Analysis of starch metabolism in South African pigeon pea (Cajanus cajan) varieties

Simple item page
dc.contributor.advisorLloyd, James R. en_ZA
dc.contributor.advisorPeters, Shaun Wayneen_ZA
dc.contributor.authorKulu, Nokwandaen_ZA
dc.contributor.otherStellenbosch University. Faculty of AgriSciences. Department of Genetics & Institute of Plant Biotechnology.en_ZA
dc.date.accessioned2023-03-09T13:38:33Z
dc.date.accessioned2023-05-18T07:10:10Z
dc.date.available2023-03-09T13:38:33Z
dc.date.available2023-05-18T07:10:10Z
dc.date.issued2023-03
dc.descriptionThesis (MScAgric)--Stellenbosch University, 2023.en_ZA
dc.description.abstractENGLISH ABSTRACT: Starch is a major storage polyglucan in plants that is composed of two fractions, amylose and amylopectin. The biosynthesis and degradation pathways of starch are well documented, with phosphoglucomutase (PGM) and ADP-glucose pyrophosphorylase (AGPase) catalysing the first two steps in its biosynthesis. This project examined starch in five pigeon pea (Cajanus cajan) varieties: uDhali, SEFA, Nondolo, Lari and India by measuring both total and resistant starches in the seeds and leaves, activities of PGM and AGPase as well as expression of the genes encoding these enzymes. The findings demonstrated that the seeds from these South African pigeon pea varieties are rich in starch, containing an average of 47% starch on a dry weight basis; however, one variety (SEFA) contained only 0.3% starch. The starch in the high- starch varieties contained a minimum of 50% resistant starch, with the India variety reaching 70%. Assessment of soluble sugars in seeds revealed sucrose to be the only sugar present in abundance in all varieties while amounts of galacto-oligosaccharides were low in all seeds. Starch in leaves was observed to be 10 fold less than that found in seeds and the amount of resistant starch in leaves was less than 2 mg/g fresh weight (7.6% of the total). The AGPase gDNA nucleotide sequence from one variety was identical to an already sequenced pigeon pea variety, whereas amplification PGM gDNA was unsuccessful. Amplification of coding sequences (CDSs) for both AGPase and PGM were also identified to be the same as the already sequenced AGPase and PGM genes from the pigeon pea genome resource database. Gene expression for both genes varied throughout a 24 h period and was at its peak during the day (light period). Activities of both AGPase and PGM were determined in seeds from all varieties whereas the AGPase enzyme activity was the same in leaves throughout the day while PGM activity varied between the day (light) and night (dark).en_ZA
dc.description.abstractAFRIKAANSE OPSOMMING: Geen opsomming beskikbaar.af_ZA
dc.description.versionMastersen_ZA
dc.format.extentxi, 73 pages : illustrations (some color)en_ZA
dc.identifier.urihttp://hdl.handle.net/10019.1/127214
dc.language.isoen_ZAen_ZA
dc.publisherStellenbosch : Stellenbosch Universityen_ZA
dc.rights.holderStellenbosch Universityen_ZA
dc.subject.lcshPigeon pea (Cajanus cajan) -- South Africa -- Evaluationen_ZA
dc.subject.lcshPigeon pea -- Seeds -- Varieties -- Indiaen_ZA
dc.subject.lcshStarch -- Nutritional aspectsen_ZA
dc.subject.lcshStarch -- Analysisen_ZA
dc.subject.lcshBiosynthesisen_ZA
dc.subject.lcshGenetic engineeringen_ZA
dc.subject.lcshPlant gene expressionen_ZA
dc.subject.nameUCTDen_ZA
dc.titleAnalysis of starch metabolism in South African pigeon pea (Cajanus cajan) varietiesen_ZA
dc.typeThesisen_ZA
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
kulu_analysis_2023.pdf
Size:
2.67 MB
Format:
Adobe Portable Document Format
Description:
Download
Collections
Masters Degrees (Genetics)