Biology Department, Colorado State University, Fort Collins, CO 80523, USA.
New Phytol. 2011 Jul;191(1):120-131. doi: 10.1111/j.1469-8137.2011.03670.x. Epub 2011 Mar 4.
• Few studies have investigated plant-plant interactions involving hyperaccumulator plants. Here, we investigated the effect of selenium (Se) hyperaccumulation on neighboring plants. • Soil and litter Se concentrations were determined around the hyperaccumulators Astragalus bisulcatus and Stanleya pinnata and around the nonhyperaccumulators Medicago sativa and Helianthus pumilus. We also compared surrounding vegetative cover, species composition and Se concentration in two plant species (Artemisia ludoviciana and Symphyotrichum ericoides) growing either close to or far from Se hyperaccumulators. Then, Arabidopsis thaliana germination and growth were compared on soils collected next to the hyperaccumulators and the nonhyperaccumulators. • Soil collected around hyperaccumulators contained more Se (up to 266 mg Se kg(-1) ) than soil collected around nonhyperaccumulators. Vegetative ground cover was 10% lower around Se hyperaccumulators compared with nonhyperaccumulators. The Se concentration was higher in neighboring species A. ludoviciana and S. ericoides when growing close to, compared with far from, Se hyperaccumulators. A. thaliana showed reduced germination and growth, and higher Se accumulation, when grown on soil collected around Se hyperaccumulators compared with soil collected around nonaccumulators. • In conclusion, Se hyperaccumulators may increase the surrounding soil Se concentration (phytoenrichment). The enhanced soil Se contents around hyperaccumulators can impair the growth of Se-sensitive plant species, pointing to a possible role of Se hyperaccumulation in elemental allelopathy.
• 很少有研究调查过涉及超积累植物的植物-植物相互作用。在这里，我们研究了硒（Se）超积累对邻近植物的影响。 • 测定了超积累植物黄芪和扁荚黄芪以及非超积累植物紫花苜蓿和向日葵周围的土壤和凋落物硒浓度。我们还比较了两种生长在靠近或远离硒超积累植物的植物（紫菀和互生草）周围的植被覆盖、物种组成和硒浓度。然后，比较了在靠近超积累植物和非超积累植物的土壤上收集的拟南芥的发芽和生长。 • 超积累植物周围的土壤中含有更多的硒（高达 266mg Se kg(-1) ），而超积累植物周围的土壤中含有更多的硒。与非超积累植物相比，超积累植物周围的植被地面覆盖率低 10%。当邻近物种 A. ludoviciana 和 S. ericoides 生长在靠近 Se 超积累植物的地方时，它们的 Se 浓度比生长在远离 Se 超积累植物的地方时更高。与在非积累植物周围采集的土壤相比，当在采集自 Se 超积累植物周围的土壤中生长时，拟南芥的发芽和生长减少，Se 积累增加。 • 总之，Se 超积累植物可能会增加周围土壤 Se 浓度（植物富集）。超积累植物周围土壤 Se 含量的增加会损害 Se 敏感植物物种的生长，这表明 Se 超积累可能在元素化感作用中发挥作用。
