Performing Department
Plant & Environmental Sciences
Non Technical Summary
The increasing frequency and intensity of drought pose a major threat to crop production by reducing the arable land. Also, increasing pressure on agricultural lands to feed the growing population could be partly alleviated by bringing droughted marginal lands back to mainstream agriculture. The above two could materialize only if robust practices are formulated to enable crops to tolerate drought. Breeding for drought tolerance in crop plants is a viable, but time-consuming strategy. Microorganisms associated with plant roots have been shown to provide drought tolerance to native, ruderal plant species, which could be adopted in crop production. However, transferring these microbiomes from ruderal species to crops without losing the functional trait of drought tolerance is rarely achieved due to the complexity of plant-microbe interactions and the lower persistence of the introduced microorganisms under field conditions. The proposed research focuses on identifying the microbiome that imparts drought tolerance in ruderal plants and devising strategies to transfer the microbiome-mediated drought tolerance trait to crop plants. Using field sampling and greenhouse experiments, the researchers will select and characterize the highly drought-tolerant microbiome from the native grass Andropogon virginicus adapted to drought conditions. Further, the effectiveness of the microbiome to impart drought tolerance in corn will be tested using a series of greenhouse experiments. The challenge of supporting the beneficial microbiome under field conditions will be achieved by selecting ideal grass cover crop species that are functionally similar to andropogon and corn. This would be achieved by selecting cover crop biotypes with a similar root exudate profile as that of Andropogon, and hence would sustain a similar microbiome community. The selection of a functionally similar cover crop would provide an ideal environment to amplify the microbiome in the field before corn is planted. Field experiments will be conducted to evaluate the efficiency of cover crops to amplify the inoculum of the selected microbiome and further the potential of this microbiome to provide drought resilience to corn.Overall, the proposed approach will enable the selection and application of microbiome in crop production systems to enhance drought resilience in crops.
Animal Health Component
0%
Research Effort Categories
Basic
50%
Applied
40%
Developmental
10%
Goals / Objectives
Frequent and intense drought caused by changing climate presents a major threat to cropping systems worldwide. It is increasingly recognized that rhizosphere microbial communities (rhizobiome) that associate with plants can impart drought tolerance in ruderal species. However, the transfer of rhizobiome imparted drought resilience from the lab or greenhouse to the field settings is rarely achieved, which prevents the large-scale utilization of rhizobiome mediated drought resilience in agro-ecosystems.The overall goal of this project is to enhance the drought-resilience of crops through the cross-inoculation of drought-resistant rhizobiome from ruderal species and to build up the beneficial rhizobiome in agricultural fields through compatible cover cropping. The PIs postulate that 1) ruderal plants adapted to droughted conditions can select and sustain a unique rhizobiome that imparts drought resilience; 2) the observed drought resilience is an outcome of the composition of the overall rhizobiome (system property), rather than being driven by a single/few microbial species; 3) the beneficial rhizobiome of the ruderal species could be shared and sustained across closely related crop species under environmental stress, but not under optimal growing conditions; 4) specific cover crops that have similar composition of root exudates as that of the ruderal species can help assemble and amplify targeted beneficial rhizobiome in the field.The main objectives of the project are to:i) identify the beneficial rhizobiome that facilitates drought tolerance in ruderal plants that thrive in droughted environments,ii) test the cross-infection compatibility and effectiveness of the beneficial rhizobiome to impart drought resilience in phylogenetically related crop species, andiii) utilize cover crops to propagate and stabilize the beneficial rhizobiome under field conditions.
Project Methods
Rhizobiome of Andropogon virginicus will be collected from multiple sites across the southern US that experience a gradient of droughted conditions. Greenhouse experiments will be conducted to evaluate the effects of field-collected rhizobiome on the growth performance of A. virginicus under drought and ambient moisture conditions. Additional experiments will test if the observed drought tolerance is a system-property. Plant growth performance, physiological and morphological responses will be measured. The diversity of rhizosphere bacterial and fungal microbial communities will be assessed using Illumina MiSeq amplicon sequencing, targeting 16S rRNA and ITS2 genes. Functional analysis of the microbiome will be conducted using metatranscriptomic approaches. Further, greenhouse experiments will be conducted to evaluate the effects of selected rhizobiome on the growth performance of corn under drought conditions. Using hydroponics experiments, cover crop species that are functionally similar to Andropogon with respect to their root exudate profiles will be selected. Field experiments will be conducted to evaluate the efficiency of the above cover crops to multiply the selected rhizobiome in the field, and the efficiency of the resulting microbiome to impart drought resilience in corn.