Strategies for Crop Improvement Against Salinity and Drought Stress: An Overview

  • H. R. Athar
  • M. Ashraf
Part of the Tasks for Vegetation Sciences book series (TAVS, volume 44)


Abiotic stresses such as salinity, drought, nutrient defi ciency or toxicity, and fl ooding limit crop productivity world-wide. However, this situation becomes more problematic in developing countries, where they cause food insecurity for large populations and poverty, particularly in rural areas. For example, drought stress has affected more than 70 million hectares of rice-growing land world-wide. While salt stress and nutrient stress render more than 100 million hectares of agricultural land uncultivable thereby resulting in low outputs, poor human nutrition and reduced educational and employment opportunities. Thus, abiotic stresses are the major factors of poverty for millions of people. In this scenario, it is widely urged that strategies should be adopted which may be used to get maximum crop stand and economic returns from stressful environments. Major strategies include breeding of new crop varieties, screening and selection of the existing germ-plasm of potential crops, production of genetically modifi ed (GM) crops, exogenous use of osmoprotec-tants etc. In the last century, conventional selection and breeding program proved to be highly effective in improving crops against abiotic stresses. Therefore, breeding for abiotic stress tolerance in crop plants (for food supply) should be given high research priority. However, extent and rate of progress in improving stress tolerance in crops through conventional breeding program is limited. This is due to complex mechanism of abiotic stress tolerance, which is controlled by the expression of several minor genes. Furthermore, techniques employed for selecting tolerant plants are time consumable and consequently expensive. During the last decade, using advanced molecular biology techniques different researchers showed some promising results in understanding molecular mechanisms of abiotic stress tolerance as well as in inducing stress tolerance in some potential crops. These fi ndings emphasized that future research should focus on molecular, physiological and metabolic aspects of stress tolerance to facilitate the development of crops with an inherent capacity to withstand abiotic stresses. This would help stabilize the crop production, and signifi cantly contribute to food and nutritional security in developing countries and semi-arid tropical regions.


Abiotic stresses food insecurity molecular breeding QTLs salinity transgenic plants water stress 


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  1. Abebe T, Guenzi AC, Martin B, Chushman JC (2003) Tolerance of mannitol-accumulating transgenic wheat to water stress and salinity. Plant Physiol 131: 1748–1755.PubMedCrossRefGoogle Scholar
  2. Alvim P deT (1985) Theobroma cacao. In: Halvey AH (ed) Handbook of Flowering. CRC Press, Boca Raton, FL, pp 357–365.Google Scholar
  3. Apse MP, Aharon GS, Snedden WS, Blumwald E (1999) Salt tolerance conferred by overexpression of a vacuolar Na+/H+ antiporter in Arabidopsis. Science 285: 1256–1258.PubMedCrossRefGoogle Scholar
  4. Araus JL, Slafer GA, Reynolds MP, Royo C (2002) Plant breeding and drought in C3 cereals: what to breed for?. Ann Bot 89: 925–940.PubMedCrossRefGoogle Scholar
  5. Araus JL, Bort J, Steduto P, Villegas D, Royo C (2003) Breeding cereals for Mediterranean conditions: ecophysiological clues for biotechnology application. Ann Appl Biol 142: 129–141.CrossRefGoogle Scholar
  6. Araus JL, Slafer GA, Reynolds MP, Royo C (2004) Physiology of yield and adaptation in wheat and barley breeding. In: Blum A, Nguyen H (eds) Physiology and Biotechnology Integration for Plant Breeding. Marcel Dekker, New York, pp 1–49.Google Scholar
  7. Ashraf M (1994) Breeding for salinity tolerance in plants. Crit Rev Plant Sci 13: 17–42.CrossRefGoogle Scholar
  8. Ashraf M (2004) Some important physiological selection criteria for salt tolerance in plants. Flora 199: 361–376.Google Scholar
  9. Ashraf M, Harris PJC (2004) Potential biochemical indicators of salinity tolerance in plants. Plant Sci 166: 3–16.CrossRefGoogle Scholar
  10. Ashraf M, Sharif R (1998) Assessment of inter-cultivar/line variation of drought resistance in a potential oil-seed crop, Ethiopian mustard (Brassica carinata). J Plant Nutr 43: 251–265.Google Scholar
  11. Ashraf M, Nawazish S, Athar HR (2007) Are chlorophyll fl uo-rescence and photosynthetic capacity, potential physiological determinants of drought tolerance in maize (Zea mays L.)?. Pak J Bot 39(4): 1123–1131.Google Scholar
  12. Ashraf M, Athar HR, Harris PJC, Kwon TR (2008) Some prospective strategies for improving crop salt tolerance. Adv Agron 97: 45–110.CrossRefGoogle Scholar
  13. Babu CR, Nguyen BD, Chamarerk V, Shanmugasundaram P, Chezhian P, Juyaprakash P, Ganesh SK, Palchamy A, Sadasivam S, Sarkarung S, Wade LJ, Nguyen TH (2003) Genetic analysis of drought resistance in rice by molecular markers: association between secondary traits and fi eld performance. Crop Sci 43: 1457–1469.Google Scholar
  14. Bajaj S, Targolli J, Liu LF, Ho THD, Wu R (1999) Transgenic approaches to increase dehydration-stress tolerance in plants. Mol Breed 5: 493–503.CrossRefGoogle Scholar
  15. Bartels D, Sunkar R (2005) Drought and salt tolerance in plants. Crit Rev Plant Sci 24: 23–58.CrossRefGoogle Scholar
  16. Blum A (1985) Breeding for crop varieties for stress environments. Crit Rev Plant Sci 2: 199–238.CrossRefGoogle Scholar
  17. Bohnert HJ, Gong Q, Li P, Ma S (2006) Unraveling abiotic stress tolerance mechanisms - getting genomics going. Curr Opin Plant Biol 9: 180–188.PubMedCrossRefGoogle Scholar
  18. Borlaug NE, Dowswell CR (2005) Feeding a world of ten billion people: a 21st century challenge. In: Tuberosa T, Phillips RL, Gale M (eds) Proceedings of “In the Wake of the Double Helix: From the Green Revolution to the Gene Revolution”, 27–31 May 2003, at Bologna, Italy. Avenue Media, Bologna, Italy pp 3–24.Google Scholar
  19. Boyer JS (1982) Plant productivity and environment. Science 218: 443–448.PubMedCrossRefGoogle Scholar
  20. Bray EA, Bailey-Serres J, Weretilnyk E (2000) Responses to abiotic stresses. In: Gruissem W, Buchannan B, Jones R (eds) Biochemistry and Molecular Biology of Plants. American Society of Plant Physiologists, Baltimore, MD, pp 1158–1249.Google Scholar
  21. Cattivelli L, Rizza F, Badeck FW, Mazzucotelli E, Mastrangelo AM, Francia E, Mare C, Tondelli A, Stanca AM (2008) Drought tolerance improvement in crop plants: an integrated view from breeding to genomics. Field Crop Res 105: 1–14.CrossRefGoogle Scholar
  22. Chinnusamy V, Jagendorf A, Zhu JK (2005) Understanding and improving salt tolerance in plants. Crop Sci 45: 437–448.Google Scholar
  23. Colmer TD, Munns R, Flowers TJ (2005) Improving salt tolerance of wheat and barley: future prospects. Aust J Exp Agr 45: 1425–1443.CrossRefGoogle Scholar
  24. Cuartero J, Bolarín MC, Asíns MJ, Moreno V (2006) Increasing salt tolerance in the tomato. J Exp Bot 57: 1045–1058.PubMedCrossRefGoogle Scholar
  25. Dasgan HY, Aktas H, Abak K, Cakmak I (2002) Determination of screening techniques to salinity tolerance in tomatoes and investigation of genotype responses. Plant Sci 163: 695–703.CrossRefGoogle Scholar
  26. De Block M, Verduyn C, De Brouwer D, Conelissen M (2005) Poly(ADP-ribose) polymerase in plants affects energy homeo-stasis, cell death and stress tolerance. Plant J 41: 95–106.PubMedCrossRefGoogle Scholar
  27. Diab AA, Teulat B, This D, Ozturk NZ, Benscher D, Sorrells ME (2004) Identifi cation of drought-inducible genes and differentially expressed sequence tags in barley. Theor Appl Genet 109: 1417–1425.PubMedCrossRefGoogle Scholar
  28. Dubouzet JG, Sakuma Y, Ito Y, Kasuga M, Dubouzet EG, Miura S, Seki M, Shinozaki K, Yamaguchi-Shinozaki K (2003) OsDREB genes in rice, Oryza sativa L., encode transcription activators that function in drought-, high salt and cold responsive gene expression. Plant J 33: 751–763.PubMedCrossRefGoogle Scholar
  29. Epstein E, Norlyn JD, Rush DW, Kingsbury R, Kelley DB, Wrana AF (1980) Saline culture of crops: a genetic approach. Science 210: 399–404.PubMedCrossRefGoogle Scholar
  30. FAO (Food and Agriculture Organization, United Nations) (2003) Unlocking the water potential of agriculture. Accessed 7 April 2006.
  31. FAO (2008) FAO Land and Plant Nutrition Management Service.
  32. Flexas J, Bota J, Cifre J (2004) Understanding down regulation of photosynthesis under water stress, future prospects and searching for physiological tools for irrigation management. Ann Appl Biol 144: 273–283.CrossRefGoogle Scholar
  33. Flowers TJ (2004) Improving crop salt tolerance. J Exp Bot 55: 307–319.PubMedCrossRefGoogle Scholar
  34. Foolad MR, Lin GY, Chen FQ (1999) Comparison of QTLs for seed germination under non-stress, cold stress and salt stress in tomato. Plant Breed 118: 167–173.CrossRefGoogle Scholar
  35. Garg AK, Kim JK, Owens TG, Ranwala AP, Choi YD, Kochian LV, Wu RJ (2002) Trehalose accumulation in rice plants confers high tolerance levels to different abiotic stresses. PNAS USA 99: 15898–15903.PubMedCrossRefGoogle Scholar
  36. Gaxiola RA, Li J, Undurraga S, Dang LM, Allen GJ, Alper SL, Fink GR (2001) Drought- and salt-tolerant plants result from overexpression of the AVP1 H&pron;pump. PNAS USA 98: 11444–11449.PubMedCrossRefGoogle Scholar
  37. Gelburd DE (1985) Managing salinity, lesson from the past. J Soil Water Conserv 40: 329–331.Google Scholar
  38. Genc Y, McDonald GK, Tester M (2007) Reassessment of tissue Na+ concentration as a criterion for salinity tolerance in bread wheat. Plant Cell Environ 30: 1486–1498.PubMedCrossRefGoogle Scholar
  39. Greenway H, Munns R (1980) Mechanisms of salt tolerance in non-halophytes. Annu Rev Plant Physiol 312: 149–190.CrossRefGoogle Scholar
  40. Harris K, Subudhi PK, Borrel A, Jordan D, Rosenow D, Nguyen H, Klein P, Klein R, Mullet J (2007) Sorghum stay-green QTL individually reduce post-fl owering drought-induced leaf senescence. J Exp Bot 58: 327–338.PubMedCrossRefGoogle Scholar
  41. Hasegawa PM, Bressan RA, Zhu J-K, Bohnert HJ (2000) Plant cellular and molecular responses to high salinity. Annu Rev Plant Physiol Plant Mol Biol 51: 463–499.PubMedCrossRefGoogle Scholar
  42. Hsieh TH, Lee JT, Charng YY, Chan MT (2002) Tomato plants ectopically expressing Arabidopsis CBF1 show enhanced resistance to water defi cit stress. Plant Physiol 130: 618–626.PubMedCrossRefGoogle Scholar
  43. Hussain SS (2006) Molecular breeding for abiotic stress tolerance: drought perspective. Proc Pakistan Acad Sci 43(3): 189–210.Google Scholar
  44. Ito Y, Katsura K, Maruyama K, Taji T, Kobayashi M, Seki M, Shinozaki K, Yamaguchi-Shinozaki K (2006) Functional analysis of rice DREB1/CBF-type transcription factors involved in cold-responsive gene expression in transgenic rice. Plant Cell Physiol 47: 141–153.PubMedCrossRefGoogle Scholar
  45. Kauser R, Athar HR, Ashraf M (2006) Chlorophyll fl uorescence: a potential indicator for rapid assessment of water stress tolerance in Canola (Brassica napus L.). Pak J Bot 38(5): 1501–1509.Google Scholar
  46. Kavi Kishore PB, Hong Z, Miao G-H, Hu CAA, Verma DPS (1995) Overexpression of Δ-pyrroline-5-carboxylate synthetase increase proline production and confers osmol-tolerance in transgenic plants. Plant Physiol 108: 1387–1394.Google Scholar
  47. Krishnamurthy L, Serraj R, Hash CT, Dakheel AJ, Reddy BVS (2007) Screening sorghum genotypes for salinity tolerant biomass production. Euphytica 156: 15–24.CrossRefGoogle Scholar
  48. Kumar D (2005) Breeding for drought resistance. In: Ashraf M, Harris PJC (eds) Abiotic Stress: Plant Resistance Through Breeding and Molecular Approaches. Haworth Press, New York, pp 145–175.Google Scholar
  49. Lanceras JC, Pantuwan G, Jongdee B, Toojinda T (2004) Quantitative trait loci associated with drought tolerance at reproductive stage in rice. Plant Physiol 135: 384–399.PubMedCrossRefGoogle Scholar
  50. Laporte MM, Shen B, Tarczynski MC (2002) Engineering for drought avoidance: expression of maize NADP-malic enzyme in tobacco results in altered stomatal function. J Exp Bot 53: 699–705.PubMedCrossRefGoogle Scholar
  51. Lewis LN (1984) A vital resource in danger. Calif Agr 38: 2.Google Scholar
  52. Liang ZS, Ding ZR, Wang STR (1992) Study on type of water stress adaptation in both Brassica napus and B. junceaL. species. Acta Botanika 12: 38–45.Google Scholar
  53. Maccaferri M, Sanguineti MC, Corneti S, Araus-Ortega JL, BenSalem M, Bort J, DeAmbrogio E, del Moral LFG, Demontis A, El-Ahmed A, Maalouf F, Machlab H, Martos V, Moragues M, Motawaj J, Nachit M, Nserallah N, Ouabbou H, Royo C, Slama A, Tuberosa R (2008) Quantitative trait loci for grain yield and adaptation of durum wheat (Triticum durumDesf.) across a wide range of water availability. Genetics 178: 489–511. DOI: 10.1534/genetics.107.077297Google Scholar
  54. Mano Y, Takeda K (1997) Mapping quantitative trait loci for salt tolerance at germination and the seedling stage in barley (Hordeum vulgare L.). Euphytica 94: 263–272.CrossRefGoogle Scholar
  55. Mano Y, Takeda K (2001) Genetic resources of salt tolerance at germination and seedling stage in wheat. Jpn J Crop Sci 70: 215–220.Google Scholar
  56. Masle J, Gilmore SR, Farquhar GD (2005) The ERECTA gene regulates plant transpiration effi ciency in Arabidopsis. Nature 436: 866–870.PubMedCrossRefGoogle Scholar
  57. Moreno LS, Maiti RK, Gonzales AN, Star JV, Foroughbakhch R, Gonzales HG (2000) Genotypic variability in bean culti-vars (Phaseolus vulgaris L.) for resistance to salinity at the seedling stage. Indian Agr 44: 1–12.Google Scholar
  58. Morgan JM (2000) Increases in grain yield of wheat by breeding for an osmoregulation gene: relationship to water supply and evaporative demand. Aust J Agr Res 51: 971–978.CrossRefGoogle Scholar
  59. Morgan JM, Tan MK (1996) Chromosomal location of a wheat osmoregulation gene using RFLP analysis. Aust J Plant Physiol 23: 803–806.CrossRefGoogle Scholar
  60. Munns R (2002) Comparative physiology of salt and water stress. Plant Cell Environ 25: 239–250.PubMedCrossRefGoogle Scholar
  61. Munns R (2005) Genes and salt tolerance: bringing them together. New Phytol 167(3): 645–663.PubMedCrossRefGoogle Scholar
  62. Munns R (2007) Utilizing genetic resources to enhance productivity of salt-prone land. CAB Rev: Perspect Agr Vet Sci Nutr Natl Res 2: (009).Google Scholar
  63. Munns R (2008) Strategies for crop improvement in saline soils. In: Ashraf M, Ozturk M, Athar HR (eds) Salinity and Water Stress: Improving Crop Effi ciency. Springer, The Netherlands, pp 99–110.Google Scholar
  64. Munns R, Tester M (2008) Mechanisms of salinity tolerance. Annu Rev Plant Biol 59: 651–681.PubMedCrossRefGoogle Scholar
  65. Munns R, Husain S, Rivelli AR, James RA, Condon AG, Lindsay MP, Lagudah ES, Schachtman D, Hare RA (2002) Avenues for increasing salt tolerance of crops, and the role of physiologically based selection traits. Plant Soil 247: 93–105.CrossRefGoogle Scholar
  66. Munns R, James RA, Laüchli A (2006) Approaches to increasing the salt tolerance of wheat and other cereals. J Exp Bot 57: 1025–1043.PubMedCrossRefGoogle Scholar
  67. Neumann PM (2008) Coping mechanisms for crop plants in drought-prone environments. Ann Bot 101: 901–907.PubMedCrossRefGoogle Scholar
  68. Nguyen TT, Klueva N, Chamareck V, Aarti A, Magpantay G, Millena AC, Pathan MS, Nguyen HT (2004) Saturation mapping of QTL regions and identifi cation of putative candidate genes for drought tolerance in rice. Mol Gen Genomics 272: 35–46.CrossRefGoogle Scholar
  69. Park BJ, Liu Z, Kanno A, Kameya T (2005) Genetic improvement of Chinese cabbage for salt and drought tolerance by constitutive expression of a B. napusLEA gene. Plant Sci 169: 553–558.CrossRefGoogle Scholar
  70. Parry MAJ, Flexas J, Medrano H (2005) Prospects for crop production under drought: research priorities and future directions. Ann Appl Biol 147: 211–226.CrossRefGoogle Scholar
  71. Pellegrineschi A, Reynolds M, Pacheco M, Brito BM, Almeraya R, Yamaguchi-Shinozaki K, Hoisington D (2004) Stress induced expression in wheat of the Arabidopsis thaliana DREB1A gene delays water stress symptoms under green-houde conditions. Genome 47: 493–500.PubMedCrossRefGoogle Scholar
  72. Peng S, Ismail AM (2004) Physiological basis of yield and environmental adaptation in rice. In: Blum A, Nguyen H (eds) Physiology and Biotechnology Integration for Plant Breeding. Marcel Dekker, New York, pp 83–140.Google Scholar
  73. Quesada V, García-Martínez S, Piqueras P, Ponce MR, Mico JL (2002) Plant Physiol 130: 951–963.PubMedCrossRefGoogle Scholar
  74. Rehman S, Harris PJC, Ashraf M (2005) Stress environments and their impact on crop production. In: Ashraf M, Harris PJC (eds) Abiotic Stresses: Plant Resistance Through Breeding and Molecular Approaches. Haworth Press, New York, pp 3–18.Google Scholar
  75. Rengasamy P (2006) World salinization with emphasis on Australia. J Exp Bot 57(5): 1017–1023.PubMedCrossRefGoogle Scholar
  76. Reynolds M, Tuberosa R (2008) Translational research impacting on crop productivity in drought-prone environments. Curr Opin Plant Biol 11: 171–179.PubMedCrossRefGoogle Scholar
  77. Reynolds MP, Mujeeb-Kazi A, Sawkins M (2005) Prospects for utilizing plant-adaptive mechanisms to improve wheat and other crops in drought and salinity-prone environments. Ann Appl Biol 146: 239–259.CrossRefGoogle Scholar
  78. Ribaut J-M, Ragot M (2007) Marker-assisted selection to improve drought adaptation in maize: the backcross approach, perspectives, limitations, and alternatives. J Exp Bot 58(2): 351–360.PubMedCrossRefGoogle Scholar
  79. Richards RA, Rebetzke GJ, Condon AG, Herwaarden AF (2002) Breeding opportunities for increasing the effi ciency of water use and crop yield in temperate cereals. Crop Sci 42: 111 –121.PubMedGoogle Scholar
  80. Rogers ME, Noble CL (1992) Variation in growth and ion accumulation between two selected populations of Trifolium repens L differing in salt tolerance. Plant Soil 146: 131 –136.CrossRefGoogle Scholar
  81. Rogers ME, Noble CL, Halloran GM, Nicolas ME (1997) Selecting for salt tolerance in white clover (Trifolium repens): chloride ion exclusion and its heritability. New Phytol 135: 645 –654.CrossRefGoogle Scholar
  82. Rogers ME, Craig AD, Munns R, Colmer TD, Nichols PGH, Malcolm CV, Barrett-Lennard EG, Brown AJ, Semple WS, Evans PM, Cowley K, Hughes SJ, Snowball R, Bennett SJ, Sweeney GC, Dear BS, Ewing MA (2005) The potential for developing fodder plants for the salt-affected areas of southern and eastern Australia: an overview. Aust J Exp Agr 45: 301 –329.CrossRefGoogle Scholar
  83. Sakuma Y, Maruyama K, Osakabe Y, Qin F, Seki M, Shinozaki K, Yamaguchi-Shinozaki K (2006) Functional analysis of Arabidopsis transcription factor, DREB2A, involved in drought-responsive gene expression. Plant Cell 18: 1292 –1309.PubMedCrossRefGoogle Scholar
  84. Salvi S, Tuberosa R (2005) To clone or not to clone plant QTLs: present and future challenges. Trends Plant Sci 10: 297 –304.PubMedCrossRefGoogle Scholar
  85. Saranga Y, Cahaner A, Zamir D, Marani A, Rudich J (1992) Breeding tomatoes for salt tolerance inheritance of salt tolerance and related traits in inter-specifi c populations. Theor Appl Genet 84: 390 –396.CrossRefGoogle Scholar
  86. Schwabe KA, Iddo K, Knap KC (2006) Drain water management for salinity mitigation in irrigated agriculture. Am J Agr Ecol 88: 133 –140.CrossRefGoogle Scholar
  87. Serraj R, Sinclair TR (2002) Osmolyte accumulation: can it really help increase crop yield under drought conditions? Plant Cell Environ 25: 333 –341.PubMedCrossRefGoogle Scholar
  88. Serraj R, Hash TC, Buhariwalla HK, Bidinger FR, Folkertsma RT, Chandra S, Gaur PM, Kashiwagi J, Nigam SN, Rupakula A, Crouch JH (2005a) Marker-assisted breeding for crop drought tolerance at ICRISAT: achievements and prospects. In: Tuberosa R, Phillips RL, Gale M (eds) Proceedings of the International Congress “In the Wake of the Double Helix: From the Green Revolution to the Gene Revolution”. Avenue Media, Bologna, Italy, pp 217 –238.Google Scholar
  89. Serraj R, Hash CT, Rizvi SM, Sharma A, Yadav RS, Bidinger FR (2005b) Recent advances in marker assisted selection for drought tolerance in pearl millet. Plant Prod Sci 8: 334 –337.CrossRefGoogle Scholar
  90. Serrano R, Mulet JM, Rios G, Marquez JA, de Larrinoa IF, Leube MP, Mendizabal I, Pascual-Ahuir A, Proft M, Ros R, Montesinos C (1999) A glimpse of mechanisms of ion homeostasis during salt stress. J Exp Bot 50: 1023 –1036.CrossRefGoogle Scholar
  91. Shinozaki K, Yamaguchi-Shinozaki K (2007) Gene networks involved in drought stress response and tolerance. J Exp Bot 58: 221 –227.PubMedCrossRefGoogle Scholar
  92. Slafer GA, Satorre EH (1999) An introduction to the physiological-ecological analysis of wheat yield. In: Satorre EH, Slafer GA (eds) Wheat: Ecology and Physiology of Yield Determination. Food Product Press, New York, pp 3 –12.Google Scholar
  93. Subbarao G V, Ito O, Serraj R, Crouch JJ, Tobita S, Okada K, Hash CT, Ortiz R, Berry WL (2005) Physiological perspectives on improving crop adaptation to drought —justifi cation for a systematic component-based approach. In: Pessarakli M (ed) Handbook of Photosynthesis, 2nd edn. Marcel and Dekker, New York, pp 577 –594.Google Scholar
  94. Syv änen AC (2005) Toward genome-wide SNP genotyping. Nat Genet 37: S5 –S10.CrossRefGoogle Scholar
  95. Tambussi EA, Bort J, Araus JL (2007) Water use effi ciency in C3 cereals under Mediterranean conditions: a review of physiological aspects. Ann Appl Biol doi:10.1111/j.1744-7348.2007.00143.x.Google Scholar
  96. Tondelli A, Francia E, Barabaschi D, Aprile A, Skinner JS, Stockinger EJ, Stanca AM, Pecchioni N (2006) Mapping regulatory genes as candidates for cold and drought stress tolerance in barley. Theor Appl Genet 112: 445 –455.PubMedCrossRefGoogle Scholar
  97. Tuberosa R, Giuliani S, Parry MAJ, Araus JL (2007a) Improving water use effi ciency in Mediterranean agriculture: what limits the adoption of new technologies? Ann Appl Biol 150: 157 –162.CrossRefGoogle Scholar
  98. Tuberosa R, Salvi S, Giuliani S, Sanguineti MC, Bellotti M, Conti S, Landi P (2007b) Genome-wide approaches to investigate and improve maize response to drought. Crop Sci 47(S3): S120 –S141.Google Scholar
  99. UN Millennium Project (2003) Halving global hunger. Background Paper of the Millennium Task Force on Hunger. UNDP, New York.Google Scholar
  100. Vinocur B, Altman A (2005) Recent advances in engineering plant tolerance to abiotic stress: achievements and limitations. Curr Opin Biotechnol 16: 123 –132.PubMedCrossRefGoogle Scholar
  101. Wang W, Vinocur B, Altman A (2003) Plant responses to drought, salinity and extreme temperatures: towards genetic engineering for stress tolerance. Planta 218: 1 –14.PubMedCrossRefGoogle Scholar
  102. Yamaguchi T, Blumwald E (2005) Developing salt-tolerant crop plants: challenges and opportunities. Trends Plant Sci 10: 615 –620.PubMedCrossRefGoogle Scholar
  103. Yeo A (1998) Molecular biology of salt tolerance in the context of whole-plant physiology. J Exp Bot 49: 915 –929.CrossRefGoogle Scholar
  104. Yeo AR, Yeo ME, Flowers TJ (1988) Selection of lines with high and low sodium transport from within varieties of an inbreeding species: rice (Oryza sativa L). New Phytol 110: 13 –19.CrossRefGoogle Scholar
  105. Zhang HX, Hodson JN, Williams JP, Blumwald E (2001) Engineering salt-tolerant Brassica plants: characterization of yield and seed oil quality in transgenic plants with increased vacuolar sodium accumulation. PNAS USA 98: 12832 –12836.PubMedCrossRefGoogle Scholar
  106. Zhao XQ, Xu J-L, Zhao M, Lafi tte R, Zhu L-H, Fu B-Y, Gao Y-M, Li Z-K (2008) QTLs affecting morph-physiological traits related to drought tolerance detected in overlapping intro-gression lines of rice (Oryza sativa L.). Plant Sci 174: 618 –625.CrossRefGoogle Scholar
  107. Zheng BS, Yang L, Zhang WP, Mao CZ, Wu YR, Yi KK, Liu FY, Wu P (2003) Mapping QTLs and candidate genes for rice root traits under different water supply conditions and comparative analysis across three populations. Theor Appl Genet 107: 1505 –1515.PubMedCrossRefGoogle Scholar
  108. Zhu BC, Su J, Chan MC, Verma DPS, Fan YL, Wu R (1998) Over expression of a —pyrroline-5-carboxylate synthetase gene and analysis of tolerance to water stress and salt stress in transgenic rice. Plant Sci 139: 41 –48.CrossRefGoogle Scholar

Copyright information

© Springer Science + Business Media B.V. 2009

Authors and Affiliations

  • H. R. Athar
    • 1
  • M. Ashraf
    • 2
  1. 1.Institute of Pure and Applied Biology, Bahauddin Zakariya UniversityMultanPakistan
  2. 2.Department of BotanyUniversity of AgricultureFaisalabadPakistan

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