biostudies-literatureJuhasz GPNew National Excellence Program of the Ministry for Innovation and Technology from the source of the National Research, Development and Innovation Fund, HungaryNational Research, Development and Innovation OfficeNational Research, Development and Innovation Office Fund of Hungary586https://www.ebi.ac.uk/biostudies/studies/S-EPMC10051171biostudies-literatureUnknown11(3)To evaluate the effects of the cyanobacterial toxin microcystin-LR (MCY-LR, a protein phosphatase inhibitor) and diquat (DQ, an oxidative stress inducer) on the organization of tonoplast, the effect of MCY-LR on plastid stromule formation and on mitochondria was investigated in wild-type Arabidopsis. Tonoplast was also studied in PP2A catalytic (<i>c3c4</i>) and regulatory subunit mutants (<i>fass-5</i> and <i>fass-15</i>). These novel studies were performed by CLSM microscopy. MCY-LR is produced during cyanobacterial blooms. The organization of tonoplast of PP2A mutants of Arabidopsis is much more sensitive to MCY-LR and DQ treatments than that of wild type. In <i>c3c4</i>, <i>fass-5</i> and <i>fass-15</i>, control and treated plants showed increased vacuole fragmentation that was the strongest when the <i>fass-5</i> mutant was treated with MCY-LR. It is assumed that both PP2A/C and B" subunits play an important role in normal formation and function of the tonoplast. In wild-type plants, MCY-LR affects mitochondria. Under the influence of MCY-LR, small, round-shaped mitochondria appeared, while long/fused mitochondria were typical in control plants. Presumably, MCY-LR either inhibits the fusion of mitochondria or induces fission. Consequently, PP2A also plays an important role in the fusion of mitochondria. MCY-LR also increased the frequency of stromules appearing on chloroplasts after 1 h treatments. Along the stromules, signals can be transported between plastids and endoplasmic reticulum. It is probable that they promote a faster response to stress.MicroorganismsMicrocystin-LR, a Cyanobacterial Toxin, Induces Changes in the Organization of Membrane Compartments in Arabidopsis.PMC10051171TKP2021-EGA-20K120638, K132685K132685ÚNKP-22-4-I-DE-11K120638Freytag CVasas GJuhasz GPKeki SMathe CDekany-Adamoczky AGarda TfalseMicrocystin-LR, a Cyanobacterial Toxin, Induces Changes in the Organization of Membrane Compartments in Arabidopsis.To evaluate the effects of the cyanobacterial toxin microcystin-LR (MCY-LR, a protein phosphatase inhibitor) and diquat (DQ, an oxidative stress inducer) on the organization of tonoplast, the effect of MCY-LR on plastid stromule formation and on mitochondria was investigated in wild-type Arabidopsis. Tonoplast was also studied in PP2A catalytic (<i>c3c4</i>) and regulatory subunit mutants (<i>fass-5</i> and <i>fass-15</i>). These novel studies were performed by CLSM microscopy. MCY-LR is produced during cyanobacterial blooms. The organization of tonoplast of PP2A mutants of Arabidopsis is much more sensitive to MCY-LR and DQ treatments than that of wild type. In <i>c3c4</i>, <i>fass-5</i> and <i>fass-15</i>, control and treated plants showed increased vacuole fragmentation that was the strongest when the <i>fass-5</i> mutant was treated with MCY-LR. It is assumed that both PP2A/C and B" subunits play an important role in normal formation and function of the tonoplast. In wild-type plants, MCY-LR affects mitochondria. Under the influence of MCY-LR, small, round-shaped mitochondria appeared, while long/fused mitochondria were typical in control plants. Presumably, MCY-LR either inhibits the fusion of mitochondria or induces fission. Consequently, PP2A also plays an important role in the fusion of mitochondria. MCY-LR also increased the frequency of stromules appearing on chloroplasts after 1 h treatments. Along the stromules, signals can be transported between plastids and endoplasmic reticulum. It is probable that they promote a faster response to stress.2023-01-01T00:00:00Z2023 Feb2025-08-30T03:08:45.096Z2025-02-19T01:13:07.849ZS-EPMC100511713698516010.3390/microorganisms11030586