Consequences of agricultural advances on soil and maize microbiomes
Raglin, Sierra Summer
This item is only available for download by members of the University of Illinois community. Students, faculty, and staff at the U of I may log in with your NetID and password to view the item. If you are trying to access an Illinois-restricted dissertation or thesis, you can request a copy through your library's Inter-Library Loan office or purchase a copy directly from ProQuest.
Permalink
https://hdl.handle.net/2142/120404
Description
Title
Consequences of agricultural advances on soil and maize microbiomes
Author(s)
Raglin, Sierra Summer
Issue Date
2023-04-24
Director of Research (if dissertation) or Advisor (if thesis)
Kent, Angela D
Doctoral Committee Chair(s)
Yang, Wendy
Committee Member(s)
Ngumbi, Esther N
Marshall-Colon, Amy
Heath, Katy
Department of Study
Natural Res & Env Sci
Discipline
Natural Res & Env Sciences
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
maize
Zea mays
microbiome
rhizosphere
nitrification
herbivory
herbivore-induced volatile compounds
nitrogen
nitrification suppression
plant growth-promoting
Abstract
Soil microorganisms drive agroecosystems sustainability through soil stabilization, nutrient provisioning, and multi-trophic interactions which alter pathogen and pest resistance. However, agricultural advances directly manipulate soil microbiomes by modifying nutrient ecology with the addition of industrial nitrogen fertilizers, temporally changing soil health. Indirectly, agricultural management influences soil microbiomes by plant species, diverging the rhizosphere microbiome across cultivars within a species due to domestication and breeding. Therefore, this dissertation seeks to understand direct and indirect manipulation of soil microbiomes by exploring management-driven changes in soil nitrogen cycling microbiota, as well as microbe-maize-pest multitrophic interactions important for minimizing pest damage. Long-term changes in nitrogen fertilization, both inorganic and organic, alter nitrification potential due to changes in nitrogen availability, as well as the physiochemical characteristics of soil important for nitrifying activity. Breeding of maize within these fertilized systems alters the selective environment, causing a decrease in maize nitrogen-acquisition symbioses, seen as a reduction of rhizosphere nitrification inhibition throughout maize’s breeding history.
Breeding may have altered the multi-trophic interactions between microbes-plants-herbivore through the manipulation of herbivore-induced volatile compounds. Jasmonic acid and terpenoid volatiles were altered throughout maize’s breeding history, potentially due to selection for aboveground architecture. Moreover, this resulted in an enrichment of endophytic Rhodocyclaceae within modern varieties, potentially due to changes in polyunsaturated fatty acid contents in maize roots. Unfortunately, managing the rhizosphere microbiome for enhanced volatile production is highly variable, due to genotype-specific dynamics in both volatile compound and root microbiome composition. Bacillus altitudinus, plant-growth-promoting rhizobacteria had minimal effect on HIPV composition and abundance, suggesting not all rhizobacteria interact with the plant volatilome. Transitioning industrial systems to low-input systems that minimize the adverse effects of agriculture on environmental health requires understanding how microbiomes are manipulated through industrial practices and should identify microbiome-associated phenotypes that can be leveraged to maximize agricultural sustainability and reduce the reliance on synthetic additives.
Use this login method if you
don't
have an
@illinois.edu
email address.
(Oops, I do have one)
IDEALS migrated to a new platform on June 23, 2022. If you created
your account prior to this date, you will have to reset your password
using the forgot-password link below.
