Biology subjects

Swift, J. F.

Publications and source records attributed to Swift, J. F..

3 recordsLinked to original sources

bioRxiv2020

Root system influence on high dimensional leaf phenotypes over the grapevine growing season

O_LIIn many perennial crops, grafting the root system of one individual to the shoot system of another individual has become an integral part of propagation performed at industrial scales to enhance pest, disease, and stress tolerance and to regulate yield and vigor. Grafted plants offer important experimental systems for understanding the extent and seasonality of root system effects on shoot system biology. C_LIO_LIUsing an experimental vineyard where a common scion Chambourcin is growing ungrafted and grafted to three different rootstocks, we explore associations between root system genotype and leaf phenotypes in grafted grapevines across a growing season. We quantified five high-dimensional leaf phenotyping modalities: ionomics, metabolomics, transcriptomics, morphometrics, and physiology and show that rootstock influence is subtle but ubiquitous across modalities. C_LIO_LIWe find strong signatures of rootstock influence on the leaf ionome, with unique signatures detected at each phenological stage. Moreover, all phenotypes and patterns of phenotypic covariation were highly dynamic across the season. C_LIO_LIThese findings expand upon previously identified patterns to suggest that the influence of root system on shoot system phenotypes is complex and broad understanding necessitates volumes of high-dimensional, multi-scale data previously unmet. C_LI

plant biology↗

bioRxiv2020

Grapevine microbiota reflect diversity among compartments and complex interactions within and among root and shoot systems

BackgroundWithin an individual plant, different compartments (e.g. roots, leaves, fruits) host distinct communities of microorganisms due to variation in structural characteristics and resource availability. Grafting, which joins the root system of one individual with the shoot system of a second genetically distinct individual, has the potential to bring the microbial communities of different genotypes together. An important question is the extent to which unique root system and shoot system genotypes, when grafted together, influence the microbiota of the graft partner. Our study sought to answer this question by utilizing an experimental vineyard composed of Chambourcin vines growing ungrafted and grafted to three different rootstocks, replicated across three irrigation treatments. We characterized bacterial and fungal communities in roots, leaves, and berries, as well as surrounding soil. Our objectives were to (1) characterize the microbiota of compartments within the root system (roots and adjacent soil) and the shoot system (leaves and berries), (2) determine the influence of rootstock genotypes, irrigation, and their interaction on the microbiota of aboveground and belowground compartments, and (3) investigate the distribution of microorganisms implicated in the late-season grapevine bunch rot disease sour rot (Acetobacterales and Saccharomycetes). ResultsCompartments were significantly differentiated in bacterial and fungal richness and composition. Abundance-based machine learning accurately predicted the compartment and differential abundance analysis showed a large portion of taxa differed significantly across compartments. Rootstock genotypes did not differ significantly in microbial community richness or composition; however, individual microbial taxa exhibited significant differences in abundance based on rootstock and irrigation treatment. The relative abundance of Acetobacterales and Saccharomycetes in the berry was influenced by complex interactions among rootstock genotype and irrigation. ConclusionOur results indicate that grapevine compartments retain distinct core microbiota regardless of the rootstock to which they are grafted. While rootstock genotype generally had a subtle impact on global patterns of microbial diversity, we found associations between rootstock genotypes and specific groups of microorganisms. Further experimental validation is needed in order to understand how associations with these microorganisms impacts a vines susceptibility to sour rot upon damage and whether the characteristics of wine are impacted.

plant biology↗

bioRxiv2020

Understanding how an amphicarpic species with a mixed mating system responds to fire: a population genetic approach

Amphicarphic species produce both aboveground and belowground seeds; the belowground seeds have been proposed to be an adaptation to disturbed sites because they are protected belowground, enabling them to persist and recolonize a site after disturbance. However, it is unknown whether such seeds indeed serve as the main colonizers after a disturbance. The amphicarpic species Polygala lewtonii is endemic to fire-prone Florida sandhill and scrub and is among only a few species with three flower types (aboveground chasmogamous flowers and both above and belowground cleistogamous flowers). The goal of this study was to understand whether recolonization of sites by P. lewtonii was accomplished primarily through germination of belowground seed. First, we quantified the outcrossing rate in seeds produced by aboveground chasmogamous flowers to determine whether we could detect differences in colonization of between seeds produced aboveground vs. belowground. Approximately 25% of seeds from aboveground chasmogamous flowers showed evidence of cross pollination and the seeds showed greater heterozygosity and lower inbreeding coefficients than pure selfing, indicating that it is possible to differentiate between selfed and non-selfed seed types in postfire colonization. Second, we analyzed genetic diversity, inbreeding, and genetic structure of the populations before and after a prescribed fire. If heterozygosity and admixture increased, and spatial population genetic structure and inbreeding decreased, this would indicate that fire promoted germination of outcrossed seed from aboveground flowers. However, inbreeding increased and spatial genetic structure and admixture decreased after fire, suggesting that selfed seed produced by belowground flowers predominantly recolonized the site after fire. Thus, amphicarpy is a powerful adaptation to fire-maintained environments by producing seeds that are well suited to the range of conditions presented by a highly variable, disturbance prone habitat.

plant biology↗