Structural and biochemical response of chloroplasts in tolerant and sensitive barley genotypes to drought stress.
The aim of this research was to characterize the changes of structural organization of chloroplasts of sensitive (Maresi) and tolerant (Cam/B1) barley genotypes upon soil drought (10days), which was applied in two stages of plant growth, i.e. seedlings and flag leaves. The electron paramagnetic resonance (EPR) technique was used for the determination of changes in the concentration and nature of long-lived radicals and metal ions (Mn, Fe), measured directly in the structures of fresh leaves, occurring after stress treatment. Stronger variations of EPR parameters were found after drought stress application in the flag-leaf phase and for sensitive genotype. Chloroplasts of Cam/B1 were characterized by a larger surface area and less degradation of their structure during drought stress in comparison to Maresi. The data obtained from Raman spectra showed that better stress tolerance of the genotype was accompanied by greater accumulation of carotenoids in chloroplasts and was correlated with an increase in carotenoid radicals. The increase of the value of the electrokinetic potential (relative to control), which was slightly larger for the chloroplasts of Maresi than of Cam/B1, indicated the chemical reconstruction of the membrane leading to a reduction of their polarity during drought action.
Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239 Cracow, Poland; Institute of Biology, Pedagogical University, Podchorążych 2, 30-084 Cracow, Poland.
Maria
M
Filek
Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Cracow, Poland.
Maria
M
Łabanowska
Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Cracow, Poland. Electronic address: kurdziel@chemia.uj.edu.pl.
Magdalena
M
Kurdziel
Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Cracow, Poland.
Aleksandra
A
Wesełucha-Birczyńska
Faculty of Biology and Environment Protection, Nicolaus Copernicus University, Gagarina 11, 87-100 Torun, Poland.
Elżbieta
E
Bednarska-Kozakiewicz
D000222:Adaptation, Physiological; D002736:Chloroplasts / Q000378:metabolism*; D055864:Droughts; D004578:Electron Spin Resonance Spectroscopy; D005838:Genotype; D001467:Hordeum / Q000235:genetics* / Q000502:physiology*; D018515:Plant Leaves / Q000166:cytology; D012015:Reference Standards; D036226:Seedlings / Q000166:cytology; D013059:Spectrum Analysis, Raman; D013312:Stress, Physiological
Barley genotypes; Chloroplasts structure; Drought stress; Electrokinetic potential; Long-lived radicals; Paramagnetic metal ions