@article{CastellanosFriedrichPetrovicetal.2020, author = {Castellanos, Reynel Urrea and Friedrich, Thomas and Petrovic, Nevena and Altmann, Simone and Brzezinka, Krzysztof and Gorka, Michal and Graf, Alexander and B{\"a}urle, Isabel}, title = {FORGETTER2 protein phosphatase and phospholipase D modulate heat stress memory in Arabidopsis}, series = {The plant journal}, volume = {104}, journal = {The plant journal}, number = {1}, publisher = {Wiley}, address = {Hoboken}, issn = {0960-7412}, doi = {10.1111/tpj.14927}, pages = {7 -- 17}, year = {2020}, abstract = {Plants can mitigate environmental stress conditions through acclimation. In the case of fluctuating stress conditions such as high temperatures, maintaining a stress memory enables a more efficient response upon recurring stress. In a genetic screen forArabidopsis thalianamutants impaired in the memory of heat stress (HS) we have isolated theFORGETTER2(FGT2) gene, which encodes a type 2C protein phosphatase (PP2C) of the D-clade.Fgt2mutants acquire thermotolerance normally; however, they are defective in the memory of HS. FGT2 interacts with phospholipase D alpha 2 (PLD alpha 2), which is involved in the metabolism of membrane phospholipids and is also required for HS memory. In summary, we have uncovered a previously unknown component of HS memory and identified the FGT2 protein phosphatase and PLD alpha 2 as crucial players, suggesting that phosphatidic acid-dependent signaling or membrane composition dynamics underlie HS memory.}, language = {en} } @article{ThirumalaikumarGorkaSchulzetal.2020, author = {Thirumalaikumar, Venkatesh P. and Gorka, Michal and Schulz, Karina and Masclaux-Daubresse, Celine and Sampathkumar, Arun and Skirycz, Aleksandra and Vierstra, Richard D. and Balazadeh, Salma}, title = {Selective autophagy regulates heat stress memory in Arabidopsis by NBR1-mediated targeting of HSP90.1 and ROF1}, series = {Autophagy}, volume = {17}, journal = {Autophagy}, number = {9}, publisher = {Taylor \& Francis}, address = {Abingdon}, issn = {1554-8635}, doi = {10.1080/15548627.2020.1820778}, pages = {2184 -- 2199}, year = {2020}, abstract = {In nature, plants are constantly exposed to many transient, but recurring, stresses. Thus, to complete their life cycles, plants require a dynamic balance between capacities to recover following cessation of stress and maintenance of stress memory. Recently, we uncovered a new functional role for macroautophagy/autophagy in regulating recovery from heat stress (HS) and resetting cellular memory of HS inArabidopsis thaliana. Here, we demonstrated that NBR1 (next to BRCA1 gene 1) plays a crucial role as a receptor for selective autophagy during recovery from HS. Immunoblot analysis and confocal microscopy revealed that levels of the NBR1 protein, NBR1-labeled puncta, and NBR1 activity are all higher during the HS recovery phase than before. Co-immunoprecipitation analysis of proteins interacting with NBR1 and comparative proteomic analysis of annbr1-null mutant and wild-type plants identified 58 proteins as potential novel targets of NBR1. Cellular, biochemical and functional genetic studies confirmed that NBR1 interacts with HSP90.1 (heat shock protein 90.1) and ROF1 (rotamase FKBP 1), a member of the FKBP family, and mediates their degradation by autophagy, which represses the response to HS by attenuating the expression ofHSPgenes regulated by the HSFA2 transcription factor. Accordingly, loss-of-function mutation ofNBR1resulted in a stronger HS memory phenotype. Together, our results provide new insights into the mechanistic principles by which autophagy regulates plant response to recurrent HS.}, language = {en} }