An overview on Azelaic Acid: Biosynthesis, signalling and the action under stress conditions in plants

Plants are exposed to various biotic and abiotic stress factors throughout their lives. For this reason, they have developed some defense mechanisms. They can induce systemic acquired resistance (SAR), which provides long-lasting protection against diverse pathogen attacks. In recent years, several chemical inducers (salicylic acid, glyceraldehyde-3-phosphate, azelaic acid, pipecolic acid, and dehydroabietic acid) have been determined to play roles in this mechanism. The transfer of these signal molecules from infected tissue to non-infected tissues through phloem provides potent defence communication. Azelaic acid is a well-known molecule that triggers salicylic acid accumulation under biotic stress as a priming factor to induce SAR, although little is known about its role under abiotic stress. Here, this review aims to call attention to the effects of AzA under abiotic stress conditions as well as biosynthesis, transport and signalling

Investigation of Comparative Regulation on Antioxidant Enzyme System under Copper Treatment and Drought Stress in Maize (Zea mays L.)

The present study was conducted to present the responses of drought-sensitive ‘Shemal’ and drought-tolerant ‘71MAY69’ maize cultivars under drought condition (20% Polyethylene glycol, -0.40 MPa) and three different copper concentrations (0.5 mM, 1 mM, 1.5 mM CuSO4.5H2O) for 5 days to determine the enzymatic responses of copper treatment in maize leaves. Copper treatments alone did not change stomatal conductance, relative water content, malondialdehyde, proline, hydrogen peroxide content and abscisic acid level according to control groups. Combined treatment (drought and copper) alleviated the damage of PEG- induced drought stress in maize leaves. Superoxide dismutase (SOD), catalase (CAT), glutatione reductase (GR) activity increased and glutathione -S transferase (GST) activity decreased, while ascorbate peroxidase (APX) activity did not change under drought stress in the tolerant cultivar. SOD, CAT and APX were decreased and GST activities were increased while GR did not change in ‘Shemal’. Also SOD, APX and CAT activity increased by copper treatment alone in both cultivars. Otherwise combined treatment increased SOD, APX and CAT activity at all concentrations, but GR and GST activity increased only by (PEG+1.5 mM) treatment when compared with PEG treatment alone in sensitive ones. As a result, exogenous copper alleviated drought stress, while it induced an oxidative damage by increasing antioxidant enzyme activities differently from drought tolerance. Copper tolerance in maize is not a common response of its defense mechanism because of different response to copper and drought in the same cultivar

The Effects of NPR1 Dependent Salicylic Acid Change in Increasing Salt Tolerance of Soybean Leaves by Acclimation

Non-expressor of Pathogen Related 1 (NPR1) is a regulatory gene of the salicylic acid (SA) signaling pathway, the detailed mechanism of which is still not well understood. This study investigated the effects of NPR1-dependent SA level change on increasing salt tolerance of soybean leaves with acclimation. Salt-sensitive (‘SA88’) and salt-tolerant (‘Erensoy’) soybean (Glycine max L.) plants were treated with increasing NaCl concentrations (25, 50, 75, and 100 mM; acclimation) and with 100 mM NaCl directly (non-acclimation) in two groups. The results showed that acclimation treatment alleviated salt-induced damage in the sensitive cultivar with increasing superoxide anion radical scavenging activity, and decreasing hydrogen peroxide (H2O2) and malondialdehyde (MDA) content. However, the APX, CAT, and GST enzyme activities were increased by acclimation treatment, with the highest increase observed in GST enzymes. Interestingly, the Gmnpr1 gene expression was upregulated in all treatments but was more pronounced in non-acclimation. Furthermore, the highest increase in endogenous SA level was under acclimation treatment in ‘SA88’. In conclusion, the results firstly showed that an acclimation process is useful for increasing salt tolerance in sensitive soybean plants with only ROS-inducted NPR1-independent SA accumulation but not through the NPR1-dependent SA signaling pathway

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

The present study was conducted to investigate the effects of guano (organic fertilizer) on germination and growth parameters of wheat (Triticum durum L. Karakılcık). Guano was applied into germination medium at a rate of 6g /100 ml - for 3 days. Following the germination of seeds, one group was water stressed by applying a water deficit for 7 days and the other group was irrigated ordinarily. The germination rate and the dry weights of germinated seeds were higher in guano-applied group. In vegetative stage, guano treatments improved relative water content (RWC) and relative growth rate (RGR) under water stress. Water stress increased malondialdehyde (MDA) and hydrogen peroxide (H2O2) content but both parameters did not significantly change in combined water stress and guano treatments. At the seedling stage, ABA (abscisic acid) content decreased in guano group and under water stress but guano treatment increased ABA contents under water stress. It was concluded herein that guano treatments improved germination and growth parameters of wheat seeds and protected the wheat seedlings from oxidative da mages under water stress.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

Effect of accelerated aging test on fungi formation in stored eggplant seeds

Solanaceae familyasına ait etli meyveliler grubunda tohumlar fermantasyon gibi özel işlemlere gerek duymaktadır.Fermantasyon yöntemlerinden biri olan asit uygulamaları etli meyveliler grubunda yaygın olarak kullanılmakta,hızlı ve pratik sonuç vermektedir. Hızlı yaşlandırma testi tohumların yüksek nem ve sıcaklıkta depolanabilmeözelliklerini belirlemenin yanında çeşitli önlemler alınmadığı takdirde fungal kontaminasyonu artmaktadır.Yürütülen çalışmada, iki farklı tohum olgunluk döneminde (50 ve 65 günlük) hasat edilmiş ve üç farklıfermantasyon uygulamasına (su, 10 dak. HCl, 20 dak. HCl) tabi tutulan 4 ºC sıcaklıkta depolanmış 8 yıllık Kemerpatlıcan çeşidi tohumlarının hızlı yaşlandırma testi ile tohum gücündeki azalış ve fungal kontaminasyon oranlarıbulunmuştur. Hızlı Yaşlandırma testi (HYT); yüzey sterilizasyon (%2 lik NaOCl ile 2 dak.) yapılan (SS) veyapılmayan (NSS) iki gruba ait tohumlarda 41 ºC de 72sa süre ile yapılmıştır. Bunu takiben çimlenmeye alınantohum partilerinde ilk hafta % fungal kontaminasyon hesaplanmıştır. Sonuçlara göre; HYT yapılmayan tohumpartilerinde en hızlı (ortalama çimlenme zamanı; 5 gün) ve en yüksek çimlenme oranı (ortalama çimlenme oranı;%73) ile 50 günde hasat edilen ve 20 dakika HCl fermantasyonu uygulanmış tohum partisinden elde edilmiştir. 65 günlük tohum olgunluğunda hasat edilmiş partilerde ortalama çimlenme zamanı ve oranı sırasıyla %67 ve 5 günolarak hesaplanmıştır. HYT sonuçlarına göre ise; yüksek değerleri veren 50 günlük tohumlarda SS partilerdecanlılık %20 azalmış, fungal kontaminasyon %2 oranında iken ve NSS partilerinde canlılık %3 azalmış, bulaşmaoranı ise %25 olarak bulunmuştur. Genel olarak yüzey sterilizasyon uygulaması toplam uygulama gruplarının%67’sinde kontaminasyonu engellemiştir. Tohum yüzeyinde görülen patojenlerden; Penicillium spp., Aspergillusspp. ve Alternaria spp. etmenleri elimine edilmiştir.Seeds of fleshy fruits group in Solanaceaea family need specific processes such as fermentation. Acid applications,which is one of the fermentation methods are widely used in the fleshy fruits group, are given fast and practicalresults. Accelerated aging test determines the ability of seeds to be stored at high humidity and temperature andbesides, if various measures are not taken, fungal contamination is increased. In this study, Kemer eggplant seeds,which were harvested two different seed maturity period (50 and 65 days after anthesis) and were subjected threedifferent fermentation treatments (water, 10 min. HCl, 20 min. HCl) and stored at 4 C for 8 years, seed vigor andfungal contamination rates were decreased with accelerated aging test. Accelerated aging test (AAT) was carriedout; surface sterilization (2% of NaOCl 2 min.) treated (SS) and untreated (NSS) with 41 C at 72 h period in theseed of the two groups. In the next stage, percentage of fungal contamination was calculated at the first week ofgerminated seed lots. According to the results; the fastest (mean germination time, 5 days) and the highestgermination rate (average germination rate, 73%) obtained from the seed lots which control and harvested 50 daysand were treated with HCl fermentation at 20 minutes. 65 days harvested seed lot’s mean germination time andrate were calculated as 67% and 5 days, respectively. According AAT results; 50 days after harvest anthesis seedsthat were given high value, viability decreased by 20% and fungal contamination was 2%, in the NSS group seedviability decreased 3% and infection was found 25%. Generally, surface sterilization treatment preventedcontamination of 67% of total treatments. Pathogens which found at the surface of seed are Penicillium spp.,Aspergillus spp. ve Alternaria spp. eliminated

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