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Abiotic stresses, such as drought, can induce different morphological, physiological and molecular responses in the tea plants. Since there have not been any experiments on the screening of tea genotypes in terms of drought tolerance, this study was conducted to screen the drought resistance of 14 tea clones of Iran germplasm in a randomized complete block design with three replications, separately in two stressed and non-stressed conditions at Fashalam tea station. The results of grouping the clones under normal and stress conditions and comparing their results with the results of mean comparison of the agronomic and biochemical traits showed that in all cases, clones 100, Bazri and 399 were in the group that can be identified as the drought-tolerant group. Also, the results showed that in the most cases, clones 278, 276 and 285 were placed in a group that had low values for all of the traits and could be considered as a group that are susceptible to drought stress.

Species of Plantago are mostly grown as weed, but some of them are used for local medicines. In order to achieve the genetic determinants of agronomic traits, a comprehensive genome-wide association mapping was performed on 39 selected ecotypes using 24 start codon targeted (SCoT) primers. To this end, two species of Plantago (Plantago psyllium and Plantago ovata) were used. The primers produced 431 remarkable bands with an average of 88.48% polymorphism, demonstrating the ability of these markers to distinguish the studied genotypes appropriately. A cluster analysis and population structure was performed for each species separately. The structure analysis grouped the 22 Plantago ovata ecotypes into three sub-groups. Moreover, the structure analysis also grouped the Plantago psyllium into 2 sub-groups. Among the 22 Plantago ovata ecotypes, eight ecotypes were admixture, while among the 17 Plantago psyllium ecotypes, two ecotypes were admixture. In the association analysis, according to the results of MLM model using both Q and K factors, 16 markers associated with the measured traits were identified. The markers included three loci associated with spike weight, two loci associated with plant height, number of spikes, spike length, days to flowering, days to maturity, one locus associated with 1000 grain weight, number of grain/spike and grain yield. Interestingly, 4 out of 24 SCoT loci were linked with more than one agronomic trait. These markers would enhance the efficiency of allele selection in Plantago breeding programs.

Tane verimi ve bitkilerde kantitatif kalitimli ve dogrudan secme yontemini kullanilan ekonomik onemi olan ozelliklerin cogunun buyuk bir gelisme gostermedigi saptanmistir. Dolayisiyla, etkili bir ozellige sahip tane verimi artirmak icin en etkin yontemlerden dolayli secimlerinden biri, seleksiyon endeksini kullanilmaktadir. Bu arastirmada 42 adet Iran yerel ve gelismis pirinc cesidi, 2014 yili boyunca normal sulama ve kuraklik stresi olmak uzere iki ayri kosulda uc tekerrurlu olarak tesadufi tam blok deneme deseninde incelenmis ve 12 ozellik degerlendirilmistir. Her iki kosulda optimum ve baz indekslerine dayanan 10 farkli secim indeksinin tahmin edilmesi, ekonomik agirlik olarak dogrudan path katsayilarinin kullanilmasiyla bitki basina tane verimi, 1000 tane agirligi, basakta dolu tane sayisi, kanopi sicakligi ve stres olmayan kosullar altinda bitki basina basak sayisi, bitki basina tane verimi ve stres kosullarinda 1000 tane agirligi ve her bir basakta basakcik sayisinin populasyonun iyilestirilmesi icin uygun bir secim kriteri olacagini isaret etmektedir. Sonuclar, her iki kosulda da optimum ve baz indekslerine dayali secilen cesitlerin neredeyse benzer oldugunu gostermistir. Boylece, stres olmayan kosullarindaki optimum ve baz indeksleri, stres kosullarinda yuksek verimli cesitlerin secimi icin bir kriter olarak onerilmektedir.

Soil salinity is established as one of the major environmental problems, decreasing crop productivity worldwide, thereby threatening sustainable agriculture. In the present study, we evaluated the effects of titanium dioxide nanoparticles (nTiO2) for ameliorating soil salinity in broad bean, an important leguminous crop. As nTiO2 is known to have pro-oxidant and antioxidant properties, the effects of three different nTiO2 concentrations (0·01%, 0·02% and 0·03%) were compared with respect to plant growth and stress responses. The 0·01% nTiO2 application significantly increased shoot length, leaf area and root dry weight of plants under normal conditions. These growth-promoting effects were simultaneous with increased levels of chlorophyll b, soluble sugars and proline and enhanced activities of antioxidant enzymes. Under saline soil conditions, although proline level and enzymatic antioxidant activities were increased, plant growth significantly reduced. The 0·01% nTiO2 supplementation significantly increased the activities of enzymatic antioxidants and levels of soluble sugars, amino acids and proline in salt-affected plants versus plants subjected to salinity alone. Thus, the increased antioxidant enzyme activities contributed to the observed reduction in hydrogen peroxide and malondialdehyde contents, while enhanced levels of proline and other metabolites contributed to osmoprotection, collectively resulting in significant plant growth improvement under salinity. Furthermore, nTiO2-mediated positive effects were concentration dependent with 0·01% nTiO2 being the most effective, whereas 0·02% showed an intermediate response and 0·03% was almost ineffective under both control and saline soil conditions. Our findings provide a foundation for nTiO2 application in improving growth of plants cultivated on naturally contaminated saline soils. Copyright © 2017 John Wiley & Sons, Ltd.

Salinity stress is the most important and common environmental stresses throughout the world, including Iran. The aim of this study was to investigate the expression of several important genes involved in the salinity tolerance of the rice cultivars differing in salt sensitivity. In this research, the expression of four mitochondrial genes, H2O2, malondialdehyde (MDA), proline, sodium, potassium and superoxide dismutase (SOD), was measured in Iranian rice cultivars and two well-known international varieties as checks in response to 100 mM salt stress. The results show that the activity of SOD in the tolerant cultivars is much higher than in the susceptible ones under saline conditions (100 mM NaCl). The study of the gene expression in the tolerant and sensitive cultivars also showed that the expression of the genes increased in the early hours of the stress, with the exception of the OsGR1. Moreover, the amount of the expression in the tolerant cultivars was far more than the susceptible ones. The result of this study showed that the function of a set of antioxidant enzymes can lead to detoxification of the reactive oxygen species, so in order to better understand ROS scavengers, a comprehensive study on the antioxidant system should be conducted.

In this study, the positive role of hydrogen peroxide (H2O2) pretreatment in mitigating the adverse impacts of seawater stress has been evaluated in two wheat (Triticum aestivum L.) cultivars, namely Gemmiza 11 as a salt-sensitive and Misr 1 as a salt-tolerant cultivar, with contrasting phenotypes in response to the salinity stress. Under normal conditions, wheat seeds eustress with H2O2 have shown significant effects on the improvement of plant growth parameters, such as dry weight and root and shoot lengths. Under salt stress conditions, seeds eustress with H2O2 have shown a reduction in damage to plant growth and physiological parameters as compared to the seeds kept as un-primed in both wheat cultivars. In addition, eustress of seeds with H2O2 has induced an increment in the pigments content, proline level and mineral uptake (K+, Ca2+ and Mg2+). Moreover, seeds eustress with H2O2 have shown significant decrement in Na+ content uptake in plants and that subsequently reduced lipid peroxidation. Seawater stress has increased the activity of the antioxidant system based on catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) in both cultivars, except POD in Gemmiza 11. Similarly, the application of H2O2 has further enhanced the activity of the antioxidant system in stressed plants and this enhancement of the antioxidant system further reduced Na+ content in plants and subsequently increased the growth parameters. Results of inter-simple sequence repeat (ISSR) markers have shown clear differentiation among the treatments and have provided strong evidence in support of the hypothesis proposed in this study that H2O2 eustress improves seed tolerance and enhances plant growth parameters under seawater stress.

Metal tolerance proteins (MTPs) play an important role in the transport of metals at the cellular, tissue and whole plant levels. In the present study, 11 MTP genes were identified and these clustered in three major sub-families Fe/Zn-MTP, Zn-MTP, and Mn-MTP, and seven groups, which are similar to the grouping of MTP genes in both Arabidopsis and rice. Vitis vinifera metal tolerance proteins (VvMTP) ranged from 366 to 1092 amino acids, were predicted to be located in the cell vacuole, and had four to six putative TMDs, except for VvtMTP12 and VvMTP1. The VvMTPs had putative cation diffusion facilitator (CDF) domains and the putative Mn-MTPs also had zinc transporter dimerization domains (ZD-domains). V. vinifera Mn-MTPs had gene structures and motif distributions similar to those of the Fe/Zn-MTP and Zn-MTP sub-families. The upstream regions of VvMTP genes had variable frequencies of cis-regulatory elements that could indicate regulation at different developmental stages and/or differential regulation in response to stress. Comparison of the VvMTP coding sequences with known miRNAs found in various plant species indicated the presence of 13 putative miRNAs, with 7 of these associated with VvMTPs. Temporal and spatial expression profiling indicates a potential role for VvMTP genes during growth and development in grape plants, as well as the involvement of these genes in plant responses to environmental stress, especially osmotic stress. The data generated from this study provides a basis for further investigation of the roles of MTP genes in grapes.

Soil salinity is a major abiotic stress affecting the performance of crop plants around the world adversely. Salinity can create a mix of complex interactions that affect plant nutrient uptake, metabolism, and susceptibility to biotic stresses. This negative interaction may reduce nutrient use efficiency and thus reduces the growth parameters. In addition to various management operations, such as crop management, to reduce the negative effects of salinity on plant growth, application of salinity-tolerant varieties or genotypes is a very interesting strategy to reduce the cost of salinity and environmental contamination. Salinity tolerance in plants not only varies widely among different species but is also strongly influenced by the environmental conditions. The salinity tolerance mechanisms of the plant are investigated at three levels of whole plant- cellular, and molecular levels. Particularly, the response at the whole plant is vital for some plants but is generally not used for all plants. It seems that cellular responses are conserved among many plants. Considering the advances made in recent decades, breeding for increased tolerance through gene transfer and the production of transgenic plants is considered as excellent and low-cost method. Perhaps the most valuable outcome of the biotechnology program is to use molecular tools for the breeding programs. Identifying tightly linked molecular markers with the target gene and mapping it on the chromosome is an important goal for cloning the genes and marker-assisted selection (MAS).

Knowledge of genetic diversity could aid in providing useful information in the selection of material for breeding such as hybridization programs and quantitative trait loci mapping. The present study was conducted to evaluate salinity tolerance of Iranian rice varieties. This research was carried out in three separate experiments (control, 6 and 12 dS m−1 NaCl) each based on completely randomized design with 44 rice varieties and three replications. Fourteen days after salt treatments, root and shoot fresh and dry weight, Na+ and K+ concentration, Na+/K+ ratio, root and shoot length, biomass gain, total fresh weight, root/shoot length ratio and shoot/root weight ratio were measured. The varieties were also genotyped for 12 closely linked microsatellite markers to SalTol. Haplotype and association analysis was conducted using these SSR markers for identification of loci related to salt tolerance. The tolerance scores under salinity stress showed that the varieties FL478, Hassani, Gharib, Shahpasand, Nemat, Domzard, Ghasroddashti, Ahlamitarom, Hassansaraee and Binam with more biomass, root and shoot lengths, and low Na+/K+ ratio were tolerant to salinity stress. Association analysis was indicated that there are some informative markers on chromosome 1 in the local and improved Iranian rice varieties genetic background including RM8094, RM1287, AP3206 and RM3412 explaining considerable percentage of the salt tolerance-related traits. These informative markers can be used in future breeding programs such as marker-assisted selection.

Caucasian whortleberry (Vaccinium arctostaphylos L.) plant traditionally has been included among important medicines as remedy for diabetic patients and also in modern medicine found to be effective against cardiovascular diseases. V. arctostaphylos leaves are known to be rich in phytochemicals, however, no comprehensive and reliable protocol has been developed to date in order to produce plant materials for conservation purposes and/or to generate secondary metabolites under in vitro conditions. Therefore, present study was designed to develop a micropropagation system having high genetic fidelity and considerable potential to produce secondary chemicals from V. arctostaphylos. No morphological dissimilarities have been observed in tissue culture-produced shoots after their successfully placement in a greenhouse with high survival rate (≥ 90%). At the end of 2nd subculture, woody plant medium (WPM) containing moderate level of plant growth regulators (PGRs) such as Zeatin (2 ppm) and Auxin (Indole-3-butyric acid - IBA; 0.1 ppm) has significantly increased shoot length and shoot numbers per explants, whereas, other vegetative growth characteristics have shown significant increase in mediums containing the highest Zeatin and IBA concentrations. Half-strength WPM medium containing IBA (1 ppm) and activated charcoal (AC; 0.2%) showed maximum root length, number of roots and rooted explants and that the increasing concentrations of IBA and AC have positively improved root induction. Genetic homogeneity of the micropropagated plants has been analyzed using four pairs of simple sequence repeats (SSR) markers. Proliferated plants showed monomorphic bands identical to the donor plant and manifested the genetic stability of the newly produced plants. Different assays were used to measure the antioxidant potential and phenolic compound from in vitro, acclimatized and mother plant leaves. In all experiments, PGRs esp., Zeatin has shown significant effects on antioxidant scavenging, phenolic and flavonoid content of micropropagated plants. Metabolite screening using Infrared Spectroscopy (IR) indicated the presence of various functional groups such as amines, amides, carboxylic acids, esters, alkanes and aliphatic amine similar to mother plants. Results from present study have clearly indicated that the acclimatized plants of V. arctostaphylos could have been a reliable source for in vitro or ex-situ conservation and breeding program and, therefore, its conservation may highly be important due to availability of medicinally valuable plant secondary metabolites.

In this study, the positive role of hydrogen peroxide (H2O2) pretreatment in mitigating the adverse impacts of seawater stress has been evaluated in two wheat (Triticum aestivum L.) cultivars, namely Gemmiza 11 as a salt-sensitive and Misr 1 as a salt-tolerant cultivar, with contrasting phenotypes in response to the salinity stress. Under normal conditions, wheat seeds eustress with H2O2 have shown significant effects on the improvement of plant growth parameters, such as dry weight and root and shoot lengths. Under salt stress conditions, seeds eustress with H2O2 have shown a reduction in damage to plant growth and physiological parameters as compared to the seeds kept as un-primed in both wheat cultivars. In addition, eustress of seeds with H2O2 has induced an increment in the pigments content, proline level and mineral uptake (K+, Ca2+ and Mg2+). Moreover, seeds eustress with H2O2 have shown significant decrement in Na+ content uptake in plants and that subsequently reduced lipid peroxidation. Seawater stress has increased the activity of the antioxidant system based on catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) in both cultivars, except POD in Gemmiza 11. Similarly, the application of H2O2 has further enhanced the activity of the antioxidant system in stressed plants and this enhancement of the antioxidant system further reduced Na+ content in plants and subsequently increased the growth parameters. Results of inter-simple sequence repeat (ISSR) markers have shown clear differentiation among the treatments and have provided strong evidence in support of the hypothesis proposed in this study that H2O2 eustress improves seed tolerance and enhances plant growth parameters under seawater stress.

Changes in the antioxidant enzymes, lipid peroxidation, sodium and potassium, chlorophyll, H2O2 and proline content were monitored in the leaves of 42 rice varieties which were not yet well-documented for the salinity tolerance under different salinity levels. The tolerant varieties (FL478, Hassani, Shahpasand, Gharib and Nemat) showed signs of tolerance (lower Na+/K+ ratio, high proline accumulation, less membrane damage, lower H2O2 production, and higher superoxide dismutase and catalase activity) very well. The positive relationship between the level of salt tolerance and the amount of proline accumulation in the rice varieties support the important role of proline under the salt stress. The varieties were genotyped for 12 microsatellite markers that were closely linked to SalTol QTL. The results of association analysis indicated that RM1287, RM8094, RM3412 and AP3206 markers had the high value of R2 for the regression models of the studied traits. It shows the important role of SalTol in controlling physio-biochemical traits. The results can be used in the future marker assisted selection (MAS) directly, if the results are confirmed.

Drought stress is a severe environmental constraint to plant productivity. In this study, gene expression of WRKY1 and EREBP1 genes and activity of two enzymes were investigated in two genotypes, G9 (as resistance) and G12 (as susceptible) of 10 days-old lemon balm seedlings. Experiments were done according to factorial design on the base of completely randomized design with three replications for expression analysis and enzyme assays. Seedlings were cultured in MS medium suspensions, including 0, 3, 6, 12 and 15 % w/v PEG 6000. Leaf samples were subsequently collected at 0, 3, 6, 24, 48, 72 h after culture. According to the results of the enzyme assay, SOD activity in resistant genotype was more than in sensitive one. POD activity was high in G9 in severe drought condition and in G12 this activity was increased at initial times of drought stress. The survey results revealed that the expression levels of both genes, EREBP1 and WRKY1, in G9 variety were more than G12, and in this respect we can say that the G9 variety is more resistant to drought.

For fast and easy isolation of inhibitor-free genomic DNA even from the toughest plant leaf samples, including those high in polyphenols and polysaccharides, a protocol has been developed. To prevent the solubility of polysaccharides in the DNA extract, high salt concentration (1.4 M) was used in the extraction buffer. Polyvinylpyrrolidone (PVP) was used for the removal of polyphenols as polymerase chain reaction (PCR) inhibitors. Proteins like various enzymes were degraded by proteinase K and removed by centrifugation from plant extracts during the isolation process resulting in pure DNA and RNA ready to use in downstream applications including PCR, quantitative polymerase chain reaction (qPCR), ligation, restriction and sequencing. This protocol yielded a high molecular weight DNA and RNA isolated from leaves and roots of recalcitrant plants which was free from contamination and color. The average yields of total RNA from roots and shoot of Betula and Grape ranged from 285 to 364 ng/µl with A260/A280 between 1.9 and 2.08. The RNA isolated with this protocol was verified to be suitable for PCR, quantitative real-time PCR, semi-quantitative reverse transcription polymerase chain reaction, cDNA synthesis and expression analysis. This protocol shown here is reproducible and can be used for a broad spectrum of plant species which have polyphenols and polysaccharide compounds.