences. PNAS is published weekly in print, and daily online in PNAS Early Edition. The PNAS impact factor is 9.598 for 2007.

Abstract  Many studies have shown that individuals from invasive populations of many different plant species grow larger than individuals from native populations and that this difference has a genetic basis. This increased vigor in invasive populations is thought to be due to life history tradeoffs, in which selection favors the loss of costly defense traits, thereby freeing resources that can be devoted to increased growth or fecundity. Despite the theoretical importance of such allocation shifts for invasions, there have been no efforts to understand apparent evolutionary shifts in defense-growth allocation mechanistically. Reallocation of nitrogen (N) to photosynthesis is likely to play a crucial role in any growth increase; however, no study has been conducted to explore potential evolutionary changes in N allocation of introduced plants. Here, we show that introduced Ageratina adenophora, a noxious invasive plant throughout the subtropics, appears to have evolved increased N allocation to photosynthesis (growth) and reduced allocation to cell walls, resulting in poorer structural defenses. Our results provide a potential mechanism behind the commonly observed and genetically based increase in plant growth and vigor when they are introduced to new ranges.