TY - JOUR
T1 - A novel TIPT double mutation in EPSPS conferring glyphosate resistance in tetraploid Bidens subalternans
AU - Takano, Hudson K.
AU - Fernandes, Vanessa N. A.
AU - Adegas, Fernando S.
AU - Oliveira Jr, Rubem S.
AU - Westra, Philip
AU - Gaines, Todd A.
AU - Dayana, Franck E.
PY - 2020/1/1
Y1 - 2020/1/1
N2 - BACKGROUND Bidens subalternans (greater beggarticks) is a tetraploid and troublesome weed infesting annual crops in most tropical regions of the world. A glyphosate-resistant (GR) B. subalternans biotype was detected in a soybean field from Paraguay. A series of physiological and molecular analyses were conducted to elucidate its resistance mechanisms. RESULTS The GR biotype had a high level of resistance (> 15-fold LD50), relative to a glyphosate-susceptible (GS) biotype. Shikimate accumulation was up to ten-fold greater for GS compared with GR. We found no differences in sensitivity when plants were treated and kept under lower (10/4 degrees C) or higher temperatures (25/20 degrees C). GS and GR had the same relative EPSPS gene copy number, and similar glyphosate absorption and translocation rates. Neither biotype metabolized glyphosate. A double amino acid substitution (TIPT - Thr102Ile and Pro106Thr) was found in only one EPSPS allele from one of the two EPSPS homoeologs present in tetraploid GR B. subalternans. CONCLUSION This is the first report of a TIPT double mutation conferring high levels of glyphosate resistance in a weed species. The presence of both wild-type and TIPT mutant EPSPS on the polyploid genome of GR B. subalternans may offset a potential fitness cost, requiring additional research to confirm the absence of deleterious effects. (c) 2019 Society of Chemical Industry
AB - BACKGROUND Bidens subalternans (greater beggarticks) is a tetraploid and troublesome weed infesting annual crops in most tropical regions of the world. A glyphosate-resistant (GR) B. subalternans biotype was detected in a soybean field from Paraguay. A series of physiological and molecular analyses were conducted to elucidate its resistance mechanisms. RESULTS The GR biotype had a high level of resistance (> 15-fold LD50), relative to a glyphosate-susceptible (GS) biotype. Shikimate accumulation was up to ten-fold greater for GS compared with GR. We found no differences in sensitivity when plants were treated and kept under lower (10/4 degrees C) or higher temperatures (25/20 degrees C). GS and GR had the same relative EPSPS gene copy number, and similar glyphosate absorption and translocation rates. Neither biotype metabolized glyphosate. A double amino acid substitution (TIPT - Thr102Ile and Pro106Thr) was found in only one EPSPS allele from one of the two EPSPS homoeologs present in tetraploid GR B. subalternans. CONCLUSION This is the first report of a TIPT double mutation conferring high levels of glyphosate resistance in a weed species. The presence of both wild-type and TIPT mutant EPSPS on the polyploid genome of GR B. subalternans may offset a potential fitness cost, requiring additional research to confirm the absence of deleterious effects. (c) 2019 Society of Chemical Industry
KW - 5-enolpyruvylshikimate-3-phosphate synthase
KW - KASP (Kompetitive Allele-Specific PCR) genotyping
KW - Herbicide resistance
KW - Herbicide resistance mechanism
KW - Polyploid
KW - Target site resistance
UR - https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=uwapure5-25&SrcAuth=WosAPI&KeyUT=WOS:000480454900001&DestLinkType=FullRecord&DestApp=WOS
U2 - 10.1002/ps.5535
DO - 10.1002/ps.5535
M3 - Article
C2 - 31251461
SN - 1526-498X
VL - 76
SP - 95
EP - 102
JO - Pest Management Science
JF - Pest Management Science
IS - 1
ER -