Role of natural products in belowground interactions between plant species

Kudsk

Ding

et al. 2022

Plants compete with their neighbors about the limited resources available to them. Plants under induced stress resulting from competition may alter their metabolome to increase their resilience or enhance their defense mechanisms. In the present study, rye (Secale cereale) plants were cocultivated with different densities (3, 12, and 18 plants per pot) of Austrian pea (Pisum sativum subsp. arvense), hairy vetch (Vicia villosa), and Alexandrian clover (Trifolium alexandrinum L.) to elucidate the changes in the rye metabolome in response to the different levels of competition. Global metabolic profiling by liquid chromatography triple quadrupole tandem mass spectrometry (LC-QqQ-MS), liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS), and gas chromatography time-of-flight mass spectrometry (GC-TOF-MS) was performed on rye plants, and the acquired data were analyzed using uni- and multivariate statistics. Targeted analysis showed that a high level of competition reduced the concentration of aglycone benzoxazinoids (BXs) and increased glycoside BXs in rye roots. Untargeted metabolomics analysis indicated an increase in the rye root content of the allelopathic compounds 4-hydroxybenzoic acid and uracil in response to competition. Untargeted analysis of rye shoots revealed that the plant competition increased the d-pyroglutamic acid, which is an elicitor of reactive oxygen species (ROS). Our results have enhanced the knowledge of the biochemical response of plant species to cocultivation.

Section: Introductionmentioning

confidence: 99%

Integrated LC–MS and GC–MS-Based Metabolomics Reveal the Effects of Plant Competition on the Rye Metabolome

Kudsk

Ding

et al. 2022

“…Benzoxazinoids (BXs) are allelochemicals exuded from the roots of a number of gramineous species into the rhizosphere, where they can have multiple functions such as a plant defense system reducing the growth of neighboring plants and altering root-associated fungal and bacterial infections. − Roots exude BX glucosides into the rhizosphere where they are hydrolyzed releasing aglucones, which, in general, are more biologically active than the glucosides. , Bioactive aglucones, such as the benzoxazinoids 2,4-dihydroxy-(2 H )-1,4-benzoxazin-3(4 H )-one (DIBOA) and 2,4-dihydroxy-7-methoxy-(2 H )-1,4-benzoxazin-3(4 H )-one (DIMBOA) proved to be the main compounds responsible for allelopathic effects of wheat, maize, and rye. , Although there are studies that investigated the weed suppression ability of BXs, their root exudation and possible uptake by neighboring plants are not well studied. This could be due to the lack of suitable methods for root exudate extraction and the fast degradation of exuded metabolites in the rhizosphere …”

Section: Introductionmentioning

confidence: 99%

Root-Exuded Benzoxazinoids: Uptake and Translocation in Neighboring Plants

Fomsgaard

Kudsk

2020

Plants have evolved advanced chemical defense mechanisms, including root exudation, which enable them to respond to changes occurring in their surroundings rapidly. Yet, it remains unresolved how root exudation affects belowground plant–plant interactions. The objective of this study was to elucidate the fate of benzoxazinoids (BXs) exuded from the roots of rye (Secale cereale L.) plants grown with hairy vetch (Vicia villosa). A rapid method that allows nondestructive and reproducible chemical profiling of the root exudates was developed. Targeted chemical analysis with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was performed to investigate the changes in the composition and concentration of BXs in the rye plant, and its root exudate in response to cocultivation with hairy vetch. Furthermore, hairy vetch plants were screened for the possible uptake of BXs from the rhizosphere and their translocation to the shoot. Rye significantly increased the production and root exudation of BXs, in particular 2-β-d-glucopyranosyloxy-4-hydroxy-1,4-benzoxazin-3-one (DIBOA-glc) and 2-β-d-glucopyranosyloxy-4-hydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA-glc), in response to cocultivation with hairy vetch. DIBOA-glc and DIMBOA-glc were absorbed by the roots of the cocultivated hairy vetch plants and translocated to the shoots. These findings will strongly improve our understanding of the exudation of BXs from the rye plant and their role in interaction with other plant species.

“…Through exudation of a wide range of compounds, the roots regulate the soil microbial community in the rhizosphere, encourage beneficial and mutualist symbioses, modify the chemical and physical properties of the soil, and inhibit the growth of competing plant species. 5 In particular, flavonoids identified in legume root exudates play a crucial role in regulating inter-plant and plant–microbe interactions, 6 , 7 and they are pivotal for the activation of nod genes in N-fixing bacteria (node inducer compounds), allowing bacteria to enter plant roots and begin the formation of nodules. 8 , 9 Moreover, flavonoids released in the rhizosphere can modify the chemical soil composition and nutrient availability through their activity as reducers or metal chelators.…”

Section: Introductionmentioning

confidence: 99%

Determination of the Effect of Co-cultivation on the Production and Root Exudation of Flavonoids in Four Legume Species Using LC–MS/MS Analysis

Leoni

Fomsgaard

et al. 2021

Flavonoids play a key role in the regulation of plant–plant and plant–microbe interactions, and factors determining their release have been investigated in most of the common forage legumes. However, little is known about the response of flavonoid production and release to co-cultivation with other crop species. This study investigated alterations in the concentration of flavonoids in plant tissues and root exudates in four legumes [alfalfa ( Medicago sativa L. ), black medic ( Medicago polymorpha L. ), crimson clover ( Trifolium incarnatum L. ), and subterranean clover ( Trifolium subterraneum L. )] co-cultivated with durum wheat [ Triticum turgidum subsp. durum (Desf.) Husn.]. For this purpose, we carried out two experiments in a greenhouse, one with glass beads as growth media for root exudate extraction and one with soil as growth media for flavonoid detection in shoot and root biomass, using LC–MS/MS analysis. This study revealed that interspecific competition with wheat negatively affected legume growth and led to a significant reduction in shoot and root biomass compared with the same legume species grown in monoculture. In contrast, the concentration of flavonoids significantly increased both in legume biomass and in root exudates. Changes in flavonoid concentration involved daidzein, genistein, medicarpin, and formononetin, which have been found to be involved in legume nodulation and regulation of plant–plant interaction. We hypothesize that legumes responded to the co-cultivation with wheat by promoting nodulation and increasing exudation of allelopathic compounds, respectively, to compensate for the lack of nutrients caused by the presence of wheat in the cultivation system and to reduce the competitiveness of neighboring plants. Future studies should elucidate the bioactivity of flavonoid compounds in cereal-legume co-cultivation systems and their specific role in the nodulation process and inter-specific plant interactions such as potential effects on weeds.