Group leader: László Szabados

Email: szabados.laszlo[at]brc.hu

Group website:

 

Group members


Name

Title

Publications

CV

László Szabados

Scientific advisor

publications

CV

Gábor Rigó

Senior Research Associate

publications

CV

Laura Zsigmond

Senior Research Associate

publications

CV

Norbert Andrási

Research Associate

publications

CV

Dóra Faragó

Research Associate

publications

CV

Dániel Benyó

Junior Research Associate

publications

CV

Kamal Kant

Ph.D. Student

 

 

Annamária Király

Laboratory Assistant

 

 

Research


Genetic and molecular dissection of abiotic stress responses.

 

Extreme environmental conditions such as drought and high soil salinity lead to osmotic, ionic and oxidative stresses which hinders plant growth and limits agricultural productivity. Using Arabidopsis thaliana as model organism, we study the regulation of molecular and physiological responses to these stress conditions. Using various genetic techniques, we have identified several regulatory genes from Arabidopsis or its halophytic relatives which encode novel transcription factors, protein kinases or enzymes which control growth, metabolic responses or cellular defences in stress conditions.

 

Regulation and function of proline metabolism in stress conditions.

 

Proline accumulation during drought or salt stress is a well-known phenomenon in plants. Proline is a multifunctional amino acid, which can contribute to stress tolerance in several ways including osmoprotection, regulation of redox balance or function as metabolic signal (Szabados et al., 2010, Lehman et al., 2010). Regulation of proline biosynthesis has been studied in our laboratory and included the identification and characterization of key Arabidopsis genes P5CS1 and P5CS2, which control the glutamate-derived biosynthetic pathway (Strizhov et al., 1987, Ábrahám et al., 2003, Fabro et al., 2004, Székely et al., 2008). We have confirmed the importance of proline accumulation in maintaining cellular homeostasis and redox balance in plants under salt stress (Székely et al., 2008). We showed that proline accumulates during phosphate starvation, and such response is regulated by PHR1 and PHL1 transcription factors which recognize a cis regulatory motif in the first intron of P5CS1 (Aleksza et al., 2017). Stress-dependent proline accumulation is controlled by ABA-dependent and independent signals, and is influenced by light, which upregulates proline biosynthesis and reduces catabolism (Ábrahám et al., 2003, Kovács et al., 2019). We found that light regulation of P5CS1 is controlled by the bZIP factor HY5, which binds to G-box and C-box motifs of P5CS1 promoter region (Kovács et al., 2019).

Ongoing research tries to decipher the role of proline metabolism in coordinating plastid and mitochondrial functions during stress, understand the importance of proline metabolism in stabilizing photosynthesis and reveal the interaction of stress, ABA and light signals which control proline accumulation in plants.

 

Characterization of novel stress regulatory genes.

 

Using novel genetic screens we have identified several regulatory genes which control responses to extreme environmental conditions. The Arabidopsis heat shock factor HSFA4A controls stress tolerance by regulating redox balance of Arabidopsis plants exposed to salinity, oxidative stress or combination of heat and salt stresses. HSFA4A is phosphorylated by MAP kinases MPK3, MPK4 and MPK6, which promotes its multimerisation and activity (Pérez-Salamó et al., 2014, Faragó et al., 2018, Andrási et al., 2019). The zinc finger factor ZFP3 regulates ABA sensitivity of germinating seedlings, interfere with red light signals and plant development (Joseph et al., 2014). The ERFVII-type transcription factor RAP2.12 together with its close relatives RAP2.2 and RAP2.3 was found to regulates responses to low oxygen conditions, osmotic and oxidative stresses and interfere with ABA signals (Papdi et al., 2008, Papdi et al., 2015). The CRK5 kinase controls geotropism through modulating auxing transport. Various PIN transporters are targets of CRK5, which modulates their activity and therefore controls auxin levels of elongating tissues (Rigó et al., 2013, Baba et al., 2018, Baba et al., 2019). Several genes have been identifdied in the halophyte plant Lepidium crassifolium which could enhance tolerance of transgenic Arabidopsis plants to salt, osmotic or oxidative stress conditions (Rigó et al., 2016).

 

Development of genetic and imaging tools

 

Genetics offer powerful tools to identify novel regulatory genes controlling plant development, stress responses or hormonal signals. In collaboration with partners in the Max-Planck Institut für Züchtungsforschung, several genetic technologies were developed or improved in our laboratory to identify novel regulatory genes in Arabidopsis (Papdi et al., 2009, Papdi et al., 2010). A T-DNA tagged Arabidopsis mutant collection was established and insertion sites mapped on Arabidopsis chromosomes (Szabados et al., 2002) or used for genetic screens to identify stress regulatory genes (Zsigmond et al., 2008). Firefly luciferase was employed for gene trapping and could be used to identify mutants of stress-responsive genes (Alvarado et al., 2004). The Conditional cDNA Overexpression System (COS) was developed for random cDNA transfer and conditional overexpression of the inserted cDNA and facile gene identification in transgenic Arabidopsis lines (Papdi et al., 2008, Rigó et al., 2012). The COS system generates conditional dominant phenotypes which is particularly suitable for the identification of stress regulatory genes (Papdi et al., 2008). We have adapted the COS technology for large-scale interspecific gene transfer to identify genes in extremophile plants which can enhance stress tolerance of Arabidopsis and other stress sensitive plants (Rigó et al., 2016).

Plant size, shape and color are important parameters of plants, which have traditionally been measured by destructive and time-consuming methods. We have developed a non-invasive image-based technology, which measures basic morphological and physiological parameters of in vitro cultured plants. Images are analyzed with the new computer application PlantSize, which calculates plant parameters such as rosette size, convex area, convex ratio, chlorophyll and anthocyanin contents of plants (Faragó et al., 2018). Recently we have acquired an automatic plant phenotyping platform (PSI, Czech Republic) which is being used to characterize multiple morphological and physiological parameters of large number of plants in controlled environmental conditions.

 

Research material available

 

List of 1000 T-DNA insertion lines with indexed insertion sites (Szabados et al., 2002)

 

List of 200 LUC-tagged Arabidopsis lines generated by pTluc promoter trap vector (Alvarado et al., 2004).

 

Pooled 40.000 transgenic Arabidopsis lines carrying random cDNA clones of the halophytic plant Lepidium crassifolium (Rigó et al., 2016).

 

PlantSize image analysis softvare (Faragó et al., 2018).

 

Education activity

 

We are actively involved in pre and postgraduate training of Hungarian and Foreign students. 15 students have acquired their Ms.C. degree who made their thesis work under guidance of senior group members. 16 Ph.D. students made their research program in our group, succesfully defended their thesis and got their degree. Our group is active in other educational activities such as training of ITC students (one-year International Training Course, offered by BRC for foreign postgraduate students). Group members are participating in educational programs by giving lectures and courses in the University of Szeged, Hungary and the Babes-Bólyai University of Cluj, Romania.

 

Selected Publications

 

Andrasi N, Rigo G, Zsigmond L, Perez-Salamo I, Papdi C, Klement E, Pettko-Szandtner A, Baba AI, Ayaydin F, Dasari R, Cseplo A, Szabados L (2019) The mitogen-activated protein kinase 4-phosphorylated heat shock factor A4A regulates responses to combined salt and heat stresses. J Exp Bot 70: 4903-4918

 

Baba AI, Andrasi N, Valkai I, Gorcsa T, Koczka L, Darula Z, Medzihradszky KF, Szabados L, Feher A, Rigo G, Cseplo A (2019) AtCRK5 Protein Kinase Exhibits a Regulatory Role in Hypocotyl Hook Development during Skotomorphogenesis. Int J Mol Sci 20: 3432

 

Kovacs H, Aleksza D, Baba AI, Hajdu A, Kiraly AM, Zsigmond L, Toth SZ, Kozma-Bognar L, Szabados L (2019) Light Control of Salt-Induced Proline Accumulation Is Mediated by ELONGATED HYPOCOTYL 5 in Arabidopsis. Front Plant Sci 10: 1584

 

Baba AI, Rigo G, Ayaydin F, Rehman AU, Andrasi N, Zsigmond L, Valkai I, Urbancsok J, Vass I, Pasternak T, Palme K, Szabados L, Cseplo A (2018) Functional Analysis of the Arabidopsis thaliana CDPK-Related Kinase Family: AtCRK1 Regulates Responses to Continuous Light. Int J Mol Sci 19: 1282

Farago D, Sass L, Valkai I, Andrasi N, Szabados L (2018) PlantSize Offers an Affordable, Non-destructive Method to Measure Plant Size and Color in Vitro. Front Plant Sci 9: 219

 

Aleksza D, Horvath GV, Sandor G, Szabados L (2017) Proline Accumulation Is Regulated by Transcription Factors Associated with Phosphate Starvation. Plant Physiol 175: 555-567

 

Rigo G, Valkai I, Farago D, Kiss E, Van Houdt S, Van de Steene N, Hannah MA, Szabados L (2016) Gene mining in halophytes: functional identification of stress tolerance genes in Lepidium crassifolium. Plant Cell Environ 39: 2074-2084

 

Papdi C, Perez-Salamo I, Joseph MP, Giuntoli B, Bogre L, Koncz C, Szabados L (2015) The low oxygen, oxidative and osmotic stress responses synergistically act through the ethylene response factor VII genes RAP2.12, RAP2.2 and RAP2.3. Plant J 82: 772-784

 

Joseph MP, Papdi C, Kozma-Bognar L, Nagy I, Lopez-Carbonell M, Rigo G, Koncz C, Szabados L (2014) The Arabidopsis ZINC FINGER PROTEIN3 Interferes with Abscisic Acid and Light Signaling in Seed Germination and Plant Development. Plant Physiol 165: 1203-1220

 

Perez-Salamo I, Papdi C, Rigo G, Zsigmond L, Vilela B, Lumbreras V, Nagy I, Horvath B, Domoki M, Darula Z, Medzihradszky K, Bogre L, Koncz C, Szabados L (2014) The heat shock factor A4A confers salt tolerance and is regulated by oxidative stress and the mitogen-activated protein kinases MPK3 and MPK6. Plant Physiol 165: 319-334

 

Rigo G, Ayaydin F, Tietz O, Zsigmond L, Kovacs H, Pay A, Salchert K, Darula Z, Medzihradszky KF, Szabados L, Palme K, Koncz C, Cseplo A (2013) Inactivation of Plasma Membrane-Localized CDPK-RELATED KINASE5 Decelerates PIN2 Exocytosis and Root Gravitropic Response in Arabidopsis. Plant Cell 25: 1592-1608

 

Rigo G, Papdi C, Szabados L (2012) Transformation using controlled cDNA overexpression system. Methods Mol Biol 913: 277-290

 

Lehmann S, Funck D, Szabados L, Rentsch D (2010) Proline metabolism and transport in plant development. Amino Acids 39: 949-962

 

Papdi C, Leung J, Joseph MP, Salamo IP, Szabados L (2010) Genetic screens to identify plant stress genes. Methods Mol Biol 639: 121-139

 

Szabados L, Savoure A (2010) Proline: a multifunctional amino acid. Trends Plant Sci 15: 89-97

 

Papdi C, Joseph, M.P., Pérez-Salamó, I., Szabados, L. (2009) Genetic technologies for the identification of Arabidopsis genes controlling environmental stress responses. Funct Plant Biol 36: 696-720

 

Papdi C, Abraham E, Joseph MP, Popescu C, Koncz C, Szabados L (2008) Functional identification of Arabidopsis stress regulatory genes using the controlled cDNA overexpression system. Plant Physiol 147: 528-542

 

Székely G, Ábrahám E, Cséplö A, Rigó G, Zsigmond L, Csiszár J, Ayaydin F, Strizhov N, Jasik J, Schmelzer E, Koncz C, Szabados L (2008) Duplicated P5CS genes of Arabidopsis play distinct roles in stress regulation and developmental control of proline biosynthesis. Plant J 53: 11-28

 

Zsigmond L, Rigo G, Szarka A, Szekely G, Otvos K, Darula Z, Medzihradszky KF, Koncz C, Koncz Z, Szabados L (2008) Arabidopsis PPR40 connects abiotic stress responses to mitochondrial electron transport. Plant Physiol 146: 1721-1737

 

Alvarado MC, Zsigmond LM, Kovacs I, Cseplo A, Koncz C, Szabados LM (2004) Gene trapping with firefly luciferase in Arabidopsis. Tagging of stress-responsive genes. Plant Physiol 134: 18-27

 

Fabro G, Kovacs I, Pavet V, Szabados L, Alvarez ME (2004) Proline accumulation and AtP5CS2 gene activation are induced by plant-pathogen incompatible interactions in Arabidopsis. Mol Plant Microbe Interact 17: 343-350

 

Abraham E, Rigo G, Szekely G, Nagy R, Koncz C, Szabados L (2003) Light-dependent induction of proline biosynthesis by abscisic acid and salt stress is inhibited by brassinosteroid in Arabidopsis. Plant Mol Biol 51: 363-372

 

Szabados L, Kovacs I, Oberschall A, Abraham E, Kerekes I, Zsigmond L, Nagy R, Alvarado M, Krasovskaja I, Gal M, Berente A, Redei GP, Haim AB, Koncz C (2002) Distribution of 1000 sequenced T-DNA tags in the Arabidopsis genome. Plant J 32: 233-242

 

Strizhov N, Abraham E, Okresz L, Blickling S, Zilberstein A, Schell J, Koncz C, Szabados L (1997) Differential expression of two P5CS genes controlling proline accumulation during salt-stress requires ABA and is regulated by ABA1, ABI1 and AXR2 in Arabidopsis. Plant J 12: 557-569

 


 

Ph.D. thesis in the last 5 years

 

Norbert Andrási (2019) The Arabidopsis Heat Shock Factor A4A connects MAPK signaling with stress responses. University of Szeged, Hungary.

 

Abu Imran Baba (2019) Functional analysis of the CDPK-Related Kinase (CRK) family in Arabidopsis thaliana. University of Szeged, Hungary.

 

Dóra Faragó (2019) Characterization of SPQ genes conferring stress tolerance to higher plants. University of Szeged, Hungary.

 

Dávid Aleksza (2018) Phosphate starvation promoter stress-related proline accumulation in Arabidopsis. University of Szeged, Hungary.

 

Ildikó Valkai (2018) Gene mining in halophytes: functional identification of stress tolerance genes in Lepidium crassifolium. University of Szeged, Hungary.

 

Cecilia Ruibal (2015) Evaluación funcional de proteínas de respuesta al estrés abiótico en las plantas modelo Physcomitrella patens y Arabidopsis thaliana. University of Montevideo, Uruguay.

 

 

Patents

Szabados L, Zsigmond L, Koncz Cs: Improvement of stress tolerance in higher plants. Patent Application No.: P0500811, date: 31/08/2005

 

Szabados L, Koncz C, Ábrahám E, Papdi C, Joseph MP (2008) Controlled cDNA Overexpression System in Arabidopsis, Hungarian Patent No.: P0800351, 2008.05.30.