UNDERSTANDING THE C4 PHOTOSINTHESIS IN SETARIA VIRIDIS BY A PROTEOMICAL APPROACH.

CALACE, PAULA; MARGARIT. EZEQUIEL; TONETTI, TOMÁS; FIGUEROA, CARLOS; ANDREO, CARLOS S.; GERRARD WHEELER, MARIEL C.; SAIGO, MARIANA

Congreso; LI Reunión anual de SAIB; 2020

Currently, the study of C4 photosynthesis is receiving great attention worldwide given the high demand for efficient systems in the production of biomass. The plants that perform C4 photosynthesis have a higher productivity per crop area related to an optimized use of water and nutrients. This is achieved through a series of anatomical and biochemical features that allow the concentration of CO2 around Rubisco. C4 plants partition the photosynthetic reactions between two cell types, they initially fix the carbon to C4 acids within the mesophyll cells (MC) and then transport these compounds to the bundle sheath cells (BSC), where they are decarboxylated so that the resulting CO2 is incorporated into the Calvin cycle (CC). Depending on the decarboxylating enzyme involved, C4 species can be classified as NADP-malic enzyme (NADP-ME) subtype or NAD-malic enzyme (NAD-ME) subtype. In NADP-ME subtype species, malate is the C4 acid transported from MC to BSC and it is decarboxylated in plastids by NADP-ME. In NAD-ME subtype species, aspartate is transported between cells and further transformed to malate, which is decarboxylated in mitochondria by NAD-ME. Recent findings suggest that C4 photosynthesis can involve more than one decarboxylase. This work describes the activities focused on the comparative analysis of the proteins present in MC and BSC of S. viridis, a C4 model system close relative of several major feed, fuel, and bioenergy grasses.