Low Magnesium with High Potassium Supply Changes Sugar Partitioning and Root Growth Pattern Prior to Visible Magnesium Deficiency in Leaves of Rice (Oryza sativa L.)

Yuchuan Ding, Guohua Xu

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DOI: 10.4236/ajps.2011.24071                

Abstract

This research was conducted to investigate the effects of low magnesium (Mg) with high potassium (K) supply on the Mg concentration, sugar partitioning and root growth of rice (Oryza sativa L. cv. Wuyunjing 7) plants grown in hydroponics under greenhouse conditions, at Nanjing Agricultural University, China. The nutrient solution contained 0.01 and 1.0 mM Mg concentration, with K at 1.0 and 6.0 mM. Compared with the control (1mM Mg and K) treatment, the soluble sugar content at the treatment of low Mg (0.01 mM) with high K (6 mM) decreased by 35.7% in leaves, whereas increased 29.2% in roots at day 15 after treatment initiation. The shoot dry weight (DW) declined 12.9%, but root DW increased 12.1% leading to the significant increase in the root to shoot ratio at day 30. Furthermore, the total root length, total root surface area, root volume, average root diameter, total length of 0 - 0.5 mm and 0.5 - 1.0 mm diameter roots at day 30 significantly increased by 11.8%, 16.4%, 25.3%, 8.1%, 16.6% and 12.5%, respectively. Correlation analysis revealed the root to shoot ratio is closely related to the soluble sugar contents in roots and root morphological parameters of rice at day 15 and day 30. The typical visible symptoms of Mg deficiency in leaves of rice were obtained in the treatment of low Mg with high K at day 35. These findings indicated that low Mg with high K supply altered sugar partitioning and root morphological parameters, resulting in the increased root to shoot ratio prior to visible Mg deficiency symptoms in rice leaves. The increase in root to shoot ratio maybe an important adaptive mecha-nism for rice plants to respond to low-Mg stress during the early growth stage.

Keywords

Magnesium, Potassium, Sugar Partitioning, Root Growth Parameter, Rice

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	H. Marschner, “Mineral Nutrition of Higher Plants,” 2nd Edition, Academic Press, London, 1995.
[2]	O. Shaul, “Magnesium Transport and Function in Plants: the Tip of the Iceberg,” Biometals, Vol. 15, No. 3, September 2002, pp. 309-323. doi:10.1023/A:1016091118585
[3]	S. Shabala and Y. Hariadi, “Effects of Magnesium Availability on the Activity of Plasma Membrane Ion Transporters and Light-Induced Responses from Broad Bean Leaf Mesophyll,” Planta, Vol. 221, No. 1, April 2005, pp. 56-65. doi:10.1007/s00425-004-1425-0
[4]	C. Hermans, F. Bourgis, M. Faucher, R. J. Strasser, S. Delrot and N. Verbruggen, “Magnesium Deficiency in Sugar Beets Alters Sugar Partitioning and Phloem Loading in Young Mature Leaves,” Planta, Vol. 220, No. 4, October 2005, pp. 541-549. doi:10.1007/s00425-004-1376-5
[5]	K. Mengel and E. A. Kirkby, “Principles of Plant Nutrition,” 4th Edition, International Potash Institute, Switzerland, 1987.
[6]	C. Hermans, J. P. Hammond, P. J. White and N. Verbruggen, “How Do Plants Respond to Nutrient Shortage by Biomass Allocation?” Trends in Plant Science, Vol. 11, No. 12, December 2006, pp. 610-617. doi:10.1016/j.tplants.2006.10.007
[7]	H. Marschner, E. A. Kirkby and I. Cakmak, “Effect of Mineral Nutritional Status on Shoot-Root Partitioning of Photoassimilates and Cycling of Mineral Nutrients,” Journal of Experimental Botany, Vol. 47, No. Special Issue, August 1996, pp. 1255-1263. doi:10.1093/jxb/47.Special-Issue.1255
[8]	I. Cakmak, C. Hengeler and H. Marschner, “Partitioning of Shoot and Root Dry Matter and Carbohydrates in Bean Plants Suffering from Phosphorus, Potassium and Magnesium Deficiency,” Journal of Experimental Botany, Vol. 45, No. 9, September 1994, pp. 1245-1250.
[9]	T. Ericsson, “Growth and Shoot: Root Ratio of Seedlings in Relation to Nutrient Availability,” Plant and Soil, Vol. 168-169, No. 1, 1995, pp. 205-214.
[10]	C. Hermans, G. N. Johnson, R. J. Strasser and N. Verbruggen, “Physiological Characterization of Magnesium Deficiency in Sugar Beet: Acclimation to Low Magnesium Differentially Affects PhotosystemsⅠand Ⅱ,” Planta, Vol. 220, No. 2, 2004, pp. 344-355. doi:10.1007/s00425-004-1340-4
[11]	R. K. Tewari, P. Kumar and P. N. Sharma, “Magnesium Deficiency Induced Oxidative Stress and Antioxidant Responses in Mulberry Plants,” Scientia Horticulturae, Vol. 108, No. 1, March 2006, pp. 7-14. doi:10.1016/j.scienta.2005.12.006
[12]	N. K. Fageria, “Dry Matter Yield and Nutrient Uptake by Lowland Rice at Different Growth Stages,” Journal of Plant Nutrition, Vol. 27, No. 6, 2004, pp. 947-958.
[13]	S. Yoshida, D. A. Forno, G. H. Cock and K. A. Gomez, “Laboratory Manual for Physiological Studies of Rice,” 2nd Edition, International Rice Research Institute, Los Banos, 1972.
[14]	J. R. Lowther, “Use of a Single Sulphuric-Hydrogen Peroxide Digest for the Analysis of Pinus radiate Needles,” Communications in Soil Science and Plant Analysis, Vol. 11, No. 2, 1980, pp. 175-188.
[15]	L. Villarreal-Ruiz, I. C. Anderson and I. J. Alexander, “Interaction between an Isolate from the Hymenoscyphus Ericae Aggregate and Roots of Pinus and Vaccinium,” New Phytologist, Vol. 164, No. 1, October 2004, pp. 183-192. doi:10.1111/j.1469-8137.2004.01167.x
[16]	Y. Ding, W. Luo and G. Xu, “Characterization of Magnesium Nutrition and Interaction of Magnesium and Potassium in Rice,” Annals of Applied Biology, Vol. 149, No. 2, October 2006, pp. 111-123. doi:10.1111/j.1744-7348.2006.00080.x
[17]	T. Ohno and D. L. Grunes, “Potassium-Magnesium Interaction Affecting Nutrient Uptake by Wheat Forage,” Soil Science Society of America Journal, Vol. 49, No. 3, 1985, pp. 685-690.
[18]	S. C. Huber, “Biochemical Mechanism for Regulation of Sucrose Accumulation in Leaves during Photosynthesis,” Plant physiology, Vol. 91, No. 2, October 1989, pp. 656- 662.
[19]	I. A. Wardlaw, “The Control of Carbon Partitioning in Plants,” New Phytologist, Vol. 116, No. 3, November 1990, pp. 341-381.
[20]	U. Druege, S. Zerche, R. Kadner and M. Ernst, “Relation between Nitrogen Status, Carbohydrate Distribution and Subsequent Rooting of Chrysanthemum Cuttings as Affected by Pre-Harvest Nitrogen Supply and Coldstorage,” Annals of Botany, Vol. 85, No. 5, May 2000, pp. 687-701. doi:10.1006/anbo.2000.1132
[21]	J. López-Bucio, A. Cruz-Ramirez and L. Herrera-Estrella, “The Role of Nutrient Availability in Regulating Root Architecture,” Current Opinion in Plant Biology, Vol. 6, No. 3, Jun 2003, pp. 280-287. doi:10.1016/S1369-5266(03)00035-9
[22]	I. Cakmak and H. Marschner, “Magnesium Deficiency and High Light Intensity Enhance Activities of Superoxide Dismutase, Ascorbate Peroxidase, and Glutathione Reductase in Bean Leaves,” Plant Physiology, Vol. 98, No. 4, April 1992, pp. 1222-1227.
[23]	I. Cakmak, C. Hengeler and H. Marschner, “Changes in Phloem Export of Sucrose in Leaves in Response to Phosphorus, Potassium and Magnesium Deficiency in Bean Plants,” Journal of Experimental Botany, Vol. 45, No. 9, September 1994, pp. 1251-1257.
[24]	E. S. Fischer, G. Lohaus, D. Heineke and H. W. Heldt, “Magnesium Deficiency Results in Accumulation of Carbohydrates and Amino Acids in Source and Sink Leaves of Spinach,” Physiologia Plantarum, Vol. 102, No.1, January 1998, pp. 16-20.
[25]	C. Hermans and N. Verbruggen, “Physiological Characterization of Mg Deficiency in Arabidopsis Thaliana,” Journal of Experimental Botany, Vol. 56, No. 418, August 2005, pp. 2153-2161. doi:10.1093/jxb/eri215
[26]	F. Rolland, B. Moore and J. Sheen, “Sugar Sensing and Signaling in Plants,” The Plant Cell, Vol. 14, No. Supply, May 2002, pp. 185-205. doi:10.1105/tpc.010455
[27]	T. J. Chiou and D. R. Bush, “Sucrose Is a Signal Molecule in Assimilate Partitioning,” Proceedings of the National Academy of Sciences of the United States of America, Vol. 95, No. 8, April 1998, pp. 4784-4788.
[28]	F. Rook and M. W. Bevan, “Genetic Approaches to Understanding Sugar-Response Pathways,” Journal of Experimental Botany, Vol. 54, No. 382, January 2003, pp. 495-501. doi:10.1093/jxb/erg054
[29]	H. Wang, Y. Inukai and A. Yamauchi, “Root Deveiop- ment and Nutrient Uptake,” Critical Reviews in Plant Sciences, Vol. 25, No. 3, May 2006, pp. 279-301. doi:10.1080/07352680600709917
[30]	W. R. John, L. P. Linda and R. S. Charles, “Partitioning of Sugar between Growth and Nitrate Reduction in Cotton Roots,” Plant Physiology, Vol. 62, No. 4, October 1978, pp. 550-553.