Biology subjects

Pruitt, R.

Publications and source records attributed to Pruitt, R..

3 recordsLinked to original sources

bioRxiv2021

Range contractions of the Broad-winged Hawk in the Northeast United States

The Broad-winged Hawk (BWHA, Buteo platypterus) is a small, secretive hawk with distinguishing broad black tail bands that breeds in northeastern North America. The hawk nests in deciduous or mixed forest, often near water, and close to clearings or forest edges. Land conversion and fragmentation alters the landscape and reduces the area of contiguous forest used by BWHA. This study seeks to determine the landscape characteristics influencing the apparent breeding range declines of the BWHA at the landscape scale. Landscape characteristics and BWHA presence data from 18,684 Breeding Bird Atlas blocks (each about 25km2) from Ohio, West Virginia, Maryland, Pennsylvania, and New York for two atlas period (1st Atlas: 1980s, 2nd Atlas: 2000s) were analyzed. Bayesian latent Gaussian models were fitted using INLA to determine best fit model for predicting the landscape characteristics associated with BWHA presence. The best models included landscape changes in land cover, including forest, water, urban, barren, farmland, and wetland and fragmentation of the landscape. Trends in loss were especially prevalent around the regions largest cities: New York, Philadelphia, Baltimore and Washington DC. Loss of BWHA at the block-level was associated with areas with less forest in the 2000s, a decline in size of largest forest patches, lower elevations and lower latitudes. We suggest that both habitat loss and climate change may be contributing to the range contraction of the Broad-winged Hawk in the northeast United States.

ecology↗

bioRxiv2020

Convergent evolution of distinct immune sensor systems for fungal polygalacturonases in Brassicaceae

Plant pattern recognition receptors (PRRs) facilitate recognition of microbial surface patterns and mediate activation of plant immunity. Arabidopsis thaliana RLP42, a leucine-rich repeat (LRR) receptor protein (LRR-RP), senses fungal endopolygalacturonases (PGs) through a ternary complex comprising RLP42, the adapter kinase SOBIR1, and SERK proteins. Several fungal PGs harbor a conserved 9-amino acid fragment pg9(At), which is sufficient to activate RLP42-dependent plant immunity. Domain swap experiments using RLP42 and paralogous RLP40 sequences revealed a dominant role of the island domain (ID) for ligand binding and PRR complex assembly. Involvement of the ID in plant receptor function is reminiscent of plant phytosulfokine (PSK) perception through the receptor, PSKR, a LRR receptor kinase. Sensitivity to pg9(At), which is restricted to A. thaliana, exhibits notable accession specificity as active RLP42 alleles were found in only 16 of 52 accessions tested. Arabidopsis arenosa and Brassica rapa, two Brassicaceae species closely related to A. thaliana, perceive plant immunogenic PG fragments pg20(Aa) or pg36(Bra), which are distinct from pg9(At). Our study unveils unprecedented complexity and dynamics of PG pattern recognition receptor evolution within a single plant family. PG perception systems may have evolved rather independently as a result of convergent evolution even among closely related species.

plant biology↗

bioRxiv2018

Sulfated RaxX, which represents an unclassified group of ribosomally synthesized post-translationally modified peptides, binds a host immune receptor

The rice immune receptor XA21 is activated by the sulfated microbial peptide RaxX (required for activation of XA21-mediated immunity X) produced by Xanthomonas oryzae pv. oryzae (Xoo). Mutational studies and targeted proteomics revealed that RaxX is processed and secreted by the protease/transporter RaxB, whose function can be partially fulfilled by a noncognate peptidase-containing transporter B (PctB). RaxX is cleaved at a Gly-Gly motif, yielding a mature peptide that retains the necessary elements for RaxX function as an immunogen and host peptide hormone mimic. These results indicate that RaxX is a founding member of a previously unclassified and understudied group of tyrosine sulfated RiPPs (ribosomally synthesized, post-translationally modified peptides). We further demonstrate that sulfated RaxX directly binds XA21 with high affinity. This work reveals a complete, previously uncharacterized biological process: bacterial RiPP biosynthesis, secretion, binding to a eukaryotic receptor and triggering of a robust host immune response.

microbiology↗