Salinity reduces plant growth and yield by affecting morphological and physiological processes. To alleviate the harmful effects of salt stress various approaches involving plant hormones are used. In this study several parameters involving the measurement of cell membrane injury were used to observe whether stress tolerance could be enhanced in Chinese cabbage (B. oleracea capitata L. Chinensis group) by soaking the seeds for 10 h in distilled water (control), or in 100, 150 or 200 mg l−1 gibberellic acid (GA3). The NaCl concentrations were 0 (control), 50, 100 and 150 mM. Seed treated with GA3 showed increased water uptake and decreased electrolyte leakage as compared to that of distilled water-primed seeds even 24 h after soaking under control conditions. Seed priming with GA3 increased the final germination and the germination rate (1/t50, where t50 is the time to 50% germination) under salt stress conditions. Seed priming also alleviated the harmful effect of salt stress on cabbage in terms of fresh and dry weights. Leaf area was higher in plants raised from seeds primed with the higher GA3 concentrations as compared with those raised from seeds treated with distilled water under control conditions (without NaCl) or at 50 mM NaCl stress. The chlorophyll content increased with the NaCl concentration, especially in plants grown from seeds primed with GA3. Plants grown from GA3-primed seeds also suffered lower cellular injury both under control conditions and under NaCl stress.
Authors:G. Kovács, S. Sorvari, P. Scott, and O. Toldi
The purpose of this work was to further investigate the regulatory interplay between pyrophosphate:fructose 6-phosphate 1-phosphotransferase (PFP) and its positive effector, fructose 2,6-bisphosphate (Fru-2,6-P
), in the storage organs of cold- and drought-stressed plants. Since there is no detectable cytoplasmic fructose-1,6-bisphosphatase (cytFBPase) activity in the taproots of carrot plants, PFP is the only enzyme that can replace its function when stored starch is converted to transportable sucrose. The working hypothesis was that PFP is likely to be involved in the mobilisation of energy reserves and might have a special role in storage organs such as carrot taproots upon stress. Both cold and drought stress resulted in a marked increase in the endogenous Fru-2,6-P
levels. It is suggested that the significant changes in photosynthate allocation are the direct results of the stimulation of PFP activity by elevated Fru-2,6-P
levels. PFP stimulated by Fru-2,6-P
operated in the gluconeogenic direction in the taproots of stressed carrot plants, whereas the glycolytic direction was dominant in the non-stressed controls. This suggests that the metabolic status determining the net activity of PFP depends on the physiological stress situation, making PFP an important sensor of environmental changes. The experimental data indicated that PFP is involved in the mobilisation of energy reserves during unfavourable environmental changes by promoting the re-synthesis of transportable sucrose in taproots.
Authors:T. Janda, M. Cséplő, Cs. Németh, Gy. Vida, M. Pogány, G. Szalai, and O. Veisz
Treatment with various concentrations (0, 5, 15 and 20%) of PEG was used to simulate water stress, followed by inoculation with
(DTR) at two different points of time (6 and 72 h after the PEG treatment) in two DTR resistant (M-3 and Mv Magvas) and two sensitive (Bezostaya 1 and Glenlea) wheat varieties. The reduction in biomass production due to the PEG treatments was more pronounced in the shoots than in the roots. While in the case of Bezostaya 1 5% PEG reduced the level of infection, 20% PEG treatment lowered the tolerance level of M-3. DTR infection may be more efficient in inducing antioxidative defence systems than water stress. However, there was no direct correlation between the activity of the individual antioxidant enzymes and the drought or DTR tolerance of wheat plants.
Authors:Abeer H. Ali, Usama Radwan, Soad El-Zayat, and Magdi A. El-Sayed
leading to death ( Sanghera et al., 2011 ). Recently, there is a worldwide trend to minimize the negative effects of the abioticstress by the applications of genetic approaches ( Fahad et al., 2017 ). Cullen plicata (Delile) C. H. Stirt is one of the
-mediated alleviation of abioticstresses in higher plants: A review . Environ. Pollut. 147 , 422 – 428 .
Liang , Y. , Nikolic , M. , Belanger , R. , Gong , H. and Song , Liang ( 2015 )a): Silicon and insect pest resistance . In: Y. Liang et al