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Item Role Of Sulfur Metabolism In Acquiring Of Boron Tolerance In Arabidopsis Thaliana(TURKISH JOURNAL OF BOTANY, 2024) Yirmibes, Seda; Kayihan, Ceyhun; Cicek, Nuran; Ekmekci, YaseminThe purpose of this study was to assess whether sulfate treatment (pre- and combined) caused changes in the tolerance against boron (B) toxicity in Arabidopsis thaliana at the physiological, biochemical, and molecular levels. Germinated plants were grown in a controlled climate chamber (22 +/- 1 degrees C temperature, 16/8 s photoperiod, 200 mu mol m -2 s -1 light intensity and 50%-60% humidity) for 12 days. The sulfate pretreatment groups (PS-3B and PS-5B) were then transferred to nutrient medium containing Mg2SO4- type sulfate for 3 days. Afterward, they were transferred to petri dishes containing different boron concentrations (3 and 5 mM H3BO3), along with the nonpretreatment and combined (S+3B and S+5B) treatment groups, and exposed to boron toxicity for 10 days. The leaf area, plant biomass, and total chlorophyll content decreased significantly depending on the accumulation of B. Toxic levels of B adversely affected the structure and functionality of the photosynthetic apparatus. Changes were seen in the specific and phenomenological energy fluxes, quantum yields, and efficiency of the photosystem II (PSII) donor and acceptor sides. These changes led to decreases in the photosynthetic performance of the plants. Although B toxicity adversely affected the integrity of the membrane and the amount of photosynthetic pigment in the antenna and reaction centers (RCs), this effect was not at a level that completely blocked the functionality of the photosystems, and this negative effect was alleviated with the sulfate treatment. The increases in the antioxidant enzyme activities (especially peroxidase) and phenolic compounds with the sulfate treatment may have provided tolerance against toxicity and oxidative damage by regulating the defense systems. Moreover, B toxicity affected the relative expression of genes related to sulfate uptake, transport, and sulfur metabolism. In fact, the genes of sulfate transporters ( SULTR ); SULTR3;1, SULTR3;3, and SULTR3;5 were more expressed in PS-B group. The glutamate cysteine ligase (GSH1) and glutathione synthetase 1 (GSH2) relative gene expressions were increased in the treatment groups, indicating induced glutathione metabolism. In conclusion, plants may have acquired tolerance against B toxicity by assimilating sulfate, especially that provided by sulfate pretreatment.Item Are the Photosynthetic Performance Indexes and the Drought Factor Index Satisfactory Selection Criterion for Stress?(2015) Cicek, Nuran; Arslan, Ozlem; Culha-Erdal, Sekure; Eyidogan, Fusun; Ekmekci, Yasemin; ACA-9644-2022This study was conducted to assess the drought stress and the recovery responses of twenty one chickpea cultivars (Cicer arietinum L.) grown in Turkey. 20-day-old seedlings were subjected to mild drought conditions for 7 days, recovery period of 3 days followed. Then a moderate stress period of 10 days was applied, followed by recovery period of 4 days. Finally, severe stress period of 13 days was applied, followed by recovery period of 5 days. Drought stress treatments were observed to have an adverse effect on photosynthetic efficiency, but also malondialdehyde, total chlorophyll (app. half of cultivars) and carotenoid contents of leaf tissue have increased when compared with their controls. 21 chickpea cultivars were classified into four groups; highly tolerant, tolerant, less tolerant and sensitive, according to the drought factor index (DFI), the values calculated by photosynthetic performance index (PItotal). Only four cultivars recovered from severe drought stress conditions. Aziziye and Diyar 95 cultivars may be suggested to be cultivated in drought-prone areas. In general, the present results indicate that: 1. PItotal and DFI are very satisfactory selection criterion for drought stress. 2. The recovery processes of plants exposed to environmental constraints should be investigated to make the right selection.Item Does Sublethal Temperature Treatment Provide Any Tolerance in Tetraploid Wild and Durum Wheat Seedlings Exposed to Lethal Heat Stress?(2016) Eyidogan, Fusun; Terzioglu, Serpil; Ekmekci, Yasemin; ACA-9644-2022In this study, the effects of sublethal heat application before lethal heat treatment on thermotolerance mechanisms of tetraploid two wild wheats (Aegilops biuncialis and Aegilops cylindrica), and two durum wheats (Triticum turgidum L. cv. Kiziltan-91 and Harran-95) have been investigated. Eight-day-old seedlings were exposed sublethal heat pretreatment followed by lethal heat treatment [39 +/- 1 degrees C for 24h afterwards 50 +/- 1 degrees C for 1 h (T1)] and lethal heat treatment [50 +/- degrees C for 1 h (T2)]. When plants exposed to direct lethal temperature (T2), seedling lengths were significantly reduced in all genotypes. The sub-lethal treatment enabled the seedlings to tolerate the lethal effects of heat stress with respect to seedling length but this effect was not observed in Kiziltan-91 cultivar. T1 and T2 applications caused a decrease in relative water content in leaves of all genotypes. Total chlorophyll and carotenoid contents of tetraploid wild species were significantly decreased after all heat treatments. The sub-lethal heat pretreatment caused an accumulation of total chlorophyll and carotenoid contents in only Kiziltan-91 cultivar. Ae. cylindrica was found to be sensitive to heat but its degree of protection was higher than other genotypes. This tetraploid wild genotype probably withstands heat with better upregulating protective mechanisms.Item Comparative physiological and proteomic analysis of cultivated and wild safflower response to drought stress and re-watering(2021) Culha Erdal, Sekure; Eyidogan, Fusun; Ekmekci, Yasemin; 33707869Drought is one of the major environmental stress that adversely affect the growth and development of oil seed plant, safflower. There is a limited knowledge on proteomic responses to support physiological, biochemical changes in how safflowers can regulate growth and metabolism under drought conditions and followed by re-watering. The changes in morphological, physiological, biochemical and proteomics of safflower genotypes (Carthamus tinctorius L.; Remzibey-05 and Linas, tolerant and sensitive cultivars, respectively, and C. oxyacantha M. Bieb., wild type) after exposure to drought and followed by re-watering have been examined. Drought negatively affected the shoot weight, water content, chlorophyll fluorescence, and biochemical parameters, including photosynthetic pigment, proline, MDA, and H2O2 contents and antioxidant enzyme activities in all genotypes, while the re-watering period allowed Remzibey-05 to recover, and it even provided the wild type completely recovered (approximately 100%). A total of 72 protein spots were observed as differently accumulated under treatments. The identified proteins were mainly involved in photosynthesis and carbohydrate, protein, defense, and energy metabolisms. Protein accumulation related to these metabolisms in Remzibey-05 were decreased under drought, while increased following re-watering. However, sensitive cultivar, Linas, could not exhibit an effective performance under drought and recovery when compared with other safflower genotypes.