Antioxidant system response of different wheat cultivars under drought: field and in vitro studies

2001 ◽  
Vol 28 (11) ◽  
pp. 1095 ◽  
Author(s):  
Hernán R. Lascano ◽  
Gerardo E. Antonicelli ◽  
Celina M. Luna ◽  
Mariana N. Melchiorre ◽  
Leonardo D. Gómez ◽  
...  

The participation of the antioxidant system in the drought tolerance of wheat cultivars (Triticum aestivum L.) was studied under field and in vitro conditions. Under field conditions, drought tolerance was evaluated by the capacity to maintain the grain yield under drought, which was higher in cvv. Elite and La Paz than in the sensitive cvv. Oasis and Cruz Alta. Tolerant cultivars showed lower relative water content (RWC) and lower above-ground vegetative biomass than sensitive cultivars. Field assays did not show a clear correlation between water-stress tolerance and antioxidant system behaviour. However, when leaves of cvv. with contrasting drought tolerance were subjected to osmotic stress in vitro, clear differences in the antioxidant system activity and oxidative damage between cvv. were observed. In the tolerant cultivar Elite, it was possible to observe an increase in ascorbate peroxidase (APX), superoxide dismutase (SOD) and glutathione reductase (GR) activities, a higher glutathione (GSH) and ascorbate content and less oxidative damage than in the sensitive cultivar Oasis, which showed no changes or only slight decreases in the enzyme activities. These results indicate that water stress tolerance is in part associated with the antioxidant system activity, and suggest that the behaviour of the antioxidant systemin vitro assays can be used as an early selection tool.

Plant Science ◽  
1997 ◽  
Vol 128 (2) ◽  
pp. 217-223 ◽  
Author(s):  
Quintero-Higuera Marı́a Fernanda ◽  
Santos-Dı́az Marı́a del Socorro ◽  
Garcı́a-de la Cruz Ramón Fernando

CORD ◽  
2012 ◽  
Vol 28 (2) ◽  
pp. 9
Author(s):  
L Perera

Coconuts show a remarkable yield drop due to long dry periods caused by global climatic changes. Thus, breeding for drought tolerance has become a priority in coconut breeding in Sri Lanka. Five coconut varieties indigenous to Sri Lanka, namely Ran thembili, Gon thembili, Porapol, Bodiri and Red dwarf were screened for their drought tolerance potential in vitro. Mature zygotic embryos collected from self pollinated nuts of each variety were germinated and developed into plants with one photosynthetic leaf in Y3 medium. Water stress condition was induced by application of Polyethylene Glycol (PEG) into the culture medium. The level of PEG in culture medium was gradually increased from 2% to 7% until the plants showed water stress symptoms in leaves; yellowing and necrosis. More than 75% of zygotic embryos of all tested coconut varieties successfully germinated in vitro and developed into plants. Plants of all tested coconut varieties survived water stress caused by 4% to 6% PEG and the percentages of plant survival at different levels of PEG varied among different coconut varieties. Variety Ran thembili showed the highest survival rate (27%) at 6% PEG and overall best plant growth performances at 4% PEG among the five coconut varieties tested. Red dwarf showed the lowest survival rate at 4% to 6% PEG indicating its susceptibility to water stress. Among the coconut varieties tested, zygotic embryos of Ran thembili showed the highest drought tolerance potential.


2022 ◽  
Vol 46 (1) ◽  
Author(s):  
Almoataz Bellah Ali El-Mouhamady ◽  
Abdul Aziz M. Gad ◽  
Ghada S. A. Abdel Karim

Abstract Background Water stress, specifically the limited water resources needed to grow strategic crops, especially rice, poses a great threat to crop productivity. So, it was imperative that scientists all work together to try genetically improving the rice for drought tolerance in light of these environmental challenges. The aim of this study is trying to know the genetic behavior responsible for water-deficit tolerance in rice genotypes but at the molecular level. Moreover, this attempt will be an important leap in the process of genetic improvement in rice for water stress tolerance in Egypt. Results Twenty-three rice genotypes including eight parents and their fifteen F1 crosses or (the first hybrid generation) by line X tester analysis were evaluated for water stress tolerance during two experiments (the control and drought experiment) besides some molecular–biochemical studies for eight parents and the highest selected five crosses for water stress tolerance. The research revealed that five rice crosses out of fifteen hybrids were highly tolerant to water stress compared to the normal conditions. Data of biochemical markers indicated the presence of bands that are considered as molecular genetic markers for water-deficit tolerance in some rice genotypes, and this is the scientific progress achieved in this research. This was evident by increasing the density and concentration of SDS-protein electrophoresis besides enhancing the activities of peroxidase (POD) and polyphenol oxidase (PPO) under water-deficit conditions, which confirmed the tolerance of drought stress in the eight rice genotypes and the best five crosses from the first hybrid generation. Conclusion The five promising and superior rice hybrids showed an unparalleled tolerance to water stress in all evaluated traits under water stress treatment compared to the standard experiment. Also, biochemical and molecular parameters evidence confirmed the existence of unquestionable evidence that it represents the main nucleus for producing rice lines tolerated for drought stress under Egyptian conditions.


2016 ◽  
Vol 18 (2) ◽  
pp. 71-78 ◽  
Author(s):  
KK Sarkar ◽  
MA Mannan ◽  
MM Haque ◽  
JU Ahmed

An experiment was conducted to study the effects of water stress on physiological parameters associated to drought tolerance in soybean at the Department of Agronomy, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh during January to April, 2015. Four soybean genotypes namely i) BU Soybean 1 ii) Binasoybean 1 iii) Galarsum and iv) BARI Soybean 5 were grown in two watering regimes viz. control (80% of the field capacity) and water stress (50% of the field capacity). Genotypic variability was found in water stress tolerance in soybean. Highest accumulation of leaf proline, sugar and water content and lower accumulation of malondialdehyde were found in Binasoybean 1 compared to other genotypes. Lowest yield reduction was found in Binasoybean 1. Binasoybean 1 showed relatively higher drought tolerance whereas BARI Soybean 5 was found susceptible to yield. It was found that higher water stress tolerance in Binasoybean 1 was associated with better water relations and higher accumulation of sugar and proline and lower accumulation of malondialdehyde content in leaf.Bangladesh Agron. J. 2015, 18(2): 71-78


2012 ◽  
Vol 48 (No. 4) ◽  
pp. 178-184 ◽  
Author(s):  
M.A.R.F. Sultan ◽  
L. Hui ◽  
L.J. Yang ◽  
Z.H. Xian

Wheat is one of the most important crops in the world. Its yield is greatly influenced by global climate change and scarcity of water in the arid and semi-arid areas of the world. So, exploration of gene resources is of importance to wheat breeding in order to improve the crop ability of coping with abiotic stress environment. Wild relatives of wheat are rich repositories of beneficial genes that confer tolerance or resistance not only to drought but also to other environmental stresses. In the present study, the changes in leaf relative water content (RWC), free proline content, and malondialdehyde (MDA) accumulation of five wild wheat species including T. boeticum (YS-1L), T. dicoccum var. dicoccoides (YS-2L), T. araraticum (ALLT), and two cultivated varieties of T. turgidum ssp. durum (MXLK and 87341), with two well-known common wheat cultivars (SH6 and ZY1) possessing strong drought resistance and sensitiveness, respectively, as references were investigated during 3-day water stress and 2-day recovery, in order to assess the drought tolerance of these wild wheat species. The laboratory experiment was conducted under two water regimes (stress and non-stress treatments). Stress was induced to hydroponically grown two weeks old wheat seedlings with 20% PEG 6000. Stress treatment caused a much smaller decrease in the leaf RWC and rise in MDA content in YS-1L compared to the other wheat species. From the data it was obvious that YS-1L was the most drought tolerant among studied species having significantly higher proline and RWC while lower MDA content under water stress conditions. The order of water stress tolerance of these species according to the three parameters is: YS-1L > YS-2L > SH6 > 87341 > ZY1 > MXLK > ALLT. We speculate that the observed drought stress tolerance at a cellular level was associated with the ability to accumulate proline and high water level conservation.


Agronomy ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2004
Author(s):  
Muhammad Tajammal Khan ◽  
Shakil Ahmed ◽  
Anis Ali Shah ◽  
Adnan Noor Shah ◽  
Mohsin Tanveer ◽  
...  

Climatic variations adversely affect the limited water resources of earth which leads to water stress and influences agricultural production worldwide. Therefore, a novel approach has been introduced to improve the tolerance against water stress in herbaceous nature medicinal plants such as Coriandrum sativum by the usage of nanotechnology (foliar applied nanoparticles of ZnOx) coupled with the application of water deficit irrigation. This is an alternative water saving strategy that proved to be efficient to mitigate the Coriandrum sativum tolerance against water stress regimes for sustainable yield production through the activation of antioxidant system. Thus, the phenomena of green synthesis have been deployed for the formation of Zinc oxide nanoparticles (ZnOx NPs) from the leaf extract of Camellia sinensis L. and zinc acetate dihydrate was used as precursor. Different techniques have been used for the thorough study and confirmation of ZnOx NPs such as UV-vis spectroscopy (UV-vis) X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and Elemental dispersive spectroscopy (EDS). The prepared ZnOx NPs exhibit hexagonal wurtzite crystal nature has an average size of 37 nm with high purity. These ZnOx NPs have been further studied for their role in amelioration of water stress tolerance in Coriandrum sativum in a pot experiment. Two levels of water stress regimes were employed, IR75 (moderate) and IR50 (Intense) to evaluate the behavior of plant compared to full irrigation (FI). Results showed that under water stress regimes, the 100 ppm of prepared NPs stimulate the antioxidant system by increasing the activity of catalases (CAT), super oxidases (SOD) and ascorbate peroxidase (APX) enzymes and found the maximum at IR50, while the concentration of malondialdehyde (MDA) decreased due to increase in activity of antioxidative enzymes. Furthermore, chlorophyll content and amount of proline also enhanced by the foliar application of prepared ZnOx NPs under moderate water stress (IR75). The results suggested that all the investigated agronomic attributes significantly increased, including plant biomass and economic yield (EY), compared to non-treated ZnOx NPs plants, except for the number of primary branches and LAI. Further, the 100 ppm of prepared ZnOx NPs have great potential to improve water stress tolerance in Coriandrum sativum by improving the antioxidant enzymes activity that enhance agronomic attributes for high crop productivity that require further research at transcriptomic and genomic level.


2010 ◽  
Vol 76 (16) ◽  
pp. 5452-5462 ◽  
Author(s):  
Matthias Kurz ◽  
Adrien Y. Burch ◽  
Britta Seip ◽  
Steven E. Lindow ◽  
Harald Gross

ABSTRACT The foliar pathogen Pseudomonas syringae pv. syringae exhibits an exceptional ability to survive on asymptomatic plants as an epiphyte. Intermittent wetting events on plants lead to osmotic and matric stresses which must be tolerated for survival as an epiphyte. In this study, we have applied bioinformatic, genetic, and biochemical approaches to address water stress tolerance in P. syringae pv. syringae strain B728a, for which a complete genome sequence is available. P. syringae pv. syringae B728a is able to produce the compatible solutes betaine, ectoine, N-acetylglutaminylglutamine amide (NAGGN), and trehalose. Analysis of osmolyte profiles of P. syringae pv. syringae B728a under a variety of in vitro and in planta conditions reveals that the osmolytes differentially contribute to water stress tolerance in this species and that they interact at the level of transcription to yield a hierarchy of expression. While the interruption of a putative gene cluster coding for NAGGN biosynthesis provided the first experimental evidence of the NAGGN biosynthetic pathway, application of this knockout strain and also a gfp reporter gene fusion strain demonstrated the small contribution of NAGGN to cell survival and desiccation tolerance of P. syringae pv. syringae B728a under in planta conditions. Additionally, detailed investigation of ectC, an orphan of the ectoine cluster (lacking the ectA and ectB homologs), revealed its functionality and that ectoine production could be detected in NaCl-amended cultures of P. syringae pv. syringae B728a to which sterilized leaves of Syringa vulgaris had been added.


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