Page 62 - Plant Canada 2024 Proceeding

PLANT CANADA 2024

Tuesday, July 9

Dr. Eric Patterson
Michigan State University

“Building weed genomics resources through
international collaboration and exciting new
discoveries from the genomics frontier”

Abstract: The classic dogma of herbicide
resistance evolution stats that random genetic
variation in wild weed populations contains initially
rare resistance alleles that then increase in time with
herbicide selection pressure. A fundamental
question then becomes, where does genetic variation come from? One source of
variation is random small polymorphisms that occur during DNA replication. Classic
target site mechanisms from SNPs most likely start this way; however, thanks the
advent of cheap, third generation sequencing and chromosome level genome
assemblies, we are discovering that genomic rearrangements are also frequently
sources of herbicide resistance traits. This phenomenon is most obvious in the case of
glyphosate, where at least 8 species have developed some sort of target site copy
number variation. Each species evolves glyphosate resistance independently and
utilizes different rearrangement mechanisms, but the end result is the same. Recently,
target site copy number variation was also cited as providing glufosinate resistance in
Amaranthus palmeri and ACCase resistance in Digitaria sanguinalis. In separate,
extraordinary case of genomic rearrangements, a transposable element inserted into an
intron and changed splicing of a target site. These discoveries are only the beginning of
the insights that weed genomes have to offer.

Bio: Eric Patterson is an Assistant Professor in Weed Science in the Department of Plant, Soil,
and Microbial Sciences at Michigan State University where he teaches weed science to
Undergraduate and Graduates. His research focuses on more basic aspects of weed science
including weed genomics, molecular biology of resistance mechanisms, rapid molecular weed
diagnostics, and herbicide mode of action discovery. His lab is especially interested in how
genome rearrangements (i.e. transposable elements and copy number variation) form and are
utilized as novel sources of genetic variation for weed adaptation to abiotic stresses.

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