TY - JOUR

T1 - Gene expression profiles of seed coats and biochemical properties of seed coats and cotyledons of two field pea (Pisum sativum) cultivars contrasting in green cotyledon bleaching resistance

AU - Ubayasena, Lasantha

AU - Vijayan, Perumal

AU - Bett, Kirstin E.

AU - Gray, Gordon R.

AU - Küster, Helge

AU - Warkentin, Thomas D.

N1 - Funding information: Acknowledgments Funding for this research Project was provided by the Saskatchean Pulse Growers Association and the Agricultural Development Fund of the Saskatchewan Ministry of Agriculture. Technical support provided by Brent Barlow, Kari-Lynne McGowan and Amila Heendeniya, and the staff of the University of Saskatchewan Pulse Research Laboratory are greatly appreciated. Authors would also like to thanks Dr. Vikrum Misra and Norin Rapin, Western College of Veterinary Medicine, University of Saskatchewan for providing the microarray imaging facilities.

PY - 2013/9/1

Y1 - 2013/9/1

N2 - Visual quality is one of the major factors determining the market value of field pea (Pisum sativum L.). Breeding for improved visual quality of pea seeds is currently a challenging task, mainly because of the complexity and the lack of sound genetic knowledge of the traits. The objectives of this research were to characterize post-harvest cotyledon bleaching resistance in green pea at the biochemical and gene expression levels. Seed coats and cotyledons of two pea cultivars, CDC Striker (bleaching resistant) and Orb (bleaching susceptible) at three developmental stages [14, 21 and 28 days after flowering (DAF)] and following exposure to accelerated bleaching conditions after harvest (0, 3, 6, and 13 days after bleaching (DAB) were evaluated. CDC Striker had a slower rate of chlorophyll degradation in cotyledons, and a higher total carotenoids to chlorophyll ratio in seed coats, than Orb when seed samples were exposed to high intensity light. An oligo-nucleotide microarray (Ps6kOLI1) revealed that gene expression profiles of the CDC Striker and Orb seed coats were significantly different during seed developmental stages. A significant up regulation of genes involved in the production and accumulation of secondary metabolites responsible for antioxidant properties including epiafzelechin, epicatechin, epigallocatechin, kaempferide, kaempferol 3-O-β-d-sophorotrioside, O-quercetin and rutin, in the seed coats of CDC Striker were observed. Thus, bleaching resistance in field pea could be due to the accumulation of specific carotenoids and phenolic compounds which quench excess light or scavenge free radical singlet oxygen molecules. The candidate genes identified in this project will need to be validated using qPCR to further support their involvement with bleaching resistance before being used for the development of gene specific markers.

AB - Visual quality is one of the major factors determining the market value of field pea (Pisum sativum L.). Breeding for improved visual quality of pea seeds is currently a challenging task, mainly because of the complexity and the lack of sound genetic knowledge of the traits. The objectives of this research were to characterize post-harvest cotyledon bleaching resistance in green pea at the biochemical and gene expression levels. Seed coats and cotyledons of two pea cultivars, CDC Striker (bleaching resistant) and Orb (bleaching susceptible) at three developmental stages [14, 21 and 28 days after flowering (DAF)] and following exposure to accelerated bleaching conditions after harvest (0, 3, 6, and 13 days after bleaching (DAB) were evaluated. CDC Striker had a slower rate of chlorophyll degradation in cotyledons, and a higher total carotenoids to chlorophyll ratio in seed coats, than Orb when seed samples were exposed to high intensity light. An oligo-nucleotide microarray (Ps6kOLI1) revealed that gene expression profiles of the CDC Striker and Orb seed coats were significantly different during seed developmental stages. A significant up regulation of genes involved in the production and accumulation of secondary metabolites responsible for antioxidant properties including epiafzelechin, epicatechin, epigallocatechin, kaempferide, kaempferol 3-O-β-d-sophorotrioside, O-quercetin and rutin, in the seed coats of CDC Striker were observed. Thus, bleaching resistance in field pea could be due to the accumulation of specific carotenoids and phenolic compounds which quench excess light or scavenge free radical singlet oxygen molecules. The candidate genes identified in this project will need to be validated using qPCR to further support their involvement with bleaching resistance before being used for the development of gene specific markers.

KW - Bleaching

KW - cDNA

KW - Field pea

KW - Gene expression

KW - Microarray

KW - Pigments

UR - http://www.scopus.com/inward/record.url?scp=84881554014&partnerID=8YFLogxK

U2 - 10.1007/s10681-013-0914-2

DO - 10.1007/s10681-013-0914-2

M3 - Article

AN - SCOPUS:84881554014

VL - 193

SP - 49

EP - 65

JO - EUPHYTICA

JF - EUPHYTICA

SN - 0014-2336

IS - 1

ER -