Time-Course Studies on Accumulation of Hydrophilic Antioxidants to Different Stress Regimes Followed by Recovery in Contrasting Cultivars of Wheat

Under unpredictable climatic scenarios, drought is one of the major environmental constraints limiting plant growth and productivity in arid and semi-arid regions. Rapid recovery from drought is of paramount importance for the persistence and survival of different crops growing worldwide. The boiling soluble proteins, BSPs (proteins remaining soluble upon boiling in aqueous solution) forms an instrumental part of the response to water deficit conditions and might be of key importance for the survival of plants under unfavourable environmental conditions. These BSPs are typified by two unique properties: high hydrophilicity and high thermal stability. The main objective of the study was to determine drought-induced changes in the markers of oxidative stress along with modulation in the activity of the boiling soluble antioxidants in response to different stress regimes followed by re-watering in Triticum aestivum L. In this study, we determined the indices of oxidative stress (membrane injury index (MII) and lipid peroxidation in terms of malondialdehyde (MDA) content) and activities of boiling soluble antioxidant enzymes in seeds of sensitive and tolerant cultivars of wheat at different duration of stress (3, 6 and 10 days) followed by recovery (post stress harvest). Water content recorded a decline in the sensitive (PBW 343 and PBW 621) as well as tolerant (PBW 527 and PBW 175) cultivars in stress duration and cultivar dependent manner and this was reversed following re-watering in all the cultivars. Oxidative stress indicators also increased in all the cultivars at different stress intensities but this was reversed following re-watering in the tolerant cvs. PBW 175 and PBW 527. At 3 and 6 days, boiling soluble monodehydroascorbate reductase (BsMDAR), boiling soluble protein disulphide isomerase (BsPDI) activity increased in both the tolerant cvs. PBW 175 and PBW 527 whereas boiling soluble guaiacol peroxidase (BsGPX) increased in the sensitive cv. PBW 343. However, as the stress intensity increased to 10 days, BsMDAR, boiling soluble glutathione-S-transferase (BsGST) and BsGPX increased only in the tolerant cvs. PBW 175 and PBW 527, thus accentuating their cardinal roles in stress tolerance under harsh drought conditions. Upon re-watering the stress plants after 10 days, BsMDAR increased only in the tolerant cv. PBW 175. On the other hand, boiling soluble protein disulphide isomerase (BsPDI) increased in both the tolerant cv. PBW 175 and susceptible cv. PBW 343, but with a greater enhancement in the cv. PBW 175. Based upon our results, biochemical significance of the boiling soluble antioxidants in the cultivars of wheat differing in drought resistance during different stress intensities and recovery is discussed.     

Bound Water in Durum Wheat under Drought Stress

To study drought stress effects on bound water, adsorption isotherms and pressure-volume curves were constructed for two durum wheat (Triticum durum Desf.) cultivars: Capeiti 8 (drought tolerant) and Creso (drought sensitive). Plants were grown under well-watered and water-stressed conditions in a controlled environment. Differential enthalpy (ΔH) was calculated through van't Hoff analysis of adsorption isotherms at 5 and 20°C, which allowed us to determine the strength of water binding. ΔH reached the most negative values at approximately 0.06 gram H₂O/gram dry weight and then increased rapidly for well-watered plants (until 0.10 gram H₂O/gram dry weight) or more slowly for drought-stressed plants (until 0.15-0.20 gram H₂O/gram dry weight). Bound water values from pressure-volume curves were greater for water-stressed (0.17 gram H₂O/gram dry weight) than for well-watered plants (0.09 gram H₂O/gram dry weight). They may be estimates of leaf moisture content where ΔH reaches the less negative values and hence some free water appears. With respect to the well-watered plants, tightly bound water tended to be less bound during drought, and more free water was observed in cv Creso compared to cv Capeiti 8 at moisture contents >0.10 gram H₂O/gram dry weight.     

Differential drought-induced modulation of ozone tolerance in winter wheat species

Recent reports challenge the widely accepted idea that drought may offer protection against ozone (O(3)) damage in plants. However, little is known about the impact of drought on the magnitude of O(3) tolerance in winter wheat species. Two winter wheat species with contrasting sensitivity to O(3) (O(3) tolerant, primitive wheat, T. turgidum ssp. durum; O(3) sensitive, modern wheat, T. aestivum L. cv. Xiaoyan 22) were exposed to O(3) (83ppb O(3), 7h d(-1)) and/or drought (42% soil water capacity) from flowering to grain maturity to assess drought-induced modulation of O(3) tolerance. Plant responses to stress treatments were assessed by determining in vivo biochemical parameters, gas exchange, chlorophyll a fluorescence, and grain yield. The primitive wheat demonstrated higher O(3) tolerance than the modern species, with the latter exhibiting higher drought tolerance than the former. This suggested that there was no cross-tolerance of the two stresses when applied separately in these species/cultivars of winter wheat. The primitive wheat lost O(3) tolerance, while the modern species showed improved tolerance to O(3) under combined drought and O(3) exposure. This indicated the existence of differential behaviour of the two wheat species between a single stress and the combination of the two stresses. The observed O(3) tolerance in the two wheat species was related to their magnitude of drought tolerance under a combination of drought and O(3) exposure. The results clearly demonstrate that O(3) tolerance of a drought-sensitive winter wheat species can be completely lost under combined drought and O(3) exposure.     

Comparison of drought-induced polypeptides and ion leakage in three tomato cultivars

An attempt has been made to determine if drought-induced proteins could be used as a selection marker to differentiate between tolerant and sensitive cultivars. Three Indian tomato (Lycopersicon esculentum Mill.) cultivars (Pusa Ruby, Arka Vikas and Pusa Early Dwarf) were subjected to drought stress in vivo as well as in vitro and the pattern of polypeptide expression was determined using one-dimensional SDS-PAGE. In all the three cultivars, a new 29 kDa polypeptide accumulated in leaves, in response to gradual drought stress and its accumulation was fastest in Pusa Ruby. Drought stress also resulted in an increase in ion leakage from leaf discs of all the three cultivars but the rate was lower in Pusa Ruby than in other two. Therefore, it was concluded that Pusa Ruby is most tolerant to drought stress among the three tomato cultivars investigated.     

Drought-induced expression of aquaporin genes in leaves of two common bean cultivars differing in tolerance to drought stress

Aquaporin proteins are part of the complex response of common bean (Phaseolus vulgaris L.) to drought which affects the quality and quantity of yield of this important crop. To better understand the role of aquaporins in common bean, drought-induced gene expression of several aquaporins was determined in two cultivars, the more drought tolerant Tiber and the less tolerant Starozagorski ?ern. The two bean cultivars were selected among 16 European genotypes based on the tolerance to drought determined by time needed for plants to wilt after withholding irrigation and yield at harvest. The expression patterns of two plasma membrane intrinsic proteins, PvPIP1;2 and PvPIP2;7, and two tonoplast intrinsic proteins, PvTIP1;1 and PvTIP4;1 in leaves of 21 day old plants were determined by RT-qPCR in both cultivars under three degrees of drought stress, and under rehydration and control conditions. Gene expression of all four examined aquaporins was down-regulated in drought stressed plants. After rehydration it returned to the level of control plants or was even higher. The responses of PvPIP2;7 and PvTIP1;1 during drought and rehydration were particularly pronounced. The gene expression of PvPIP2;7 and PvTIP4;1 during drought was cultivar specific, with greater down-regulation of these two aquaporins in drought tolerant Tiber. Under drought stress the relative water content and water potential of leaves were higher in Tiber than in Starozagorski plants. The differences in these physiological parameters indicate greater prevention of water loss in Tiber during drought, which may be associated with rapid and adequate down-regulation of aquaporins. These results suggest that the ability of plants to conserve water during drought stress involves timely and sufficient down-regulation of gene expression of specific aquaporins.     

Effect of light and gibberellic acid on coleoptile and first-foliage-leaf growth in durum wheat (Triticum durum Desf.)

A comparison has been made of the relative effectiveness of light quality and quantity and gibberellic acid (GA₃) treatment on the elongation growth of the coleoptile and the first foliage leaf in durum wheat (Triticum durum Desf. cvs. Cappelli and Creso). The cultivar Creso is a shortstrawed variety carrying the Gai 1 gene on chromosome 4A, which influences both plant height and insensitivity to applied gibberellins. The main conclusions are as follows: 1) coleoptile elongation growth appears to be modulated via the fluencerate-dependent action of a blue-light receptor and via a low energy response of phytochrome; 2) the inhibition of first-foliage-leaf growth depends on the operation of a single blue-light-responsive photoreceptor; 3) high energy blue light produces the same inhibitory effect on the two wheat cultivars, whereas at relatively low fluences of white and blue light, the cultivar Creso is more sensitive; 4) the insensitivity to applied GA₃ exerted by the gene Gai 1 in Creso is independent of light; 5) in Cappelli, the action of light on coleoptiles appears to be independent of the applied GA₃, whereas the hormone is able to change the pattern of growth inhibition of the first-foliage-leaf.Abbreviations BL blue light - FR far-red light - GA gibberellin - GA₃ gibberellic acid - R red light - WL white light     

Photosynthetic characteristics and enzymatic antioxidant capacity of leaves from wheat cultivars exposed to drought

Two durum (Triticum durum L.), Barakatli-95 and Garagylchyg-2; and two bread (Triticum aestivum L.) wheat cultivars, Azamatli-95 and Giymatli-2/17 with different sensitivities to drought were grown in the field on a wide area under normal irrigation and severe water deficit. Drought caused a more pronounced inhibition in photosynthetic parameters in the more sensitive cvs Garagylchyg-2 and Giymatli-2/17 compared with the tolerant cvs Barakatli-95 and Azamatli-95. Upon dehydration, a decline in total chlorophyll and relative water content was evident in all cultivars, especially in later periods of ontogenesis. Potential quantum yield of PS II (F(v)/F(m) ratio) in cv Azamatli-95 was maximal during stalk emergency stage at the beginning of drought. This parameter increased in cv Garagylchyg-2, while in tolerant cultivar Barakatli-95 significant changes were not observed. Contrary to other wheat genotypes in Giymatli-2/17 drought caused a decrease in PS II quantum yield. Drought-tolerant cultivars showed a significant increase in CAT activity as compared to control plants. In durum wheat cultivars maximal activity of CAT was observed at the milk ripeness and in bread wheat cultivars at the end of flowering. APX activity also increased in drought-treated leaves: in tolerant wheat genotypes maximal activity occurred at the end of flowering, in sensitive ones at the end of ear formation. GR activity increased in the tolerant cultivars under drought stress at all stages of ontogenesis. SOD activity significantly decreased in sensitive cultivars and remained at the control level or increased in resistant ones. This article is part of a Special Issue entitled: Photosynthesis Research for Sustainability: from Natural to Artificial.     

Co-existence of salt and drought tolerance in Triticeae

Cell membrane stability (CMS) technique was used to screen for drought tolerance, salt tolerant accessions of three Aegilops species, Ae. tauschii, Ae. cylindrica, Ae. geniculata and two hexaploid wheat (Tricitum aestivum L.) cultivars comprising salt tolerant LU-26 and drought tolerant Chakwal-86. The objectives were to see how valid it is for a salt tolerant plant to be drought tolerant as well and to identify the character(s) that may contribute to drought tolerance. Three moisture levels equal to 100, 50 and 25% saturation capacity of the soil were used for plant cultivation. Injury percentage (IP) based on in-vitro desiccation induced by polyethylene glycol (PEG) in leaf tissue was measured through the conductivity of the electrolyte leakage. Injury percentage decreased in all the test material with decrease in soil moisture contents. Ae. cylindrica exhibited minimum injury at 100% soil moisture level followed by Ae. tauschii and Ae. geniculata while drought tolerant wheat cultivars exhibited the maximum. The wheat cultivar Chakwal-86 has been developed for dry areas, with low soil moisture levels, and high water potential enhances the injury percentage. Aegilops cylindrica is a salt tolerant species and can thus tolerate water deficit conditions created due to low osmotic potential. Potassium appeared to play an important role in drought tolerance which was evident from high K+ contents and low K+ leakage from Aegilops cylindrica and drought tolerant wheat cultivar Chakwal-86. It was inferred from the study that salt tolerant species might prove drought tolerant in the areas where water deficit prevails due to the ability to create low intracellular osmotic potentials.     

Sensing drought- and salinity-imposed stresses on tomato leaves by means of fluorescence techniques

In our study, we investigated whether multiple fluorescence indices may be used to sense physiological changes in tomato plants (Solanum lycopersicum L.) caused by salinity and water deficit as single or combined stresses. The fluorescence intensity in the blue (B), red (R) and far-red (FR) spectral regions and the pulse-amplitude-modulated (PAM) chlorophyll fluorescence, were recorded on a weekly basis in the scope of a long-term experiment. The results indicate the coefficient of photochemical quenching (qL), the B to FR fluorescence ratio and the logarithm of the FR fluorescence ratio after R and UV-light excitation as appropriate parameters to sense the response of plants to the imposed stress. The qL revealed the impact of water deficiency, whereas the two multispectral ratios revealed the influence of combined salinity and water shortage. Despite minor changes in the chlorophyll concentration, salinity and water deficit, when combined, had an additive impact on the chlorophyll fluorescence. Overall, the fluorescence signals of ‘Rio Grande’ were more affected by the induced stresses compared to ‘Harzfeuer’. The multiparametric fluorescence technique, confirming the trends obtained with the PAM-method, reveals promising perspectives for the ‘in situ’ evaluation of the physiological status of horticultural crops.     

Chlorophyll fluorescence parameters,CO2 photosynthetic rate and regeneration capacity as a result of complete submergence and subsequent re-emergence in rice (Oryza sativa L.)

Regeneration capacity of submerged rice (Oryza sativa) seedlings in terms of CO₂ photosynthetic rate, chlorophyll a fluorescence and chlorophyll and carbohydrate content were investigated in three Indica rice cultivars namely FR 13A, Kalaputia and IR 42 that differed in submergence tolerance. Twenty-one day old plants were completely submerged under water for 8 days. Subsequently, plants were kept under normal conditions with 5–10 cm of stagnant water above soil surface for a further period of 15 days. After complete submergence, all genotypes showed inhibition of CO₂ photosynthetic rate. Submergence treatment resulted in a significant reduction of Rubisco activity. Maximal photochemical efficiency (F_v/F_m) of PS II and area above the fluorescence curve between F_o and F_m decreased more under submergence especially in susceptible cultivar IR 42. When re-aerated, the plants recovered to various degrees. The carbohydrate content of plants was found to be significantly and positively associated with submergence tolerance and regeneration growth. The tolerant cultivar (FR 13A) could survive submergence apparently because it possessed 1.9–2.0 and 3.2–3.7-fold more non-structural carbohydrate content before and after submergence compared to the susceptible cultivar (IR 42) and it had a better capability to restore its photosynthetic capacity during post-submergence periods.     

Comparison of the Drought Stress Responses of Tolerant and Sensitive Wheat Cultivars During Grain Filling: Changes in Flag Leaf Photosynthetic Activity,ABA Levels,and Grain Yield

Water status parameters, flag leaf photosynthetic activity, abscisic acid (ABA) levels, grain yield, and storage protein contents were investigated in two drought-tolerant (Triticum aestivum L. cv. MV Emese and cv. Plainsman V) and two drought-sensitive (cvs. GK élet and Cappelle Desprez) wheat genotypes subjected to soil water deficit during grain filling to characterize physiological traits related to yield. The leaf water potential decreased earlier and at a higher rate in the sensitive than in the tolerant cultivars. The net CO₂ assimilation rate (P _N) in flag leaves during water deficit did not display a strict correlation with the drought sensitivity of the genotypes. The photosynthetic activity terminated earliest in the tolerant cv. Emese, and the senescence of flag leaves lasted 7 days longer in the sensitive Cappelle Desprez. Soil drought did not induce characteristic differences between sensitive and tolerant cultivars in chlorophyll a fluorescence parameters of flag leaves during post-anthesis. Changes in the effective quantum yield of PSII (Φ_PSII) and the photochemical quenching (qP) depended on the genotypes and not on the sensitivity of cultivars. In contrast, the levels of ABA in the kernels displayed typical fluctuations in the tolerant and in the sensitive cultivars. Tolerant genotypes exhibited an early maximum in the grain ABA content during drought and the sensitive cultivars maintained high ABA levels in the later stages of grain filling. In contrast with other genotypes, the grain number per ear did not decrease in Plainsman and the gliadin/glutenin ratio was higher than in the control in Emese during drought stress. A possible causal relationship between high ABA levels in the kernels during late stages of grain filling and a decreased grain yield was found in the sensitive cultivars during drought stress.     

小麦干旱诱导蛋白及相关基因研究进展

干旱胁迫条件下,小麦相关基因受到激活并表达产生干旱胁迫蛋白,主动适应干旱环境、维持个体存活和产量形成。介绍了小麦中一些干旱诱导蛋白及相关基因的研究进展,包括不同小麦品种、胁迫程度、发育阶段的差异性反应和共性特征、对主要干旱信号物质ABA和Ca²⁺的差异应答、以及新近发现的干旱诱导蛋白及相关基因的生物学特性及主要功能等。对于干旱诱导蛋白来说,研究手段和目标从过去以单向电泳技术为主、揭示蛋白条带的表达差异转到现在以双向电泳技术为主、以揭示蛋白质组中干旱诱导蛋白结构和功能的耦合。对于干旱诱导蛋白相关基因来说,研究内容主要包括功能基因和调控基因两大类,功能基因研究主要集中在LEA蛋白基因和透物质合成酶基因等几大类型上,而调控基因研究主要集中在转录因子和蛋白激酶等相关基因及其作用。对干旱诱导蛋白及相关基因在小麦栽培管理和产量育种中的应用前景展开了讨论。     

Screening for drought tolerance in mutant germplasm of sesame (Sesamum indicum) probing by chlorophyll a fluorescence

Drought is one of the major constraints limiting crop productivity in African Sahel. The aim of this study was to select mutant sesame (Sesamum indicum L.) lines with improved levels of drought resistance. Twenty-one M4-M5 sesame lines of unknown drought tolerance, and their three parental sources with well-known and contrasting drought tolerance levels were evaluated at the vegetative stage in a factorial pot experiment, using a completely randomized design with three replicates. After 2 weeks of growth, water was withheld for 16 days as drought stress treatment. Chlorophyll a fluorescence data, as well as stomatal conductance and flag leaf temperature were recorded during the stress period. Recorded chlorophyll a fluorescence transients were analyzed by the JIP-test to translate stress-induced damage in these transients to changes in biophysical parameters allowing quantification of the energy flow through the photosynthetic apparatus. Large genotypic differences in the extent to which drought stress affected chlorophyll a fluorescence transients were observed. Drought stress reduced the performance index and stomatal conductance, and increased flag leaf temperature but had little effect on maximum quantum yield of primary photochemistry. A drought factor index is proposed in this work to screen for improved drought tolerance in twenty-one M4-M5 sesame lines. Mutant lines shi165, lc162, mc112, lc164, icn115, icn141, mt169, dwf172 and cc102 exhibited drought factor index values superior to those of the known drought tolerant cultivars Birkan and 38-1-7. A significant and negative relationship was found between the drought factor index and the leaf temperature index. Finally, we succeeded in obtaining drought tolerant lines with good secondary traits by using mutagenesis and chlorophyll fluorescence technique.     

Involvement of nitric oxide-mediated alternative pathway in tolerance of wheat to drought stress by optimizing photosynthesis

Key message

NO-mediated alternative pathway plays an important role in protecting wheat seedlings against drought stress through dissipating excessive reducing equivalents generated by photosynthesis.

Abstract

Alternative pathway (AP) has been proven to be involved in responses to various stresses. However, the mechanisms of AP in defense response to drought stress are still lacking. The aims of this work are to investigate the role of AP in drought tolerance and how AP is induced under drought stress using two wheat cultivars with different drought tolerance. Our results showed that Longchun22 cultivar is more tolerant to drought than 98SN146 cultivar. Seedlings exposed to drought led to a significant increase in AP, and it increased more in Longchun22. Furthermore, chlorophyll fluorescence parameters (Fv/Fm, ΦPSII, qP) decreased significantly in drought-treated seedlings, especially in 98SN146, indicating that photoinhibition occurred under drought stress. Pretreatment with SHAM, the malate–oxaloacetate shuttle activity and photosynthetic efficiency were further inhibited in drought-treated seedlings, resulting in more serious oxidative damage as indicated by higher levels of malondialdehyde and hydrogen peroxide. Moreover, NO modulated AP under drought stress by increasing AOX1a expression and pyruvate content. Taken together, these results indicate that NO-mediated AP is involved in optimizing photosynthesis under drought stress by avoiding the over-reduction of photosynthetic electron transport chain, thus reducing reactive oxygen species production and oxidative damage in wheat leaves.

     

A morpho-physiological approach differentiates bread wheat cultivars of contrasting tolerance under cyclic water stress

Leaf micromorphological traits and some physiological parameters with potential relevance to drought tolerance mechanisms were investigated in four selected winter wheat varieties. Plants were subjected to two cycles of drought treatment at anthesis. Yield components confirmed contrasting drought-sensitive and -tolerant behavior of the genotypes. Drought tolerance was associated with small flag leaf surfaces and less frequent occurrence of stomata. Substantial variation of leaf cuticular thickness was found among the cultivars. Thin cuticle coincided with drought sensitivity and correlated with a high rate of dark-adapted water loss from leaves. Unlike in Arabidopsis, thickening of the cuticular matrix in response to water deprivation did not occur. Water stress induced epicuticular wax crystal depositions preferentially on the abaxial leaf surfaces. According to microscopy and electrolyte leakage measurements from leaf tissues, membrane integrity was lost earlier or to a higher extent in sensitive than in tolerant genotypes. Cellular damage and a decline of relative water content of leaves in sensitive cultivars became distinctive during the second cycle of water deprivation. Our results indicate strong variation of traits with potential contribution to the complex phenotype of drought tolerance in wheat genotypes. The maintained membrane integrity and relative water content values during repeated water limited periods were found to correlate with drought tolerance in the selection of cultivars investigated.     

Expression analysis of genes encoding translation initiation factor 3 subunit g (TaeIF3g) and vesicle-associated membrane protein-associated protein (TaVAP) in drought tolerant and susceptible cultivars of wheat

The present study deals with the characterization of genes encoding translation initiation factor 3 subunit g (TaeIF3g) and vesicle-associated membrane protein associated-protein (TaVAP), and how their expression is altered during water stress in the drought tolerant (C-306) and susceptible (HD-2329) cultivars of wheat. Bioinformatics analysis revealed that the TaeIF3g gene consists of an open reading frame (ORF) of 870 nucleotides encoding for a protein of 290 amino acid residues, with a likely molecular mass and pI of 31.47 kDa and 6.89, respectively. The TaVAP cDNA consists of an ORF of 714 nucleotides encoding for a protein of 238 amino acid residues having deduced molecular mass and pI of 25.75 kDa and 7.56, respectively. The changes in expression of the two genes in flag leaf and developing grains were studied in response to drought stress at 15 days post anthesis (DPA). The expression of TaeIF3g and TaVAP in the flag leaf, after increasing in response to mild drought stress, decreased under severe stress conditions in C-306, whereas on the contrary, it persisted in cv. HD-2329. Furthermore, the expression of TaeIF3g and TaVAP in response to drought stress was affected in a coordinated manner in leaf of both the cultivars. The effect of drought on expression of TaeIF3g and TaVAP was also different in the grains of the two cultivars thus implying that the adaptive mechanisms operating in the tissues of tolerant and susceptible cultivars are different.     

Assessment of grain yield indices in response to drought stress in wheat (Triticum aestivum L.)

Drought stress constricts crop production in the world. Increasing human population and predicted temperature increase owing to global warming will lead ruthless problems for agricultural production in near future. Hence, use of high yielding genotypes having drought tolerance and scrutinize of drought sensitive local cultivars for making them tolerant may be the proficient approaches to cope its detrimental outcomes. The current study was executed during 20015–2016 and 2016–2017 in field using randomized complete block design under factorial arrangements on 50 wheat genotypes for exploring their sensitivity and tolerance against drought. Some of the attributes of grain yield and drought tolerance indices were recorded. Grain yield showed negative correlations with tolerance index (TOL), drought index (DI) and stress susceptibility index (SSI) while positive correlation with mean productivity (MP) and geometric mean productivity (GMP) under drought condition. These findings depicted that tolerant genotypes could be chosen by high MP and GMP values and low SSI and TOL values. Based on the results, genotypes GA-02, Faisalabad-83, 9444, Sehar-06, Pirsabak-04 and Kohistan-97 were more tolerant and recognized as suitable for both normal and drought conditions. Genotypes of Chenab-00, Kohsar-95, Parwaz-94 and Kohenoor-83 confirmed more sensitive due to high grain yield loss under drought stress.     

Molecular mapping of QTLs for wheat flag leaf senescence under water-stress

A segregating population from the cross between drought sensitive (Variant-2) and drought tolerant (Cham-6) genotypes was made to identify molecular markers linked to wheat (Triticum aestivum L.) flag leaf senescence under water-stress. From 38 random amplified polymorphic DNA (RAPD) primers, 25 inter-simple sequence repeat (ISSR) primers and 46 simple sequence repeat (SRR) primers, tested for polymorphism among parental genotypes and F2 population. Quantitative trait locus (QTL) for flag leaf senescence was associated with 1 RAPD marker (Pr9), 4 ISSR markers (Pr8, AD5, AD2 and AD3), and 1 SSR marker (Xgwm382) and explained 44, 50, 35, 31, 22 and 73 % phenotypic variation, respectively. The genetic distance between flag leaf senescence gene and Pr9 was 10.0 cM (LOD score 22.9). The markers Pr8, AD5, AD2 and AD3 had genetic distances of 10.5, 14.6, 15.6 and 18.1 cM, respectively (LOD scores 22.6, 17.8, 17.5 and 14.6). The genetic distance between Xgwm382 was 3.9 cM (LOD score 33.8). Therefore, the RAPD, ISSR and SSR markers linked to the QTL for the drought-induced flag leaf senescence can be further used in breeding for drought tolerance in wheat.