Invasive Lespedeza cuneata and native Lespedeza virginica experience asymmetrical benefits from rhizobial symbionts

Abstract

Background and Aims Lespedeza cuneata (Dum. Cours.) G. Don is an invasive legume that displaces populations of native N. American congeners. Our aims are to determine the growth benefits of different rhizobacterial strains for L. cuneata and native Lespedeza virginica (L.) Britton, and to determine if these strains influence competition between these plants. Methods Plants were grown under nitrogen-limiting conditions in sterilized soil in pairs consisting of two L. cuneata, two L. virginica, or one of each species, and then plants were inoculated with one of seven rhizobial isolates, or with a no-strain control. After 3 months, plants were harvested for determination of biomass and nodulation rate. Results Five of the assayed stains improved L. cuneata biomass over uninoculated controls, but none of the strains benefited L. virginica. L. cuneata plants had more biomass and root nodules when grown in competition with L. virginica than with a conspecific. Conclusions Asymmetrical benefits from these symbionts accrued to invasive L. cuneata but not to native L. virginica, and this may provide the invader with a growth advantage in the field. Changes in the availability of effective symbionts in the soils of invaded sites can shape performance of native and invasive plants.

Identifying Sustainable Grassland Management Approaches in Response to the Invasive Legume Lespedeza cuneata: A Functional Group Approach

“…Competition with forbs produced the best performing L. cuneata individuals, while competition with legumes produced the poorest performers. The difference in responses between the native and non-native Lespedeza could be due to their origin (native vs. non-native), the greater leaf production of L. cuneata, different growth forms (branched, bush-like L. cuneata vs. slender L. capitata), or different bacterial associations [29,85]. These results illustrate that the native Lespedeza capitata is more able to coexist with species across functional groups than the non-native L. cuneata.…”

“…In a positive PSF, a plant alters the soil to benefit its own growth, either directly or indirectly, via detriment to the growth of other plants [25][26][27] affecting invasion success [28]. PSFs of L. cuneata have led to high biomass and nodulation rates [26,29,30], modified soil microbial communities [31], high symbiotic nitrogen fixation [32], and allelopathic effects [33][34][35][36][37]. However, studies of L. cuneata soil conditioning have been limited in that the specific mechanisms responsible for changes in soil composition, the effects of these changes on co-occurring native legumes other than Lespedeza spp., and differences among grass, forb, and legume functional groups have yet to be identified.…”

The Complete Chloroplast Genomes of Two Lespedeza Species: Insights into Codon Usage Bias, RNA Editing Sites, and Phylogenetic Relationships in Desmodieae (Fabaceae: Papilionoideae)

“…The high adaptability to drought and good forage quality of L. davurica are important for its use as a fodder legume [4]. Similar to most other legumes, the deep root system of the Lespedeza has nitrogen-fixing nodules that harbor the symbiotic soil bacteria, making this plant a nitrogen fertilizer [5]. Moreover, several bioactive compounds that have antidiabetic activities have been extracted from some species of Lespedeza that were used in medicine to prevent diabetes in ancient times.…”

Flavonoids Differentially Influence Rhizosphere Bacterial Communities from Native and Introduced Lespedeza Roots

“…Introduced plant species' interactions with soil microbial communities often aid in the plants' ability to effectively colonize new locales (Callaway et al 2004;Reinhart and Callaway 2006). These interactions include suppression of native mutualists (Vogelsang and Bever 2009), advantageous associations with native mutualists (Callaway et al 2011;Hu et al 2014), pathogen avoidance (Callaway et al 2011), and facilitation of native plant pathogens (Eppinga et al 2006). These interactions have been shown to rely on chemical signals exuded from plant roots (Nolan et al 2014;Yuan et al 2014).…”