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

ALBARRACÍN, ROMINA M; CORIGLIANO, MARIANA G; VILAS, JUAN M; MAIALE, SANTIAGO J; CLEMENTE, MARINA

Córdoba

Congreso; 52 Annual Meeting. Argentine Society for Biochemistry and Molecular Biology Research; 2016

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

SAG1 is the main surface antigen of the intracellular parasite Toxoplasma gondii and is a promising candidate to produce an anti-T. gondii vaccine. Previously, we reported that the fusion of Leishmania infantum Hsp83 protein to SAG1 significantly increased SAG1 expression levels in chloroplasts. However, LiHsp83-SAG1 plants showed pleiotropic effects, like growth retardation and chlorotic phenotype. Previously, we showed that the chlorotic phenotype observed in the LiHsp83-SAG1 plants could be a consequence of damage in the photosystem II. Following with the characterization of the pleiotropic effects, we found that LiHsp83-SAG1 40-60 old-days plants showed a significant decrease of net photosynthesis and a low stomatal conductance compared to the wild type plants. According to this, we also found that the content of soluble sugars and starch were highly reduced in LiHsp83-SAG1 plants. Interestingly, the quantities of RuBisCo were diminished up to 50 %. These results suggest that the pleiotropic effects in LiHsp83-SAG1 plants produce not only injuries in the photosynthesis parameters but also in the metabolic processes. Despite of this, this line is able to produce the highest vaccine antigen yields.