Pleiotropic effects induced by LiHsp83-SAG1 vaccine antigen expression in transplastomic plants

ALBARRACIN, R.; CORIGLIANO, M.; VILAS, J. M.; MAIALE, S. J.; CLEMENTE, M.

Cordoba

Congreso; LII Reunión Anual de SAIB 2016; 2016

Sociedad Argentina de Investigación Bioquímica y Biología Molecular

SAG1 is the main surface antigen of theintracellular parasite Toxoplasma gondiiand is a promising candidate to produce an anti-T. gondii vaccine. Previously, we reported that the fusion of Leishmania infantum Hsp83 protein to SAG1significantly increased SAG1 expression levels in chloroplasts. However,LiHsp83-SAG1 plants showed pleiotropic effects, like growth retardation andchlorotic phenotype. Previously, we showed that the chlorotic phenotypeobserved in the LiHsp83-SAG1 plants could be a consequence of damage in thephotosystem II. Following with the characterization of the pleiotropic effects,we found that LiHsp83-SAG1 40-60 old-days plants showed a significant decreaseof net photosynthesis and a low stomatal conductance compared to the wild typeplants. According to this, we also found that the content of soluble sugars washighly reduced in LiHsp83-SAG1 plants. Interestingly, the quantities of RuBisCowere diminished up to 50 %. These results suggest that the pleiotropic effectsin LiHsp83-SAG1 plants produce not only injuries in the photosynthesisparameters but also in the metabolic processes. Despite of this, this line isable to produce the highest vaccine antigen yields.