Freedom for Tibet
- Identification of tomato 7B-1 gene involved in cross-talk of blue light and stress signaling
OPVK: Podpora vytváření excelentních výzkumných týmů a intersektorální mobility na Univerzitě Olomouci Palackého v Olomouci (POST-UP) (7/2012-6/2015)
Supported by European Social Fond in the Czech Republic and by state budget of the Czech Republic project no. CZ.1.07/2.3.00/30.0004
- Mechanisms of light-regulated tolerance to osmotic stress in tomato Solanum lycopersicum L.
KONTAKT CS-USA bilateral project (4/2010-12/2012)
Principal investigator: Martin Fellner - Palacky University in Olomouc; supported by Ministry of Education of the CR; project no. ME10020
In some systems blue light (BL) is involved in cell osmoregulation. For example, stomatal opening stimulated by BL engages BL-induced activation of proton pumps,
potassium channels, and blocking of anion channels in guard cells. However, direct contribution of BL in the ability of plants to tolerate osmotic stress was not
reported. Results of our previous experiments strongly suggest that especially in BL, functional anion channels are involved in ability of Arabidopsis seeds to
tolerate osmotic stress. Tomato Lycopersicum esculentum L. is one of the most important crop species. Previously, we reported that recessive single gene mutant
7B-1 in tomato showing reduced de-etiolation in BL is resistant to osmotic and salt stress in seed germination only under BL, and that BL amplifies the inhibitory
effect of osmotic stress on tomato seed germination. Our other results of physiological and electrophysiological experiments indicate that functional anion and water
channels are required for germination of tomato seeds, and that their activity could be reduced regulated BL. Our results also indicate that blue light-regulated
growth of tomato seedlings involves interaction of anion channel with auxin signaling pathway. However, molecular mechanisms of these processes are still unknown.
The submitted project belongs to basic research projects in the area of plant physiology, genetics and molecular biology. The main objective of our project is to
determine mechanisms whereby BL alters plant ability to withstand osmotic stress, and to elucidate the role of 7B-1 gene in these processes. Using genetic approach
consisting in analysis of 7B-1, and other photomorphogenic mutants we will investigate mechanisms of plant tolerance to osmotic stress.
Based on our previous results, special interested is focused on elucidation of the role of BL, which play important role in plant growth and development.
Pharmacological approach in combination with electrophysiological and molecular methods will be applied to investigate how blue light regulates activity of anion
and water channels during osmotic stress. Also, we intend to study mechanisms of interaction between blue light, stress and auxin signaling in plant growth
and development. The fact that mutant 7B-1 in tomato shows unique BL-specific tolerance to abiotic stresses makes the 7B-1 mutant very interesting, with respect
to the possibility to identify a new common element involved in cross-talk between BL, stress, and auxin signaling pathways.
- Study of the BL-less sensitive 7B-1 mutant: gaining new insights on the BL-induced de-etiolation in tomato (Solanum lycopersicum L.)
GAČR project (1/2010-12/2012)
Principal investigator: Véronique Bergougnoux – Palacky University in Olomouc; supported by Czech Science Foundation; project no. P501/10/0785
Light, particularly blue light (BL) is an important environmental factor that controls plant growth and development. De-etiolation is one of the BL-regulated
physiological processes, mediated by cryptochromes (CRY) and phototropins (PHOT), the two BL-photoreceptors. Whereas studies on this topic are numerous on the plant
model Arabidopsis, few researches are developed in important crop species such as tomato. The spontaneous 7B-1 mutant in tomato, less sensitive to BL, has been
characterized as affected either in BL perception or signaling pathway. Previous studies on the 7B-1 mutant suggested that CRYs are not likely involved in this
mutation. Through physiological and molecular analysis, we will investigate the role of PHOT in the 7B-1 mutant, particularly in BL-mediated de-etiolation.
In parallel, studies will conducted on some already known elements of the PHOT-mediated signaling pathway. A DD-AFLP experiment will be performed in order to
identify down- or up-regulated genes during BL-induced de-etiolation.
- Role of boron and light signaling pathways in the activity of boron cell transporters during plant growth
GAČR project (7/2009-6/2012)
Principal investigator: Martin Fellner - Palacky University in Olomouc; supported by Czech Science Foundation; project no. 521/09/0445
Boron (B) is an essential element for vascular plants and its deficiency affects crop quality. A plasma membrane boron transporter BOR1 and a major plasma membrane boric acid channel NIP5;1 have been identified in
Arabidopsis. Both mediate transport of B under its limitation. We found that in
Arabidopsis, B at optimum concentration stimulates hypocotyl elongation, and in mutant rsw1-10 this optimum is strongly shifted to high concentrations toxic for control plants. The stimulation was associated with strong reduction of
BOR1 expression in mutant hypocotyl. Our results suggest that the stimulation is mediated by photoreceptor CRY1. In this project we will investigate if the B transporters are involved in hypocotyl elongation and how B and light regulate their functions. By molecular genetic approach we will study on the RNA level what elements of light signaling pathways are involved in boron-induced hypocotyl growth. Results will contribute to understanding of the B role in plant photomorphogenesis.
- Variability of components and interactions in plant pathosystem and impact of environmental factors on their expression
Research Plan (Záměr) (1/2005-12/2011)
Principal investigator: Aleš Lebeda - Faculty of Science, Palacky University in Olomouc); supported by Ministry of Education of the CR; project no. MSM 6198959215
Plants resist pathogen infection by inducing a defense response that is targeted specifically to combat invasion by the pathogen. A set of evidence has demonstrated that salicylic acid (SA) and jasmonic acid (JA) are important signal molecules in plant defense against pathogens. The fact that tomato mutant 7B-1 is resistant to abiotic stress specifically under blue light raised the question whether or not the mutant can tolerate biotic stress as well, and whether the resistance is dependent on light quality. The project objective is to determine whether the mutation in 7B-1 gene can result in altered responses to distinct microbial pathogens. Consequently, other project aims are to determine level of endogenous SA and JA in the 7B-1 plants, and to investigate expression of JA-and SA-inducible genes encoding pathogenesis-related proteins in the mutant.
- Vacuolar tranport equipment for growth regulation in plants
Marie Curie Research Training Networks (RTN) (1/2007-12/2010)
Coordinator: Katrin Czempinski - Universität Potsdam, Golm, Germany); supported by EU; contract no. MRTN-CT-2006-035833
The VaTEP research training network specifically targets transport proteins located in the vacuolar membrane (i.e., the tonoplast) to unravel their specific functions with respect to plant growth processes. In the corn leaf, at the junction of the blade and the sheath, a specialized structure is formed, called the auricle, which is responsible, at least partially, for the development of a leaf angle. We reported earlier that growth of auricle is proportionally associated with the size of leaf declination, which is to say the smaller leaf declination occurred for leaves with shorter auricle dimension at the blade margin. On the basis of our previous results we hypothesized that the development of upright leaves in the modern corn hybrids is due to their reduced responsiveness to auxin and altered expression of auxin-binding proteins (ABPs). There is a close relationship between the mechanism of auxin action and signaling of Ca2+. However, the interaction between them is still unresolved. The basic objective of our project is to find out the mechanism(s) by which auxin (via ABPs or not) and calcium may regulate auricle growth and thus leaf declination in corn.
- Interaction between auxin and light signaling in seedling growth and development of leaf angle in corn
Project in frame of the scientific collaboration between the Czech Republic and USA (1/2005-12/2008)
Principal investigator: Martin Fellner - Institute of Experimental Botany, AS CR, Olomouc; supported by Ministry of Education of the CR; project no. 1P05ME792
Auxin regulates two essential events in cell development: division and elongation. The auxin-binding proteins, ABPs appear to function as a putative receptor in various signal transduction pathways. Several members of the ABP gene family have been identified, such as ABP4, ABP5, or ABP57, while their role in plant growth and development remains to be determined. Our previous data indicate that auxin in interaction with light contributes to regulation of leaf angle development in corn, and analysis of abp mutants in corn suggests that ABP1 and/or ABP4 may be involved and interact, with each other, in development of leaf angle. The long-term objective of this project is to contribute to understanding the role of auxin and light in growth and development of leaves. We specifically investigate the role of the ABPs in auxin- and light-regulated development of leaf angle in corn.
- Study of the responses of Arabidopsis thaliana to elevated boron concentrations
Junior research grant project (1/2005-12/2007)
Principal investigator: Tomáš Kocábek - Institute of Molecular Biology of Plants, AS CR, České Budějovice; supported by GA AS CR; project no. KJB600510503
Boron is an essential micronutrient required for plant growth and development and it affects not only yield but also quality of several crops. The project is focused on investigation of the responses of Arabidopsis thaliana plants to elevated boron concentrations. Using cell-wall and photomorphogenic mutant lines, we will study the mechanisms of boron-altered hypocotyl growth and its regulation by various elements in light signalling pathways. The results should contribute to the better understanding of molecular basis of some roles of boron in the plant development and possible mechanisms of plant tolerance to boron.
- Analysis of putative auxin receptors in mammalian cells
Foundation grant (1/2007-12/2007)
Principal investigator: Jan Humplík - Faculty of Science, Palacky University in Olomouc); supported by Tomáš Baťa Foundation and Palacky University in Olomouc
It was shown that plant hormone auxin IAA is present in mammalian tissues, such as blood, liver, brain, lung etc. In mammalian lymphocytes, IAA induces programmed cell death and necrosis, but the mechanisms are not known. The fact that auxin IAA is present in mammals suggests logically the existence of auxin receptors in the mammalian cell. The basic objective of this project is to find homologues to Arabidopsis and corn auxin receptors, TIR and ABP1 in mammalian genomes using in silico approach and PCR-based methods.
- Study of activity of anion channels in tomato mutants affected in responsiveness to blue light
Project in frame of the scientific collaboration between AS CR and CNRS, France (1/2005 - 12/2006)
Principal investigator: Martin Fellner - Institute of Experimental Botany, AS CR, Olomouc, Hélene Barbier-Brygoo, CNRS, Gif-sur-Yvette; supported by ASCR and CNRS; project no. 18102 ÚEB - PRINCIPAL INVESTIGATOR
The importance of blue light in plant photomorphogenesis was recognized earlier. It is known that anion channels are involved in blue light-controlled hypocotyl growth. A genetic and molecular approach allowed to identify cryptochromes in tomato, which show high similarity to Arabidopsis cryptochromes, and that they control hypocotyl elongation in response to blue light. We previously identified and characterized a new mutant 7B-1 in tomato, which shows seed-specific resistance to salt and osmotic stress only in blue light. The long-term objective of this project is to contribute to the understanding of the role of light signaling pathways in plant growth and development. The basic question of the project is: Do 7B-1, cry1-1, and cry1-2 differ from corresponding WTs in activity of anion channels and their responsiveness to anion channel blockers? In the future, the availability of this mutant offers a great opportunity to identify the structure and function of 7B-1 gene.
- A role of blue light in plant tolerance to osmotic stress
Internal starting project of Academy of Sciences of the Czech Republic (9/2003-8/2004)
Principal investigator: Martin Fellner - Institute of Experimental Botany, AS CR, Olomouc); supported by AS CR; project no. I036
In field conditions, plants are often exposed to various abiotic stresses such as high salinity. One possible mechanism by which plants resist abiotic stress is via the accumulation of abscisic acid (ABA). The pivotal role of ABA in plant responses is shown in ABA-deficient mutants, which are impaired in tolerance to abiotic stresses. In plant tissues, the levels of several hormones, including ABA, are altered by light conditions as evident in numbers of photomorphogenic mutants. The level of endogenous ABA is also regulated by the blue light. It has also been suggested that light may affect the sensitivity of tissues to plant hormones. However, to the best of our knowledge, no information is available on whether the blue light affects tissue sensitivity to osmotic stress and ABA. The long-term objective of this project is to contribute to understanding of the role of light and its interaction with hormone signaling pathways in plant growth and development. The availability of a new mutant 7B-1 resistant to abiotic stress specifically under blue light thus provides a great opportunity to identify new insights into the role of blue light in plant ability to withstand abiotic stress. The project deals with two basic questions: 1) Does the mutation in 7B-1 affect a step involved in blue light signaling? b) Does blue light regulate plant sensitivity to osmotic stress and ABA?