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Changes in seed germination, and some physiological and ultra structural aspects of Calotropis procera seedlings under heat stress

Ali Ibrahim*, Ateeq Al-Zahrani, Zakria Baka, Hussain Almalki


Global warming is a problematic for many plants and understanding how the plants cope with temperature stress is an important objective. In this study, two experiments were conducted; the first one explored the effect of different temperatures on Calotropis procera seed germination, and the second disclosed the physiological and ultrastructural aspects of plant seedling. A temperature rise from 25°C to 30°C increased seed germination enormously, whereas seed incubation at 35°C significantly decreased its germination. The treatment of 40°C drastically inhibited seed germination. During the experimental periods, the seeds did not germinate at all at 45°C. Seed incubation at 30°C for 5 days notably enhanced seedling growth. This effect was accompanied by accelerated reserve mobilization and enzymes activity. A mild increase in lipid peroxidation (30% increase) and electrolyte leakage (45% increase) was also observed in response to these temperatures. Additionally, the plasma membrane moved away from the cell wall and became thicker in response to this temperature. Seeds exposure to 35°C for 5 days significantly reduced seedling growth. This adverse effect was accompanied with an increase in lipid peroxidation and electrolyte leakage by 100 and 170%, respectively over the values of 25°C treatment. Furthermore, the plasma membrane was damaged and double stranded with the 35°C application. Cytoplasmic vesiculation appeared in response to 30°C and 35°C treatments. Except for total soluble sugars which was decreased, all other biochemical changes in response to 35°C were comparable with those observed at 30°C treatment.


Cell Membrane; Cytoplasm Vesiculation; Electrolyte Leakage; Enzymes; Germination; Heat Stress; Ultrastructure.

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Intergovernmental panel on climate change (IPCC). The Physical science basis. Contribution of working group I to the fourth assessment report of the intergovernmental panel on climate change. Solomon S., Qin D., Manning M., Chen Z., Marquis M., Averyt K.B, Tignor M., and Miller H.L. (eds.), Cambridge University Press, Cambridge, U K and New York, USA, 2007.

Jha U.C., Bohra A. and Singh N.P. "Review: Heat stress in crop plants: its nature, impacts and integrated breeding strategies to improve heat tolerance." Plant Breeding 133 (2014): 679–701.

Wahid A., Gelani S., Ashraf M. and Foolad M.R. "Heat tolerance in plants: An overview." Environ. Exp. Bot. 61 ( 2007): 199–223.

Demidchik V., Straltsova D., Medvedev S.S., Pozhvanov G.A., Sokolik A. and Yurin V. "Review paper: Stress-induced electrolyte leakage: the role of K+-permeable channels and involvement programmed cell death and metabolic adjustment." J. Exp. Bot. 65 (2014): 1259-70.

Bavita A., Shashi B. and Navtej S.B. "Nitric oxide alleviates oxidative damage induced by high temperature stress in wheat." Ind. J. Exp. Biol. 50 (2012): 372-378.

Hasanuzzaman M., Nahar K., Alam M., Roychowdhury R. and Fujita M. "Review: Physiological, biochemical, and molecular mechanisms of heat stress tolerance in plants". Int. J. Mol. Sci. 14 (2013): 9643-9684.

Savicka M. and Škute N. "Effects of high temperature on malondialdehyde content, superoxide production and growth changes in wheat seedlings (Triticum aestivum L.)." Ekologija 56 (2010): 26–33.

Aldesuquy H., Baka Z. and Mickky B. "Kinetin and spermine mediated induction of salt tolerance in wheat plants: Leaf area, photosynthesis and chloroplast ultrastructure of flag leaf at ear emergence." Egypt. J. Basic. Appl. Sci. I (2014): 77-87.

Eleftheriou E.P., Adamakis I-D.S., Panteris E., and Fatsiou M. "Chromium-Induced ultrastructural changes and oxidative stress in roots of Arabidopsis thaliana." Int. J. Mol. Med. 16 (2015): 15852-15871.

Pareek A.N., Singla S.L. and Grover A. "Short-term salinity and high temperature stress - associated ultrastructural alterations in young leaf cells of Oryza sativa L." Ann. Bot. 80 (1997) 80: 629-639.

Bajji M., Kinet J.M. and Lutts S. "The use of the electrolyte leakage method for assessing cell membrane stability as a water stress tolerance test in durum wheat." Plant Growth Regul. 36 (2002): 61–70.

Campos P.S., Quartin V., Ramalho J.C. and Nunes M.A. "Electrolyte leakage and lipid degradation account for cold sensitivity in leaves of Coffea sp. plants." J. Plant Physiol. 160 (2003): 283–292.

Yeh D.M. and Lin H.F. "Thermostability of cell membranes as a measure of heat tolerance and relationship to flowering delay in chrysanthemum." J. Amer. Soc. Hort. Sci. 128 (2003): 656- 660.

Premchandra G.S., Saneoka H. and Ogata S. "Cell membrane stability, an indicator of drought tolerance as affected by applied nitrogen in soybean." J. Agri. Sci. 115 (1990): 63-66.

Wang L.C., Tsai M.C., Chang K.Y., Fan Y.S., Yeh C.H. and Wu, S.J. "Involvement of the Arabidopsis HIT1/AtVPS53 tethering protein homologue in the acclimation of the plasma membrane to heat stress." J. Exp. Bot. 62 (2011): 3609–3620.

Rolny N., Costaa L., Carrióna C. and Guiamet J. "Is the electrolyte leakage assay an unequivocal test of membrane deterioration during leaf senescence?." Plant. Physiol. Biochem. 49 (2011): 1220–122.

Hassan L.M., Galal T.M., Farahat E.A. and El- Midan M.M. "The biology of Calotropis procera (Aiton) W.T." Trees 29 (2015):311–320.

Ibrahim A.H. "Tolerance and avoidance responses to salinity and water stresses in Calotropis procera and Suaeda aegyptiaca." Turk. J. Agri. For. 37 (2013): 352-360.

Erdman M.D. and Erdman B.A. "Calotropis procera as a source of plant hydrocarbons." Econ. Bot. 35 (1981): 467–472.

Galal T.M., Farahat E.A., El-midany M.M. and Hassan L.M. "Effect of temperature, salinity, light and time of dehiscence on seed germination and seedling morphology of Calotropis procera from urban habitats". Afr. J . Biotechn . 14 (2015): 1275-1282.

Boutraa T. "'Effects of water stress on root growth, water use efficiency, leaf area and chlorophyll content in the desert Shrub Calotropis procera." J. Int. Environ. Appl. Sci. 5 (2013): 124-132.

Sadasivam S. and Manickam A. "Biochemical methods." New age international limited publishers, 2nd edition, New Delhi 1996.

de Morais G.A. and Takaki M. "Determination of amylase activity in cotyledons of Phaseolus vulgaris L. cv. Carioca." Brazil. Arch. Biol. Techn. 41 (1998): 7-25.

Bhardwaj J., Anand A. and Nagarajan S. "Biochemical and biophysical changes associated with magneto priming in germinating cucumber seeds." Plant Physiol. Biochem. 57: (2012): 67-73.

Khademi M., Koranski D.S., Hannapel D.J., Knapp A.D. and Gladon R.J. "Water stress and storage-protein degradation during germination of impatiens seed." J. Amer. Soc. Hort. Sci. 116 (1991): 302-306.

Bradford M.M. "A dye binding assay for protein." Anal. Bioch.72 (1976): 248-254.

Heath R.L. and Packer L. "Photoperoxidation in isolated chloroplast. I. Kinetics and stoichiometry of fatty acid peroxidation." Arch. Biochem. Biophys. 125 (1968):189-198.

Xing W., Wang J., Liu H., Zou D. and Zhao H. "Influence of natural saline-alkali stress on chlorophyll content and chloroplast ultrastructure of two contrasting rice (Oryza sativa L. japonica) cultivars." Aust. J. Crop. Sci. 7 (2013): 289-292.

Siddiqui M.H., Al-Khaishany M.Y., Al-Qutami M.A., Al-Whaibi M.H., Grover A., Ali H.M. and Al-Wahibi M.S. "Morphological and physiological characterization of different genotypes of faba bean under heat stress." Saudi. J. Biol. Sci. 22 (2015): 656–663.

Levitt J. "Responses of plants to environmental stress. Vol. I. Chilling, freezing and high temperature stresses." Academic Press New York 1980.

Essemine J, Ammar S. and Bouzid S. "Impact of heat stress on germination and growth of higher plants: Physiological, biochemical and molecular repercussions and mechanisms of defence." J. Biol. Sci. 10 (2010): 565-572.

Niki E. "Lipid peroxidation: physiological levels and dual biological effects." Free Radic. Biol. Med. 47 (2009):469-484.

Gulen H. and Eris A. Effect of heat stress on peroxidase activity and total protein content in strawberry plants. Plant Sci. 166 (2004): 739–744.

Gray WM, Ostin A, Sandberg GR, Romano CP and Estelle M. "High temperature promotes auxin-mediated hypocotyl elongation in Arabidopsis." Proc. Natl. Acad. Sci. USA 95 (1998): 7197–7202.

Menge E. O., Bellairs S. M. and Lawes M. J. "Seed- germination responses of Calotropis procera (Asclepiadaceae) to temperature and water stress in northern Aust." Aust. J. Bot. 64 (2016): 441-450.

Sergio E., Cobianchi R.C., Sorbo S., Conte B. and Basile A. "Ultrastructural alterations and HSP 70 induction in Elodea Canadensis Michx. exposed to heavy metals." Caryologia 60 (2007): 115-120.

Wei T. and Wang A. "Biogenesis of cytoplasmic membranous vesicles for plant potyvirus replication occurs at endoplasmic reticulum exit sites in a COPI- and COPII-dependent manner." J. Virol. 82 (2008): 12252-12264.



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