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Elucidating arabinoxylan biosynthesis pathways in oat and identification of high arabinoxylan oat lines

Frisell, David LU (2020) KBKM05 20201
Pure and Applied Biochemistry
Theoretical Chemistry
Abstract
Arabinoxylan (AX) is a dietary fibre linked to positive health effects. An oat mutant population was screened for AX content and oat lines in the range 3,63-12,4% AX and a mean of 7.5% were identified. The mean of reference oat variety Belinda was 8,05% AX. 15 potential oat AX biosynthetic genes from four different genes families (UAM, GT43, GT47, GT61) were identified. A selection of six genes identified from the AX biosynthetic pathway was successfully analysed for expression in tissues of early and late developing seeds using RT-qPCR. All analysed genes were more expressed in late developing seeds than early developing seed.
Popular Abstract
Oats are the seventh most cultivated cereal on the planet. In Sweden 700 000 tons of oats are harvested each year making up 13% of the total Swedish cereal harvest. Oat is thus an important crop for Swedish agricultural and food industries. Oats are rich in dietary fibre and protein and is good source of vitamins, micronutrients and antioxidants.
Arabinoxylan (AX) is a dietary fibre which has been linked to several positive health effects when consumed. On a molecular level AX consists of a backbone of the sugar xylose with varying amounts of the sugar arabinose distributed along the xylose backbone. In cereals, such as oat, AXs is found mainly in the cell walls in most tissues. Cereal seeds is a good source of AXs.
CropTailor (CT), a... (More)
Oats are the seventh most cultivated cereal on the planet. In Sweden 700 000 tons of oats are harvested each year making up 13% of the total Swedish cereal harvest. Oat is thus an important crop for Swedish agricultural and food industries. Oats are rich in dietary fibre and protein and is good source of vitamins, micronutrients and antioxidants.
Arabinoxylan (AX) is a dietary fibre which has been linked to several positive health effects when consumed. On a molecular level AX consists of a backbone of the sugar xylose with varying amounts of the sugar arabinose distributed along the xylose backbone. In cereals, such as oat, AXs is found mainly in the cell walls in most tissues. Cereal seeds is a good source of AXs.
CropTailor (CT), a Swedish biotech company, has developed a large population of oats with random mutations in their DNA. This population has been used to screen for mutants with desirable properties, such as high β-glucan (a dietary fibre) content and high protein content. In this thesis the CT oat population has been screened for mutants with a high AX content. Several high AX oat lines were identified. These high lines are candidates for breeding with non-mutagenized oat to develop an oat variety with a high AX content in the future. However, not only the high AX lines are interesting; the low AX lines are of interest from a genetic standpoint. The oat genome has recently been sequenced, which allows for deeper genetic studies of oat. Thus, the high and low AX lines can be used to study what mutations caused their higher or lower content.
The biological pathway for AX synthesis is not fully understood in any plant yet and nothing about it is known in oat. Some genes have however been identified to code for critical enzymes from the AX pathway in other plants such as Arabidopsis, rice, wheat and barley. In this thesis a total of 15 genes that are possibly involved in the AX synthesis in oat have been identified. They were identified using bioinformatic tools to search the oat genome for genes similar to those that have been described in other plant species.
Six of the identified genes were also investigated by quantitative reverse transcription polymerase chain reaction (RT-qPCR), a biochemical method that can be used to measure to what extent a gene is expressed in an organism. This confirmed that this selection of genes is indeed expressed in oat, and higher expressed in the late developing seed than the early developing seed. (Less)
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author
Frisell, David LU
supervisor
organization
course
KBKM05 20201
year
type
H2 - Master's Degree (Two Years)
subject
keywords
arabinoxylan, oat, applied biochemistry, tillämpad biokemi
language
English
id
9023188
date added to LUP
2020-07-06 10:50:22
date last changed
2020-07-06 10:50:22
@misc{9023188,
  abstract     = {Arabinoxylan (AX) is a dietary fibre linked to positive health effects. An oat mutant population was screened for AX content and oat lines in the range 3,63-12,4% AX and a mean of 7.5% were identified. The mean of reference oat variety Belinda was 8,05% AX. 15 potential oat AX biosynthetic genes from four different genes families (UAM, GT43, GT47, GT61) were identified. A selection of six genes identified from the AX biosynthetic pathway was successfully analysed for expression in tissues of early and late developing seeds using RT-qPCR. All analysed genes were more expressed in late developing seeds than early developing seed.},
  author       = {Frisell, David},
  keyword      = {arabinoxylan,oat,applied biochemistry,tillämpad biokemi},
  language     = {eng},
  note         = {Student Paper},
  title        = {Elucidating arabinoxylan biosynthesis pathways in oat and identification of high arabinoxylan oat lines},
  year         = {2020},
}