Wheat, an important food crop in the world, accounting for one-fifth of the total calories and protein, is a sensitive culture to the lack of soil moisture. Drought impairs plant growth and development, affects physiological and biochemical processes and reduces plant productivity. Photosynthetic assimilation of CO2 is considered to be one of the physiological processes most sensitive to drought. This review is devoted to the analysis of literature data and the results of own works on the effect of drought on the wheat photosynthetic apparatus traits at different levels of its organization — from morphological to molecular. The relevance of research on traits associated with drought resistance is due to a significant, compared to other abiotic factors, yield reduction due a drought, the frequency of dry conditions during the wheat growing season, the complex nature response of this culture’s to drought, and the need to accelerate the breeding process. The analysis of the morphological traits of the photosynthetic apparatus proves that, in addition to the direct effect of this stress on the plant assimilation surface area, it also affects the absorption and efficiency of the conversion of light energy into biomass, and also depends on the remobilization of photosynthetically assimilated carbon from the non-leafy organs of wheat. While the integral indicator — a photosynthesis rate — reduced under drought stress (the magnitude of this decrease depends on the genotype, the stage of plant development and the stress severity), individual components of photosynthetic activity can be differently. In particular, the non-photochemical quenching of chlorophyll a fluorescence in diverse wheat lines under drought conditions had a multidirectional nature. The promising features of wheat drought tolerance discovered in recent years are considered, in particular, long-term rearrangements of the photosynthetic apparatus, including changes in the structure of PSII-LHCII phosphorylation along with protein stoichiometry. The review also considered the role of antioxidant enzymes of chloroplasts, which prevent drought-induced accumulation of reactive oxygen species and thus prevent functional and structural changes in chloroplasts, chlorophyll degradation, and disruption of the integrity of thylakoid membranes. According to the literature, the role of organic and inorganic substances in maintaining the osmoregulation of plants in the water deficit was considered and the probable mechanisms of their action were analyzed. Quantitative trait loci associated with wheat drought tolerance DNA markers as mechanisms of drought tolerance in wheat are also described. Therefore, the analysis of literature and own data showed that tolerance of the photosynthetic apparatus to drought in different genotypes of wheat may be associated with different mechanisms. It is hypothesized that the combination of several/some mechanisms in one genotype offers a promising strategy for increasing crop resistance.
Keywords: wheat, drought, specific mass of leaves, photosynthesis, photosynthetic activity, antioxidant protection, osmoregulation
Full text and supplemented materials
Free full text: PDFReferences
1. http://www.fao.org/3/cb1329en/online/cb1329en.html#chapter-2_1
2. Ivanyuta, S.P. (Ed.). (2020). Climate change: consequences and adaptation measures: analytic report. Kyiv: NISD [in Ukrainian].
3. Giraldo, P., Benevente, E., Manzano-Agugliaro, F. & Gimenes, E. (2019). Worldwide researche trends in wheat and barley: a bibliometric comparative analisys. Agronomie, 9 (7), No. 352, pp. 1-18. https://doi.org/10.3390/agronomy9070352
4. Rauf, S., Zaharieva, M. & Warburton, M.L. (2015). Breaking wheat yield barriers required integrates efforts in developed countries. J. Int. Agricult., 14, No. 8, pp. 1447-1474. https://doi.org/10.1016/S2095-3119(15)61035-8
5. FAO. (2020). Food outlook - biannual report on global food markets: June 2020. Food Outlook. Rome. https://doi.org/10.4060/ca9509en
6. Shiferaw, B., Smale, M., Braun, H.J., Duveiller, E., Reynolds, M.P. & Muricho, G. (2013). Crops that feed the world 10: Past successes and future challenges to the role played by wheat in global food security. Food Security, 5, No. 3, pp. 291-317. https://doi.org/10.1007/s12571-013-0263-y
7. Morgun, V.V. & Rybalka, O.I. (2017). Strategy of cereals improvement aimed at food safety, health promotion and industry needs. Visn. Nac. Acad. Nauk Ukr., 3, pp. 54-64 [in Ukrainian]. https://doi.org/10.15407/visn2017.03.054
8. Rybalka, O.I. (2009). Genetic improvement of wheat quality. (Extended abstract of Doctor thesis). Plant Breeding and Genetics Institute. National Center of Seed and Cultivar Investigation. Odesa [in Ukrainian].
9. Likhochvor, V.V. & Prots, R.R. (2006). Winter wheat. Lviv: IAF-Ukrainian Technologies [in Ukrainian].
10. Shelepov, V.V., Gavrilyuk, N.N. & Vergunov, V.A. (2013). Wheat: biology, morphology, selection, seed production. Kyiv: Logos [in Ukrainian].
11. Zhyvotkov, L.A. (Ed.). (1989). Wheat. Kyiv: Urozhau [in Ukrainian].
12. Zulkiffal, M., Ahsan, A. & Ahmad, J. (2021). Heat and drought stresses in wheat (Triticum aestivum L.) substantial yield losses, practical achievements, improvement approaches, and adaptive mechanisms. In Plant Stress Physiology, Hossain, Akbar. (Ed.). Chapter 1, pp. 1-24. https://doi.org/10.5772/intechopen.92378
13. Zampieri, M., Ceglar, A., Dentener, F. & Toreti, A. (2017). Wheat yield loss attributable to heat waves, drought and water excess at the global, national and subnational scales. Environ. Res. Lett., 12, No. 6, pp. 064008. https://doi.org/10.1088/1748-9326/aa723b
14. Feller, U. (2019). Drought stress and carbon assimilation in a warming climate: Reversible and irreversible impacts. J. Plant Physiol., 203, pp. 84-94 https://doi.org/10.1016/j.jplph.2016.04.002
15. Reynolds, M.P., Quilligan, E., Aggarwal, P.K., Kailash, C., Bansal, K.C., Cavalieri, A.J., Chapman, S.C., Chapotin, S.M., Datta, S.K., Duveiller E., Gill, K.S., Jagadish, K.S.V., Joshi, A.K., Koehler, A.-K., Kosina, P., Krishnan, S., Lafitte, R., Mahala, R.S., Muthurajan, R., Paterson, A.H., Prasanna, B.M., Rakshit, S., Rosegrant, M.W., Sharma, I., Singh, R.P., Sivasankar, S., Vadez, V., Ravi Valluru, R., Prasad, P.V. & Yadav, O.P. (2016). An integrated approach to maintaining cereal productivity under climate change. Glob. Food Security, 8, pp. 9-18. https://doi.org/10.1016/j.gfs.2016.02.002
16. Farooq, M., Hussian, M. & Siddik, C.H.M. (2014). Drought stress in wheat during flowering and grain-filling periods. Critical Rev. Plant Sci., 33, No. 4, pp. 331-349. https://doi.org/10.1080/07352689.2014.875291
17. Almeselmani, M., Saud, A., Al-Zubi, K., Hareri, F., Al-Nassan, M., Ammar, M., Kanbar, O., Al-Naseef, H., Al-Nator, A., Al-Gazawy, A. & Al-Sael, A. (2012). Physiological attributes associated to water deficit tolerance of syrian durum wheat varieties. Exp. Agricult. Horticult., 5, pp. 21-41. https: // doi.org/1929-0861-2012-08
18. Kapoor, D., Bhardwaj, S., Landi, M., Sharma, A., Ramakrishnan, M. & Sharma, A. (2020). The impact of drought in plant metabolism: how to exploit tolerance mechanisms to increase crop production. Applied Sci., 10, No. 16, p. 5692. https://doi.org/10.3390/app10165692
19. Negisho, K. & Daksa, J. (2018). Morphological, physiological, biochemical and molecular responses of wheat vs drought stresses. J. Natur. Sci. Res., 8, No. 9, pp. 42-50.
20. Sallam, A., Alqudah, A.M., Dawood, M.F.A., Baenziger, P.S. & Borner, A. (2019). Drought stress tolerance in wheat and barley: advances in physiology, breeding and genetics research. J. Mol. Sci., 20, p. 3137. https://doi.org/10.3390/ijms20133137
21. Figueroa-Bustos, V., Palta, J.A., Chen, Y., Stefanova, K. & Siddique, K.H.M. (2020). Wheat cultivars with contrasting root system size responded differently to terminal drought. Front Plant Sci., 11, p. 1285. https://doi.org/10.3389/fpls.2020.01285
22. Khakwani, A.A., Dennett, M., Munir, M. & Abid, M. (2012). Growth and yield response of wheat varieties to water stress at booting and anthesis stages of development. Pakistan J. Bot., 44, pp. 879-886.
23. Liu, H., Searle, I.R., Mather, D.E., Able, A.J. & Able, J.A. (2015). Morphological, physiological and yield responses of durum wheat to pre-anthesis water-deficit stress are genotype-dependent. Crop Pasture Sci., 66, pp. 1024-1038. https://doi.org/10.1071/CP15013
24. Nezhadahmadi, A., Prodhan, Z.H. & Faruq, G. (2013). Drought tolerance in wheat. Sci. World J., 2013, pp. 1-12. https://doi.org/10.1155/2013/610721
25. Morgun, V.V., Priadkina, G.A. & Zborivska, O.V. (2019). Depositing ability of stem of winter wheat varieties of different periods of selection. Reg. Mech. Bio., 10, No. 2, pp. 239-244. https://doi.org/10.15421/021936
26. Dalirie, M.S., Sharifi, R.S. & Farzaneh, S. (2010). Evaluation of yield, dry matter accumulation and leaf area index in wheat genotypes as affected by terminal drought stress. Notulae Botanicae Horti Agrobotanici Cluj-Napoca, p. 38. https://doi.org/ 10.15835/nbha3814583.
27. Dhyani, K., Shukla, A. & Verma, R.S. (2017). Comparative analysis of changes in leaf area index in different wheat genotypes exposed to high temperature stress by late sown condition. J. Applied Nat. Sci., 9, No. 4, pp. 2410-2413. https://doi.org/10.31018/jans.v9i4.1546
28. Ben-Amar, A., Mahboub, S., Bouizgaren, A., Mouradi, M., Nsarellah, N.E. & El Bouhmadi, K. (2020). Relationship between leaf rolling and some physiological parameters in durum wheat under water stress. African J. Agricult. Res., 16, No. 7, pp. 1061-1068. https://doi.org/10.5897/AJAR2020.14939
29. Guendouz, A., Semcheddine, N., Moumeni, L. & Hafsi, M. (2016). The effect of supplementary irrigation on leaf area, specific leaf weight, grain yield and water use efficiency in durum wheat (Triticum durum Desf.) Ekin J. Crop Breed. Genet., 2, No. 1, pp. 82-89.
30. Ukozehasi, C. (2020). Proxy-based approach to wheat selection for photosynthetic efficiency. Rwanda J. Agricult. Sci., 2, No. 1, pp. 104-114.
31. Priadkina, G.O. & Makharynska, N.M. (2021). Assimilation apparatus of different leaves tyers in winter wheat varieties under adverse environmental conditions. Fiziol. rast. genet., 53, No. 1, pp. 74-86 [in Ukrainian]. https://doi.org/10.15407/frg2021.01.074
32. Amanullah, D.R. (2015). Specific leaf area and specific leaf weight in small grain crops wheat, rye, barley, and oats differ at various growth stages and NPK source. J. Plant Nutr., 38, No. 11, pp. 1964-1708. https://doi.org/10.1080/01904167.2015.1017051
33. Bhattacharya, A. (2019). Chapter 2 - Radiation-use efficiency under different climatic conditions. Changing climate and resource use efficiency in plants. London: Elsevier Ltd. Academic Press. https://doi.org/10.1016/B978-0-12-816209-5.00002-7
34. Shearman, V.J., Sylvester-Bradley, R., Scott, R.K. & Foulkes, M.J. (2005). Physiological processes associated with wheat yield progress in the UK. Crop Sci., 45, pp. 175-185. https://doi.org/10.2135/cropsci2005.0175
35. Priadkina, G.A., Stasik, O.O., Polevoy, A.N., Yarmolskaya, E.E. & Kuzmova, K. (2020). Radiation use efficiency of winter wheat canopy during vegetative growth. Fiziol. rast. genet., 52, No. 3, pp. 208-223. [in Ukrainian]. https://doi.org/10.15407/frg2020.03.208
36. Poorter, H., Niinemets, U., Poorter, L., Wright, I.J. & Villar, R. (2009). Causes and consequences of variation in leaf mass per area (LMA): a meta-analysis. New Phytol., 182, pp. 565-588. https://doi.org/10.1111/j.1469-8137.2009.02830.x
37. Morgun, V.V., Pryadkina, G.A., Stasik, O.O. & Zborivska, O.V. (2019). Relationships between canopy assimilation surface capacity traits and grain productivity of winter wheat genotypes under drought stress. Agricult. Sci. Pract., 6, No. 2, pp. 18-28. https://doi.org/10.15407/agrisp6.02.018
38. Joudi, M. & Van den Ende, W. (2018). Genotypic variation in pre- and post-anthesis dry matter remobilization in Iranian wheat cultivars: associations with stem characters and grain yield. Czech J. Genet. Plant Breed., 54, pp. 123-134. https://doi.org/10.17221/93/2017-CJGPB
39. Kiriziy, D.A. & Stasik, O.O. (2022). Effects of drought and high temperature on physiological and biochemical processes, and productivity of plants. Fiziol. rast. i genet., 54, No. 2, pp. 95-122 [in Ukrainian]. https://doi.org/10.15407/frg2022.02.095
40. Blum, A., Golan, G., Mayer, J., Sinmena, B. & Burra, J. (1989). The drought response of landraces of wheat from the Northern Negev desert in Israel. Euphytica, 43, pp. 87-96. https://doi.org/10.1007/BF00037900
41. Sallam, A., Mervat, H., El-Sayed, H. & Mohamed, O. (2015). Genetic variation of stem characters in wheat and their relation to kernel weight under drought and heat stresses. J. Crop Sci. Biotechnol., 18, pp. 137-146. https://doi.org/10.1007/s12892-015-0014-z
42. Morgun, V.V., Priadkina, G.A. & Zborovska, O.V. (2018). Dependence of main shoot ear grain from stem deposited ability of winter wheat varieties. Ukr. J. Ecol., 8, No. 3, pp. 113-118.
43. Ehdaie, B., Alloush, Ghiath, Madore, M.A. & Waines, J. (2006). Genotypic variation for stem reserves and mobilization in wheat: I. Postanthesis changes in internode dry matter. Crop Sci., 46, pp. 735-746. https://doi.org/10.2135/cropsci2005.04-0033er
44. Morgun, V.V., Tarasiuk, M.W., Priadkina, G.O. & Stasik, O.O. (2022). Depositing capacity of winter wheat stem segments under natural drought during grain filling in Ukrainian forest steppe conditions. Biosystems Diversity, 30, No. 2, pp. 29-38. https://doi.org/10.15421/012217
45. Semcheddine, N. & Hafsi, M. (2014). Effect of supplementary irrigation on agronomical and physiological traits in durum wheat (Triticum durum Desf.) genotypes. J. Agric. Sci., 6, No. 9, pp. 184-197. https://doi.org/10.5539/jas.v6n9p184
46. Budak, H., Hussain, B., Khan, Z., Ozturk, N.Z. & Ullah, N. (2015). From genetics to functional genomics: improvement in drought signaling and tolerance in wheat. Front. Plant Sci., 6, p. 1012. https://doi.org/10.3389/fpls.2015.01012
47. Krupa, N.M., Kirizij, D.A. & Rizhikova, P.L. (2011). The effect of soil drought on carbon dioxide gas exchange, assimilates supply and productivity of winter wheat. Fiziol. biokhim. kult. rast., 43, No. 1, pp. 72-80 [in Ukrainian].
48. Yordanov, I., Velikova, V., Georgieva, K., Ivanov, P., Tsenov, N. & Petrova, T. (2001). Change in CO2 assimilation, transpiration and stomatal resistance of different wheat cultivars experiencing drought under field conditions. J. Plant Physiol., 27, No. 3-4, pp. 20-33.
49. Zhao, W., Liu, L., Shen, Q., Yang, J., Han, X., Tian, F. & Wu J, J. (2020). Effects of water stress on photosynthesis, yield, and water use efficiency in winter wheat. Water, 12, No. 8, p. 2127. https://doi.org/10.3390/w12082127
50. Morgun, V.V., Stasik, O.O., Kiriziy, D.A., Sokolovska-Sergiienko, O.G. & Makharynska, N.M. (2019). Effects of drought at different periods of wheat development on the leaf photosynthetic apparatus and productivity Reg. Mech. in Bio., 10, No. 4, pp. 406-414. https://doi.org/10.15421/021961
51. Pinheiro, C. & Chaves, M.M. (2011). Photosynthesis and drought: can we make metabolic connections from available data? J. Exp. Bot., 62, No. 3, pp. 869-882. https://doi.org/10.1093/jxb/erq340
52. Yu, T.F., Xu, Z.S., Guo, J.K., Wang, Y.X., Abernathy, B., Fu, J.D., Chen, X., Zhou, Y.B., Chen, M., Ye, X.G. & Ma, Y.Z. (2017). Improved drought tolerance in wheat plants over expressing a synthetic bacterial cold shock protein gene SeCspA. Sci. Rep., 7, p. 44050. https://doi.org/10.1038/srep44050
53. Dunn, J., Hunt, L., Afsharinafar, M., Al Meselmani, M., Mitchell, A., Howells, R., Wallington, E., Fleming, A.J. & Gray, J.E. (2019). Reduced stomatal density in bread wheat leads to increased water-use efficiency. J. Exp. Bot., 70, Iss. 18, pp. 4737-4748. https://doi.org/10.1093/jxb/erz248
54. Mafakheri, A., Siosemardeh, A., Bahramnejad, B., Struik, P. & Sohrabi, E. (2010). Effect of drought stress on yield, proline and chlorophyll contents in three chickpea cultivars. Australian J. Crop Sci., 4, pp. 580-585.
55. Ehonen, S., Yarmolinsky, D., Kollist, H. & Kangasjarvi, J. (2019). Reactive oxygen species, photosynthesis, and environment in the regulation of stomata. Antioxid Redox Signal, 30, No. 9, pp. 1220-1237. https://doi.org/10.1089/ars.2017.7455
56. Sade, B., Soylu, S. & Yetim, E. (2011). Drought and oxidative stress. Afr. J. Biotechnol., 10, No. 54, pp. 11102-11109. https://doi.org/10.5897/AJB11.1564
57. Kolupaev, E.U. (2016). Plant cell antioxidants, their role in ROS signaling and plant resistance. Uspekhi sovremennoy biologii, 136, No. 2, pp. 181-198 [in Ukrainian].
58. Rumeau, D., Peltier, G. & Cournac, L. (2007). Chlororespiration and cyclic electron flow around PS I during photosynthesis and plant stress response. Plant, Cell and Environ, 30, No. 9, pp. 1041-1051. https://doi.org/10.1111/j.1365-3040.2007.01675.x
59. Zlatev, Z. & Lidon, F.C. (2012). An overview on drought induced changes in plant growth, water relations and photosynthesis. Emir. J. Food Agric., 24, p. 57-72. https://doi.org/10.9755/ejfa.v24i1.10599
60. Shahzad, A.L.I., Yue-Yue, X.U., Xiang-Cheng, M.A., Qian-Min, J.I.A. & Zhi-Kuan, J.I.A. (2022). Improvement in winter wheat productivity through regulating PSII photochemistry, photosynthesis and chlorophyll fluorescence under deficit irrigation conditions. J. Int. Agr., 21, Iss. 3, pp. 654-665. https://doi.org/10.1016/S2095-3119(20)63409-8
61. Hickey, K., Wood, M., Sexton, T., Sahin, Y., Nazarov, T., Fisher, J., Sanguinet, K.A., Cousins, A., Kirchhoff, H. & Smertenko, A. (2022). Drought tolerance strategies and autophagy in resilient wheat genotypes. Cells, 11, p. 1765. https://doi.org/10.3390/cells11111765
62. Chen, Y.E., Cui, J.M. & Su, Y.Q. (2017). Comparison of phosphorylation and assembly of photosystem complexes and redox homeostasis in two wheat cultivars with different drought resistance. Sci. Rep., 7, pp. 12718. https://doi.org/10.1038/s41598-017-13145-1
63. Makharynska, N.M., Pryadkina, G.O., Sytnyk, S.K. & Stasyk, O.O. (2021, June). The influence of micronutrient treatment of plants on the photosynthetic activity of winter wheat under the influence of drought. Materials of the international scientific conference «Current problems of plant physiology and genetics», dedicated to the 75th anniversary of the Institute of Plant Physiology and Genetics of the National Academy of Sciences of Ukraine (pp. 39-41), Kiev [in Ukrainian].
64. Paknejad, F., Nasri, M., Moghadam, H.R.T, Zahedi, H. & Alahmadi, M.J. (2007). Effects of drought stress on chlorophyll fluorescence parameters, chlorophyll content and grain yield of wheat cultivars. J. Bio. Sci., 7, pp. 841-847. https://doi.org/10.3923/jbs.2007.841.847
65. Todorova, D., Aleksandrov, V., Anev, S. & Sergiev, I. (2022). Photosynthesis alterations in wheat plants induced by herbicide, soil drought or flooding. Agronomy, 12, p. 390. https://doi.org/10.3390/agronomy12020390
66. Grieco, M., Jain, A., Ebersberger, I. & Teige, M. (2016). An evolutionary view on thylakoid protein phosphorylation uncovers novel phosphorylation hotspots with potential functional implications. J. Exp. Bot., 67, pp. 3883-3896. https://doi.org/10.1093/jxb/erw164
67. Kohzuma, K., Cruz, J.A., Akashi, K., Hoshiyasu, S., Munekage, Y.N., Yokota, A. & Kramer, D.M. (2009). The long-term responses of the photosynthetic proton circuit to drought. Plant Cell Environ., 32, No. 3, pp. 209-219. https://doi.org/10.1111/j.1365-3040.2008.01912.x
68. Goldschmidt-Clermont, M. & Bassi, R. (2015). Sharing light between two photosystems: Mechanism of state transitions. Current Opinion in Plant Biology, 25, pp. 71-78. https://doi.org/10.1016/j.pbi.2015.04.009
69. Grieco, M., Roustan, V., Dermendjiev, G., Rantala, S., Jain, A., Leonardelli, M., Neumann, K., Berger, V., Engelmeier, D., Bachmann, G., Ebersberger, I., Aro, E.M., Weckwerth, W. & Teige, M. (2020). Adjustment of photosynthetic activity to drought and fluctuating light in wheat. Plant, Cell & Environment, 43, No. 6, pp. 1484-1500. https://doi.org/10.1111/pce.13756
70. Terletskaya, N.V., Shcherban, A.B., Nesterov, M.A., Perfil'ev, R.N., Salina, E.A., Altayeva, N.A. & Blavachinskaya, I.V. (2020). Drought stress tolerance and photosynthetic activity of alloplasmic lines T. dicoccum x T. aestivum. Int. J. Mol. Sci., 21, No. 9, p. 3356. https://doi.org/10.3390/ijms21093356
71. Reddy, A.R., Chaitanya, M. & Vivekanandan, M. (2004). Drought-induced responses of photosynthesis and antioxidant metabolism in higher plants. J. Plant Physiol., 161, pp. 189-202. https://doi.org/10.1016/j.jplph.2004.01.013
72. Rehman, S., Bilal, M., Rana, R., Tahir, N., Shah, M., Ayalew, H. & Yan, G. (2016). Cell membrane stability and chlorophyll content variation in wheat (Triticum aestivum L.) genotypes under heat and drought conditions. Crop and Pasture Sci., 67, pp. 225-302. https://doi.org/10.1071/CP15385
73. Sharifi, P. & Mohammadkhani, N. (2016). Effect of drought stress on photosynthesis factors in wheat genotypes during grain anthesis. Cer. Res. Comm., 44, No. 2, pp. 229-239. https://doi.org/10.1556/0806.43.2015.054
74. Yasir, T.A., Wasaya, A., Hussain, M., Ijaz, M., Farooq, M., Farooq, O., Nawaz, A. & Hu, Y.G. (2019). Evaluation of physiological markers for assessing drought tolerance and yield potential in bread wheat. Int. J. Funct. Plant Biol., 25, No. 5, pp. 1163-1174. https://doi.org/10.1007/s12298-019-00694-0
75. Morgun, V.V., Stasik, O.O., Kiriziy, D.A. & Pryadkina, G.O. (2016). Relations between reactions of photosynthetic traits and grain productivity on soil drought in winter wheat varieties contrasting in their tolerance. Fiziol. rast. genet., 48, No. 5, pp. 371-381 [in Ukrainian]. https://doi.org/10.15407/frg2016.05.371
76. 117. Zhang, K., Zhang, Y., Chen, G. & Tian, J. (2009). Genetic analysis of grain yield and leaf chlorophyll content in common wheat. Cereal Res. Communicat., 37, No. 4, pp. 499-511. http://www. jstor.org/stable/ 23789994 https://doi.org/10.1556/CRC.37.2009.4.3
77. El Basyoni, I., Saadalla, M., Baenziger, S., Bockelman, H. & Morsy, S. (2017). Cell membrane stability and association mapping for drought and heat tolerance in a worldwide wheat collection. Sustainability, 9, pp. 1-16. https://doi.org/10.3390/su9091606
78. Singh, M., Srivastava, Jai & Kumar, A. (2008). Cell membrane stability in relation to drought tolerance in wheat genotypes. J. Agr. Crop Sci., 168, pp. 186-190. https://doi.org/10.1111/j.1439-037X.1992.tb00997.x
79. Bilal, M., Iqbal, I., Rana, R.M., Shoaib, U.R., Rehman, Haidery, Q.A., Ahmad, F., Ijaz, A. & Umar, H.M.I. (2015). A comprehensive review of effects of water stress and tolerance in wheat (Triticuma estivum L.). Tropical Plant Research., 2, No. 3, pp. 271-275.
80. Dulai, S., Molnar, I., Pronay, J., Csernak, A., Tarnai, R. & Molnar-Lang, M. (2006). Effects of drought on photosynthetic parameters and heat stability of PSII in wheat and in Aegilops species originating from dry habitats. Act Biol. Szegediensis, 50, pp. 11-17.
81. Qayyum, A., Al Ayoubi, S., Sher, A., Bibi, Y., Ahmad, S., Shen, Z. & Jenks, M.A. (2021). Improvement in drought tolerance in bread wheat is related to an improvement in osmolyte production, antioxidant enzyme activities, and gaseous exchange. Saudi J. Biol. Sci., 28, No. 9, pp. 5238-5249. https://doi.org/10.1016/j.sjbs.2021.05.040
82. Li-Hong, Li, Hui-Lan, Yi, Xiu-Pingk, Liu. & Hong-Xue, Qi. (2021). Sulfur dioxide enhance drought tolerance of wheat seedlings through H2S signaling. Ecotoxicology and Environmental Safety, 207, pp. 111248. https://doi.org/10.1016/j.ecoenv.2020.111248
83. Abid, M., Ali, S., Qi, L.K., Zahoor, R., Tian, Z., Jiang, D., Snider, J.L. & Dai, T. (2018). Physiological and biochemical changes during drought and recovery periods at tillering and jointing stages in wheat (Triticum aestivum L.). Scientific Reports, 8, No. 1, p. 4615. https://doi.org/10.1038/s41598-018-21441-7
84. Chorfil, A. & Taibi1, K. (2011). Biochemical screening for osmotic adjustment of wheat genotypes under drought stress. Tropicultura, 29, No. 2, pp. 82-87.
85. El Sabagh, A., Hossain, A., Barutcular, C., Gormus, O., Ahmad, Z., Hussain, S., Islam, M., Alharby, H., Bamagoos, A. & Kumar, N. (2019). Effects of drought stress on the quality of major oilseed crops: Implications and possible mitigation strategies. Appl. Ecol. Environ. Res., 17, No. 2, pp. 4019-4043. https://doi.org/10.15666/aeer/1702_40194043
86. Guo, X., Xin, Z., Yang, T., Ma, X., Zhang, Y., Wang, Z., Ren, Y. & Lin, T. (2020). Metabolomics response for drought stress tolerance in chinese wheat genotypes (Triticum aestivum). Plants (Basel)., 9, No. 4, p. 520. https://doi.org/10.3390/plants9040520
87. Smirnov, O., Karpets, L.-A., Zinchenko, A., Kovalenko, M., Belava, V. & Taran, N. (2020). Changes of morphofunctional traits of Triticum aestivum and Triticum dicoccum seedlings caused by polyethylene glycol-modeling drought. J. Central European Agricult., 21, No. 2, pp. 268-274. https://doi.org/10.5513/JCEA01/21.2.2341
88. Ibrahim, H.A. & Abdellafit, Y.M.R. (2016). Effect of maltose and tregalose on growth, yield and some biochemival components of wheat plant under water stress. Ann. Agric. Sci., 61, pp. 267-274. https://doi.org/10.1016/j.aoas.2016.05.002
89. Khamssi, N.N. (2014). Leaf proline content and yield performance of wheat genotypes under irrigated and rainfedconditions. Ind. J. Fund. Appl. LifeSci., 4 (2), pp. 295-299.
90. Zadehbagheri, M., Azarpanah, A. & Javanmardi, S. (2014). Proline metabolite transport an efficient approach in corn yield improvement as response to drought conditions. American-Eurasian J. Agric. & Environ. Sci., 14, No. 5, pp. 476-485. https:// doi.org/10.5829/idosi.aejaes.2014.14.05.12328
91. Hayat, S., Hayat, Q., Alyemeni, M.N., Wani, A.S., Pichtel, J. & Ahmad, A. (2012). Role of proline under changing environments: a review. Plant Signal. Behav., 7, No. 11, pp. 1456-1466. https://doi.org/10.4161/psb.21949
92. Jayant, K.S. & Saranji, S.K. (2014). Effect of drought stress on praline accumulation in peanut genotypes. J. Adv. Res., 2, pp. 301-309.
93. de Carvalho, K., de Campos, M.K.F., Domingues, D.S., Pereira, L.F. & Vieira, L.G.E. (2013). The accumulation of endogenous proline induces changes in gene expression of several antioxidant enzymes in leaves of transgenic Swinglecitrumelo. Mol. Biol. Rep., 40, pp. 3269-3279. https://doi.org/10.1007/s11033-012-2402-5
94. Kadam, S., Shukla, Y., Subhash N., Singh, C. & Suthar K. (2017). Screening of wheat genotypes (Triticum durum L.) in response to drought stress by some physiological and biochemical indices. J. Pure App. Biosci., 5, No. 3, pp. 969-977. https://doi.org/10.18782/2320-7051.2795
95. Shunde, S., Villamor, J.G., Lin, W., Sharma, S. & Verslues, P.E. (2016). Proline coordination with fatty acid synthesis and redox metabolism of chloroplasts and mitochondria. Plant Physiol., 172, pp. 1074-1088. https://doi.org/10.1104/pp.16.01097
96. Monirul, I., Begum, M.C., Kabir, A.H. & Alam, M.F. (2015). Molecular and biochemical mechanisms associated with differential responses to drought tolerance in wheat (Triticum aestivum L.). J. Plant Int., 10, No. 1, pp. 195-201. https://doi.org/10.1080/17429145.2015.1064174
97. Dubrovna, O.V., Stasik, O.O., Priadkina, G.O., Zborivska, O.V. & Sokolovska-Sergienko, O.G. (2020). Resistance of genetically modified wheat plants, containing a double-stranded RNA suppressor of the proline dehydrogenase gene, to soil moisture deficiency. Agricult. Sci. Pract., 7, No. 2, pp. 24-34. https://doi.org/10.15407/agrisp7.02.024
98. Lawson, T. & Matthews, J. (2020). Guard cell metabolism and stomatal function. Annu. Rev. Plant Biol., 71, pp. 273-302. https://doi.org/10.1146/annurev-arplant-050718-100251
99. Wani, S.H., Kumar, V., Shriram, V. & Sah, S.K. (2016). Phytohormones and their metabolic engineering for abiotic stress tolerance in crop plants. Crop J., 4, No. 3, pp. 162-176. https://doi.org/10.1016/j.cj.2016.01.010
100. Geiger, D., Maierhofer, T., Al-Rasheid, K.A., Scherzer, S., Mumm, P., Liese, A., Ache, P., Wellmann, C., Marten, I., Grill, E., Romeis, T. & Hedrich R. (2011). Stomatal closure by fast abscisic acid signaling is mediated by the guard cell anion channel SLAH3 and the receptor RCAR1. Sci. Signal., 4, p. 32. https://doi.org/10.1126/scisignal.2001346
101. Kim, T.H., Bohmer, M., Hu, H., Nishimura, N. & Schroeder, J.I. (2010). Guard cell signal transduction network: advances in understanding abscisic acid, CO2 and Ca2+ signaling. Annu. Rev. Plant Biol., 61, pp. 561-591. https://doi.org/10.1146/annurev-arplant-042809-112226
102. Wilkinson, S. & Davies, W.J. (2009). Drought, ozone, ABA and ethylene: New insights from cell to plant to community. Plant Cell and Environment. 33, No. 4, pp. 510-525. https://doi.org/10.1111/j.1365-3040.2009.02052.x
103. Ji, X., Dong, B., Shiran, B., Talbot, M.J., Edlington, J.E. & Hughes, T. (2011). Control of abscisic acid catabolism and abscisic acid homeostasis is important for reproductive stage stress tolerance in cereals. Plant Physiol., 156, pp. 647-662. https://doi.org/10.1104/pp.111.176164
104. Alam, M.M., Nahar, K., Hasanuzzaman, M. & Fujita, M. (2014). Exogenous jasmonic acid modulates the physiology, antioxidant defense and glyoxalase systems in imparting drought stress tolerance in different Brassica species. Plant Biotechnol., 8, pp. 279-293. https://doi.org/10.1007/s11816-014-0321-8
105. Xie, Z.J., Jiang, D., Cao, W.X., Dai, T.B. & Jing, Q. (2003). Relationships of endogenous plant hormones to accumulation of grain protein and starch in winter wheat under different post-anthesis soil water statuses. Plant Growth Regul., 41, pp. 117-127. https://doi.org/10.1023/A:1027371906349
106. Kagale, S., Divi, U.K., Krochko, J.E., Keller, W.A. & Krishna, P. (2007). Brassinosteroid confers tolerance in Arabidopsisthaliana and Brassica napusto a range of abiotic stresses. Planta, 225, pp. 353-364. https://doi.org/10.1007/s00425-006-0361-6
107. Sairam, S.K. (1994). Effects of homobrassinolide application on plant metabolism and grain yield under irrigated and moisture-stress conditions of two wheat varieties. Plant Growth Regul., 14, pp. 173-181. https://doi.org/10.1111/j.1439-037X.1994.tb00568.x
108. Ulfat, A., Majid, S.A. & Hameed, A. (2017). Hormonal seed priming improves wheat (Triticum aestivum L.) field performance under drought and non-stress conditions. Pak. J. Bot., 49, No. 4, pp. 1239-1253.
109. Tomas, M., Medrano, H., Brugnoli, E., Escalona, J., Martorell, S., Pou, A., Ribas-Cabro, M. & Flexas, J. (2014). Variability of mesohyll conductance in grapevine cultivars under water stress conditions in relation to leaf anatomy and water use efficiency. Aus. J. Grape Wina Res., 20, No. 2, pp. 272-280. https://doi.org/10.1111/ajgw.12069
110. Afzal, Z., Howton, T.C., Sun, Y. & Mukhtar, M.S. (2016). The roles of aquaporins in plant stress responses. J. Dev. Biol., 9, pp. 1-22. https://doi.org/10.3390/jdb4010009
111. Bhargava, S. & Sawant, K. (2013). Drought stress adaptation: Metabolic adjustment and regulation of gene expression. Plant Breeding, 132, pp. 21-32. https://doi.org/10.1111/pbr.12004
112. Kaur, G. & Asthir, B. (2017). Molecular responses to drought stress in plants. Biol Plant., 61, pp. 201-209. https://doi.org/10.1007/s10535-016-0700-9
113. Yang, S., Vanderbeld, B., Wan, J. & Huang, Y. (2010). Narrowing down the targets: Towards successful genetic engineering of drought-tolerant crops. Molecular. Plant., 3, pp. 469-490. https://doi.org/10.1093/mp/ssq016
114. Xu, K., Chen, S., Li, T., Ma, X., Liang, X., Ding, X., Liu, H. & Luo, L. (2015). OsGRAS23, a rice GRAS transcription factor gene, is involved in drought stress response through regulating expression of stress-responsive genes. BMC Plant Biol., 15, p. 141. https://doi.org/10.1186/s12870-015-0532-3
115. Huang, Q., Wang, Y., Li, B., Chang, J., Chen, M., Li, K., Yang, G. & He, G. (2015). TaNAC29, a NAC transcription factor from wheat, enhances salt and drought tolerance in transgenic. Arabidopsis. BMC Plant Biol., 15, p. 268. https://doi.org/10.1186/s12870-015-0644-9
116. Iuchi, S., Kobayashi, M, Taji, T., Naramoto, M., Seki, M., Kato, T., Tabata, S., Kakubari, Y, Yamaguchi-Shinozaki, K. & Shinozaki, K. (2001). Regulation of drought tolerance by gene manipulation of 9-cis-epoxycarotenoid dioxygenase, a key enzyme in abscisic acid biosynthesis in Arabidopsis. Plant J., 27, No. 4, pp.325-333. https://doi.org/10.1046/j.1365-313x.2001.01096.x
117. Gahlaut, V., Jaiswal, V., Tyagi, B.S., Singh, G., Sareen, S. & Balyan, H.S. (2017). QTL mapping for nine drought-responsive agronomic traits in bread wheat under irrigated and rain-fed environments. PLoS One, 12, p. e0182857. https://doi.org/10.1371/journal.pone.0182857
118. Ballesta, Paulina Mora Freddy & Del, Pozo Alejandro (2020). Association mapping of drought tolerance indices in wheat: QTL-rich regions on chromosome 4A. Sci. Agricola, 77, No. 2, pp. e20180153. https://doi.org/10.1590/1678-992x-2018-0153
119. Kulkarni, M., Soolanayakanahally, R., Ogawa, S., Uga, Y., Selvaraj, M.G. & Kagale, S. (2017). Drought response in wheat: key genes and stimilatory mechanisms controlling root system architecture and transpiration efficiency. Frontiers in Chem., 5, p. 106. https://doi.org/10.3389/fchem.2017.00106
120. Dhakal, A. (2021). Effect of drought stress and management in wheat - rewiev. Food and Agribusiness Managmenet, 2, No. 2, pp. 62-66. https://doi.org/10.26480/fabm.02.2021.62.66
121. Abebe, T., Guenzi, A.C., Martin, B. & Cushman, J.C. (2003). Tolerance of mannitol-accumulating transgenic wheat to water stress and salinity. Plant Physiol., 131, No. 4, pp. 1748-1755. https://doi.org/10.1104/pp.102.003616
122. Khan, S., Anwar, S., Yu, S., Sun, M. Yang, Z. & Gao, Z-q. (2019). Development of drought-tolerant transgenic wheat: achievements and limitations. Int. J. Mol. Sci., 20, No. 13, p. 3350. https://doi.org/10.3390/ijms20133350