scholarly journals Impact of gamma irradiation pretreatment on biochemical and molecular responses of potato growing under salt stress

Author(s):  
Elhamahmy Ali Mohamed ◽  
Elsadany Osama ◽  
Eid Manal ◽  
Abdelazeem Samah ◽  
Gerish Salah ◽  
...  

Abstract Background Previous literatures revealed that gamma rays have an increasing effect on salt tolerance in different plants. In vitro experiment was conducted to study the effect of gamma rays (20 Gray) on salt tolerance of four potato cultivars (Lady Rosetta, Diamante, Gold, and Santana). Results Gamma-treated Santana plantlets were more tolerant to salinity as compared to other cultivars. It showed a significant increment of fresh weight (250% over the untreated). Gamma-treated plantlets of Lady Rosetta, Diamante, and Gold showed higher activity of peroxidase (POD) and polyphenol oxidase (PPO). Isoenzymes analysis showed an absence of POD 3, 4, and 5 in Gold plantlets. The dye of most PODs and PPOs bands were denser (more active) in gamma-treated plantlets of Santana as compared to other cultivars. Both gamma-treated and untreated plantlets showed the absence of PPO1 in Lady Rosetta and Diamante, and PPO 3, 4, and 5 in Gold plantlets. Genetic marker analysis using ISSR with six different primers showed obvious unique negative and positive bands with different base pairs in mutant plantlets as compared to the control, according to primer sequence and potato genotype. The 14A primer was an efficient genetic marker between mutated and unmutated potato genotypes. Santana had a unique fingerprint in the 1430-pb site, which can be a selectable marker for the cultivar. An increment in genetic distance between Gold cultivar and others proved that the mutation was induced because of gamma rays. Conclusion We assume that irradiation of potato callus by 20-Gy gamma rays is an effective process for inducing salt resistance. However, this finding should be verified under field conditions. Graphic Abstract

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 820
Author(s):  
Clara Azzam ◽  
Sudad Al-Taweel ◽  
Ranya Abdel-Aziz ◽  
Karim Rabea ◽  
Alaa Abou-Sreea ◽  
...  

Stevia rebaudiana Bertoni is a little bush, which is cultivated on a large scale in many countries for medicinal purposes and used as a natural sweetener in food products. The present work aims to conduct a protocol for stevia propagation in vitro to produce and introduce Stevia rebaudiana plants as a new sweetener crop to Egyptian agriculture. To efficiently maximize its propagation, it is important to study the influence of stress factors on the growth and development of Stevia rebaudiana grown in vitro. Two stevia varieties were investigated (Sugar High A3 and Spanti) against salt stress. Leaves were used as the source of explants for callus initiation, regeneration, multiplication and rooting. Some stress-related traits, i.e., photosynthetic pigments, proline contents, and enzyme activity for peroxidase (POD), polyphenol oxidase (PPO), and malate dehydrogenase (MDH) were studied. Murashig and Skoog (MS) medium was supplemented with four NaCl concentrations: 500, 1000, 2000, and 3000 mgL−1, while a salt-free medium was used as the control. The data revealed that salinity negatively affected all studied characters: the number of surviving calli, regeneration%, shoot length, the number of multiple shoots, number of leaf plantlets−1, number of root plantlets−1, and root length. The data also revealed that Sugar High A3 is more tolerant than Spanti. The total chlorophyll content decreased gradually with increasing NaCl concentration. However, the opposite was true for proline content. Isozyme’s fractionation exhibited high levels of variability among the two varieties. Various biochemical parameters associated with salt tolerance were detected in POD. Namely, POD4, POD6, POD 9 at an Rf of 0.34, 0.57, and 0.91 in the Sugar High A3 variety under high salt concentration conditions, as well as POD 10 at an Rf of 0.98 in both varieties under high salt concentrations. In addition, the overexpression of POD 5 and POD 10 at Rf 0.52 and 0.83 was found in both varieties at high NaCl concentrations. Biochemical parameters associated with salt tolerance were detected in PPO (PPO1, PPO2 and PPO4 at an Rf of 0.38, 0.42 and 0.62 in the Sugar High A3 variety under high salt concentrations) and MDH (MDH 3 at an Rf of 0.40 in both varieties at high salt concentrations). Therefore, these could be considered as important biochemical markers associated with salt tolerance and could be applied in stevia breeding programs (marker-assisted selection). This investigation recommends stevia variety Sugar High A3 to be cultivated under salt conditions.


1988 ◽  
Vol 8 (10) ◽  
pp. 4557-4560
Author(s):  
O Bakker ◽  
J N Philipsen ◽  
B C Hennis ◽  
G Ab

The estrogen-dependent binding of a protein to the upstream region of the chicken vitellogenin gene was detected by using in vivo dimethyl sulfate, genomic DNase I, and in vitro exonuclease III footprinting. The site is located between base pairs -848 and -824, and its sequence resembles that of the nuclear factor I binding site. The results suggest that a nuclear factor binding to this site is involved in the regulation of the vitellogenin gene.


1991 ◽  
Vol 11 (12) ◽  
pp. 6109-6115 ◽  
Author(s):  
L M Pabón-Peña ◽  
Y Zhang ◽  
L M Epstein

Synthetic transcripts of satellite 2 DNA from newts undergo self-catalyzed, site-specific cleavage in vitro. Cleavage occurs within a domain that is similar to the hammerhead domain used by a number of self-cleaving, infectious plant RNAs. The newt hammerhead has a potentially unstable structure due to a stem composed of two base pairs and a 2-nucleotide loop, and unlike other hammerheads that have been studied, it cannot cleave as an isolated unit. Here we show that cleavage by a single newt hammerhead requires additional satellite 2 sequences flanking both ends of the hammerhead domain. We also present a structural model of a truncated satellite 2 transcript which is capable of cleavage. The structure includes an internally looped extension to one of the conserved stems of the hammerhead. By in vitro mutagenesis, the identities of each of the five nucleotides composing one of the internal loops were shown to be critical for cleavage. Additional evidence that the extension stimulates self-cleavage in a manner other than by simply stabilizing the hammerhead is presented.


2021 ◽  
pp. 39-43
Author(s):  
Ákos Mendel ◽  
László Kovács ◽  
Erzsébet Kiss

Polyamines, such as spermidine (Spd) spermine (Spm) and their direct precursor, the diamine putrescine (Put) are vital and essential aliphatic amines which are also present in plants. Although ethylene and polyamines are also involved in fruit ripening, the genes coding them must also take part in other biosynthetic pathways. In the ethylene and polyamines play an important role in development of salt stress tolerance, and in responses for biotic and abiotic stresses. Exogenous application of all three main polyamines (Put, Spd, Spm) increase salt tolerance of plants, but, accordingly to previous experiments, spermidine has the main effect on the enhancement of salt tolerance. Nicotiana tabacum L. plants were grown in vitro on MS medium, the treatments were as follows: arginine (150 mg l-1), putrescine (10 mg l-1), spermidine (10 mg l-1). Proline, chlorophyll a, b and polyamine contents were measured. The obtained results show that the arginine decarboxylase and the spermidine synthase genes involved in polyamine metabolism, cannot be enhanced by exogenous addition of their precursor molecules. On the contrary, the spermine synthase gene has a positive effect to the lower-class forms of polyamines.


2021 ◽  
Vol 12 ◽  
Author(s):  
Almaz Nigatu Tesfahun ◽  
Marina Alexeeva ◽  
Miglė Tomkuvienė ◽  
Aysha Arshad ◽  
Prashanna Guragain ◽  
...  

DNA polymerase III mis-insertion may, where not corrected by its 3′→ 5′ exonuclease or the mismatch repair (MMR) function, result in all possible non-cognate base pairs in DNA generating base substitutions. The most thermodynamically unstable base pair, the cytosine (C)⋅C mismatch, destabilizes adjacent base pairs, is resistant to correction by MMR in Escherichia coli, and its repair mechanism remains elusive. We present here in vitro evidence that C⋅C mismatch can be processed by base excision repair initiated by the E. coli formamidopyrimidine-DNA glycosylase (Fpg) protein. The kcat for C⋅C is, however, 2.5 to 10 times lower than for its primary substrate 8-oxoguanine (oxo8G)⋅C, but approaches those for 5,6-dihydrothymine (dHT)⋅C and thymine glycol (Tg)⋅C. The KM values are all in the same range, which indicates efficient recognition of C⋅C mismatches in DNA. Fpg activity was also exhibited for the thymine (T)⋅T mismatch and for N4- and/or 5-methylated C opposite C or T, Fpg activity being enabled on a broad spectrum of DNA lesions and mismatches by the flexibility of the active site loop. We hypothesize that Fpg plays a role in resolving C⋅C in particular, but also other pyrimidine⋅pyrimidine mismatches, which increases survival at the cost of some mutagenesis.


Author(s):  
Yu. Khoma ◽  
L. Khudolieieva ◽  
N. Kutsokon

Soil salinization is an important abiotic factor negatively affecting plant growth, development and productivity. Fast-growing poplar and willow trees are important plants for bioenergy production demonstrating varying degrees of adaptation to different habitats. The study of salt resistance in different clones of poplars and willows will reveal genotypes that can be planted in saline soils for producing biomass for the bioenergy industry. Therefore, the aim of the study was to investigate the effects of salt stress on poplar plants of clone 'INRA 353-38' (Populus tremula × P. tremuloides) and willow clone 'Zhytomyrska – 1' (Salix sp.) under in vitro culture. For this purpose the plants were cultivated on MS nutrient medium with the addition of sodium chloride in concentrations 25 mM, 50 mM and 100 mM. The control plants were grown on the sodium chloridefree medium. The plant status (with a 4-score scale), the intensity of their growth (by shoot length) and rooting capacity (by the number of roots) were assessed on the 10th and the 30th day of cultivation. The results obtained indicate a high level of sensitivity to sodium chloride of both studied clones under in vitro cultivation. But the willow 'Zhytomyrska – 1' had a higher sensitivity to salt stress comparing to hybrid polar 'ІNRA 353-38' since growth parameters of willow were significantly decreased even under the concentration of sodium chloride 50 mM, and in the case of short term influence (10 days) of the highest concentration of sodium chloride (100 mM) all willow plants terminated their growth and quickly died. The growth parameters of hybrid poplar were declined within a month, mainly under the highest concentration of sodium chloride, but even under such conditions some part of the shoots were able to survive.


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