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Bintarti, A. F.

Publications and source records attributed to Bintarti, A. F..

4 recordsLinked to original sources

Evaluating the legacy of drought exposure on root and rhizosphere bacterial microbiomes over two plant generations

Drought is a critical risk in developing countries for staple crops like common bean (Phaseolus vulgaris L.). We conducted an experiment to understand the legacy effects of repeated drought exposure across plant generations on the root and rhizosphere microbiome of the common bean, hypothesizing that a legacy of exposure improves overall plant microbiome resilience. We profiled the bacterial microbiome using marker gene amplicon sequencing over two plant generations in a complete factorial design for two common bean genotypes, Red Hawk and Flavert. We performed parallel experiments for Red Hawk in two different countries using soils of Pays de la Loire, France, and Michigan, USA. Despite the clear and relatively consistent drought effects on the plant phenotypes, there was neither response of the Red Hawk microbiomes to drought, nor a notable legacy of drought exposure. For Flavert, there was a minor legacy drought effect for the second generation in the rhizosphere microbiome beta diversity. This study demonstrates that rhizosphere microbiomes can be resistant to drought stress and that cross-generational legacy depends on soil origin and host genotype. Such parallel experiments across countries, while difficult to implement, are useful to inform generalities and build theory towards prediction on microbiome responses to global change.

microbiology↗

Stable, multigenerational transmission of the bean seed microbiome despite abiotic stress

Seed microbiomes initiate plant microbiome assembly, but the consequences of environmental conditions of the parent plant for seed microbiome assembly and transmission are unknown. We tracked endophytic seed bacterial communities of common bean lines exposed to drought or excess nutrients, and discovered stable transmission of 22 bacterial members regardless of parental plant treatment. This study provides insights into the maintenance of plant microbiomes across generations, even under challenging environmental stress.

microbiology↗

Endophytic microbiome variation at the level of a single plant seed

Like other plant compartments, the seed harbors a microbiome. The members of the seed microbiome are the first to colonize a germinating seedling, and they initiate the trajectory of microbiome assembly for the next plant generation. Therefore, the members of the seed microbiome are important for the dynamics of plant microbiome assembly and the vertical transmission of potentially beneficial symbionts. However, it remains challenging to assess the microbiome at the individual seed level (and, therefore, for the future individual plant) due to low endophytic microbial biomass, seed exudates that can select for particular members, and high plant and plastid contamination of resulting reads. Here, we report a protocol for extracting metagenomic DNA from an individual seed (common bean, Phaseolus vulgaris L.) with minimal disruption of host tissue, which we expect to be generalizable to other medium-and large-seed plant species. We applied this protocol to quantify the 16S rRNA V4 and ITS2 amplicon composition and variability for individual seeds harvested from replicate common bean plants grown under standard, controlled conditions to maintain health. Using metagenomic DNA extractions from individual seeds, we compared seed-to-seed, pod-to-pod, and plant-to-plant microbiomes, and found highest microbiome variability at the plant level. This suggests that several seeds from the same plant could be pooled for microbiome assessment, given experimental designs that apply treatments at the maternal plant level. This study adds protocols and insights to the growing toolkit of approaches to understand the plant-microbiome engagements that support the health of agricultural and environmental ecosystems.

microbiology↗

Abiotic treatment contributes to an alteration of the seed microbiome of common bean

There has been a growing interest in the seed microbiome due to its important role as an end and starting point of plant microbiome assembly that can have consequences for plant health. However, the effect of abiotic conditions on the seed microbial community remains unknown. We performed a pilot study in a controlled growth chamber to investigate how the endophytic seed microbiome of the common bean (Phaseolus vulgaris L. (var. Red Hawk)) was altered under abiotic treatments relevant for crop management with changing climate. Bean plants were subjected to one of three treatments: 66% water withholding to simulate mild drought, 50% Hoagland nutrient solution to simulate fertilization, or control with sufficient water and baseline nutrition. We performed 16S rRNA gene amplicon sequencing and ITS1 amplicon sequencing of the endophytic DNA to assess seed bacterial/archaeal and fungal community structure, respectively. We found that variability in the seed microbiome structure was high while alpha diversity was low, with tens of taxa present. Water withholding and nutrient addition altered the seed microbiome structure for bacterial/archaeal communities as compared to the control, and each treatment resulted in a distinct microbiome structure. There were no statistically supported differences in the fungal microbiome across treatments. While we discuss several limitations of this study, the promising results suggest that further investigation is needed to better understand abiotic or stress-induced changes in the seed microbiome, the mechanisms that drive those changes, and their implications for the health and stress responses of the next plant generation. ImportanceSeed microbiome members initiate the assembly of plant-associated microbial communities, but the environmental drivers of endophytic seed microbiome composition are unclear. Here, we exposed plants to short-term drought and fertilizer treatments during early vegetative growth and quantified the microbiome composition of the seeds that were ultimately produced. We found that seeds produced by plants stressed by water limitation or receiving nutrient addition had statistically different endophytic bacterial/archaeal microbiome compositions from each other and from seeds produced by control plants. This work suggests that the abiotic experience of a parental plant can influence the composition of its seed microbiome, with unknown consequences for the next plant generation.

microbiology↗