Alpha-tocopherol-dependent salt tolerance is more related with auxin synthesis rather than enhancement antioxidant defense in soybean roots

In this paper, we describe the alleviated effects of alpha-tocopherol (α-T) on oxidative damage and its possible role as a signal transmitter in plants during salt stress. The results show that exogenously applied α-T under salt stress increased root length and weight, but reduced hydrogen peroxide (H2O2), superoxide anion radical (O2.—) and malondialdehyde (MDA) content in soybean roots. The proline content was reduced by α-T treatment. Interestingly, endogenous auxin (IAA) level was significantly increased after α-T application as compared to salt stress alone. Moreover, α-T reduced significantly superoxide dismutase (SOD) enzyme and isoenzyme activity but upregulated peroxidase (POX) 2, 3 and glutathione-s-transferase (GST) 1, 3 isoenzyme expression. However, ascorbate peroxidase (APX) enzyme activity was not affected at all. Consequently, the results show that α-T serves as a signal molecule under salinity from leaves to roots by increasing remarkably endogenous IAA levels and increasing partially antioxidant activity in roots

Recombinant Expression and Characterization of A.thaliana Heterotrimeric G protein alpha subunit; GPA1

Current research on plant heterotrimeric G proteins is mainly focused on mutant / overexpression studies performed in model organisms, i.e. A. thaliana and O. sativa. These studies provide information about the pathways involving these proteins; however, the mechanism of G protein activation via signaling molecules remains unknown. Similarly, information on biochemical and biophysical characteristics of the plant heterotrimeric G-proteins is lacking, whereas for the mammalian counterparts, such studies have contributed unique insights into understanding their functional roles. Following this, A.thaliana heterotrimeric G protein  subunit (GPA1) is cloned into P.pastoris expression system and the recombinant protein is purified. Initial analyses reveal that GPA1 is membrane bound and N-terminally blocked indicating the presence of lipid modifications. The purified protein is GDP bound and can bind to GTP. Circular dichroism polarimetry analyses show that the dominant structure is helical and activation by receptor mimetics leads to a decrease in helical content; similar to mammalian counterparts. It appears that, contrary to mammalian G-alphas, the intrinsic fluorescence of GPA1 decreases in the presence of GTP and increases in the presence of GDP. Full characterization of GAPA1, including its nucleotide binding kinetics and dynamics, will help to establish a better understanding of the functional mechanisms of heterotrimerc G-protein activation in plants and will shed light on the level of similarity of plant and mammalian hetetrotrimeric G protein signaling pathways

Drought tolerance of knotgrass (Polygonum maritimum L.) leaves under different drought treatments

Drought stress is a major environmental stress factor for plants causing significant adverse effects on crop growth and yield. Therefore, plant resistance against drought should be determined for wild plants to alleviate such impacts. Knotgrass (Polygonum maritimum L.) is a wild plant getting rarer every day in sandy coasts. The present study was consulted to determine the responses of knotgrass (Polygonum maritimum L.) to drought stress during vegetative growth stages. Plants were drought-stressed by withholding water for (72 hours) and (10 days). Relative water content did not change under drought stress, but the chlorophyll content decreased in both drought treatments. Although, superoxide dismutase (SOD) and catalase (CAT) activity increased more in 10 days drought treatment than 72 hours treatment, ascorbate peroxidase (APX) and glutathione reductase (GR) activity of the treatments were not significantly different. Moreover, both malondialdehyde (MDA) and hydrogen peroxide (H2O2) contents did not change under drought treatments. Such findings indicated Polygonum maritimum as a tolerant species to drought stress during vegetative growth stages

Some Medical and Aromatic Plants Growing Naturally in Kumru Region (Ordu)

Karadeniz Kıyı şeridi, iklim ve coğrafi yapısı ile bitki biyoçeşitliliği açısından çok zengin bir bölgedir. Özellikle il ve ilçelerinde bulunan bu zenginliğin belirlenerek korunması, geliştirilmesi ve yaygınlaştırılması oldukça önemlidir. Bu çalışma, Ordu iline ait Kumru ilçesinin zengin yaylalarında bulunan, ormanlık ve fundalık arazilerinde yaygın bitki örtüsüne sahip olan, doğal olarak yetişen ve bölgede bulunan halkın değişik amaçlar için toplayıp kullandığı tıbbi ve aromatik bitkileri tespit etmek amacıyla yapılmıştır. 2014-2015 yıllarında gerçekleştirilen bu çalışma; kırsal kesimde yaşayan halk, ilçede bulunan semt pazarında yöresel ürün satanvatandaşlar ve aktarlarla yapılan anketler ile bölgede gerçekleştirilen arazi çalışmalarını içermektedir. Çalışma sonucunda 54 adet tıbbi ve aromatik bitki tespit edilmiş olup; bunlardan 35 tanesinin ilaç, 9 tanesinin sebze, 6 tanesinin meyve ve 4 tanesinin baharat olarak kullanıldığı belirlenmiştir. Elde edilen bitkilerin Latinceleri, familyaları, yöresel isimleri, kullanılan kısımları ve kullanılış amacı ve şekli listelenmiştir.Black Sea coastline is very rich in plant biodiversity in terms of its climate and geographical structure. Inparticular, determination, protection, development and extensification of this fortune in the cities and towns is crucial. This study was carried out in order to determine medical and aromatic plants, using by locals and growing in rich high lands of Kumru District (Ordu) which has wide shrubberies and wood lands. This research involves the question naires with people living in rural area, herbalist, the sellers of district bazaar, and the field surveys in the region in 2014 and 2015. As a result, 54 medical and aromatic plants have been identified, which are used 35 of these plants as medicine, 9 of them as vegetables, 4 of them as fruits, and 6 of them as seasoning. Latin and local names, families, utilizable parts and th epurposes of usage of these plants were listed inclusively

Guanonun Çimlenmeyi Teşviki ve Guano ve Su stresi Uygulamalarına Karşı Buğday Fidelerinin Verdiği Yanıtlar

Bu çalışma organik bir gübre olan guanonun buğday (Triticum durum L. Karakılcık) bitkisinin çimlenme ve büyüme parametreleri üzerine olan etkisini tespit etmek amacı ile yapılmıştır. Guano çimlenme ortamına üç gün boyunca 6g /100 ml oranında uygulanmıştır.Çimlenmenin ardından bir grup yedi gün boyunca su kıtlığına maruz bırakılıp diğer bir grup düzenli olarak sulanmıştır. Çimlenme oranı ve çimlenen tohumlardaki kuru ağırlık guano uygulanan grupta daha yüksek bulunmuştur.Vejetatif aşamada guano uygulamaları su stresi altında bağıl su içeriği ve bağıl büyüme oranını geliştirmiştir.Su stresi malondialdehid ve hidrojen peroksit (H2O2) içeriğini arttırmış fakat bu parametreler su stresi ve guano uygulamalarının birlikte yapıldığı grupta belirgin bir değişikliğe uğramamışlardır.Fide aşamasında aba miktarı guano ve su stresi grubunda azalmış fakat guano uygulaması su stresi altında ABA (absisik asit) miktarını arttırmıştır. Bu sonuçlara göre guano uygulamasının buğday tohumlarında çimlenme ve büyüme parametrelerini iyileştirdiği ayrıca buğday fidelerinin su stresi altında oluşan oksidatif hasardan koruduğu ortaya konulmuştur

Kumru (Ordu)Yöresinde Doğal Olarak Yetişen Bazı Tıbbi ve Aromatik Bitkiler

Karadeniz Kıyı şeridi, iklim ve coğrafi yapısı ile bitki biyoçeşitliliği açısından çok zengin bir bölgedir. Özellikle il ve ilçelerinde bulunan bu zenginliğin belirlenerek korunması, geliştirilmesi ve yaygınlaştırılması oldukça önemlidir. Bu çalışma, Ordu iline ait Kumru ilçesinin zengin yaylalarında bulunan, ormanlık ve fundalık arazilerinde yaygın bitki örtüsüne sahip olan, doğal olarak yetişen ve bölgede bulunan halkın değişik amaçlar için toplayıp kullandığı tıbbi ve aromatik bitkileri tespit etmek amacıyla yapılmıştır.2014-2015 yıllarında gerçekleştirilen bu çalışma; kırsal kesimde yaşayan halk, ilçede bulunan semt pazarında yöresel ürün satanvatandaşlar ve aktarlarla yapılan anketler ile bölgede gerçekleştirilen arazi çalışmalarını içermektedir. Çalışma sonucunda 54 adet tıbbi ve aromatik bitki tespit edilmiş olup; bunlardan 35 tanesinin ilaç, 9 tanesinin sebze, 6 tanesinin meyve ve 4 tanesinin baharat olarak kullanıldığı belirlenmiştir. Elde edilen bitkilerin Latinceleri, familyaları, yöresel isimleri, kullanılan kısımları ve kullanılış amacı ve şekli listelenmiştir

Regulation of auxin, abscisic acid and salicylic acid levels by ascorbate application under heat stress in sensitive and tolerant maize leaves

In the present study, the effect of ascorbic acid (5 mM) on some physiological parameters and three hormones (auxin, abscisic acid, salicylic acid) was determined under heat stress (40 °C) in maize tolerant cv. (MAY 69) and sensitive cv. SHEMAL (SH) at 0 h, 4 h and 8 h. Heat stress reduced total chlorophyll content (CHL), relative water content (RWC) and stomatal conductance (gs) in SH but did not lead to changes in MAY 69 at 4 h and 8 h. However, pretreatment with ascorbic acid increased (CHL), (RWC) and (gs) in SH under heat stress while it reduced MDA content significantly in both cv. We also observed that heat stress led to a reduction in SA level but increased ABA and IAA levels in SH, whereas it increased SA and IAA levels but did not change ABA level in MAY 69 at 4 h. Furthermore, in SH, ASC application under heat stress increased SA level and decreased IAA and ABA levels at 4 h, but it had no effect on SA and ABA at 8 h

Differential Response of Bean (Phaseolus vulgaris L.) Roots and Leaves to Salinity in Soil and Hydroponic Culture

The present study aimed to investigate the response of common bean (Phaseolus vulgaris L. Volare) roots and leaves to salinity in different growth mediums (soil and hydroponic culture) through physiologic and biochemical analyses. The relative water content (RWC) and total chlorophyll (CHL) content decreased with 300 mM NaCl treatment in both cultures but did not change with 150 mM treatment in soil culture. Similarly, the malondialdehyde (MDA) content did not change with 150 mM treatment in soil culture, whereas it increased in all other treatments. The highest increase in hydrogen peroxide (H2O2) content was observed with 300 mM treatment in hydroponic culture. The highest increase in superoxide dismutase (SOD) activity was observed in plant leaves in the hydroponic culture. Catalase (CAT) activity did not change with 150 mM treatment in soil culture but decreased with 300 mM treatment in both cultures. Ascorbate peroxidase (APX) activity decreased in all treatments, except in the roots in the hydroponic culture. The Na+ and Cl- contents were higher in the hydroponic culture than in the soil culture. Salt stress induced more serious oxidative damage in the hydroponic culture compared to the soil culture

Regulation of glutathione S-transferase enzyme activity with salt pre-treatment under heat stress in maize leaves

Abstract- The present study was conducted to present the responses of heat-sensitive (Shemal) and heat-tolerant (71MAY69) maize cultivars under heat stress (at 40 °C for 2 hours in 2 days) with pre-salinity treatment (50 mM NaCl) to determine the relation of salicylic acid (SA) and glutathione S-transferase (GST) enzyme activity in those responses. Relative water content (RWC), chlorophyll content (CHL), stomatal conductance (gs), hydrogen peroxide (H2O2), malondialdehyde (MDA) content, GST enzyme and isoenzyme activity and internal SA levels were investigated. While heat treatments resulted in low RWC, CHL gs and high MDA and H2O2 levels in sensitive cultivar, all these values were lower in tolerant cultivar. Compared to single heat stress treatments, heat stress with pre-salinity treatment increased GST enzyme and isozyme activity of both cultivars. Results also indicated that pre-salinity treatment triggered internal SA levels and hydrogen peroxide contents in sensitive leaves according to control groups. Such hydrogen peroxide levels also decreased by increasing total GST and isozyme activities under heat alone, pre-salinity treatment alone. As a result, it could be said that SA is a good signal for the changes of GST enzyme activity under heat stress treatment