Seeds of chickpea inoculated with Rhizobium were sown in pots supplemented with different doses of cadmium (0, 25, 50 or 100 mg per kg of soil). At the stage of 30 days after sowing (DAS), the plants were sprayed with 20 mM solution of proline and were sampled at 90 DAS to assess the various parameters. The foliar treatment of proline resulted in the alleviation of the adverse effects generated by metal exposure, which was expressed in terms of the increase in plant growth. The activity of carbonic anhydrase in the cadmium-fed plants sprayed with proline was higher than that of control. The proline applied as foliar spray increased the photosynthetic attributes and yield characteristics in the cadmium-stressed plants. The activity of antioxidative enzymes increased with increasing concentration of cadmium. Maximum values were recorded in the plants exposed to 100 mg cadmium per kg of soil.
ASHRAF, M., FOOLAD, M. R., 2007: Roles of glycine betaine and proline in improving plant abiotic stress resistance. Environmental and Experimental Botany 59, 206-216.
BALESTRASSE, K. B.,GALLEGO, S.M.,TOMARO,M. L., 2004: Cadmium-induced senescence in nodules of soybean (Glycine max L.) plants. Plant and Soil 262, 373-381.
BARCELO, J., POSCHENRIEDER, C., 1990: Plant water relations as affected by heavy metal stress: a review. Journal of Plant Nutrition 13, 1-37.
BATES, L. S.,WALDEN, R. T., TEARSE, I. D., 1973: Rapid determination of free proline for water stress studies. Plant and Soil 39, 205-207.
BEAUCHAMP, L. O., FRIDOVICH, I., 1971: Superoxide dismutase: improved assays and assay applicable to acrylamide gels. Annals of Biochemistry 44, 276-287.
CHANCE, B.,MAEHLY, A. C., 1956: Assay of catalase and peroxidase. Methods in Enzymology 2, 764-775.
CLELAND, R. E., 1999: Nature, cocurrence and fucntion of plant hormones. In: HOOYKAAS, P. J. J., HALL, M. A., LIBBENGA, K. R., (Eds.), Biochemistry and molecular biology of plant hormones, 33, 322. Elsevier, Amsterdam.
DWIVEDI, R. S., RANDHAWA, N. S., 1974: Evaluation of a rapid test of the hidden hunger of zinc in plants. Plant and Soil 40, 445-451.
GADALLAH, M. A. A., 1995: Effects of cadmium and kinetin on chlorophyll content, saccharides and dry matter accumulation in sunflower plants. Biologia Plantarum 37, 233-240.
HAMILTON, E. W.,HECKATHORN, S. A., 2001: Mitochondrial adaptation to NaCI. Complex I is protected by anti-oxidants and small heat shock proteins, whereas complex II is protected by proline and betaine. Plant Physiology 126, 1266-1274.
HARE, P. D.,CRESS,W. A., 1997: Metabolic implications of stress-induced proline accumulation in plants. Plant Growth Regulation 21, 79-102.
HASAN, S. A.,HAYAT, S.,ALI, B.,AHMAD, A., 2008: 28-homobrassinolide protects chickpea (Cicer arietinum) from cadmium toxicity by stimulating antioxidants. Environmental Pollution 151, 60-66.
HASAN, S. A.,FARIDUDDIN, Q.,ALI, B.,HAYAT, S.,AHMAD, A., 2009: Cadmium: toxicity and tolerance in plants. Journal of Environmental Biology 30, 165-174.
HAYAT, S., AHMAD, A., MOBIN, M., FARIDUDDIN, Q., AZAM, Z. M., 2001: Carbonic anhydrase, photosynthesis and seed yield in mustard plants treated with phytohormones. Photosynthetica 39, 111-114.
HAYAT, S., HAYAT, Q., 2011: Role of proline and salicylic acid in overcoming the stress of cadmium: Chickpea (Cicer arietinum). Lambert Academic Publishing, Germany.
HAYAT, S.,HAYAT, Q.,ALYEMENI, M. N.,WANI, A. S., PICHTEL, J.,AHMAD, A., 2012: Role of proline under changing environments:A Review. Plant Signaling and Behavior 7, 1-11.
HOLMSTROM, K. O., SOMERSALO, S.,MANDAL, A., PALVA, T. E.,WELIN, B., 2000: Improved tolerance to salinity and low temperature in transgenic tobacco producing glycine betaine. Journal of Experimental Botany 51, 177-185.
HOQUE, M. A., BANU, M. N. A., OKUMA, E., AMAKO, K., NAKAMURA, Y., SHIMOISHI, Y., MURATA, Y., 2007: Exogenous proline and glycine betaine increase NaCl-induced ascorbate-glutathione cycle enzyme activities, and proline improves salt tolerance more than glycine betaine in tobacco Bright Yellow-2 suspension cultured cells. Journal of Plant Physiology 164, 1457-1468.
ISLAM,M.M.,HOQUE,M. A.,EIJI, O.,BANU,M. N. A.,YASUAKI, S.,YOSHIMASA, N.,YOSHIYUKI, M., 2009: Exogenous proline and glycine betaine increase antioxidant enzyme activities and confer tolerance to cadmium stress in cultured tobacco cells. Journal of Plant Physiology 166, 1587-1597.
KIM, H. J., BRACEY, M. H., BARLETT, S. G., 1994: Nucleotide sequence of a gene encoding carbonic anhydrase in Arabidopsis thaliana. Plant Physiology 105, 449-450.
KWOK, D., SHETTY, K., 1998: Effects of proline and proline analogs on total phenolic and rosmarinic acid levels in shoot clones of thyme (Thymus vulgaris L.). Journal of Food Biochemistry 22, 37-51.
LOWRY, O. H., ROSENBROUGH, N. J., FARR, A. L., RANDALL, R. J., 1951: Protein measurement with folin phenol reagent. Journal of Biological Chemistry 193, 265-275.
MAKELA, P.,KARKKAINEN, J., SOMERSALO, S., 2000: Effect of gycine betaine on chloroplast ultrastructure, chlorophyll and protein content, and RuBPCO activities in tomato grown under drought or salinity. Biologia Plantarum 43, 471-475.
OKUMA, E., MURAKAMI, Y., SHIMOISHI, Y., TADA, M., MURATA, Y., 2004: Effects of exogenous application of proline and betaine on the growth of tobacco cultured cells under saline conditions. Soil Science and Plant Nutrition 50, 1301-1305.
PALEG, L. G., DOUGHLAS, T. J., VAN DAAL, A., KEECH, D. B., 1981: Proline and betaine protect enzymes against heat inactivation. Australian Journal of Plant Physiology 8, 107-114.
REDDY, M. P., VORA, A. B., 1986: Changes in pigment composition, Hill reaction activity and saccharide metabolism in bajra (Pennisetum typhoides S. et H.) leaves under NaCl salinity. Photosynthetica 20, 50-55.
ROYALS, J.,WORD, E., AHL-GOY, P.,METRAUX, J.P. 1992. In: WARAY, J. L. (ed.), Inducible plant proteins, 205-229. Cambridge University Press, Cambridge.
SCHNEIDER, E. A,WHITMAN, F., 1974: Metabolism of auxin in higher plants. Annual Review of Plant Physiology 25, 487-513.
SRINIVAS, V., BALASUBRAMANIAN, D., 1995: Proline is a protein-compatible hydrotrope. Langmuir 11, 2830-2833.
SZABADOS, L., SAVOURE, A., 2009: Proline: a multifunctional amino acid. Trends in Plant Science 15, 89-97.
TIWARI, A., KUMAR, P., SINGH, S., ANSARI, S. A., 2005: Carbonic anhydrase in relation to higher plants. Photosynthetica 43, 1-9.
THOMPSON,W. F.,WHITE, J. J., 1991: Physiological and molecular studies on light regulated nuclear genes in higher plants. Annual Review of Plant Physiology and PlantMolecular Biology 42, 423-466.
YANG, S. L., LAN, S. S., GONG, M., 2009: Hydrogen peroxide-induced proline and metabolic pathway of its accumulation in maize seedlings. Journal of Plant Physiology 166, 1694-1699.
ZHOU, Y. O.,HUANG, S. Z.,YU, S. L.,GU, J. G., ZHAO, J. Z.,HAN, Y. L., FU, J. J., 2010: The physiological response and sub-cellular localization of lead and cadmium in Iris pseudacorus L. Ecotoxicology 19, 69-76.