Heat and Drought Tolerance in Wheat: Integration of Physiological and Genetic Platforms for Better Performance Under Stress

Year 2016, Volume: 2 Issue: 1, 1 - 14, 01.01.2016

Vikender Kaur Sunder Singh Rishi Kumar Behl

Abstract

Heat and drought stress are currently the leading threat on world’s food supply, limiting wheat yield. The extent and severity of stress affected agricultural land is predicted to worsen as a result of inadequate irrigation resources, declining water tables and global warming. Drought/heat tolerance is crucial to stabilize and increase food production since domestication has limited the genetic diversity of crops including wild wheat, leading to cultivated species, adapted to artificial environments, and lost tolerance to stress episodes. Breeding for this trait is complicated as it is controlled by polygenes and their expressions are influenced by various environmental elements and molecular methods such as molecular markers, quantitative trait loci (QTL) mapping strategies, and expression patterns of genes should be applied to produce heat/drought tolerant genotypes. Understanding the mechanism of stress tolerance along with a plethora of genes involved in stress signaling network is important for wheat improvement. Integrating physiology and biotechnological tools with conventional breeding techniques will help to develop wheat varieties with better grain yield under stress during reproductive and grain-Şlling phases. We briefly consider mechanisms of adaptation and highlight recent research examples through a lens of their applicability to improve the efŞciency of wheat under stressful Şeld conditions. Improvement for stress tolerance can be achieved by the introduction of drought and or heat related genes and QTLs to modern wheat cultivars

Keywords

drought, heat, yield, tolerance, climate change, wheat, stress

References

• 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.
• Ahmadi AA (1998). Effect of post-anthesis water stress on yield regulating processes in wheat (Triticum aestivum L.). Ph.D. Thesis. University of London, Ashford, U.K.
• Alexander LV, Zhang X, Peterson TC, Caesar J, Gleason B, Tank A, Haylock M, Collins D, Trewin B, Rahimzadeh F, Tagipour A, Kumar KR, Revadekar J, Griffiths G, Vincent L, Stephenson DB, Burn J, Aguilar E, Brunet M, Taylor M, New M, Zhai P, Rusticucci M, Vazquez-Aguirre JL (2006). Global observed changes in daily climate extremes of temperature and precipitation. J. Geophys. Res. Atmos. 111:1-22.
• Ali Benali MA, Alary R, Joudrier P, Gautier MF (2005). Comparative expression of five lea genes during wheat seed development and in response to abiotic stresses by real-time quantitative RT-PCR. Biochim.Biophys.Acta.1730:56–65.
• Al Khatib K, Paulsen GM (1984). Mode of high temperature injury to wheat during grain development. Plant Physiol. 61:363-368.
• Al Khatib K, Paulsen GM (1990). Photosynthesis and productivity during high-temperature stress of wheat genotypes from major world regions. Crop Sci. 30:1127-1132.
• Al Khatib K, Paulsen GM (1999). High-temperature effects on photosynthetic processes in temperate and tropical cereals. Crop Sci. 39:119-125.
• Allakhverdiev SI, Kreslavski VD, Klimov VV, Los DA, Carpentier R, Mohanty P (2008). Heat stress: An overview of molecular responses in photosynthesis. Photosynth. Res. 98:541-550.
• Almeselmani M, Deshmukh PS, Sairam RK (2009). High temperature stress tolerance in wheat genotypes: role of antioxidant defence enzymes. ActaAgron. Hung. 57:1-14.
• Annual Climate Summary (2010). Issued by National Climate Centre Office of the Additional Director General of Meteorology (Research) India Meteorological Department, Pune-411 005.
• Araus JL (1996). Integrative physiological criteria associated with yield potential. In: Reynolds MP, Rajaram S, McNab A (eds.), Increasing yield potential in wheat: breaking the barriers. Workshop Proc.,Cd. Obregon, Mexico, 28-30
• Mar. 1996, Mexico, DF, CIMMYT, pp 150-166. Bahieldin A, Mahfouz HT, Eissa HF etal. (2005). Field evaluation of transgenic wheat plants stably expressing the HVA1 gene for drought tolerance. Physiol. Plant 123(4):421-427.
• Balla K, Bencze S, Janda T, Veisz O (2009). Analysis of heat stress tolerance in winter wheat. ActaAgron. Hung. 57:437-444.
• Balla K, Karsai I, Bencze S, Veisz O (2012). Germination ability and seedling vigour in the progeny of heat-stressed wheat plants. J.Acta.Agron. Hung. 60(4):299-308.
• Barnab´as B, J¨ager K, Feh´er A (2008). The effect of drought and heat stress on reproductive processes in cereals. Plant Cell Environ. 31:11-38.
• Bennett D, Izanloo A, Edwards J, Kuchel H, Chalmers K, Tester M, Reynolds MP, Schnurbusch T, Langridge P (2011). Identification of novel quantitative trait loci for days to ear emergence and flag leaf glaucousness in a bread wheat (Triticum aestivum L.) population adapted to southern Australian conditions. Theor. Appl. Genet. 124:1-15.
• Borojevic K, Borojevic K (2005). The transfer and history of “reduced height genes” (Rht) in wheat from Japan to Europe. J. Heredity. 96:455-459.
• Bota J, Flexas J, Medrano H (2004). Is photosynthesis limited by decreased Rubisco activity and RuBP content under progressive water stress? New Phytol. 162:671-681.
• Brini F, Saibi W, Amara I, Gargouri A, Masmoudi K, Hanin M (2010). Wheat dehydrin dhn-5 exerts a heat-protective effect on β-glucosidase and glucose oxidase activities. Biosci.Biotechnol. Biochem. 74:1050-1054.
• Budak H, Akpinar BA, Unver T, Turktas M (2013). Proteome changes in wild and modern wheat leaves upon drought stress by two-dimensional electrophoresis and nano LC-ESI-MS/MS. Plant Mol. Biol. 83(1-2):89-103.
• Budak H, Kantar M, KurtogluKY (2013). Drought tolerance in modern and wild wheat. The Scientific World Journal 2013:1-16.
• Byrne PF, Butler JD, Anderson GR, Haley SD (2002). QTLs for agronomic and morphological traits in spring wheat population derived from a cross of heat tolerant and heat sensitive lines. In: Plant, Animal and Microbe Genomes X Conference, San Diego, CA, pp 388.
• Campalans A, Pages M, Messeguer R (2001). Identification of differentially expressed genes by the cDNA-AFLP technique during dehydration of almond (Prunus amygdalus). Tree Physiol. 21:633-643.
• Campbell SA, Close TJ (1997). Dehydrins: genes, proteins and associations with phenotypic traits. New Phytologist, 137(1):61-74.
• Chauhan H, Khurana P (2011). Use of doubled haploid technology for development of stable drought tolerant bread wheat (Triticum aestivum L.) transgenics. Plant Biotechnology Journal 9(3):408-417.
• Chaves MM, Maroco JP and Pereira JS (2003). Understanding plant response to drought. Funct. Plant Biol. 30: 239-64.
• Chen S, Harmon AC (2006). Advances in plant proteomics. Proteomics 6(20):5504-16.
• Cheng WH, Endo A, Zhou L, Penny J, Chen HC, Arroyo A, Leon P, Nambara E, Asami T, Seo M, Koshiba T, Sheen J (2002). A unique short-chain dehydrogenase/reductase in Arabidopsis glucose signaling and abscisic acid biosynthesis and functions. The Plant Cell. 14(11):2723-2743.
• Chinnusamy V, Schumaker K, Zhu JK (2004). Molecular genetic perspectives on cross-talk and specificity in abiotic stress signaling in plants. J. Exp. Bot. 55(395):225-236.
• Ciuca M, Petcu E (2009). SSR markers associated with membrane stability in wheat (Triticum aestivum L.). Romanian Agricultural Research 26: 21-24.
• Coca M, Almoguera C, Thomas T, Jordano J (1996). Differential regulation of small heat shock genes in plants: Analysis of a water stress inducible and developmentally activated sunflower promoter. Plant Mol. Biol. 31:863-876.
• Cochard H, Venisse JS, Barigah TS, Brunel N, Herbette S, Guilliot A, Tyree MT, Sakr S (2007). Putative role of aquaporins in variable hydraulic conductance of leaves in response to light. Plant Physiol. 143:122-133.
• Cornic G (2000). Drought stress inhibits photosynthesis by decreasing stomatal aperture not by affecting ATP synthesis. Trends Plant Sci. 5:187-188.
• Curry J, Morris CF, Walker Simmons MK (1991).Sequence analysis of a cDNA encoding a group 3 LEA mRNA inducible by ABA or dehydration stress in wheat. Plant Mol. Biol. 16(6):1073-1076.
• Dashti H, Yazdi-Samadi B, Ghannadha M, Naghavi M, Quarri S (2007). QTL analysis for drought resistance in wheat using doubled haploid lines. Int. J. Agric. Biol. 9:98-102.
• Del Blanco IA, Rajaram S, Kronstad WE, Reynolds MP (2000). Physiological performance of synthetic hexaploid wheat derived populations. Crop Sci. 40:1257-1263.
• Demirevska K, Zasheva D, Dimitrov R, Simova-Stoilova L, Stamenova M, Feller U (2009). Drought stress effects on Rubisco in wheat: changes in the Rubisco large subunit. Acta Physiol. Plant.31: 1129-1138.
• Dhanda SS, Munjal R (2006). Inheritance of cellular thermotolerance in bread wheat. Plant Breed. 125:557-564.
• Dias AS, Lidon FC (2009). Evaluation of grain filling rate and duration in bread and durum wheat, under heat stress after anthesis. J. Agron. Crop Sci. 195:137-147.
• Ehdaie B, Alloush GA, Madore MA, Waines JG (2006). Genotypic variation for stem reserves and mobilization in wheat: Post-anthesis changes in Internode dry matter. Crop Sci. 46:735-746.
• Farooq M, Wahid A, Kobayashi N, Fujita D, Basra SMA (2009). Plant drought stress: effects, mechanisms and management. Agron. Sustain. Dev. 29:185-212.
• Fleury D, Jefferies S, Kuchel H, Langridge P (2010). Genetic and genomic tools to improve drought tolerance in wheat. J. Exp. Bot. 61(12):3211-3222.
• Flexas J, Bota J, Loreto F, Cornic G, Sharkey TD (2004). Diffusive and metabolic limitations to photosynthesis under drought and salinity in C3 plants. Plant Biol. 6:1-11.
• 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, Proc. Natl. Acad. Sci. USA. 99:15898-15903.
• Gasperini D, Greenland A, Hedden P, Dreos R, Harwood W, Griffiths S (2012). Genetic and physiological analysis of rht8 in bread wheat: An alternative source of semi- dwarfism with a reduced sensitivity to brassinosteroids. J. Exp. Bot. 63:4419-4436.
• Gulnaz S, Sajjad M, Khaliq I, Khan AS, Khan SH (2011). Relationship among coleoptile length, plant height and tillering capacity for developing improved wheat varieties. International Journal of Agriculture and Biology 13(1):130-133.
• Guo P, Baum M, Grando S et al. (2009). Differentially expressed genes between drought-tolerant and drought-sensitive barleygenotypes in response to drought stress during the reproductive stage. J. Exp. Bot. 60(12):3531-3544.
• Habash DZ, Kehel Z, Nachit M (2009). Genomic approaches for designing durum wheat ready for climate change with a focus on drought. J. Exp. Bot. 60(10):2805-2815.
• Hakeem KR, Chandna R, Ahmad P, Iqbal M, Ozturk M (2012). Relevance of proteomic investigations in plant abiotic stress physiology. OMICS. 16(11):621-35.
• Halford NG (2009). New insights on the effects of heat stress on crops. J. Exp. Bot. 60:4215-4216. Hansen J, Sato MK, Ruedy R (2012). Perception of climate change. Proc. Natl. Acad. Sci. 109:14726-14727.
• Hays D, Mason E, Hwa Do J, Menz M, Reynolds M (2007). Expression quantitative trait loci mapping heat tolerance during reproductive development in wheat (T. aestivum). In: Buck HT, Nisi JE, Salomo’n N (eds.), Wheat production in stressed environments. Springer, Amsterdam, pp 373-382.
• Hennessy K, Fawcett R, Kirono D, Mpelasoka F, Jones D, Bathols J, Whetton P, Stafford Smith M, Howden M, Mitchell C, Plummer N (2008).
• An assessment of the impact of climate change on the nature and frequency of exceptional climatic events. CSIRO and Bureau of Meteorology, http://www.daff.gov.au/ data/assets/ pdf file/0007/721285/csirobom-report-future-droughts.pdf Hoisington D, Ortiz R (2008). Research and field monitoring on transgenic crops by the Centro Internacional de Mejoramiento de Ma´ızyTrigo (CIMMYT). Euphytica 164(3):893-902.
• Hong Bo S, Xiao Yan C, Li Ye C, Xi Ning Z, Gang W, Yong-Bing Y, Chang-Xing Z, Zan-Min H (2006). investigation on the relationship of proline with wheat anti-drought under soil water deficits. Coll. Surf. B. 53:113-119.
• Ji X, Shiran B, Wan J, Lewis DC, Jenkins CLD, Condon AG, Richard RA, Dolferus R (2010). Importance of pre-anthesis anther sink strength for maintenance of grain number during reproductive stage water stress in wheat. Plant, Cell Environ. 33(6):926-942.
• Jiang SS, Liang XN, Li X et al. (2012). Wheat drought-responsive grain proteome analysis by linear and nonlinear 2-DE and MALDI-TOF mass spectrometry. International Journal of Molecular Sciences, 13(12):16065–16083.
• Kam J, Gresshoff P, Shorter R, Xue GP (2007). Expression analysis of RING zinc finger genes from Triticum aestivum and identification of TaRZF70 that contains four RING-H2 domains and differentially responds to water deficit between leaf and root. Plant Sci. 173 (6):650–659.
• Kaur N, Gupta AK (2005). Signal transduction pathways under abiotic stresses in plants. Curr. Sci. 88:1771-1780.
• Kaur V, Behl RK (2010). Grain yield in wheat as affected by short periods of high temperature, drought and their interaction during preand post-anthesis stages. Cereal Res. Comm. 38(4):514-520.
• Kaur V, Behl RK, Singh S, Madaan S (2011). Endosperm and pericarp size in wheat (Triticum aestivum L.) grains developed under high temperature and drought stress conditions. Cereal Res. Comm. 39(4):515-524.
• Kosová K, Vítámvás P, Prášil IT, Renaut J (2011). Plant proteome changes under abiotic stress-contribution of proteomics studies to understanding plant stress response. J. Proteomics 74(8):1301-22.
• Kumar U, Joshi AK, Kumari M, Paliwal R, Kumar S, Röder MS (2010). Identification of QTLs for stay green trait in wheat (Triticum aestivum L.) in the ‘Chirya 3’ x ‘Sonalika’ population. Euphytica 174:437-445.
• Lata C, Prasad M (2011). Role of DREBs in regulation of abiotic stress responses in plants. J. Exp. Bot. 62:4731-4748.
• Lawlor DW, Cornic G (2002). Photosynthetic carbon assimilation and associated metabolism in relation to water deficits in higher plants. Plant, Cell Environ. 25(2):275-294.
• Li Z, Peng T, Xie Q, Han S, Tian J (2010). Mapping of QTL for tiller number at different stages of growth in wheat using double haploid and immortalized F2 populations. J. Genet. 89:409-415.
• Litts JC, Colwell GW, Chakerian RL, Quatrano RS (1987). The nucleotide sequence of a cDNA clone encoding the wheat Em protein. Nucleic Acids Research 15 (8):3607-3618.
• Machado S, Paulsen GM (2001). Combined effects of drought and high temperature on water relations of wheat and sorghum. Plant Soil 233:179–187
• Maestri E, Klueva N, Perrotta C, Gulli M, Nguyen HT, Marmiroli N (2002). Molecular genetics of heat tolerance and heat shock proteins in cereals. Plant Mol. Biol. 48:667-681.
• Mart´ınez Ballesta MC, L´opez P´erez L, Muries B, Mu˜noz Azcarate O, Carvajal M (2009). Climate change and plant water balance: the role of aquaporins -a review. In: Climate Change, Intercropping, Pest Control and Beneficial Microorganisms. Lichtfouse E, (Ed.), Springer, Netherlands. Mitra R, Bhatia CR (2008). Bioenergetic cost of heat tolerance in wheat crop. Curr. Sci. 94:1049-1053.
• Mittler R (2002). Oxidative stress, antioxidants and stress tolerance. Trends Plant Sci. 7:405-410. Mohammadi M, Karimizadeh RA, Naghavi MR (2009). Selection of bread wheat genotypes against heat and drought tolerance on the base of chlorophyll content and stem reserves. J. Agric. Soc. Sci. 5:119-122.
• Mohammadi V, Zali AA, Bihamta MR (2008b). Mapping QTLs for heat tolerance in wheat. J. Agric. Sci. Technol. 10:261-267.
• Morgan J, Tan M (1996). Chromosomal location of a wheat osmoregulation gene using RFLP analysis. Funct. Plant Biol. 23:803- 806.
• Nayyar H, Walia DP (2003). Water stress induced proline accumulation in contrasting wheat genotypes as affected by calcium and abscisic acid. Biol. Plant. 46:275-279.
• Ober ES, Setter TL, Madison JT, Thompson JF, Shapiro PS (1991). Influence of water deficit on maize endosperm development. Enzyme activities and RNA transcripts of starch and zein synthesis, abscissic acid and cell division. Plant Physiol. 97:154-164.
• Paliwal R, Röder MS, Kumar U, Srivastava JP, Joshi AK (2012). QTL mapping of terminal heat tolerance in hexaploid wheat (T. aestivum L.). Theor. Appl. Genet. 125:561-575.
• Pellegrineschi A, Reynolds M, Pacheco M et al. (2004). Stress induced expression in wheat of the Arabidopsis thaliana DREB1A gene delays water stress symptoms under greenhouse conditions. Genome 47(3):493–500.
• Pinto RS, Reynolds MP, Mathews KL, McIntyre CL, Olivares Villegas J J, Chapman SC (2010). Heat and drought adaptive QTL in a wheat population designed to minimize confounding agronomic effects. Theor. Appl. Genet. 121:1001-1021.
• Pittock B (2003). Climate Change: An Australian Guide to the Science and Potential of Impacts. Department for the Environment and Heritage, Australian Greenhouse Office, Canberra, ACT.http://www. greenhouse.gov.au/science/guide/index.html
• Praba ML, Cairns JE, Babu RC, Lafitte HR (2009). Identification of physiological traits underlying cultivar differences in drought tolerance in rice and wheat. J. Agron. Crop Sci. 195:30-46.
• Prasad PVV, Staggenborg SA, Ristic Z (2008b). Impacts of drought and/or heat stress on physiological, developmental, growth, and yield processes of crop plants. In: Response of crops to limited water: Understanding and modeling water stress effects on plant growth processes, Advances in Agricultural Systems Modeling Series 1. ASA, CSSA, SSSA, Madison, WI.
• Rad RN, Kadir MA, Jaafar HZ, Gement D (2012). Physiological and biochemical relationship under drought stress in wheat (Triticum aestivum L.). Afr. J. Biotechnol. 11:1574-1578.
• Ramanjulu S, Bartels D (2002). Drought and desiccation induced modulation of gene expression in plants. Plant Cell Environ. 25:141-151.
• Rampino P, Mita G, Pataleo S, Pascali MD, Fonzo ND, Perrotta C (2009). Acquisition of thermotolerance and HSP gene expression in durum wheat (Triticum durum Desf.) cultivars. Environ. Exp. Bot. 66:257-264.
• Rebetzke G, Rattey A, Farquhar G, Richards R, Condon T (2012). Genomic regions for canopy temperature and their genetic association with stomatal conductance and grain yield in wheat. Funct. Plant Biol. 40:14-33.
• Reynolds M, Tuberosa R (2008). Translational research impacting on crop productivity in drought-prone environments. Curr.Opin. Plant Biol. 11(2):171-179.
• Reynolds MP, Balota M, Delgado MIB, Amani I, Fischer RA (1994). Physiological and morphological traits associated with spring wheat yield under hot, irrigated conditions. Aust. J. Plant Physiol. 21:717-730.
• Reynolds MP, Rebetzke G (2011). Application of plant physiology in wheat breeding. In: Bonjean AP, Angus WJ, Van Ginkel M (eds.), The World Wheat Book: A History of Wheat Breeding, Vol 2. Editions TEC, Paris, pp 877-906.
• Richards RA (1996). Defining selection criteria to improve yield under drought. Plant Grow Reg 20:157-166.
• Ried JL, Walker Simmons MK (1993). Group 3 late embryogenesis abundant proteins in desiccation-tolerant seedlings of wheat (Triticum aestivum L.). Plant Physiol. 102(1):125-131.
• Rijven AHG (1986). Heat inactivation of starch synthase in wheat endosperm. Plant Physiol. 81:448-453.
• Ristic Z, Bukovnik U, Prasad PVV (2007). Correlation between heat stability of thylakoid membranes and loss of chlorophyll in winter wheat under heat stress. Crop Sci. 47:2067-2073.
• Röder MS, Huang XQ, Börner A (2008). Fine mapping of the region on wheat chromosome 7D controlling grain weight. FunctIntegr Genomics 8:79-86.
• Sadat S, Saeid KA, Bihamta MR, Torabi S, Salekdeh SGH, Ayeneh GAL (2013). Marker assisted selection for heat tolerance in bread wheat. World App Sci J 21(8):1181-1189.
• Sairam RK, Srivastava GC, Saxena DC (2000). Increased antioxidant activity under elevated temperature: A mechanism of heat stress tolerance in wheat genotypes. Biol. Plant. 43:245-251.
• Sawahel WA, Hassan AH (2002). Generation of transgenic wheat plants producing high levels of the osmoprotectant proline. Biotechnol. Let. 24:721-725.
• Seki M, Narusaka M, Ishida J, Nanjo T, Fujita M, Oono Y, Kamiya A, Nakajima M, Enju A, Sakurai T, Satou, M, Akiyama K, Taji T, Yamaguchi-Shinozaki K, Carninci P, Kawai J, Hayashizaki Y, Shinozaki K (2002). Monitoring the expression profiles of 7000 Arabidopsis genes under drought, cold and high salinity stresses using a full length cDNA microarray. Plant J. 31(3):279-292.
• Semenov MA, Halford NG (2009). Identifying target traits and molecular mechanisms for wheat breeding under a changing climate. J. Exp. Bot. 60:2791-2804.
• Shah NH, Paulsen GM (2003). Interaction of drought and high temperature on photosynthesis and grain filling of wheat. Plant and Soil, 257:219-226.
• Shanahan JF, Edwards IB, Quick JS, Fenwick JR (1990). Membrane thermostability and heat tolerance of spring wheat. Crop Sci. 30:247-251.
• Shao HB, Chu LY, Jaleel CA, Manivannan P, Panneerselvam R, Shao MA (2009). Understanding water deficit stress induced changes in the basic metabolism of higher plants-biotechnologically and sustainably improving agriculture and the eco-environment in arid regions of the globe. Crit. Rev. Biotechnol. 29:131-151.
• Shigeoka S, Ishikawa T, Tamoi M, Miyagawa Y, Takeda T, Yabuta Y, Yoshimura K (2002). Regulation and function of ascorbate peroxidase isoenzymes. J. Exp. Bot. 53:1305-1319.
• Sivamani E, Bahieldin A, Wraith JM, Al-Niemi T, Dyer WE, Ho THD, Qu R (2000). Improved biomass productivity and water use efficiency under water deficit conditions in transgenic wheat constitutively expressing the barley HVA1 gene. Plant Sci. 155:1-9.
• Sun W, Bernard C, van de Cotte, Van Montagu M, Verbruggen N (2001). At-HSP17.6A, encoding a small heat-shock protein in Arabidopsis, can enhance osmotolerance upon overexpression. Plant J. 27:407-415.
• Szabados L, Savoure A (2010). Proline: a multifunctional amino acid. Trends Plant Sci. 15(2):89-97. Szegletes ZS, Erdei L, Tari I, Cseuz L (2000). Accumulation of osmoprotectants in wheat cultivars of different drought tolerance. Cereal Res. Comm. 28(4):403-410.
• Tahir ISA, Nakata N (2005). Remobilization of nitrogen and carbohydrate from stems of bread wheat in response to heat stress during grain filling. J. Agron. Crop Sci. 191:106-115.
• Tewolde H, Fernandez CJ, Erickson CA (2006). Wheat cultivars adapted to post-heading high temperature stress. J. Agron. Crop Sci. 192:111-120.
• Tsunewaki K, Ebana K (1999). Production of near-isogenic lines of common wheat for glaucousness and genetic basis of this trait clarified by their use. Genes. Genet. Syst. 74:33-41.
• Viswanathan C, Khanna-Chopra R (2001). Effect of heat stress on grain growth, starch synthesis and protein synthesis in grains of wheat (Triticum aestivum L.) varieties differing in grain weight stability. J. Agron. Crop Sci. 186:1-7.
• Wahid A, Gelani S, Ashraf M, Foolad MR (2007). Heat tolerance in plants: an overview. Environ. Exp. Bot. 61:199-223.
• Wang W, Vinocur B, Shoseyov O, Altman A (2004). Role of plant heat shock proteins and molecular chaperones in the abiotic stress response. Trends Plant Sci. 9:244-252.
• Wang Y, Xu H, Zhang G, Zhu H, Zhang L, Zhang Z, Zhang C, Ma Z (2009). Expression and responses to dehydration and salinity stresses of V-PPase gene members in wheat. Journal of Genetics and Genomics 36(12):711-720.
• Wei B, Jing R, Wang C et al. (2009). Dreb1 genes in wheat (Triticum aestivum L.): development of functional markers and gene mapping based on SNPs. Molecular Breeding 23(1):13-22.
• Wilkinson S, Davies WJ (2002). ABA-based chemical signalling: the co-ordination of responses to stress in plants. Plant Cell Environ. 25:195-210.
• Wollenweber B, Porter JR, Schellberg J (2003). Lack of interaction between extreme high-temperature events at vegetative and reproductive growth stages in wheat. J. Agron. Crop Sci. 189:142-150.
• Yang J, Sears RG, Gill BS, Paulsen GM (2002b). Quantitative and molecular characterization of heat tolerance in hexaploid wheat. Euphytica 126:275-282.
• Yang J, Zhang J (2006). Grain filling of cereals under soil drying.New Phytologist. 169:223-236.
• Yordanov I, Velikova V, Tsonev T (2000). Plant responses to drought, acclimation, and stress tolerance. Photosynthetica. 38(2):171-186.
• Zhu JK (2001). Plant salt tolerance. Trends Plant Sci. 6:66-71