Biology subjects

Lynch, J. P.

Publications and source records attributed to Lynch, J. P..

4 recordsLinked to original sources

bioRxiv2024

Xylem perforation plate phenotypes affect water use and drought adaptation in maize (Zea mays L.)

O_LIRationale: Xylem morphology in annual monocots is important for water use strategies in many agronomically important species. C_LIO_LIMethods: We assess how xylem perforation plates affect water use strategies in maize (Zea mays L.) through in silico modeling, empirical studies under water deficit in controlled environments, and in the field. C_LIO_LIKey Result: Significant genotypic variation for the prominence and frequency of perforation plates was observed in maize germplasm. Perforation plate phenotypes had high heritability, were associated with several QTL, and were pleiotropic across leaves, aerial nodal roots, and subterranean nodal roots. Perforation plate phenotypes did not affect vulnerability to cavitation, but modeling predicted that they should affect axial water transport, which was supported by in situ measurements of root segments. Metaxylem vessel length was correlated with the rate of root elongation, root depth, and deep-water utilization in mesocosms. Under drought stress in the field, variation in xylem vessel length was associated with leaf roll, leaf temperature, transpiration, photosynthesis, and grain yield. C_LIO_LIMain Conclusion: Phenotypic variation for xylem perforation plate phenotypes in maize directly affects axial water conductance and is part of a pleiotropic syndrome with greater root elongation and deeper rooting that improves adaptation to water deficit stress. C_LI

plant biology↗

bioRxiv2023

LEADER (Leaf Element Accumulation from Deep Roots): a nondestructive phenotyping platform to estimate rooting depth in the field

Deeper rooted crops are an avenue to increase plant water and nitrogen uptake under limiting conditions and increase long-term soil carbon storage. Measuring rooting depth, however, is challenging due to the destructive, laborious, or imprecise methods that are currently available. Here, we present LEADER (Leaf Element Accumulation from DEep Roots) as a method to estimate in-field root depth of maize plants. We use both X-Ray fluorescence spectroscopy (XRF) and ICP-OES (Inductively Coupled Plasma Optical Emission spectroscopy) to measure leaf elemental content and relate this to metrics of root depth. Principal components of leaf elemental content correlate with measures of root length in four genotypes (R2= 0.8 for total root length), and we use linear discriminant analysis to classify plants as having different metrics related to root depth across four field sites in the United States. We can correctly classify the plots with the longest root length at depth with high accuracy (accuracy greater than 0.6) at two of our field sites (Hancock, WI and Rock Spring, PA). We also use strontium (Sr) as a tracer element in both greenhouse and field studies, showing that elemental accumulation of Sr in leaf tissue can be measured with XRF and can estimate root depth. We propose the adoption of LEADER as a tool for measuring root depth in different plant species and soils. LEADER is faster and easier than any other methods that currently exist and could allow for extensive study and understanding of deep rooting.

plant biology↗

bioRxiv2023

The maternal microbiome regulates infant respiratory disease susceptibility via intestinal Flt3L expression and plasmacytoid dendritic cell hematopoiesis

Severe lower respiratory infection (sLRI) are a major cause of infant morbidity and mortality, and predispose to later chronic respiratory diseases such as asthma. Poor maternal diet during pregnancy is a risk factor for sLRI in the offspring. Here we demonstrate in mice that a maternal low-fibre diet (LFD) disrupts plasmacytoid and conventional dendritic cell (DC) hematopoiesis in the offspring, predisposing to sLRI and subsequent asthma. The LFD alters the composition of the maternal milk microbiome and assembling infant gut microbiome, ablating the induction of a developmental wave of the non-redundant DC growth factor Flt3L by neonatal intestinal epithelial cells. Therapy with a propionate-producing bacteria isolated from the milk of high-fibre diet-fed mothers, or supplementation with propionate, confers protection against sLRI by restoring gut Flt3L expression and pDC hematopoiesis. Our findings identify a microbiome-dependent Flt3L axis in the gut that regulates pDC hematopoiesis in early life and confers disease resistance. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=51 SRC="FIGDIR/small/522516v1_ufig1.gif" ALT="Figure 1"> View larger version (15K): org.highwire.dtl.DTLVardef@1a39990org.highwire.dtl.DTLVardef@1b6fe67org.highwire.dtl.DTLVardef@f8440dorg.highwire.dtl.DTLVardef@13bc67e_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2022

RootSlice: a novel functional-structural model for root anatomical phenotypes

Root anatomy is an important determinant of root metabolic costs, soil exploration, and soil resource capture. Root anatomy varies substantially within and among plant species. RootSlice is a multicellular functional-structural model of root anatomy developed to facilitate the analysis and understanding of root anatomical phenotypes. RootSlice can capture phenotypically accurate root anatomy in three dimensions of different root classes and developmental zones, of both monocotyledonous and dicotyledonous species. Several case studies are presented illustrating the capabilities of the model. For maize nodal roots, the model illustrated the role of vacuole expansion in cell elongation; and confirmed the individual and synergistic role of increasing root cortical aerenchyma and reducing the number of cortical cell files in reducing root metabolic costs. Integration of RootSlice for different root zones as the temporal properties of the nodal roots in the whole-plant and soil model OpenSimRoot/maize enabled the multiscale evaluation of root anatomical phenotypes, highlighting the role of aerenchyma formation in enhancing the utility of cortical cell files for improving plant performance over varying soil nitrogen supply. Such integrative in silico approaches present avenues for exploring the fitness landscape of root anatomical phenotypes. Summary statementRoot anatomy remains an underutilized target for crop breeding. RootSlice, a multicellular functional-structural model of root anatomy, simulates the costs and benefits of diverse root anatomical phenotypes to estimate their utility for plant fitness in unfavorable soil environments.

plant biology↗