Reduce Drought Stress Research Articles

Arbuscular Mycorrhiza and Plant Growth-promoting Bacteria Alleviate Drought Stress in Walnut

Drought stress is one of the main constraints limiting worldwide crop production. Arbuscular mycorrhizae (AM) and plant growth-promoting bacteria (PGPB) such as Azotobacter chroococcum and Azospirillium lipofrum have been shown to alleviate drought stress effects. Therefore, the interaction effect of AM fungi [Glomus mosseae, G. etunicatum, and a mix of these (G. mix), and PGPB bacteria (Azotobacter chroococcum + Azospirillium lipofrum)] was investigated in 1-year-old walnut seedlings (cv. Chandler) under normal and drought stress conditions. Drought stress reduced growth (plant height, root length, number of leaves, and fresh weight) and leaf nutrient content (N, P, and Zn) significantly of walnut plants. In contrast, proline, total soluble sugar, starch peroxidase enzyme activity, and total phenolic content of walnut leaves increased under this stress. Application of fungi or bacteria, and especially their simultaneous use, alleviated the negative effects of drought stress on walnut seedlings. AM fungi and PGPB increased significantly the content of some metabolites, including total phenolic content, proline level, peroxidase activity, total soluble sugar, and starch content as well as peroxidase enzyme activity. This led to an increase in walnut plant growth under the drought stress condition. Among AM fungi, G. etunicatum was more effective in reducing drought stress symptoms than either G. mosseae or the G. mix of fungi. In conclusion, use of G. etunicatum, along with PGPB, can reduce negative effects of drought stress on walnut seedlings.

CARK6 is involved in abscisic acid to regulate stress responses in Arabidopsis thaliana

Abscisic acid (ABA), one of phytohormones, is induced in response to abiotic stress to mediate plant acclimation to environmental challenge. Key players of the ABA-signaling pathway are the ABA-binding receptors (RCAR/PYR1/PYL), which perceive ABA and then inhibit PP2Cs to activate SnRK2s. Here, we report that a putative receptor-like cytoplasmic kinase (RLCK) in Arabidopsis named CARK6, which is a member of cytosolic ABA receptor kinases. We confirm that CARK6 interacts with ABA receptors, RCAR11-14 in vitro and in vivo. Induced overexpression of CARK6 in Arabidopsis enhances sensitivity to ABA by inhibition of seed germination and root elongation, and promotes the drought resistance. However, loss-of-function seedlings of cark6 are less sensitive to ABA and show reduced drought stress response with respect to water loss and stomatal aperture. In transgenic Arabidopsis complementation lines in the cark6 mutant background, stress responsivity was restored by CARK6. In conclusion, our data provide evidence that CARK6 plays a positive role in ABA signaling in Arabidopsis.

Calcium silicate slag reduces drought stress in rice (Oryza sativa L.)

AbstractSilicon has been reported to reduce drought stress on many crops, but limited studies have evaluated this effect with rice using calcium silicate slag from the phosphorus fertilizer industry as a source of Si. A greenhouse study was performed to address this issue. Four slag rates (0, 1,000, 2,000 and 4,000 mg/kg) and two application methods (surface application and incorporation) were evaluated under two moisture regimes (flood and 50% field capacity) for drought stress mitigation in a mineral soil that is typical for rice production. Slag application significantly elevated plant‐available Si in the soil and Si accumulation in plant tissues, and tended to improve rice shoot and root biomass relative to the untreated control under both flooding and drought stress. Increased carbon isotope discrimination (△13C) and decreased proline in rice leaves subjected to drought stress indicate that this slag may reduce drought stress in rice, which was supported by restoration of foliage density, transpiration, photosynthesis rate and sugar accumulation to at or near flooded levels following the highest slag application. This study supports the usage of calcium silicate slag in rice production as it could improve Si availability and reduce drought stress.

Effect of bio-silica on drought tolerance in plants

Drought is considered the single most devastating environmental stress, which decreases crop productivity more than any other environmental stresses. The main consequences of drought in crops are reduced rate of cell division, leaf size, stem elongation, root proliferation, disturbed stomatal oscillations, plant water and nutrient relations with diminished crop productivity. Many studies demonstrated that the deposition of silica in plant tissues can reduce drought stress. Silicon (Si) has beneficial effects on many crops, mainly under biotic and abiotic stress. Despite its abundance, silicon is never found in plants in an available form and is always combined with other elements, usually forming oxides or silicates. Monosilicic acid (H4SiO4) is the form of silicon used by plants, which is found both in liquid and adsorbed phases of silicon in soils. The concentration of the H4SiO4 in soil solution is influenced by the soil pH, clay, minerals, organic matter and Fe/Al oxides/hydroxides, which are collectively related to the geological age of the soil. Furthermore, to improve plant-available Si in the soil, silicate solubilizing microorganisms (SSM) are potentially useful in solubilizing insoluble forms of silicate. This paper aimed to review an important issue of bio-silica effects on plants under drought stress and water deficiency.

Methyl jasmonate alleviates drought stress in young sugar beet (Beta vulgaris L.) plants

AbstractDrought is the major cause of yield and economic loss for the sugar beet crop. Mechanisms to reduce drought stress, however, are lacking as sugar beets are largely produced without irrigation and drought‐tolerant varieties are not available. As jasmonates are implicated in plant drought‐stress responses, research was conducted to determine whether methyl jasmonate (MeJA) could mitigate drought effects on sugar beet. Fourteen‐day‐old plants were treated with 0, 0.01, 0.1, 1 or 10 μM MeJA. Seven days later, half of the plants were drought‐stressed by withholding water, while control plants continued to receive water. Drought caused leaf relative water content (RWC), shoot fresh and dry weights, net photosynthetic rate (Pn), transpiration rate (EVAP), stomatal conductance (Gs), water‐use efficiency (WUE) and PSII quantum efficiency to decline and substomatal CO2 concentration (Ci) and proline and betaine concentrations to increase. MeJA, at 1 and 10 μM, reduced moderate and severe drought effects on RWC, Pn, Ci and WUE and altered drought‐induced changes in proline accumulation, but had no effect on Gs, EVAP or betaine accumulation. Results indicate that MeJA delayed plant dehydration and protected the photosynthetic apparatus from drought‐induced impairment. Exogenous application of MeJA, therefore, alleviates drought stress on young sugar beets and may provide a tool to reduce the economic loss caused by dry conditions during early crop production.

The Irrigation Effect: How River Regulation Can Promote Some Riparian Vegetation

River regulation impacts riparian ecosystems by altering the hydrogeomorphic conditions that support streamside vegetation. Obligate riparian plants are often negatively impacted since they are ecological specialists with particular instream flow requirements. Conversely, facultative riparian plants are generalists and may be less vulnerable to river regulation, and could benefit from augmented flows that reduce drought stress during hot and dry periods. To consider this 'irrigation effect' we studied the facultative shrub, netleaf hackberry (Celtis reticulata), the predominant riparian plant along the Hells Canyon corridor of the Snake River, Idaho, USA, where dams produce hydropeaking, diurnal flow variation. Inventories of 235 cross-sectional transects revealed that hackberry was uncommon upstream from the reservoirs, sparse along the reservoir with seasonal draw-down and common along two reservoirs with stabilized water levels. Along the Snake River downstream, hackberry occurred in fairly continuous, dense bands along the high water line. In contrast, hackberry was sparsely scattered along the free-flowing Salmon River, where sandbar willow (Salix exigua), an obligate riparian shrub, was abundant. Below the confluence of the Snake and Salmon rivers, the abundance and distribution of hackberry were intermediate between the two upstream reaches. Thus, river regulation apparently benefited hackberry along the Snake River through Hells Canyon, probably due to diurnal pulsing that wets the riparian margin. We predict similar benefits for some other facultative riparian plants along other regulated rivers with hydropeaking during warm and dry intervals. To analyze the ecological impacts of hydropeaking we recommend assessing daily maxima, as well as daily mean river flows.

The role of non-rainfall water on physiological activation in desert biological soil crusts

Non-rainfall water (NRW, e.g. fog and dew), in addition to rainfall and snowfall, are considered important water inputs to drylands. At the same time, biological soil crusts (BSCs) are important components of drylands. However, little information is available regarding the effect of NRW inputs on BSC activation. In this study, the effects of NRW on physiological activation in three BSC successional stages, including the cyanobacteria crust stage (Crust-C), moss colonization stage (Crust-CM), and moss crust stage (Crust-M), were studied in situ. Results suggest NRW inputs hydrated and activated physiological activity (Fv/Fm, carbon exchange, and nitrogen fixation) in BSCs but led to a negative carbon balance and low rates of nitrogen fixation in BSCs. One effective NRW event could hydrate BSCs for 7 h. Following simulated rainfall, the physiological activities recovered within 3 h, and net carbon gain occurred until 3 h after hydration, whereas NRW-induced physiological recovery processes were slower and exhibited lower activities, leading to a negative carbon balance. There were significant positive correlations between NRW amounts and the recovered values of Fv/Fm in all the three BSC stages (p < .001). The thresholds for Fv/Fm activation decreased with BSC succession, and the annual effective NRW events increased with BSC succession, with values of 29.8, 89.2, and 110.7 in Crust-C, Crust-CM and Crust-M, respectively. The results suggest that moss crust and moss-cyanobacteria crust use NRW to prolong metabolic activity and reduce drought stress more efficiently than cyanobacteria crusts. Therefore, these results suggest that BSCs utilize NRW to sustain life while growth and biomass accumulation require precipitation (rainfall) events over a certain threshold.

The influence of lignocellulose and hemicellulose biochar on photosynthesis and water use efficiency in seedlings from a Northeastern U.S. pine-oak ecosystem

ABSTRACTImproving plant water use efficiency (WUE) has the potential to lower plant susceptibility to drought. Amending soils with biochar has been suggested as a way to improve WUE, as it has been shown to increase the water holding capacity of soils. Here, we investigated the influence of two different biochar soil amendments on WUE measured by gas exchange and carbon isotopes of pine-oak ecosystem species. We measured WUE of individuals grown in soils where either lignocellulose or hemicellulose biochar was applied (10% v/v). WUE increased under lignocellulose, but not hemicellulose, biochar amendment during both late spring and early fall measurement periods in a single year study. However, net photosynthesis and stomatal conductance decreased in plants grown with biochar amendments. Physiochemical and sorption data provide a partial explanation of how biochar mechanisms impact soil-water-plant relations. Our results demonstrated that lignocellulosic biochar may be added to forest soils to reduce drought stress in pine-oak systems, but amendments may not lead to increases in carbon uptake rates.

River regulation and riparian woodlands: Cottonwood conservation with an environmental flow regime along the Waterton River, Alberta

AbstractFollowing water withdrawal, riparian cottonwoods have declined downstream from some dams in western North America. Analyses of aerial photographs and field observations in the 1980s suggested that the black and narrowleaf cottonwoods (Populus trichocarpa and Populus angustifolia) along the Waterton River, Alberta, were declining due to drought stress following the 1964 damming and diversion. This raised concern for the riverine ecosystems and in 1991, “functional flows” commenced with 2 changes: (a) the minimum flow was increased from 0.9 to 2.3 m3/s (mean discharge 21.9 m3/s) and (b) flow ramping provided gradual stage recession after the spring peak. This provided an environmental flow regime that was delivered for 2 decades and this study investigated the consequent river flow patterns and riparian woodlands upstream and downstream from the Waterton Dam. Analyses of aerial photographs from 1951 to 2009 assessed 4 flow management intervals: (a) the free‐flowing predam condition, (b) the initial dammed interval to the mid‐1970s, (c) a drought interval in the 1980s, and (d) with the environmental flow regime after 1991. Analyses revealed woodland reduction from 1961 to 1985 due to losses through bank erosion with major floods and apparent decline due to low flows following a regional drought and water withdrawal for irrigation. With the subsequent environmental flow regime, there was apparent woodland recovery, despite drought in 2000 and 2001. This study demonstrated that the correspondence between river flow patterns and the extent of riparian woodlands and the benefit from the environmental flow regime that probably reduced drought stress and mortality.

Changes in biomass allocation buffer low CO2 effects on tree growth during the last glaciation

Isotopic measurements on junipers growing in southern California during the last glacial, when the ambient atmospheric [CO2] (ca) was ~180 ppm, show the leaf-internal [CO2] (ci) was approaching the modern CO2 compensation point for C3 plants. Despite this, stem growth rates were similar to today. Using a coupled light-use efficiency and tree growth model, we show that it is possible to maintain a stable ci/ca ratio because both vapour pressure deficit and temperature were decreased under glacial conditions at La Brea, and these have compensating effects on the ci/ca ratio. Reduced photorespiration at lower temperatures would partly mitigate the effect of low ci on gross primary production, but maintenance of present-day radial growth also requires a ~27% reduction in the ratio of fine root mass to leaf area. Such a shift was possible due to reduced drought stress under glacial conditions at La Brea. The necessity for changes in allocation in response to changes in [CO2] is consistent with increased below-ground allocation, and the apparent homoeostasis of radial growth, as ca increases today.

Spatial distribution of soil moisture and fine roots in rain-fed apple orchards employing a Rainwater Collection and Infiltration (RWCI) system on the Loess Plateau of China

Water is a key factor for the sustainable development of rain-fed apple orchards on the Loess Plateau. This study was conducted to investigate the spatial distribution of soil moisture and roots in the soil profiles of an apple orchard employing a Rainwater Collection and Infiltration (RWCI) system on the Loess Plateau of China. The results showed that: 1) There was a low soil moisture content (SMC) zone between depths of 40 and 80cm and the RWCI treatment significantly increased SMC in these depths; 2) The RCWI system increased SMC in the 20–140cm depth interval and depths greater than 140cm when the RCWI pit depths were 60cm (RWCI60) and 80cm (RWCI80), respectively; 3) The total dry root density under the control (CK), RWCI60 and RWCI80 treatments was 372.12, 594.76 and 491.82g/m3, respectively. The mass percentage root distributions in the 0–100, 100–200 and 200–300cm depths were: CK (69.88%, 13.74% and 16.38%); RWCI60 (70.35%, 24.08% and 5.58%); and RWCI80 (46.54%, 15.04% and 38.42%), respectively. We found that root mass was concentrated close to the wetted soil depths affected by the RWCI treatment. The RWCI system apparently reduced drought stress through increased water and nutrients uptake because of increased subsoil SMC in the RWCI treatments. This study of the RWCI systems and the effects of the RCWI pit depth are important with respect to increasing the efficient use of rainwater, reducing drought stress and demonstrating the effectiveness of RWCI water saving technology in the rain-fed orchards in the Loess Plateau, China.

Can adjustments in foliar nitrogen-use efficiency reduce drought stress impacts on boreal trees?

Can adjustments in foliar nitrogen-use efficiency reduce drought stress impacts on boreal trees?

Soil microbial communities buffer physiological responses to drought stress in three hardwood species.

Trees possess myriad adaptations for coping with drought stress, but the extent to which their drought responses are influenced by interactions with soil microbes is poorly understood. To explore the role of microbes in mediating tree responses to drought stress, we exposed saplings of three species (Acer saccharum, Liriodendron tulipifera, and Quercus alba) to a four week experimental drought in mesocosms. Half of the pots were inoculated with a live soil slurry (i.e., a microbial inoculum derived from soils beneath the canopies of mature A. saccharum, L. tulipifera or Q. alba stands), while the other half of the pots received a sterile soil slurry. Soil microbes ameliorated drought stress in L. tulipifera by minimizing reductions in leaf water potential and by reducing photosynthetic declines. In A. saccharum, soil microbes reduced drought stress by lessening declines in leaf water potential, though these changes did not buffer the trees from declining photosynthetic rates. In Q. alba, soil microbes had no effects on leaf physiological parameters during drought stress. In all species, microbes had no significant effects on dynamic C allocation during drought stress, suggesting that microbial effects on plant physiology were unrelated to source-sink dynamics. Collectively, our results suggest that soil microbes have the potential to alter key parameters that are used to diagnose drought sensitivity (i.e., isohydry or anisohydry). To the extent that our results reflect dynamics occurring in forests, a revised perspective on plant hydraulic strategies that considers root-microbe interactions may lead to improved predictions of forest vulnerability to drought.

Plant diversity moderates drought stress in grasslands: Implications from a large real-world study on 13C natural abundances

Land-use change and intensification play a key role in the current biodiversity crisis. The resulting species loss can have severe effects on ecosystem functions and services, thereby increasing ecosystem vulnerability to climate change. We explored whether land-use intensification (i.e. fertilization intensity), plant diversity and other potentially confounding environmental factors may be significantly related to water use (i.e. drought stress) of grassland plants. Drought stress was assessed using δ13C abundances in aboveground plant biomass of 150 grassland plots across a gradient of land-use intensity. Under water shortage, plants are forced to increasingly take up the heavier 13C due to closing stomata leading to an enrichment of 13C in biomass. Plants were sampled at the community level and for single species, which belong to three different functional groups (one grass, one herb, two legumes).Results show that plant diversity was significantly related to the δ13C signal in community, grass and legume biomass indicating that drought stress was lower under higher diversity, although this relation was not significant for the herb species under study. Fertilization, in turn, mostly increased drought stress as indicated by more positive δ13C values. This effect was mostly indirect by decreasing plant diversity. In line with these results, we found similar patterns in the δ13C signal of the organic matter in the topsoil, indicating a long history of these processes.Our study provided strong indication for a positive biodiversity-ecosystem functioning relationship with reduced drought stress at higher plant diversity. However, it also underlined a negative reinforcing situation: as land-use intensification decreases plant diversity in grasslands, this might subsequently increases drought sensitivity. Vice-versa, enhancing plant diversity in species-poor agricultural grasslands may moderate negative effects of future climate change.

Overexpression of a harpin-encoding gene popW from Ralstonia solanacearum primed antioxidant defenses with enhanced drought tolerance in tobacco plants.

The tobacco plants transformed with popW gene showed enhanced drought tolerance, and the mechanism was found with primed antioxidant defenses and reduced drought stress damages in the transgenic lines. Harpin proteins are elicitors produced by several gram-negative plant pathogenic bacteria, triggering multiple beneficial responses in plants, such as induction of defense response against diverse pathogens and insects, growth promotion, and drought tolerance. In this study, the harpin-encoding gene popW derived from Ralstonia solanacearum ZJ3721 was transferred to tobacco. We examined the tolerance of transgenic tobacco plants toward drought stress under greenhouse conditions and analyzed the molecular mechanisms underlying the enhanced drought tolerance. The results revealed that the transgenic lines primed antioxidant defenses and reduced drought stress damages. In addition, they displayed lower malondialdehyde and relative electrical conductivity, while higher relative water content and recovery intension than the tobacco plants transformed with empty vector pBI121 and the wild-type (WT) plants under drought stress. Furthermore, the transgenic lines displayed a significant increase in peroxidase, superoxide dismutase, catalase activities, and ascorbic acid content compared with control plants under drought stress, and these levels were up to 1.95, 1.68, 1.34, and 1.43 times higher than those of WT plants, respectively. Overexpression of popW in tobacco also significantly enhanced the relative transcript levels of oxidative stress-responsive genes NtAPX, NtCAT1, NtGST, and NtCu/Zn-SOD under drought stress. The relative transcript levels of these genes in the transgenic line PW12 were up to 1.94, 2.36, 5.24, and 3.62 times higher than those of WT plants, respectively. These results confirmed that the popW gene, which was transformed into tobacco primed antioxidant responses, increased tolerance to drought stress in tobacco plants.

An ecohydrological approach to managing dryland forests: integration of leaf area metrics into assessment and management

Author(s): Osem, Y; O'Hara, K | Abstract: We review the use of leaf area metrics (LAM) for assessing and managing dryland forests. We propose a framework integrating individual tree to whole-ecosystem metrics representing a variety of forest features and review theory, empirical evidence and knowledge gaps. Four basic concepts underlie the LAM framework: (1) Max-LAI - an ecosystem can be characterized by an upper potential leaf area index (LAI) dictated mainly by water availability, (2) Leaf area distribution - the distribution of leaf area is proportional to the distribution of resources among vegetation components, (3) Safe-LAI - maintaining Ecosystem-LAI below Max-LAI is a way to reduce drought stress and (4) tree leaf area (TLA) - the leaf area of an individual tree as a proportion of its potential TLA, represents its vigour. Implementation of the LAM strategy requires the following: (1) better understanding how edaphic conditions and vegetation characteristics interact with climate in determining Max-LAI, (2) better understanding how leaf area is related to water use across species, vegetation strata and light regimes, (3) better understanding the interaction between LAI development and stand dynamics, (4) better capability of measuring or estimating individual tree leaf area and (5) development of species-specific references for tree vigour based on leaf area. The LAM strategy is promising for managing dryland forests under increasing drought stress.

Effects of silicon and drought stress on biochemical characteristics of leaves of upland rice cultivars

Silicon (Si) has beneficial effects on many crops, mainly under biotic and abiotic stress. Silicon can affect biochemical, physiological, and photosynthetic processes and, consequently, reduce drought stress. However, the effects of Si on rice (Oryza sativa L.) plants under drought stress are not well known. The objective of this study was to evaluate the effects of supplemental Si on proline content and peroxidase activity in upland rice plants in the presence and absence of drought stress. The experiment was conducted under greenhouse conditions and was arranged in completely randomized blocks in a 2 x 2 x 2 factorial scheme. Treatments comprised combinations of (1) presence or absence of Si supply (0 or 350 kg ha-1 of Si), (2) presence or absence of a water deficit (-0.050 MPa or -0.025 MPa soil water potential values, respectively), and (3) two upland rice cultivars: Caiapo (traditional type) and Maravilha (modern type), with eight replications. Under water stress conditions, silicon fertilization reduced the proline content in the vegetative and reproductive phases of upland rice plants and increased peroxidase activity in the plants' reproductive phase, which could be indicative of stress tolerance.

The shifting influence of drought and heat stress for crops in northeast Australia.

Characterization of drought environment types (ETs) has proven useful for breeding crops for drought-prone regions. Here, we consider how changes in climate and atmospheric carbon dioxide (CO2 ) concentrations will affect drought ET frequencies in sorghum and wheat systems of northeast Australia. We also modify APSIM (the Agricultural Production Systems Simulator) to incorporate extreme heat effects on grain number and weight, and then evaluate changes in the occurrence of heat-induced yield losses of more than 10%, as well as the co-occurrence of drought and heat. More than six million simulations spanning representative locations, soil types, management systems, and 33 climate projections led to three key findings. First, the projected frequency of drought decreased slightly for most climate projections for both sorghum and wheat, but for different reasons. In sorghum, warming exacerbated drought stresses by raising the atmospheric vapor pressure deficit and reducing transpiration efficiency (TE), but an increase in TE due to elevated CO2 more than offset these effects. In wheat, warming reduced drought stress during spring by hastening development through winter and reducing exposure to terminal drought. Elevated CO2 increased TE but also raised radiation-use efficiency and overall growth rates and water use, thereby offsetting much of the drought reduction from warming. Second, adding explicit effects of heat on grain number and grain size often switched projected yield impacts from positive to negative. Finally, although average yield losses associated with drought will remain generally higher than that for heat stress for the next half century, the relative importance of heat is steadily growing. This trend, as well as the likely high degree of genetic variability in heat tolerance, suggests that more emphasis on heat tolerance is warranted in breeding programs. At the same time, work on drought tolerance should continue with an emphasis on drought that co-occurs with extreme heat.

Reducing Drought Stress in Transplanted Trees Using Mycorrhizae©aaThe presented data is a subset of a larger data set presented elsewhere.

Reducing Drought Stress in Transplanted Trees Using Mycorrhizae^©aaThe presented data is a subset of a larger data set presented elsewhere.

Influence of trinexapac-ethyl in improving drought resistance of wheatgrass and tall fescue

Various methods are available for improving drought resistance in turfgrasses. Several studies have reported the application of plant growth regulators as an effective method for reducing drought stress effects. A factorial experiment based on a randomized complete block design with three replications was performed in 2011 and 2012 to investigate the effects of the gibberellic acid (GA) inhibitors trinexapac-ethyl (TE) and drought stress on the physiological responses of wheatgrass (Agropyron desertorum) and tall fescue (Festuca arundinacea) to drought stress. The foliage of wheatgrass and tall fescue were sprayed with 1.95 ml L−1 TE at 0.113 % a.i. 14 days prior to and at the beginning of the drought stress. Both TE-treated and untreated plants were placed to well-watered and no water circumstances for 45 days in field conditions. Results indicated that drought stress reduced turf quality (color, density, and uniformity), relative water content (RWC), and total chlorophyll content, but increased proline content, electrolyte leakage (EL), malondialdehyde (MDA) and soluble sugar content (SSC) in both species. Superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), and peroxidase (POD) activities in the two turfgrass species initially increased transiently, but declined subsequently. TE application increased SOD, APX, POX, and CAT activities, especially under drought stress conditions. Correlation analysis showed that there were significantly positive correlation between turf quality and RWC and negative correlation between turf quality and proline content, EL, MDA and SSC in both species. The use of TE seems to have enhanced resistance to drought stress in both species by improving proline, SSC and antioxidant activities.