TY - JOUR A1 - Zwickel, Theresa A1 - Kahl, Sandra M. A1 - Klaffke, Horst A1 - Rychlik, Michael A1 - Müller, Marina E. H. T1 - Spotlight on the Underdogs-An Analysis of Underrepresented Alternaria Mycotoxins Formed Depending on Varying Substrate, Time and Temperature Conditions JF - Toxins N2 - Alternaria (A.) is a genus of widespread fungi capable of producing numerous, possibly health-endangering Alternaria toxins (ATs), which are usually not the focus of attention. The formation of ATs depends on the species and complex interactions of various environmental factors and is not fully understood. In this study the influence of temperature (7 degrees C, 25 degrees C), substrate (rice, wheat kernels) and incubation time (4, 7, and 14 days) on the production of thirteen ATs and three sulfoconjugated ATs by three different Alternaria isolates from the species groups A. tenuissima and A. infectoria was determined. High-performance liquid chromatography coupled with tandem mass spectrometry was used for quantification. Under nearly all conditions, tenuazonic acid was the most extensively produced toxin. At 25 degrees C and with increasing incubation time all toxins were formed in high amounts by the two A. tenuissima strains on both substrates with comparable mycotoxin profiles. However, for some of the toxins, stagnation or a decrease in production was observed from day 7 to 14. As opposed to the A. tenuissima strains, the A. infectoria strain only produced low amounts of ATs, but high concentrations of stemphyltoxin III. The results provide an essential insight into the quantitative in vitro AT formation under different environmental conditions, potentially transferable to different field and storage conditions. KW - Alternaria infectoria KW - A. tenuissima KW - mycotoxin profile KW - wheat KW - rice KW - Alternaria toxin sulfates KW - modified Alternaria toxins KW - altertoxins KW - altenuic acid KW - HPLC-MS/MS Y1 - 2016 U6 - https://doi.org/10.3390/toxins8110344 SN - 2072-6651 VL - 8 SP - 570 EP - 583 PB - MDPI CY - Basel ER - TY - GEN A1 - Zwickel, Theresa A1 - Kahl, Sandra M. A1 - Klaffke, Horst A1 - Rychlik, Michael A1 - Müller, Marina E. H. T1 - Spotlight on the underdogs BT - an analysis of underrepresented alternaria mycotoxins formed depending on varying substrate, time and temperature conditions N2 - Alternaria (A.) is a genus of widespread fungi capable of producing numerous, possibly health-endangering Alternaria toxins (ATs), which are usually not the focus of attention. The formation of ATs depends on the species and complex interactions of various environmental factors and is not fully understood. In this study the influence of temperature (7 °C, 25 °C), substrate (rice, wheat kernels) and incubation time (4, 7, and 14 days) on the production of thirteen ATs and three sulfoconjugated ATs by three different Alternaria isolates from the species groups A. tenuissima and A. infectoria was determined. High-performance liquid chromatography coupled with tandem mass spectrometry was used for quantification. Under nearly all conditions, tenuazonic acid was the most extensively produced toxin. At 25 °C and with increasing incubation time all toxins were formed in high amounts by the two A. tenuissima strains on both substrates with comparable mycotoxin profiles. However, for some of the toxins, stagnation or a decrease in production was observed from day 7 to 14. As opposed to the A. tenuissima strains, the A. infectoria strain only produced low amounts of ATs, but high concentrations of stemphyltoxin III. The results provide an essential insight into the quantitative in vitro AT formation under different environmental conditions, potentially transferable to different field and storage conditions T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 353 KW - Alternaria infectoria KW - A. tenuissima KW - mycotoxin profile KW - wheat KW - rice KW - Alternaria toxin sulfates KW - modified Alternaria toxins KW - altertoxins KW - altenuic acid KW - HPLC-MS/MS Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-400438 ER - TY - GEN A1 - Sharma, Niharika A1 - Dang, Trang Minh A1 - Singh, Namrata A1 - Ruzicic, Slobodan A1 - Müller-Röber, Bernd A1 - Baumann, Ute A1 - Heuer, Sigrid T1 - Allelic variants of OsSUB1A cause differential expression of transcription factor genes in response to submergence in rice T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Background: Flooding during seasonal monsoons affects millions of hectares of rice-cultivated areas across Asia. Submerged rice plants die within a week due to lack of oxygen, light and excessive elongation growth to escape the water. Submergence tolerance was first reported in an aus-type rice landrace, FR13A, and the ethylene-responsive transcription factor (TF) gene SUB1A-1 was identified as the major tolerance gene. Intolerant rice varieties generally lack the SUB1A gene but some intermediate tolerant varieties, such as IR64, carry the allelic variant SUB1A-2. Differential effects of the two alleles have so far not been addressed. As a first step, we have therefore quantified and compared the expression of nearly 2500 rice TF genes between IR64 and its derived tolerant near isogenic line IR64-Sub1, which carries the SUB1A-1 allele. Gene expression was studied in internodes, where the main difference in expression between the two alleles was previously shown. Results: Nineteen and twenty-six TF genes were identified that responded to submergence in IR64 and IR64-Sub1, respectively. Only one gene was found to be submergence-responsive in both, suggesting different regulatory pathways under submergence in the two genotypes. These differentially expressed genes (DEGs) mainly included MYB, NAC, TIFY and Zn-finger TFs, and most genes were downregulated upon submergence. In IR64, but not in IR64-Sub1, SUB1B and SUB1C, which are also present in the Sub1 locus, were identified as submergence responsive. Four TFs were not submergence responsive but exhibited constitutive, genotype-specific differential expression. Most of the identified submergence responsive DEGs are associated with regulatory hormonal pathways, i.e. gibberellins (GA), abscisic acid (ABA), and jasmonic acid (JA), apart from ethylene. An in-silico promoter analysis of the two genotypes revealed the presence of allele-specific single nucleotide polymorphisms, giving rise to ABRE, DRE/CRT, CARE and Site II cis-elements, which can partly explain the observed differential TF gene expression. Conclusion: This study identified new gene targets with the potential to further enhance submergence tolerance in rice and provides insights into novel aspects of SUB1A-mediated tolerance. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 619 KW - submergence tolerance KW - SUB1A KW - rice KW - transcription factors Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-423508 SN - 1866-8372 IS - 619 ER - TY - JOUR A1 - Schmidt, Romy A1 - Schippers, Jos H. M. A1 - Mieulet, Delphine A1 - Watanabe, Mutsumi A1 - Hoefgen, Rainer A1 - Guiderdoni, Emmanuel A1 - Müller-Röber, Bernd T1 - Salt-Rresponsive ERF1 is a negative regulator of grain filling and gibberellin-mediated seedling establishment in rice JF - Molecular plant N2 - Grain quality is an important agricultural trait that is mainly determined by grain size and composition. Here, we characterize the role of the rice transcription factor (TF) SALT-RESPONSIVE ERF1 (SERF1) during grain development. Through genome-wide expression profiling and chromatin immunoprecipitation, we found that SERF1 directly regulates RICE PROLAMIN-BOX BINDING FACTOR (RPBF), a TF that functions as a positive regulator of grain filling. Loss of SERF1 enhances RPBF expression resulting in larger grains with increased starch content, while SERF1 overexpression represses RPBF resulting in smaller grains. Consistently, during grain filling, starch biosynthesis genes such as GRANULE-BOUND STARCH SYNTHASEI (GBSSI), STARCH SYNTHASEI (SSI), SSIIIa, and ADP-GLUCOSE PYROPHOSPHORYLASE LARGE SUBUNIT2 (AGPL2) are up-regulated in SERF1 knockout grains. Moreover, SERF1 is a direct upstream regulator of GBSSI. In addition, SERF1 negatively regulates germination by controlling RPBF expression, which mediates the gibberellic acid (GA)-induced expression of RICE AMYLASE1A (RAmy1A). Loss of SERF1 results in more rapid seedling establishment, while SERF1 overexpression has the opposite effect. Our study reveals that SERF1 represents a negative regulator of grain filling and seedling establishment by timing the expression of RPBF. KW - RPBF KW - rice KW - grain filling KW - germination KW - SERF1 KW - gibberellic acid Y1 - 2014 U6 - https://doi.org/10.1093/mp/sst131 SN - 1674-2052 SN - 1752-9867 VL - 7 IS - 2 SP - 404 EP - 421 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Andrade, Luis A1 - Lu, Yunlong A1 - Cordeiro, Andre A1 - Costa, João M. F. A1 - Wigge, Philip Anthony A1 - Saibo, Nelson J. M. A1 - Jaeger, Katja E. T1 - The evening complex integrates photoperiod signals to control flowering in rice JF - Proceedings of the National Academy of Sciences of the United States of America : PNAS N2 - Plants use photoperiodism to activate flowering in response to a particular daylength. In rice, flowering is accelerated in short-day conditions, and even a brief exposure to light during the dark period (night-break) is sufficient to delay flowering. Although many of the genes involved in controlling flowering in rice have been uncovered, how the long- and short-day flowering pathways are integrated, and the mechanism of photoperiod perception is not understood. While many of the signaling components controlling photoperiod-activated flowering are conserved between Arabidopsis and rice, flowering in these two systems is activated by opposite photoperiods. Here we establish that photoperiodism in rice is controlled by the evening complex (EC). We show that mutants in the EC genes LUX ARRYTHMO (LUX) and EARLY FLOWERING3 (ELF3) paralogs abolish rice flowering. We also show that the EC directly binds and suppresses the expression of flowering repressors, including PRR37 and Ghd7. We further demonstrate that light acts via phyB to cause a rapid and sustained posttranslational modification of ELF3-1. Our results suggest a mechanism by which the EC is able to control both long- and short-day flowering pathways. KW - rice KW - flowering KW - ELF3 KW - LUX KW - Evening Complex Y1 - 2022 U6 - https://doi.org/10.1073/pnas.2122582119 SN - 0027-8424 SN - 1091-6490 VL - 119 IS - 26 PB - National Acad. of Sciences CY - Washington ER -