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Elucidating the genetic basis of antioxidant status in lettuce (Lactuca sativa).

Damerum A, Selmes SL, Biggi GF, Clarkson GJ, Rothwell SD, Truco MJ, Michelmore RW, Hancock RD, Shellcock C, Chapman MA, Taylor G - Hortic Res (2015)

Bottom Line: Analysis of a QTL on linkage group 3, which accounted for >30% of the variation in AO potential, revealed several candidate genes encoding multiple MYB transcription factors which regulate flavonoid biosynthesis and flavanone 3-hydroxylase, an enzyme involved in the biosynthesis of the flavonoids quercetin and kaempferol, which are known to have powerful AO activity.Follow-up quantitative RT-PCR of these candidates revealed that 5 out of 10 genes investigated were significantly differentially expressed between the wild and cultivated parents, providing further evidence of their potential involvement in determining the contrasting phenotypes.These results offer exciting opportunities to improve the nutritional content and health benefits of lettuce through marker-assisted breeding.

View Article: PubMed Central - PubMed

Affiliation: Centre for Biological Sciences, University of Southampton, Life Sciences , University Road, Southampton SO17 1BJ, UK.

ABSTRACT
A diet rich in phytonutrients from fruit and vegetables has been acknowledged to afford protection against a range of human diseases, but many of the most popular vegetables are low in phytonutrients. Wild relatives of crops may contain allelic variation for genes determining the concentrations of these beneficial phytonutrients, and therefore understanding the genetic basis of this variation is important for breeding efforts to enhance nutritional quality. In this study, lettuce recombinant inbred lines, generated from a cross between wild and cultivated lettuce (Lactuca serriola and Lactuca sativa, respectively), were analysed for antioxidant (AO) potential and important phytonutrients including carotenoids, chlorophyll and phenolic compounds. When grown in two environments, 96 quantitative trait loci (QTL) were identified for these nutritional traits: 4 for AO potential, 2 for carotenoid content, 3 for total chlorophyll content and 87 for individual phenolic compounds (two per compound on average). Most often, the L. serriola alleles conferred an increase in total AOs and metabolites. Candidate genes underlying these QTL were identified by BLASTn searches; in several cases, these had functions suggesting involvement in phytonutrient biosynthetic pathways. Analysis of a QTL on linkage group 3, which accounted for >30% of the variation in AO potential, revealed several candidate genes encoding multiple MYB transcription factors which regulate flavonoid biosynthesis and flavanone 3-hydroxylase, an enzyme involved in the biosynthesis of the flavonoids quercetin and kaempferol, which are known to have powerful AO activity. Follow-up quantitative RT-PCR of these candidates revealed that 5 out of 10 genes investigated were significantly differentially expressed between the wild and cultivated parents, providing further evidence of their potential involvement in determining the contrasting phenotypes. These results offer exciting opportunities to improve the nutritional content and health benefits of lettuce through marker-assisted breeding.

No MeSH data available.


Related in: MedlinePlus

Phenotyping the RIL population. Analysis of antioxidant-related phenotypes in the parental lines (L. sativa and L. serriola), highest RIL (Max RIL) and lowest RIL (low Min RIL). Letters indicate significant differences. (a) total antioxidant potential (one-way ANOVA; F3,32 = 11.38, P ≤ 0.001), (b) total carotenoids (F3,31 = 27.09, P ≤ 0.001) and (c) total chlorophyll (F3,31 = 58.63, P ≤ 0.01). Bars represent the mean ± standard error.
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fig1: Phenotyping the RIL population. Analysis of antioxidant-related phenotypes in the parental lines (L. sativa and L. serriola), highest RIL (Max RIL) and lowest RIL (low Min RIL). Letters indicate significant differences. (a) total antioxidant potential (one-way ANOVA; F3,32 = 11.38, P ≤ 0.001), (b) total carotenoids (F3,31 = 27.09, P ≤ 0.001) and (c) total chlorophyll (F3,31 = 58.63, P ≤ 0.01). Bars represent the mean ± standard error.

Mentions: The AO potential of L. serriola acc. UC96US23, the wild parent of the RILs, was over threefold greater than that of L. sativa cv. Salinas, the cultivated parent (38.68 ± 7.72 vs. 9.83 ± 0.53 mmol, respectively; one-way ANOVA, F3,32=11.38, P < 0.001). No significant differences were observed between the RIL with the highest AO potential (59.17 ± 11.69 mmol) and L. serriola nor the RIL with the lowest AO potential (11.19 ± 0.96 mmol) and L. sativa; however, there was evidence of transgressive segregation in that some RILs had a higher AO potential than the L. serriola parent (Figure 1A).


Elucidating the genetic basis of antioxidant status in lettuce (Lactuca sativa).

Damerum A, Selmes SL, Biggi GF, Clarkson GJ, Rothwell SD, Truco MJ, Michelmore RW, Hancock RD, Shellcock C, Chapman MA, Taylor G - Hortic Res (2015)

Phenotyping the RIL population. Analysis of antioxidant-related phenotypes in the parental lines (L. sativa and L. serriola), highest RIL (Max RIL) and lowest RIL (low Min RIL). Letters indicate significant differences. (a) total antioxidant potential (one-way ANOVA; F3,32 = 11.38, P ≤ 0.001), (b) total carotenoids (F3,31 = 27.09, P ≤ 0.001) and (c) total chlorophyll (F3,31 = 58.63, P ≤ 0.01). Bars represent the mean ± standard error.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4660231&req=5

fig1: Phenotyping the RIL population. Analysis of antioxidant-related phenotypes in the parental lines (L. sativa and L. serriola), highest RIL (Max RIL) and lowest RIL (low Min RIL). Letters indicate significant differences. (a) total antioxidant potential (one-way ANOVA; F3,32 = 11.38, P ≤ 0.001), (b) total carotenoids (F3,31 = 27.09, P ≤ 0.001) and (c) total chlorophyll (F3,31 = 58.63, P ≤ 0.01). Bars represent the mean ± standard error.
Mentions: The AO potential of L. serriola acc. UC96US23, the wild parent of the RILs, was over threefold greater than that of L. sativa cv. Salinas, the cultivated parent (38.68 ± 7.72 vs. 9.83 ± 0.53 mmol, respectively; one-way ANOVA, F3,32=11.38, P < 0.001). No significant differences were observed between the RIL with the highest AO potential (59.17 ± 11.69 mmol) and L. serriola nor the RIL with the lowest AO potential (11.19 ± 0.96 mmol) and L. sativa; however, there was evidence of transgressive segregation in that some RILs had a higher AO potential than the L. serriola parent (Figure 1A).

Bottom Line: Analysis of a QTL on linkage group 3, which accounted for >30% of the variation in AO potential, revealed several candidate genes encoding multiple MYB transcription factors which regulate flavonoid biosynthesis and flavanone 3-hydroxylase, an enzyme involved in the biosynthesis of the flavonoids quercetin and kaempferol, which are known to have powerful AO activity.Follow-up quantitative RT-PCR of these candidates revealed that 5 out of 10 genes investigated were significantly differentially expressed between the wild and cultivated parents, providing further evidence of their potential involvement in determining the contrasting phenotypes.These results offer exciting opportunities to improve the nutritional content and health benefits of lettuce through marker-assisted breeding.

View Article: PubMed Central - PubMed

Affiliation: Centre for Biological Sciences, University of Southampton, Life Sciences , University Road, Southampton SO17 1BJ, UK.

ABSTRACT
A diet rich in phytonutrients from fruit and vegetables has been acknowledged to afford protection against a range of human diseases, but many of the most popular vegetables are low in phytonutrients. Wild relatives of crops may contain allelic variation for genes determining the concentrations of these beneficial phytonutrients, and therefore understanding the genetic basis of this variation is important for breeding efforts to enhance nutritional quality. In this study, lettuce recombinant inbred lines, generated from a cross between wild and cultivated lettuce (Lactuca serriola and Lactuca sativa, respectively), were analysed for antioxidant (AO) potential and important phytonutrients including carotenoids, chlorophyll and phenolic compounds. When grown in two environments, 96 quantitative trait loci (QTL) were identified for these nutritional traits: 4 for AO potential, 2 for carotenoid content, 3 for total chlorophyll content and 87 for individual phenolic compounds (two per compound on average). Most often, the L. serriola alleles conferred an increase in total AOs and metabolites. Candidate genes underlying these QTL were identified by BLASTn searches; in several cases, these had functions suggesting involvement in phytonutrient biosynthetic pathways. Analysis of a QTL on linkage group 3, which accounted for >30% of the variation in AO potential, revealed several candidate genes encoding multiple MYB transcription factors which regulate flavonoid biosynthesis and flavanone 3-hydroxylase, an enzyme involved in the biosynthesis of the flavonoids quercetin and kaempferol, which are known to have powerful AO activity. Follow-up quantitative RT-PCR of these candidates revealed that 5 out of 10 genes investigated were significantly differentially expressed between the wild and cultivated parents, providing further evidence of their potential involvement in determining the contrasting phenotypes. These results offer exciting opportunities to improve the nutritional content and health benefits of lettuce through marker-assisted breeding.

No MeSH data available.


Related in: MedlinePlus