Effects of autotoxicity and allelopathy on seed germination and seedling growth in Medicago truncatula

Abstract

Autotoxicity is a form of intraspecific allelopathy, in which a plant species inhibits the establishment or growth of the same species through the release of toxic chemical compounds into the environment. The phenomenon of autotoxicity in crops is best traced in alfalfa (Medicago sativa). A close relative of alfalfa, M. truncatula, has been developed into an excellent model species for leguminous plants. However, it is not known whether M. truncatula has autotoxicity. In this study, M. truncatula root exudates showed a negative impact on the growth of M. truncatula seedlings, indicating autotoxicity. Detailed analyses with plant extracts from M. truncatula and alfalfa revealed varying degrees of suppression effects in the two species. The extracts negatively affected seed germination potential, germination rate, radicle length, hypocotyl length, synthetic allelopathic effect index, plant height, root growth, fresh weight, dry weight, net photosynthetic rate, transpiration rate, and stomatal conductance in both M. truncatula and alfalfa. The results demonstrated that autotoxicity and allelopathic effects exist in M. truncatula. This opens up a new way to use M. truncatula as a model species to carry out in-depth studies of autotoxicity and allelopathy to elucidate biochemical pathways of allelochemicals and molecular networks controlling biosynthesis of the chemicals.

Effects of water extracts of Flaveria bidentis on the seed germination and seedling growth of three plants

“…The allelopathic effects of plants are mainly reflected in the germination of seeds, seedling height and root length of seedlings 23 – 26 . In the natural environment, allelochemicals are released into the environment and affect the surrounding plants.…”

Transcriptomics and metabolomics revealed the synthesis and potential role of flavonoids in pea roots under continuous cropping obstacles

“…In this study, biochanin A, calycosin, and genistein were found to be DAMs only in the roots of Y8, suggesting that these isoflavonoids may be associated with pea sensitivity to continuous cropping and deserve to be looked at. Studies have confirmed that the change of soil microbial community structure is the key to the occurrence of continuous cropping obstacles (Tan et al, 2021), and crops are subjected to oxidative stress in continuous cropping systems (Wang et al, 2021;Yang et al, 2020). To this end, we further validated the antimicrobial and antioxidant effects of the isoflavonoids biochanin A, calycosin, and genistein in the Y8 roots.…”

Vanillin, a Newly Discovered Autotoxic Substance in Long-Term Potato Continuous Cropping Soil, Inhibits Plant Growth by Decreasing the Root Auxin Content and Reducing Adventitious Root Numbers

“…For example, plants like cucumber, P. ginseng, Medicago sativa, tobacco, and maize changed their root architecture as a result of the reduction in the root length and root numbers. Consistent with the results of this experiment, autotoxicity reduced AR numbers and total root length of the potato.…”