Browsing by Author "Li, Wenrao"

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    Chlorophyll fluorescence characteristics and H2O2 contents of Chinese tallow tree are dependent on population origin, nutrients and salinity
    (Oxford University Press, 2024) He, Mengyue; Ge, Lihong; Hui, Xue; Li, Wenrao; Ding, Jianqing; Siemann, Evan
    Plants from invasive populations often have higher growth rates than conspecifics from native populations due to better environmental adaptability. However, the roles of improved chlorophyll fluorescence or antioxidant defenses in helping them to grow better under adverse situations are insufficient, even though this is a key physiological question for elucidating mechanisms of plant invasion. Here, we conducted experiments with eight native (China) and eight introduced (USA) populations of Chinese tallow tree (Triadica sebifera). We tested how salinity, nutrients (overall amount or N:P in two separate experiments) and their interaction affected T. sebifera aboveground biomass, leaf area, chlorophyll fluorescence and antioxidant defenses. Plants from introduced populations were larger than those from native populations, but salinity and nutrient shortage (low nutrients or high N:P) reduced this advantage, possibly reflecting differences in chlorophyll fluorescence based on their higher PSII maximum photochemical efficiency (Fv/Fm) and PSI maximum photo-oxidizable P700 in higher nutrient conditions. Native population plants had lower Fv/Fm with saline. Except in high nutrients/N:P with salinity, introduced population plants had lower electron transfer rate and photochemical quantum yield. There were no differences in antioxidant defenses between introduced and native populations except accumulation of hydrogen peroxide (H2O2), which was lower for introduced populations. Low nutrients and higher N:P or salinity increased total antioxidant capacity and H2O2. Our results indicate that nutrients and salinity induce differences in H2O2 contents and chlorophyll fluorescence characteristics between introduced and native populations of an invasive plant, illuminating adaptive mechanisms using photosynthetic physiological descriptors in order to predict invasions.
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    Introduced Populations of an Invasive Tree Have Higher Soluble Sugars but Lower Starch and Cellulose
    (Frontiers, 2020) Li, Wenrao; Wang, Luwei; Tian, Baoliang; Ding, Jianqing; Siemann, Evan
    Native and introduced plant populations vary in leaf physiology, biochemistry, and biotic interactions. These aboveground traits may help invasive plants in competition for resources with co-occurring native species. Root physiological traits may affect invasive plant performance because of the roles of roots in resource absorption. The aim of this study was to test this prediction, using invasive Chinese tallow tree (Triadica sebifera), as a model species. Here we examined carbohydrate (soluble sugar, sucrose, fructose, starch, and cellulose) concentrations and the mass of roots, stems, and leaves, along with root water potential and arbuscular mycorrhizal fungi (AMF) colonization of soil-cultured T. sebifera seedlings from 10 native (China) and 10 introduced (United States) populations in a common garden. Introduced populations had a significantly greater stem and leaf mass than native populations but their root masses did not differ, so they had lower R:S. Introduced populations had higher soluble sugar concentrations but lower starch and cellulose concentrations in their leaves, stems, and roots. Introduced populations had more negative root water potentials and higher AMF colonization. Together, our results indicate that invasive plants shift their carbohydrate allocation, leading to faster growth and a greater aboveground allocation strategy. Higher AMF colonization and more negative water potential in invasive plants likely facilitate more efficient water absorption by the roots. Thus, such physiological variation in root characteristics could play a role in plant invasion success.