A nitrogén-monoxid (NO) hatékony jelátviteli molekula a növények környezeti hatásokra adott gyors válaszreakcióiban. Pályázatunkban a NO szerepét tanulmányoztuk: a gyökér architektúra fejlődésében ozmotikus stressz alatt; a fotoszintetikus elektron transzportlánc működésének szabályozásában és a nehéz fémek (NF) által előidézett stressz-válaszban.
Az ozmotikus stressz- és az auxin-indukálta NO képződés különböző jellegű folyamatok a gyökér fejlődésében: az auxin-indukálta gyökér architektúra fejlődést a NO képződés párhuzamosan kísérte, ozmotikus stressz alatt ezt a folyamatot egy gyors, tranziens NO képződés előzte meg. Ez a tranziens búza esetében is megjelent. Arabidopsis nitrát reduktáz (NR) hiánymutánsok (nia1, nia2) és Atnoa1(korábban Atnos1) mutáns segítségével kimutattuk, hogy a NO forrása az auxin-indukálta gyökér fejlődés során a NR.
A fotoszintetikus elektron transzportláncra vonatkozólag in vivo klorofill fluoreszcencia mérések szerint a NO gátolja a steady-state fotokémiai és nem-fotokémiai kioltási reakciókat és modulálja a reakciócentrumhoz kapcsolódó nem-fotokémiai kioltást.
A különböző NF fajták, mint a Cu2+ és a Cd2+, különböző mértékben idézik elő a NO képződését. Réz ionok esetében két-fázisú kinetika jelent meg; a kezelés utáni az első 6 órában gyors NO tranziens után lassú, fokozatosan növekvő NO szint jelent meg. Ez a tranziens új jelenség, melyet még nem írtak le a növények nehézfém-stressz alatti válaszreakcióiban.
Results in English
Nitrogen oxide (NO) is a potent signalling molecule in fast responses to environmental stimuli in plants. Three types of stress responses were investigated: the role of NO and its source in the development of root architecture under osmotic stress, in the regulation of photosynthetic electron transport, and in heavy metal (HM) stress responses.
We found that osmotic stress- and the auxin-induced NO generations were distinct processes in root development in pea plants since changes in root architecture occurred in parallel with an intensified NO generation while under osmotic stress they were preceded by a transient burst of NO. The early NO burst appeared also in wheat. As for the source of NO, using nitrate reductase (NR)-deficient nia1, nia2 and Atnoa1(former Atnos1) mutants of Arabidopsis, we showed out that NR is responsible for exogenous auxin-induced NO synthesis.
In the regulation of photosynthetic electron transport as studied by in vivo chlorophyll fluorescence detection, NO inhibited the steady-state photochemical and non-photochemical quenching processes and appeaed to modulate reaction-center-associated non-photochemical quenching.
For the NO production the most effective metals were Cu2+ and Cd2+; in case of Cu2+, a fast NO burst appeared in the first six hours followed by a slower, gradual increase. The fast appearance of NO in the presence of cupric ions suggests a novel reaction hitherto not studied in plants under heavy metal stress.
Wodala B., Deák Zs., Vass I., Erdei L., Horváth F.: Nitric oxide modifies photosynthetic electron transport in pea leaves., Acta Biol. Szeged. 49(1-2): 7-8., 2005
Bartha B., Erdei L.: Effect of cadmium, copper and zinc on root growth and macroelement composition in Pisum sativum L. and Brassica juncea L. Czern., Abstracts, p. 48. COST ACTION 859 WG1 Root to shoot Translocation of Pollutants and Nutrients. 22-44 June 2006, Santiago de Compostela, Spain, 2006
Kolbert Zs., Erdei L.: Relationship between nitric oxide (NO) and auxin during root processing of Pisum sativum L., Abstracts, p. 120. III. EPSO Conference, 28 May - 1 June 2006, Visegrád, Hungary, 2006
Kolbert Zs., Erdei L.: Time- and concentration dependence of exogenous auxin-effect on NO generation and root development properties in pea., Abstarcts, p. 94. XV. FESPB Congress, 17-21 July 2006, Lyon, France, 2006
Wodala B., Deák Zs., Vass I., Erdei L., Horváth F.: Nitric oxide hinders photosynthetic electron transport in pea leaves., Abstarcts, p. 128. XV. FESPB Congress, 17-21 July 2006, Lyon, France, 2006
Paslaru O.M.: Researches concerning potato (Solanum tuberosum L.) viral infection evolution and "in vitro" methods used for its reduction., "Banat" University of Agricultural Sciences. PhD Thesis. Related Chapters 5.3.5.4. pp.243-273. Timisoara, Romania, 2006
Kolbert Zs., Bartha B., Erdei L.: Osmotic stress- and indole-3-butyric acid-induced NO generations are partially distinct processes in root growth and development in Pisum sativum L., Physiol. Plant. 133: 406-416. doi: 10.1111/j.1399-3054.2008.01.056.x, 2008
Kolbert Zs., Bartha B., Erdei L.: Exogenous auxin-induced NO synthesis is nitrate reductase –associated in Arabidopsis thaliana root primordia., J. Plant Phys. J. Plant Phys. 165: 967-975. On-line: doi: 10.1016/j.jplph.2007.07.019., 2008
Erdei L., Kolbert Zs.: Nitric oxide as a potent signalling molecule in plants, Acta Biol. Szeged. 52:1-5., 2008
Wodala B., Deák Zs., Vass I., Erdei L., Altorjay I., Horváth F.: In vivo target sites of NO in photosynthetic electron transport a studied by chlorophyll fluorescence in pea leaves., Plant Physiol. 146: 1920-1927. doi: 10.1104/pp.107.110205., 2008
Kolbert Zs., Erdei L.: Involvement of nitrate reductase in auxin-induced NO synthesis., Plant Signaling and Behavior 3(11): 972-973., 2008
Kolbert Zs., Sahin N., Erdei L: Early nitric oxide (NO) responses to osmotic stress in pea, Arabidopsis and wheat., Acta Biol. Szeged. 52:63-65., 2008
Erdei L., Dergez Á., Bartha B., Vashegyi Á., Pataki Sz., Mécs I.: Root development and growth of Salix viminalis cuttings in the presence of chromium, lead and zinc as affected by bacterial consortia isolated from the rhizosphere., COST 859 Workshop on Fate of pollutants in the plant/rhizosphere syste. Vilnius, 30 May- 1 June, 2007. Abstract Book, pp. 145-146., 2007
Erdei L., Bartha B., Vashegyi Á., Kolbert Zs.: Interaction between heavy metals and macroelements: review and a case study., Abstracts, p. 41. COST ACTION 859 WG1 Root to shoot Translocation of Pollutants and Nutrients. 22-44 June 2006, Santiago de Compostela, Spain, 2006
Bartha B., Kolbert Zs., Erdei L.: Nitric oxide production induced by heavy metals in Brassica juncea L. Czern. and Pisum sativum, Acta Biol. Szeged. 49(1-2): 9-12., 2005
Kolbert Zs., Bartha B., Erdei L.: .: Generation of nitric oxide in roots of Pisum sativum, Triticum aestivum and Pertoselinum crispum plants under osmotic and drought stress, Acta Biol. Szeged. 49(1-2): 13-16., 2005
