scholarly journals Morpho-Physio-Biochemical and Molecular Responses of Maize Hybrids to Salinity and Waterlogging during Stress and Recovery Phase

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1345
Author(s):  
Umer Mahmood ◽  
Saddam Hussain ◽  
Sadam Hussain ◽  
Basharat Ali ◽  
Umair Ashraf ◽  
...  

Maize is one of the most economically important cereal crops worldwide. Salinity coupled with waterlogging is a major challenge for successful crop production. Understanding the underlying mechanisms and impacts of individual and combined salinity and waterlogging stress on the morpho-physio-biochemical and molecular responses and oxidative metabolism of maize during stress and recovery periods is essential. The present study was carried out to assess the response of four hybrid maize cultivars viz. DK-6142, FH-1231, FH-949, and MALKA-2016 under individual and combined salinity and waterlogging conditions. The treatments comprised the control (no stress), NaCl (salinity with 10 dSm−1), WL (waterlogged conditions with 3 cm flooding), and NaCl + WL (combined salinity and waterlogging stress). The data regarding morpho-physiological attributes were collected at 22 days after sowing (DAS; stress phase) and 30 DAS (recovery phase). The results revealed that both stresses, either individually or in combination, substantially reduced the root-shoot length, root-shoot fresh and dry weights, leaf width, and the number of leaves per plant as well as the leaf chlorophyll (Chl) and carotenoids contents; however, the inhibitory effects were more severe in combined stresses than for individual stress factors in many cultivars. Both individual and combined stress conditions enhanced hydrogen peroxide (H2O2) accumulation, whereas the antioxidant enzyme activities, i.e., superoxide dismutase (SOD), peroxidase (POD) catalase (CAT), and ascorbate peroxidase (APX), remained higher under stress conditions compared to the control. The expression levels of antioxidant genes (CAT and POD) were also upregulated under stress conditions. All of the cultivars recovered better from individual stresses than combined stress conditions; however, the hybrid DK-6142 performed better than the other maize hybrids under stress conditions and showed faster recovery.

2020 ◽  
Vol 13 (5) ◽  
pp. 563-573 ◽  
Author(s):  
Lei Yu ◽  
Haojie Dong ◽  
Zhijun Li ◽  
Zhanjiang Han ◽  
Helena Korpelainen ◽  
...  

Abstract Aims Drought and salinity are severe abiotic stress factors, which limit plant growth and productivity, particularly in desert regions. In this study, we employed two desert poplars, Populus euphratica Oliver and Populus pruinosa Schrenk seedlings, to compare their tolerance to drought, salinity and combined stress. Methods We investigated species-specific responses of P. euphratica and P. pruinosa in growth, photosynthetic capacity and pigment contents, nonstructural carbohydrate concentrations, Cl− allocation, osmotic regulation and the accumulation of reactive oxygen species (ROS) under drought, salinity and the combined stress. Important Findings Populus pruinosa exhibited greater growth inhibitory effects, photosynthesis decline, stomatal closure and ROS accumulation, and lower antioxidant enzyme activities and osmotic regulation compared with P. euphratica under drought, salinity and especially under their combined stress. On the other hand, salt-stressed P. euphratica plants restricted salt transportation from roots to leaves, and allocated more Cl− to coarse roots and less to leaves, whereas salt-stressed P. pruinosa allocated more Cl− to leaves. It was shown that there is species-specific variation in these two desert poplars, and P. pruinosa suffers greater negative effects compared with P. euphratica under drought, salinity and especially under the combined stress. Therefore, in ecological restoration and afforestation efforts, species-specific responses and tolerances of these two poplar species to drought and salinity should be considered under climate change with increasing drought and soil salinity developing.


2020 ◽  
Vol 12 (2) ◽  
pp. 376-386
Author(s):  
Dorina BONEA

Drought is one of the major abiotic stress factors limiting crops production in Oltenia area, Romania. In order to study the response of six maize hybrids to drought stress, the trials were conducted in research field of ARDS Simnic – Craiova, during 2017-2018 (non-stressed conditions) and 2018-2019 (drought stress). Six tolerance indices including: abiotic tolerance index (ATI), stress susceptibility percentage index (SSPI), Stress tolerance index (STI), mean productivity (MP), relative drought index (RDI) and golden mean (GM), were utilized on the basis of grain yield. Results from analysis of variance showed that there is a significant difference in 1% of probability level among hybrids in terms of grain yield and tolerance indices. The yield in non-stress conditions (Yp) showed significant positive correlations with ATI, SSPI, STI and MP, and negative correlation with RDI and GM. The yield  in drought conditions (Ys) showed significant positive correlation with RDI and GM, and negative correlation with ATI and SSPI. None of the tolerance indices used could identify the high yielding hybrids under drought and non-stress conditions. Based on the ranking method, the hybrids ‘Felix’ and ‘P 9903’ were the most droughts tolerant. Therefore, they hybrids are recommended to be grown under drought prone areas and to be used as parents for breeding of drought tolerance in other cultivars.


2012 ◽  
pp. 203-210
Author(s):  
Krisztina Molnár ◽  
Róbert Vig ◽  
Eszter Nemeskéri ◽  
Attila Dobos

The successfulness of crop production is significantly affected by not only the the average yields that provide cost effectiveness, but also the success of striving for yield safety, therefore, varieties and hybrids tolerant to environmental stress factors are worth being included into the sowing structure. Our aim was to further the decision making of producers in prepaering the right sowing structure by the evaluation of sweet maize hybrids’ tolerance to excess rainfall.We performed our examinations in an extremely wet year (2010) on chernozem soil on three sweet maize hybrids (GSS 8529, GSS 1477, Overland) in 12 replications. Comparing the yields of 2010 with those that can be expected under optimal rainfall conditions, we showed that the examined hybrids react to the amount of rainfall higher than their needs with yield depression. The excess rainfall tolerance of the examined hybrids is different in the case of each hybrid.


Author(s):  
Fatima Aerts-Kaya

: In contrast to their almost unlimited potential for expansion in vivo and despite years of dedicated research and optimization of expansion protocols, the expansion of Hematopoietic Stem Cells (HSCs) in vitro remains remarkably limited. Increased understanding of the mechanisms that are involved in maintenance, expansion and differentiation of HSCs will enable the development of better protocols for expansion of HSCs. This will allow procurement of HSCs with long-term engraftment potential and a better understanding of the effects of the external influences in and on the hematopoietic niche that may affect HSC function. During collection and culture of HSCs, the cells are exposed to suboptimal conditions that may induce different levels of stress and ultimately affect their self-renewal, differentiation and long-term engraftment potential. Some of these stress factors include normoxia, oxidative stress, extra-physiologic oxygen shock/stress (EPHOSS), endoplasmic reticulum (ER) stress, replicative stress, and stress related to DNA damage. Coping with these stress factors may help reduce the negative effects of cell culture on HSC potential, provide a better understanding of the true impact of certain treatments in the absence of confounding stress factors. This may facilitate the development of better ex vivo expansion protocols of HSCs with long-term engraftment potential without induction of stem cell exhaustion by cellular senescence or loss of cell viability. This review summarizes some of available strategies that may be used to protect HSCs from culture-induced stress conditions.


Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 354
Author(s):  
El-Sayed M. Desoky ◽  
Elsayed Mansour ◽  
Mohamed M. A. Ali ◽  
Mohamed A. T. Yasin ◽  
Mohamed I. E. Abdul-Hamid ◽  
...  

The influence of 24-epibrassinolide (EBR24), applied to leaves at a concentration of 5 μM, on plant physio-biochemistry and its reflection on crop water productivity (CWP) and other agronomic traits of six maize hybrids was field-evaluated under semi-arid conditions. Two levels of irrigation water deficiency (IWD) (moderate and severe droughts; 6000 and 3000 m3 water ha−1, respectively) were applied versus a control (well-watering; 9000 m3 water ha−1). IWD reduced the relative water content, membrane stability index, photosynthetic efficiency, stomatal conductance, and rates of transpiration and net photosynthesis. Conversely, antioxidant enzyme activities and osmolyte contents were significantly increased as a result of the increased malondialdehyde content and electrolyte leakage compared to the control. These negative influences of IWD led to a reduction in CWP and grain yield-related traits. However, EBR24 detoxified the IWD stress effects and enhanced all the above-mentioned parameters. The evaluated hybrids varied in drought tolerance; Giza-168 was the best under moderate drought, while Fine-276 was the best under severe drought. Under IWD, certain physiological traits exhibited a highly positive association with yield and yield-contributing traits or CWP. Thus, exogenously using EBR24 for these hybrids could be an effective approach to improve plant and water productivity under reduced available water in semi-arid environments.


Life ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 545
Author(s):  
Kumar Nishant Chourasia ◽  
Milan Kumar Lal ◽  
Rahul Kumar Tiwari ◽  
Devanshu Dev ◽  
Hemant Balasaheb Kardile ◽  
...  

Among abiotic stresses, salinity is a major global threat to agriculture, causing severe damage to crop production and productivity. Potato (Solanum tuberosum) is regarded as a future food crop by FAO to ensure food security, which is severely affected by salinity. The growth of the potato plant is inhibited under salt stress due to osmotic stress-induced ion toxicity. Salinity-mediated osmotic stress leads to physiological changes in the plant, including nutrient imbalance, impairment in detoxifying reactive oxygen species (ROS), membrane damage, and reduced photosynthetic activities. Several physiological and biochemical phenomena, such as the maintenance of plant water status, transpiration, respiration, water use efficiency, hormonal balance, leaf area, germination, and antioxidants production are adversely affected. The ROS under salinity stress leads to the increased plasma membrane permeability and extravasations of substances, which causes water imbalance and plasmolysis. However, potato plants cope with salinity mediated oxidative stress conditions by enhancing both enzymatic and non-enzymatic antioxidant activities. The osmoprotectants, such as proline, polyols (sorbitol, mannitol, xylitol, lactitol, and maltitol), and quaternary ammonium compound (glycine betaine) are synthesized to overcome the adverse effect of salinity. The salinity response and tolerance include complex and multifaceted mechanisms that are controlled by multiple proteins and their interactions. This review aims to redraw the attention of researchers to explore the current physiological, biochemical and molecular responses and subsequently develop potential mitigation strategies against salt stress in potatoes.


2021 ◽  
Author(s):  
Margaret shiraku ◽  
Richard Odongo Magwanga ◽  
Xiaoyan Cai ◽  
Joy Nyangasi Kirungu ◽  
Yanchao Xu ◽  
...  

Abstract BackgroundCotton is an important economic crop and the primary source of natural fiber. The effects of drought and salt stresses threaten strong fiber and large quantity production. However, due to the ever-changing climatic conditions, plants have evolved various mechanisms to cope with the effects of various stress factors. One of the plant's transcription factors with positive effects in alleviating effects of drought and salt stresses is the Ribosomal protein Large (RPL) gene families. This has prompted the functional characterization of the RPL14B gene previously identified in the QTL region as a candidate gene that responds to stress and initiates mechanisms that enhance stress tolerance. ResultsComprehensive identification and functional analysis were conducted in this study, in which 26, 8, and 5 proteins containing the RPL14B domain were identified in G. hirsutum, G. raimondii, and G. arboreum, respectively. Moreover, Cis-regulatory elements associated with the RPL genes were identified. The Myb binding sites (MBS), Myb, Abscisic acid-responsive element (ABRE), CAAT-box, TATA box, TGACG-motif, and CGTCA-motif responsive to Meja, and TCA- motif responsive to salicylic acid were identified. Validation of the candidate gene through virus-induced gene silencing (VIGS) revealed that the Gh_D01G0234 (RPL14B) knockdown significantly affected the cotton seedling's performance under drought/ salt stress conditions as evidenced by a significant reduction in various morphological and physiological traits. Moreover, antioxidant enzyme levels were significantly reduced in VIGS-plants, with substantially higher oxidant enzyme levels, as evidenced by the higher concentration level of Malondialdehyde (MDA). ConclusionThe results revealed the potential role of the gene, and it can be further exploited to breed climate-smart cotton varieties resilient to drought and salt stress conditions


Plants ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 154
Author(s):  
Naveed Mushtaq ◽  
Yong Wang ◽  
Junmiao Fan ◽  
Yi Li ◽  
Jing Ding

Environmental stresses negatively affect the growth and development of plants. Several previous studies have elucidated the response mechanisms of plants to drought and heat applied separately; however, these two abiotic stresses often coincide in environmental conditions. The global climate change pattern has projected that combined drought and heat stresses will tend to increase in the near future. In this study, we down-regulated the expression of a cytokinin receptor gene SlHK2 using RNAi and investigated the role of this gene in regulating plant responses to individual drought, heat, and combined stresses (drought + heat) in tomato. Compared to the wild-type (WT), SlHK2 RNAi plants exhibited fewer stress symptoms in response to individual and combined stress treatments. The enhanced abiotic stress tolerance of SlHK2 RNAi plants can be associated with increased membrane stability, osmoprotectant accumulation, and antioxidant enzyme activities. Furthermore, photosynthesis machinery was also protected in SlHK2 RNAi plants. Collectively, our results show that down-regulation of the cytokinin receptor gene SlHK2, and consequently cytokinin signaling, can improve plant tolerance to drought, heat, and combined stress.


Weed Science ◽  
2021 ◽  
pp. 1-26
Author(s):  
Jéssica F. L. Leal ◽  
Amanda dos S. Souza ◽  
Junior Borella ◽  
André Lucas S. Araujo ◽  
Ana Claudia Langaro ◽  
...  

Abstract Herbicide-resistant weed management is one of the greatest agricultural challenges in crop production. Thus, the quick identification of resistant-herbicide weeds is extremely important for management. This study aimed to evaluate resistance to PSI-inhibitor herbicides (diquat) of Sumatran Fleabane [(Erigeron sumatrensis (Retz.) E.Walker)] and physiological response to paraquat application. The research was conducted with two E. sumatrensis biotypes, one susceptible and the other with multiple resistance to herbicides from five different modes of action (glyphosate, paraquat, diuron, saflufenacil, and 2,4-D). A dose-response assay was carried out to evaluate herbicide resistance to diquat in paraquat-resistant E. sumatrensis biotype. The enzymatic activities of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX), hydrogen peroxide (H2O2) content, and chlorophyll a fluorescence were measured in both biotypes after paraquat (400 g ai ha−1) application. The dose-response assay confirmed resistance of E. sumatrensis to diquat with resistance factor levels of 26-fold and 6-fold for LD50 and GR50 values, respectively, compared with the susceptible biotype. The accumulation of H2O2 occurred faster in the paraquat-susceptible biotype than in the resistant ones. Paraquat treatment caused an increase in SOD and APX activity in the susceptible biotype, but antioxidant enzyme activities were unaffected by paraquat in the resistant one at 5 hours after application (HAA). Chlorophyll a fluorescence increased along the first 4 HAA in both resistant and susceptible biotypes. However, at 24 HAA the resistant biotype showed a decline in fluorescence close to untreated plants while susceptible one died, which can be used to diagnose paraquat resistance at 24 HAA. There is confirmed resistance to diquat in a paraquat-resistant E. sumatrensis biotype. The paraquat-resistant biotype does not induce antioxidative enzymes, as a possible mechanism of resistance to paraquat, but shows a fast recovery of photosynthesis and continuous growth when subjected to paraquat, while the paraquat-susceptible biotype does not survive.


2019 ◽  
Vol 97 (5) ◽  
pp. 581-588
Author(s):  
Suphia Rafique

In the present work, tropical maize genotypes were evaluated for multiple stresses (drought × low-N and waterlogging × low-N) applied simultaneously to 30-day-old maize seedlings. Two-dimensional gel electrophoresis was used to examine the protein changes induced by combined stress, in leaves, of tolerant and susceptible genotypes. Moreover, physiological and biochemical parameters were assessed to understand the physiological status of tolerant and susceptible genotypes under combined stress. The results show that up-regulated proteins of the tolerant genotype have a significant role in activating defense response, restoration of plant growth, and to maintain metabolic homeostasis under stressful conditions. Therefore, they contribute to improve and maintain the state of acclimation of the genotype under stress. Alternatively in the susceptible genotype, the up-regulated proteins are representative biomarkers of stress or are involved in the defense against pathogens and efforts to maintain energy metabolism. Thus, protecting the survival of the genotype under multiple stress conditions. We conclude that depending on the given stress treatment, tolerant and susceptible genotypes differed in stress-enduring approaches. Therefore, the study provides insight to comprehend the response of tolerant and susceptible genotypes under combined stress conditions, which could be valuable for further research and will demonstrate that it is advantageous to select combined stress-tolerant genotypes.


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