Abstract
The overall effect of a live soil inoculum collected from nature on plant biomass is often negative. One hypothesis to explain this phenomenon is that the overall net pathogenic effect of soil microbial communities reduces plant performance. Induced plant defenses triggered by the application of the plant hormones jasmonic acid (JA) and salicylic acid (SA) may help to mitigate this pathogenic effect of live soil. However, little is known about how such hormonal application to the plant affects the soil and how this, in turn, impacts plant growth. We grew four plant species in sterilized and inoculated live soil and exposed their leaves to two hormonal treatments (JA and SA). Two species (Jacobaea vulgaris and Cirsium vulgare) were negatively affected by soil inoculation. In these two species foliar application of SA increased biomass in live soil but not in sterilized soil. Two other species (Trifolium repens and Daucus carota) were not affected by soil inoculum and for these two species foliar application of SA reduced plant biomass in both the sterilized and live soil. Application of JA reduced plant biomass in both soils for all species. We subsequently carried out a multiple generation experiment for one of the plant species, J. vulgaris. In each generation, the live soil was a mixture of 10% soil from the previous generation and 90% sterilized soil and the same hormonal treatments were applied. The negative effects of live soil on plant biomass were similar in all four generations, and this negative effect was mitigated by the application of SA. Our research suggests that the application of SA can mitigate the negative effects of live soil on plant growth. Although the inoculum of soil containing a natural live soil microbial community had a strong negative effect on the growth of J. vulgaris, we found no evidence for an increase or decrease in negative plant-soil feedback in either the control or the SA treated plants. Also plant performance did not decrease consistently with succeeding generations.
Highlights
IntroductionJ. Zhang et al / Basic and Applied Ecology 56 (2021) 144À155 which, in turn, will impact plant growth
The interactions between plants and soil microorganisms have long been recognized for their importance in terrestrialJ
We addressed four questions: (1) Do the effects of live soil on plant biomass differ among plant species? (2) Does the foliar application of jasmonic acid (JA) and salicylic acid (SA) alter the effects of the live soil on plant biomass for those species that were negatively affected by the live soil? (3) Does the negative effect of live soil change in four successive generations of J. vulgaris for control plants and plants treated with SA or JA
Summary
J. Zhang et al / Basic and Applied Ecology 56 (2021) 144À155 which, in turn, will impact plant growth. Zhang et al / Basic and Applied Ecology 56 (2021) 144À155 which, in turn, will impact plant growth This process is called plant-soil feedback (Bever, Westover & Antonovics, 1997; van Breemen & Finzi, 1998). From natural situations and agriculture, it is well-known that soil can become less suitable for a species if this species is grown in the same soil for multiple generations. This negative effect is thought to be caused by soil pathogens or root herbivores, allelopathy, nutrient immobilization or nutrient depletion (Miki, 2012). Plants cause positive plant-soil feedbacks and these can be mediated by plants promoting rhizobacteria, mycorrhizal fungi or other unknown mechanisms (Revillini, Gehring & Johnson, 2016; van der Putten, 2017)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
