Bu çalışmanın amacı, seradaki UV radyasyonunun biber (Capsicum longum A.DC.) bitkilerinin strüktür ve
ultrastrüktürü üzerine etkilerini değerlendirmektir. Bu bitkiler, büyüme odalarında standart bir ...çevrede yetiştirilmiştir
ve 35 gün sonra sırasıyla 15 ve 8 gün UV-A ve UV-C'ye maruz bırakılmıştır. Bu çalışmada, kök büyümesinde
değişikliklerin önemli olmadığı bulunmuştur, fakat UV-R'ye maruz kalmış bitkilerde filizin büyümesi azalmış ve bu
azalma UV-C muamelesinde kayda değerdir. UV-R'ye maruz bırakılmış bitkilerde yaprak alanı da küçülmüştür ve bu
küçülme UV-C muamelesinde önemlidir. Kök kalınlığı, UV uygulamasında etkilenmemiştir, fakat yaprak ve gövde
kalınlığı hem UV-A hem de UV-C muamelelerinde önemli bir şekilde artmıştır. UV-R'ye maruz bırakılmış bitkilerde
stomanın sayısı ve büyüklüğü de artmıştır. Ultrastrüktür seviyede, kloroplast tilakoidlerinin şiştiği ve nişastanın azaldığı
gözlenmiştir. UV muamelesi, mezofil hücrelerin peroksizomlarındaki kristalize kalıntının oluşması ile sonuçlanmıştır.
Bu kristallerin oluşumu antioksidan bir enzim olan katalazın aktivitesinin artmasından dolayıdır. Bu çalışma, biber
bitkilerinin UV'ye duyarlı olduğunu göstermiş ve bu bulgular, UV'ye maruz kalma esnasında fizyolojik değişikliklerin
anlaşılmasını sağlamıştır ve bu bitkilerin UV-A radyasyonundan daha çok UV-C'ye duyarlı olduğunu göstermiştir.
The objective of this study was to evaluate the effects on the structure and ultrastructure of pepper plants
(Capsicum longum A.DC.) exposed to UV radiation under greenhouse conditions. The plants were grown in a growth
chamber under uniform environmental conditions and after 35 days were exposed to UV-A and UV-C radiation for 15
and 8 days, respectively. Changes in root growth were not significant, but shoot growth decreased in UV-R-exposed
plants and decreased significantly in UV-C-exposed plants. Leaf area also decreased in UV-R-exposed plants and
decreased significantly in UV-C-exposed plants. Root thickness was not affected by UV treatment, but stem and leaf
thickness significantly increased in response to UV-A and UV-C treatment. Stomata increased in number and size in UVR-
exposed plants. At the ultrastructural level, chloroplast thylakoids were dilated and starch reduction was observed.
UV treatment resulted in the formation of crystals in the peroxisomes of mesophyll cells. The formation of these crystals
was due to an increase in catalase activity, which is an antioxidant enzyme. The study shows that pepper plants were
sensitive to UV and the findings provide insight into the physiological changes during UV exposure, and indicate this
plant was more sensitive to UV-C radiation than to UV-A radiation.
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Pseudoroegneria ve ilişkili cinslerde, poliploidlerin filogenetik ilişkilerini ve maternal vericilerini araştırmak için,
31 Triticeae örneğinin kloroplast trnL-F dizileri analiz edildi. Bu çalışmada ...trnL-F dizilerinin yer değişim doygunluk
analizleri filogenetik analizler için uygunluğu önerdi. trnL-F dizilerine ait ağaçda, dört büyük dal şekillendi. (a) St/E dalı
Roegneria, Elytrigia, Douglasdeweya ve Lophopyrumile birlikte tümPseudoroegneria türlerini içerdi; (b) A. cristatum, A.
mongolicum ve A. pectinatum subsp. retrofractum türleri P/W dalını şekillendirdi; (c) Ns dalı Psathyrostachys türlerini
içerdi; (d) H dalı Hordeum türlerinden oluştu. Sonuçlar (a) trnL-F dizileri yüksek oranda benzerlik gösteren
Pseudoroegneria, Roegneria, Douglasdeweya ve Elytrigia cinsleri içinde yer alan St içeren poliploid türlerin maternal
vericilerinin diploid Pseudoroegneria türleri olduğunu; (b) P ve W genomlarının çok yakın ilişkili, Agropyron ve
Australopyrum türlerinin trnL-F dizilerinin benzer olduğunu; (c) H veya Ns genomlu türlerin trnL-F dizilerinin büyük
ölçüde St, E, P veya W genomlu türlerden farklılaştığını önerdi.
To investigate the maternal donors and phylogenetic relationships of polyploids in Pseudoroegneria and related
genera, the chloroplast trnL-F sequences of 31 Triticeae accessions were analyzed. The substitution saturation analysis
of trnL-F sequences in this study suggested that they are suitable for phylogenetic analysis. In the trnL-F sequences tree,
4 major clades were formed: (a) the St/E clade comprised all of the Pseudoroegneria species together with species in
Roegneria, Elytrigia, Douglasdeweya and Lophopyrum; (b) A. cristatum, A. mongolicum, and A. pectinatum subsp.
retrofractum formed the P/W clade; (c) the Ns clade included species in Psathyrostachys; and (d) the H clade consisted
of Hordeum species. The results suggested that: (a) diploid Pseudoroegneria species were the maternal donors of Stcontaining
polyploid species in Pseudoroegneria, Roegneria, Douglasdeweya, and Elytrigia, and the trnL-F sequences
were highly similar among them; (b) the trnL-F sequences of Agropyron species and Australopyrum species were similar,
and the P genome was closely related to the W genome; and (c) the trnL-F sequences of species with the H or Ns genomes
diverged greatly from that of species with the St, E, P, or W genomes.
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Several species in the genus Peperomia Ruiz & Pav. have giant chloroplasts in the palisade parenchyma of their
leaves. Because of this unique feature, Peperomia metallica L. Linden & Rodigas has ...become a valuable model plant for
studying plastid biology. However, the use of Peperomia for molecular studies has been limited by the lack of efficient
regeneration and transformation protocols. In this work, we aimed to develop a reliable regeneration system for Peperomia
from leaf explants. Using MS medium complemented with different combinations of phytohormones, a highly efficient
in vitro regeneration protocol was developed for P. metallica and P. peduncularis, another species with giant chloroplasts.
Regeneration occurs through direct organogenesis from leaf discs at a very high frequency. Our protocol can provide a
reliable tissue culture system for future Peperomia genetic transformation experiments.
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Yüksek sicaklik stresine karsi farkli hassasiyetleri olan Karacadag ve Firat bugday çesitleri üzerine 37°C veya
45°C, 8 saat yüksek sicaklik stresinin etkileri klorofil a floresansi, fotosentetik ...pigment içeriginin tayini ve
tilakoid membran 2-D SDS poliamid jel elektroforezi (PAJE) yoluyla arastirilmistir. 45°C, 8 saat uygulamasi
klorofil birikimini inhibe etmistir. 37°C veya 45°C, 8 saat uygulamalari ise klorofil a floresansi ve
fotosentezde önemli derecede degisimlere yol açmistýr. Iki bugday çesidinin tilakoid membran proteinlerinin
2D-SDS PAJE yoluyla analizi 37°C veya 45°C, 8 saat uygulamalarinin kontrol sicakligina göre herhangi bir
proteinin sentezini uyarmadigini veya baskilamadigini göstermistir. Karacadag çesidinin fotosentetik yanitlari
Firat çesidine göre klorofil içeriginde, FV ve FV/FM parametrelerinde Firat çesidine göre daha az düsme
gösterdiginden ve F0 parametresi yalnizca Firat çesidinde 45°C, 8 saat uygulamasinda arttigindan, Yüksek
sicakliga dayanikli çesit olarak tanimlanan Karacadag çesidi daha sicak bölgelerde ekim için kullanilabilir.
The effects of heat stress at 37°C and 45°C for 8 h on the seedlings of Karacadag and Firat
wheat cultivars differing in sensitivity was investigated by means of chlorophyll a fluorescence,
photosynthetic pigment content and 2-D SDS polyacrylamide gel electrophoresis of the
thylakoid membrane. Heat stress inhibited chlorophyll accumulation at 45°C for 8 h and
caused marked alterations in the chlorophyll a fluorescence and photosynthesis in the primary
leaves of the wheat cultivars at 37°C and 45°C for 8 h. Examination of the 2-D SDS
polyacrylamide gel electrophoresis analysis of the thylakoid membrane proteins from the two
wheat cultivars showed that while a heat treatment at 37°C and 45°C did not induce or
enhance the synthesis of any protein. While the synthesis of some proteins were repressed
when compared to the control temperature cultivars, the photosynthetic responses of
Karacadag were less altered than Firat to the effect that; Karacadag showed lower reduction
in the chlorophyll content, FV and FV/FM parameters where the F0 parameter only increased
in the Firat cultivar at 45°C. Therefore, Karacadag was determined to be a heat tolerant
cultivar that can be used for cultivation in warmer regions.
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Crocus L. is of interest to the horticultural, culinary and pharmacological fields. Our aims herein are to obtain information
based on genetic diversity and to investigate existing levels of genetic ...variation within and among the Crocus species sampled.
Since the classification of this species has not been clarified to date, this research may shed some more light on methods for
classification of Crocus L. RAPD and ISSR markers systems were used to estimate genetic diversity of 56 individuals
representing 19 Crocus taxa from Western Turkey. RAPD and ISSR banding matrix were calculated to construct a dendrogram
(Ward) by a cluster analysis performed by JMP software.
High level of genetic variation detected among sampled Crocus species. Genetic distance (GD) values ranged between 0.06
and 0.52 GD. DNA markers based clustering of Crocus L. did not coincide with morphological classifications.
This taxon should be reconsidered in terms of classification at the DNA-based level using nuclear, mitochondrial, and chloroplast
DNA, as well as more types of robust DNA markers such as AFLP and SSR. The existing high level of genetic variation shows
that Turkey could be one of the centers of origin for Crocus L.
The genetic engineering of algae has gained considerable importance in the last 2 decades. Considering the enormous biodiversity of micro and macroalgae and recent developments in genetic ...engineering, this group of organisms represents one of the most promising sources for new products and applications. With the development of sophisticated culture and screening techniques, algal transformation can already meet the high demands of both the food and pharmaceutical industries. This review also focuses on different kinds of applications, i.e. within physiology, biochemistry, molecular biology, phylogeny, industry and environmental science. Since the first alga transformed by foreign genes was Chlamydomonas reinhardtii, special attention has been given to the formation of such an organism. This review also discuusses the genetic engineering of different unicellular multicellular, colonialand macroalgae and their possible exploitation for commercial production after being improving its characters by introducing valuable foreign genes. Although eukaryotic algae are of value both as organisms for fundamental biological research and as a resource for the biotechnology industry, their importance in these areas would be enchanced significantly by the availability of a genetic engineering methodolgy. The immediate future promises to be an exciting time in which the genetic manipulation of these algae will lead to important new insights into their biology and the creation of new strains of commercial value. This can be accomplished by genetic transformation.
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8.
Phenolic cycle in plants and environment BORSARI, Bruno; KEFELİ, Valentine I; KALEVITCH, Maria V
Journal of cell and molecular biology,
2003, Volume:
2, Issue:
1
Journal Article
Peer reviewed
Open access
Fenolik maddeler bitkilerde ve toprakta sentezlenir. Bunlar polimerler ve monomerler şeklinde bulunurlar.
Fenoliklerin monomer grubu bitki hücresinin kloroplastlarında biraraya gelirken, toprak ...fenolikleri toprak
misellerinin alumino-silikat matriksi üzerinde humus oluşum olayı ile uyumluluk gösterir. Bitki büyürken hücre
vakuollerinde fenolikler birikir veya sekonder hücre çeperlerine sağlamlık kazandıran ligninlere polimerize olurlar.
Bunlara ilave olarak fenolikler hücre uzamasını düzenleyerek bazı fizyolojik ifllevlere de sahiptirler. Bitki kök
sistemlerinden salındıkları zaman hemen yakınındaki rizosferlerde büyümeyi inhibe edici etki meydana getirirler. Bu
çalışma fenolik sentezlerinin en son deneysel verilerini ve çevredeki dönüşümlerini sunarken, bitki-toprak
ilişkilerindeki etkilerini anlamamıza yardım etmektedir.
Phenolic substances are synthesized in plants and in the soil. They exist in the form of polymers and monomers. The
latter group of phenolics is assembled within the chloroplasts of plant cells, whereas soil phenolics are associated
with the process of humus formation on the alumino-silicate matrix of the soil micelle. As plants grow, phenolics
accumulate in cell vacuoles, or polymerize into lignin, which strengthens the secondary cell walls. In addition to this,
phenolics possess also some physiological functions as they regulate cell elongation. When they are excreted from
plant root systems they exert inhibitory growth function within adjacent rhizospheres. This work presents the latest
experimental evidence of phenolic synthesis and transformation in the environment, while providing an
understanding of their effect in plant-soil relations.
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Restriction fragment length polymorphism analysis of some Aegilops and Triticum species were performed in this study. An intergenic spacer region of chloroplast DNA (cpDNA) was digested by five ...different restriction endonuclease enzymes. Obtained fragments were investigated on agarose gel electrophoresis technique. Phylogenetic relationships among Triticum and Aegilops species were discussed, based on the resultant data.
Heat inactivation of various photosynthetic electron transport reactions were investigated in the presence/absence of glycinebetaine (betaine) in unstacked thylakoid membranes from spinach. The ...activity of Photosystem II (PS II) is more sensitive to heat than that of Cytochrome bf (cyt.bf) and Photosytem I (PS I) complexes. The data obtained clearly demonstrated the protection of PS II and PS I electron transfer by betaine under high temperatures. The phenomena observed are probably related to the stabilization of the higher-order structures of PS II and PS I by betaine.
