Full Length Research Paper

Photoinhibition influences protein utilisation during seed germination in Cleome gynandra L.

Julius O. Ochuodho^1*, Albert T. Modi¹ and Mervyn Beukes²

¹School of Agricultural Sciences and Agribusiness (Crop Science) University of KwaZulu Natal, Private Bag X01, Scottsville 3209, Pietermaritzburg

²School of Molecular and Cellular Biosciences (Genetics), University of KwaZulu Natal, Private Bag X01, Scottsville 3209, Pietermaritzburg.

*Corresponding author. Email: seedtechjo@yahoo.com.

Accepted 30 August, 2007

Seed storage proteins are mobilised during germination, especially at radicle protrusion. The objective of this study was to examine changes in protein expression during germination of Cleome gynandra in the presence or absence of light and at constant or alternating temperatures. Seeds were germinated at alternating 30/20 or 20^oC in darkness and in continuous white light. Four prominent proteins of 28 - 32 kDa and 18 - 20 kDa, and a fifth low molecular weight protein of 13 kDa were observed in seeds harvested at brown pod maturity. These proteins remained unchanged during photoinhibition as shown on SDS-PAGE gels. Photoinhibition is a pseudodormancy condition during which seed storage proteins are not utilised.

Key words: Cleome gynandra, photoinhibition, seed germination, seed storage proteins.