TY - JOUR
T1 - Isolating an active and inactive CACTA transposon from lettuce color mutants and characterizing their family
AU - Gurdon, Csanad
AU - Kozik, Alexander
AU - Tao, Rong
AU - Poulev, Alexander
AU - Armas, Isabel
AU - Michelmore, Richard W.
AU - Raskin, Ilya
N1 - Funding Information:
C.G. was supported by the National Institutes of Health under a T32 Fellowship from the National Center for Complementary and Integrative Health (AT004094). I.A. was partially supported by a fellowship from the USA?Spain Fulbright Commission and a research assistantship from Rutgers University. I.R. was funded by grants 2-P50 AT002776-06 and 1R01AT008618 from the NIH-NCCIH and Office of Dietary Supplements (NIH-ODS). A.K. and R.W.M. were supported by the University of California Davis.
Funding Information:
C.G. was supported by the National Institutes of Health under a T32 Fellowship from the National Center for Complementary and Integrative Health (AT004094). I.A. was partially supported by a fellowship from the USA–Spain Fulbright Commission and a research assistantship from Rutgers University. I.R. was funded by grants 2-P50 AT002776-06 and 1R01AT008618 from the NIH-NCCIH and Office of Dietary Supplements (NIH-ODS). A.K. and R.W.M. were supported by the University of California Davis.
Publisher Copyright:
© The Author(s) 2021.
PY - 2021/6
Y1 - 2021/6
N2 - Dietary flavonoids play an important role in human nutrition and health. Flavonoid biosynthesis genes have recently been identified in lettuce (Lactuca sativa); however, few mutants have been characterized. We now report the causative mutations in Green Super Lettuce (GSL), a natural light green mutant derived from red cultivar NAR; and GSL-Dark Green (GSL-DG), an olive-green natural derivative of GSL. GSL harbors CACTA 1 (LsC1), a 3.9-kb active nonautonomous CACTA superfamily transposon inserted in the 50 untranslated region of anthocyanidin synthase (ANS), a gene coding for a key enzyme in anthocyanin biosynthesis. Both terminal inverted repeats (TIRs) of this transposon were intact, enabling somatic excision of the mobile element, which led to the restoration of ANS expression and the accumulation of red anthocyanins in sectors on otherwise green leaves. GSL-DG harbors CACTA 2 (LsC2), a 1.1-kb truncated copy of LsC1 that lacks one of the TIRs, rendering the transposon inactive. RNA-sequencing and reverse transcription quantitative PCR of NAR, GSL, and GSL-DG indicated the relative expression level of ANS was strongly influenced by the transposon insertions. Analysis of flavonoid content indicated leaf cyanidin levels correlated positively with ANS expression. Bioinformatic analysis of the cv Salinas lettuce reference genome led to the discovery and characterization of an LsC1 transposon family with a putative transposon copy number greater than 1,700. Homologs of tnpA and tnpD, the genes encoding two proteins necessary for activation of transposition of CACTA elements, were also identified in the lettuce genome.
AB - Dietary flavonoids play an important role in human nutrition and health. Flavonoid biosynthesis genes have recently been identified in lettuce (Lactuca sativa); however, few mutants have been characterized. We now report the causative mutations in Green Super Lettuce (GSL), a natural light green mutant derived from red cultivar NAR; and GSL-Dark Green (GSL-DG), an olive-green natural derivative of GSL. GSL harbors CACTA 1 (LsC1), a 3.9-kb active nonautonomous CACTA superfamily transposon inserted in the 50 untranslated region of anthocyanidin synthase (ANS), a gene coding for a key enzyme in anthocyanin biosynthesis. Both terminal inverted repeats (TIRs) of this transposon were intact, enabling somatic excision of the mobile element, which led to the restoration of ANS expression and the accumulation of red anthocyanins in sectors on otherwise green leaves. GSL-DG harbors CACTA 2 (LsC2), a 1.1-kb truncated copy of LsC1 that lacks one of the TIRs, rendering the transposon inactive. RNA-sequencing and reverse transcription quantitative PCR of NAR, GSL, and GSL-DG indicated the relative expression level of ANS was strongly influenced by the transposon insertions. Analysis of flavonoid content indicated leaf cyanidin levels correlated positively with ANS expression. Bioinformatic analysis of the cv Salinas lettuce reference genome led to the discovery and characterization of an LsC1 transposon family with a putative transposon copy number greater than 1,700. Homologs of tnpA and tnpD, the genes encoding two proteins necessary for activation of transposition of CACTA elements, were also identified in the lettuce genome.
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U2 - 10.1093/PLPHYS/KIAB143
DO - 10.1093/PLPHYS/KIAB143
M3 - Article
C2 - 33768232
AN - SCOPUS:85108716633
VL - 186
SP - 929
EP - 944
JO - Plant Physiology
JF - Plant Physiology
SN - 0032-0889
IS - 2
ER -