scholarly journals Foliar selenium application for improving drought tolerance of sesame (Sesamum indicum L.)

2021 ◽  
Vol 6 (1) ◽  
pp. 93-101
Author(s):  
Le Vinh Thuc ◽  
Jun-Ichi Sakagami ◽  
Le Thanh Hung ◽  
Tran Ngoc Huu ◽  
Nguyen Quoc Khuong ◽  
...  

Abstract Drought is the main constraint for crop growth worldwide. Selenium reportedly plays an important role in improving plant tolerance to drought stress. In this study, two experiments were conducted to investigate the effects of foliar selenium application on the drought tolerance of sesame. Five selenium concentrations (0, 5, 10, 20, and 40 mg/L) were used in the first experiment. Water deficit was triggered 25 days after sowing. The application of 5 or 10 mg/L of selenium maintained the number of leaves and increased the number of capsules. However, higher concentrations induced necrosis. The second experiment aimed to study the effect of selenium concentrations (5 and 10 mg/L) and the number of applications (one to three times). Drought stress was triggered 50 days after sowing, and selenium was sprayed 50, 55, and 60 days after sowing. The results indicated that a one-time foliar selenium application of 5 mg/L was able to maintain the number of leaves and to increase proline accumulation, plant biomass, and grain weight per plant. This finding confirms that selenium can be applied to enhance sesame’s tolerance to drought stress.

2021 ◽  
Author(s):  
Weiwei Gao ◽  
Mingkang Li ◽  
Songguang Yang ◽  
Chunzhi Gao ◽  
Yan Su ◽  
...  

AbstractInduced abscisic acid (ABA) biosynthesis plays an important role in plant tolerance to abiotic stresses, including drought, cold and salinity. However, regulation pathway of the ABA biosynthesis in response to stresses is unclear. Here, we identified a rice miRNA, osa-miR2105 (miR2105), which plays a crucial role in ABA biosynthesis under drought stress. Analysis of expression, transgenic rice and cleavage site showed that OsbZIP86 is a target gene of miR2105. Subcellular localization and luciferase activity assays showed that OsbZIP86 is a nuclear transcription factor. In vivo and in vitro analyses showed that OsbZIP86 directly binds to the promoter of OsNCED3, and interacts with OsSAPK10, resulting in enhanced-expression of OsNCED3. Transgenic rice plants with knock-down of miR2105 or overexpression of OsbZIP86 showed higher ABA content, more tolerance to drought, a lower rate of water loss, more stomatal closure than wild type rice ZH11 under drought stress. These rice plants showed no penalty with respect to agronomic traits under normal conditions. By contrast, transgenic rice plants with miR2105 overexpression, OsbZIP86 downregulation, or OsbZIP86 knockout displayed less tolerance to drought stress and other phenotypes. Collectively, our results show that a regulatory network of ‘miR2105-OsSAPK10/OsbZIP86-OsNCED3’ control ABA biosynthesis in response to drought stress.One-sentence summary‘miR2105-OsbZIP86-OsNCED3’ module plays crucial role in mediating ABA biosynthesis to contribute to drought tolerance with no penalty with respect to agronomic traits under normal conditions.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Samantha J. Monohon ◽  
Daniel K. Manter ◽  
Jorge M. Vivanco

AbstractRhizobacterial communities can contribute to plant trait expression and performance, including plant tolerance against abiotic stresses such as drought. The conditioning of microbial communities related to disease resistance over generations has been shown to develop suppressive soils which aid in plant defense responses. Here, we applied this concept for the development of drought resistant soils. We hypothesized that soils conditioned under severe drought stress and tomato cultivation over two generations, will allow for plant selection of rhizobacterial communities that provide plants with improved drought resistant traits. Surprisingly, the plants treated with a drought-conditioned microbial inoculant showed significantly decreased plant biomass in two generations of growth. Microbial community composition was significantly different between the inoculated and control soils within each generation (i.e., microbial history effect) and for the inoculated soils between generations (i.e., conditioning effect). These findings indicate a substantial effect of conditioning soils on the abiotic stress response and microbial recruitment of tomato plants undergoing drought stress.


2021 ◽  
Vol 913 (1) ◽  
pp. 012016
Author(s):  
A Wulansari ◽  
A Purwito ◽  
D Sukma ◽  
TM Ermayanti

Abstract Taro genetic improvement through polyploidy induction is expected to be tolerant to abiotic stress. Several studies have shown that polyploidy plants have a higher adaptability to dry environments. In vitro selection technique for evaluation of plant tolerance to drought stress can be done by applying polyethylene glycol (PEG) as a selection agent. The aim of the research was to investigate the growth response of diploid and tetraploid taro shoot culture to drought stress using PEG. The experiment was conducted using a completely randomized design with two factors. The first factor was the concentration of PEG at 0, 5, 10, 15 and 20%. The second factor was Bentul taro clones which were 1 diploid clone and 2 tetraploid clones (clones 4.6.3 and 5.4.4). PEG was added to liquid MS medium containing 2 mg/l BAP. Observations of growth variables were carried out every week until the six weeks of culture. Fresh and dry weights, mortality percentage and proline content were determined at six weeks of culture. The results showed that the addition of PEG in liquid medium significantly affected the number of leaves, petiole length, number of roots, fresh and dry weights, as well as shoot mortality percentage. Differences in clones significantly affected the number of leaves, fresh and dry weights. The two factors tested (PEG and clones), gave an interaction on the number of leaves, fresh and dry weights. The proline content in all diploid and tetraploid clones showed an increase with increasing PEG concentration. The LC50 value in diploid clones was 9.82%, in tetraploid clones 4.6.3 and 5.4.4 were 14.14 and 15.45%, respectively. The results showed that PEG at 10% and 15% could be used for in vitro selection to drought stress both for diploid and tetraploid taro.


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.


2009 ◽  
Vol 3 (1) ◽  
pp. 116-121 ◽  
Author(s):  
M. Hassanzadeh ◽  
A. Asghari ◽  
Sh. Jamaati-e-Somarin ◽  
M. Saeidi ◽  
R. Zabihi-e-Mahmoodabad ◽  
...  

2015 ◽  
Vol 21 ◽  
pp. 109-122 ◽  
Author(s):  
Soran Sharafi ◽  
Kazem Ghassemi Golezani ◽  
Soleyman Mohammadi ◽  
Shahram Lak ◽  
Behzad Sorkhy

Context: Evaluation of tolerance of different barley genotypes to drought stress, an experiment carried out in randomized block design (RCBD) with three replication during 2009-2010 growing seasons and 20 barley genotypes were studied in normal and water deficit in post anthesis stage conditions at the Saatloo Research Farm Azerbaiejan, Iran. Results: The result of variance analysis showed that there were highly significant differences between genotypes in all of the studied traits, also it was cleared that all of traits except spike length reduced in water deficit condition as compared to normal condition and seed yield, biomass and 1000 seed weight traits had the most reduction (31, 25 and 20 percent, respectively). To identify of tolerance barley genotypes to drought stress, drought tolerance indices (STI, TOL, SSI, MP, HM and GMP), correlation coefficients, principal components analysis and cluster analysis were used. The result of correlation coefficients indicated that there were significant and positive correlation between seed yield in normal and stress conditions and drought tolerance indices. Also the result of principal components analysis showed that two components justified 99% of total variations. MP, GMP, STI and HM indices and TOL and SSI indices had the most coefficients in the first and second component, respectively, so are named tolerance and sensitivity component, respectively. Conclusion: MP, HM, STI and GMP indices were appropriate indices to select of drought tolerance barley genotypes. On the other hand, the result of cluster analysis showed that 13, 14 and 7 genotypes and 18, 1 and 2 genotypes were tolerance and sensitivity genotypes to water deficit at post anthesis stage. DOI: http://dx.doi.org/10.3329/jbs.v21i0.22525 J. bio-sci. 21: 109-122, 2013


Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 259
Author(s):  
Mahmoud F. Seleiman ◽  
Nasser Al-Suhaibani ◽  
Nawab Ali ◽  
Mohammad Akmal ◽  
Majed Alotaibi ◽  
...  

Drought stress, being the inevitable factor that exists in various environments without recognizing borders and no clear warning thereby hampering plant biomass production, quality, and energy. It is the key important environmental stress that occurs due to temperature dynamics, light intensity, and low rainfall. Despite this, its cumulative, not obvious impact and multidimensional nature severely affects the plant morphological, physiological, biochemical and molecular attributes with adverse impact on photosynthetic capacity. Coping with water scarcity, plants evolve various complex resistance and adaptation mechanisms including physiological and biochemical responses, which differ with species level. The sophisticated adaptation mechanisms and regularity network that improves the water stress tolerance and adaptation in plants are briefly discussed. Growth pattern and structural dynamics, reduction in transpiration loss through altering stomatal conductance and distribution, leaf rolling, root to shoot ratio dynamics, root length increment, accumulation of compatible solutes, enhancement in transpiration efficiency, osmotic and hormonal regulation, and delayed senescence are the strategies that are adopted by plants under water deficit. Approaches for drought stress alleviations are breeding strategies, molecular and genomics perspectives with special emphasis on the omics technology alteration i.e., metabolomics, proteomics, genomics, transcriptomics, glyomics and phenomics that improve the stress tolerance in plants. For drought stress induction, seed priming, growth hormones, osmoprotectants, silicon (Si), selenium (Se) and potassium application are worth using under drought stress conditions in plants. In addition, drought adaptation through microbes, hydrogel, nanoparticles applications and metabolic engineering techniques that regulate the antioxidant enzymes activity for adaptation to drought stress in plants, enhancing plant tolerance through maintenance in cell homeostasis and ameliorates the adverse effects of water stress are of great potential in agriculture.


2021 ◽  
Author(s):  
Hassaan Ahmad ◽  
Syed Adeel Zafar ◽  
Muhammad Kashif Naeem ◽  
Sajid Shokat ◽  
Safeena Inam ◽  
...  

Optimum soil water availability is vital for maximum yield production in rice which is challenged by increasing spells of drought. The reproductive stage drought is among the main limiting factors leading to the drastic reduction in grain yield. Objective of this study was to investigate the molecular and morpho-physiological responses of pre-anthesis stage drought stress in green super rice. The study assessed the performance of 26 rice lines under irrigated and drought conditions. Irrigated treatment was allowed to grow normally while drought stress was imposed for 30 days at pre-anthesis stage. Three important physiological traits including pollen fertility percentage (PFP), cell membrane stability (CMS) and normalized difference vegetative index (NDVI) were recorded at anthesis stage during the last week of drought stress. Agronomic traits of economic importance including grain yield were recorded at maturity stage. The analysis of variance demonstrated significant variation among the genotypes for most of the studied traits. Correlation and principal component analyses demonstrated highly significant associations of particular agronomic traits with grain yield, and genetic diversity among genotypes, respectively. Our study demonstrated a higher drought tolerance potential of GSR lines compared to local cultivars, mainly by higher pollen viability, plant biomass, CMS, and harvest index under drought. In addition, the molecular basis of drought tolerance in GSR lines was related to upregulation of certain drought responsive genes including OsSADRI, OsDSM1, and OsDT11. Our study identified novel drought tolerance related genes (OsDRG-1, OsDRG-2, OsDRG-3 and OsDRG-4) that could be further characterized using reverse genetics to be utilized in molecular breeding for drought tolerance.


2018 ◽  
Vol 51 (3) ◽  
pp. 125-131
Author(s):  
Okanlawon Lekan Jolayemi ◽  
Jelili Titilola Opabode ◽  
Gueye Badara

Abstract In vitro selection of drought-tolerant cassava varieties is essential for rapid breeding for drought tolerance. The objectives of this study were to determine the response of three contrasting cassava varieties to mannitol-induced drought stress to establish its suitability for in vitro screening and examine relationships among growth parameters. Plantlets were raised from nodal segments on Murashige and Skoog (MS) medium containing 0 (control), 5, 10, 15, 20, 25 and 30 g/l mannitol. Variety CH 140 had the highest survival of explants and frequency of root formation, while MV 99/0395 recorded the highest number of chlorotic leaves and the lowest survival of explants. The lowest numbers of leaves were produced at 25 and 30 g/l mannitol by the three varieties. In CH 140, the highest number of leaves was produced in medium free of mannitol, while the highest number of leaves was produced at 5 and 10 g/l mannitol in MV 99/0395 and TMS 01/1206, respectively. In TMS 01/1206, number of roots produced decreased as the concentration of mannitol in culture media increased, whereas in CH140, number of roots increased as the concentration of mannitol increased before decreasing; while in MV 99/0395, number of roots was not affected by an increase in mannitol concentration. As the concentration of mannitol in the culture media increased shoot height of plantlets decreased with a sharp decline at 20 mg/l mannitol. Concentration of mannitol and survival of explants had significant negative correlation with all parameters. However, frequency of root formation only had significant positive correlation with shoot length. The study concluded that differential responses were expressed by the three varieties to mannitol-induced drought stress and mannitol at 20 g/l concentration was a suitable in vitro drought inducing-agent for screening cassava varieties for drought tolerance.


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