AbstractApple food allergen Mal d 1 and birch pollen allergen Bet v 1 belong to the same pathogen related protein 10 (PR10) family. When each of these allergens was expressed as a secretory protein by fusion with the GFP reporter in transgenic rice by ligating an N terminal signal peptide and a C terminal KDEL ER retention signal under the control of the maize ubiquitin constitutive promoter, the GFP:Mald1 highly accumulated in various tissues, whereas the accumulation level of GFP:Betv1 was remarkably reduced in vegetative tissues except for seed. Analysis by RT-PCR exhibited that there was little difference in transcript levels between them, indicating the involvement of post-transcriptional regulation. To investigate the cause of such difference in accumulation levels, deletion analysis of the Mal d 1 and domain swapping between them were carried out in transgenic rice. These results showed that the region between positions 41-90 in the Mal d 1 is predominantly implicated in higher level accumulation in vegetative tissues as well as seed compared with the Bet v 1. It is notable that GFP:Mald1 directed by the ubiquitin promoter is deposited in huge PBs in aleurone layer rather than starchy endosperm.HighlightSpecific region of PR10 proteins is mainly implicated in their stability in vegetative tissues when expressed in transgenic rice.
Difference in accumulation pattern of the allergens within the same PR10 family in transgenic rice
