Biology subjects

Weinig, C.

Publications and source records attributed to Weinig, C..

3 recordsLinked to original sources

bioRxiv2018

Rhizosphere microbes influence host circadian clock function

The circadian clock is an important determinant of individual fitness that is entrained by local conditions. In addition to known abiotic inputs that entrain the circadian clock, individual pathogenic soil bacteria affect the circadian period of plant hosts. Yet, in nature, plants interact with diverse microbial communities including hundreds to thousands of microbial taxa, and the effect of these communities on clock function remains unclear. In Arabidopsis thaliana, we used diverse rhizosphere inoculates and both wild-type and clock mutant genotypes to test the effect of complex rhizosphere microbial communities on the host circadian clock. Host plants with an intact rhizosphere microbiome expressed a circadian period that was closer to 24 hrs in duration and significantly shorter (by 60 minutes on average) relative to plants grown with a disrupted microbiome. Wild-type host genotypes differed significantly in clock sensitivity to microbiome treatments, where the effect was most pronounced in the Landsberg erecta genotype and least in the Columbia genotype. Rhizosphere microbes collected from a host genotype with a short-period phenotype (toc1-21) and used as inoculate significantly shortened the long-period phenotype of the ztl-1 clock mutant genotype. The results indicate that complex rhizosphere microbial communities significantly affect host clock function.

plant biology↗

bioRxiv2018

Rhizosphere microbes and host plant genotype influence the plant metabolome and reduce insect herbivory

O_LIRhizosphere microbes affect plant performance, including plant resistance against insect herbivores; yet, the relative influence of rhizosphere microbes vs. plant genotype on herbivory levels and on metabolites related to defense remains unclear.\nC_LIO_LIIn Boechera stricta, we tested the effects of rhizosphere microbes and plant genotype on herbivore resistance, the primary metabolome, and select secondary metabolites.\nC_LIO_LIPlant populations differed significantly in the concentrations of 6 glucosinolates (GLS), secondary metabolites known to provide herbivore resistance in the Brassicaceae, and the population with lower GLS levels experienced ~60% higher levels of aphid (Aphis spp.) attack; no effect was observed of GLS on damage by a second herbivore, flea beetles (Altica spp.). Rhizosphere microbiome (intact vs. disrupted) had no effect on plant GLS concentrations. However, aphid number and flea beetle damage were respectively ~3-fold and 7-fold higher among plants grown in the disrupted rhizosphere microbiome treatment, and distinct (as estimated from 16s rRNA amplicon sequencing) intact native microbiomes also differed in their effects on herbivore damage. These differences may be attributable to shifts in primary metabolic pathways.\nC_LIO_LIThe findings suggest that rhizosphere microbes can play a greater role than plant genotype in defense against insect herbivores, and act through mechanisms independent of plant genotype.\nC_LI

plant biology↗

bioRxiv2017

The plant circadian clock influences rhizosphere community structure and function

Plants alter chemical and physical properties of soil, and thereby influence rhizosphere microbial community structure. The structure of microbial communities may in turn affect plant performance. Yet, outside of simple systems with pairwise interacting partners, the plant genetic pathways that influence microbial community structure remain largely unknown, as are the performance feedbacks of microbial communities selected by the host plant genotype. We investigated the role of the plant circadian clock in shaping rhizosphere community structure and function. We performed 16S rRNA gene sequencing to characterize rhizosphere bacterial communities of Arabidopsis thaliana between day and night time points, and tested for differences in community structure between wild-type (Ws) vs. clock mutant (toc1-21, ztl-30) genotypes. We then characterized microbial community function, by growing wild-type plants in soils with an overstory history of Ws, toc1-21 or ztl-30 and measuring plant performance. We observed that rhizosphere community structure varied between day and night time points, and clock misfunction significantly altered rhizosphere communities. Finally, wild-type plants germinated earlier and were larger when inoculated with soils having an overstory history of wild-type in comparison to clock mutant genotypes. Our findings suggest the circadian clock of the plant host influences rhizosphere community structure and function.

plant biology↗