engleski

RECOVERY OF DROUGHT STRESSED BARLEY SEEDLINGS BY RE‐ WATERING

Drought tolerance is one of the most studied features considering the global problem of water deficit. Here we investigated recovery of dehydrated and poorly viable barley seedlings upon re‐watering. Barley seedlings (Hordeum vulgare L. cv. Bravo) were cultivated in the growth chamber (16 h day, ~65 μmol m‐2 s‐1, 22±1 oC ; 8 h night, 19 oC) for ten days and then subjected to drought induced by withholding water. After 8 days, when leaf relative water content (RWC) was about 20% seedlings were watered daily with the same amount of water as controls. For all measurements, first fully developed leaves were sampled before stress (0th day), 8th day of drought and every 24 h during rehydration period of four days. Increased performance index (PIABS), the parameter of chlorophyll a fluorescence called index vitality, and immunodetection of Rubisco LSU revealed efficient photosynthetic apparatus after re‐watering period. Increasing of RWC, decreasing the lipid peroxidation level, and degradation of accumulated proline indicated high tendency for the establishment of homeostasis previously disrupted by drought. We can conclude that despite the low RWC and downregulated photosynthesis under severe drought, seedlings were able to recover their overall photosynthetic efficiency (PIABS) at the end of rehydration period. Obtained results might be helpful to barley breeders during selection of cultivars in order to create a new generation of genotypes better adapted to water deficit.

Hordeum vulgare; drought stress; recovery; leaf relative water content; photosynthesis

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