UNREVEALING THE ROLE OF MITOCHONDRIAL SMALL HEAT SHOCK PROTEIN IN ARABIDOPSIS THALIANA

FEUSSNER I; ESCOBAR MR; VALLE EM

Córdoba

Congreso; XXXII Reunión Argentina XVI Congreso Latinoamericano de Fisiología Vegetal; 2018

Sociedad Argentina de Fisiología Vegetal

Small heat shock proteins (sHSPs) play an important role in stress conditions like high temperatures, although sHSPs also accumulate in response to different stresses. They bind to other proteins, stabilize the structure and facilitate the proper folding of denatured proteins. All sHSPs proteins share a conserved alpha-crystallin domain and include members targeted to the nuclear-cytosolic compartment, chloroplasts, mitochondria, endoplasmic reticulum and peroxisomes. In Arabidopsis thaliana two mitochondrial sHSPs (M-sHSP) has been reported, sHSP23.5 and sHSP23.6, and we found another putative M-sHSP, sHSP26.5. Single, double and triple mutants of M-sHSP genes were constructed and analyzed. The phenotype of single and double (23.5-23.6) mutants were similar under normal and heat conditions, but the triple mutant was different to the wild type (WT) plants. The triple mutant plants are smaller, with chlorotic leaves and shorter roots, showed higher electrolyte leakage and lower amounts of chlorophyll than the WT plants. Differences in the metabolome of triple mutant seedlings and WT were also observed, particularly in the primary metabolism of sugars and amino acids. The severe phenotype given by knocking down the three M-sHSP genes suggests the important role that these proteins play in the normal Arabidopsis development, not only in the stress response.