Synergistic and additive effects of drought stress and simulated herbivory on two goldenrods, Solidago altissima and S. gigantea

Botany ◽  
2016 ◽  
Vol 94 (8) ◽  
pp. 635-642 ◽  
Author(s):  
Zoryana Shibel ◽  
Stephen B. Heard

Understanding the combined effects of stressors on plants is important for understanding how they will tolerate herbivory and other damage under unfavorable conditions. When two stresses have synergistic effects, plants may experience particularly strong impacts. We examined individual and combined effects of drought stress and clipping (simulated herbivory) on two species of goldenrods (Solidago altissima L. and S. gigantea Ait.). Each stress reduced production of most plant structures, with drought stress having stronger impacts than clipping. The effects of the two stresses were additive for S. gigantea but synergistic for S. altissima, at least for aboveground biomass and inflorescence biomass. Both species, when under stress, reallocated resources toward asexual reproduction (rhizomes) and away from sexual reproduction (inflorescences). Our results suggest that even closely related plants may tolerate damage differently when under abiotic stresses, and that predicting the additive vs. synergistic action of combined stresses will be difficult.

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 261
Author(s):  
Md. Mahadi Hasan ◽  
Milan Skalicky ◽  
Mohammad Shah Jahan ◽  
Md. Nazmul Hossain ◽  
Zunaira Anwar ◽  
...  

In recent years, research on spermine (Spm) has turned up a lot of new information about this essential polyamine, especially as it is able to counteract damage from abiotic stresses. Spm has been shown to protect plants from a variety of environmental insults, but whether it can prevent the adverse effects of drought has not yet been reported. Drought stress increases endogenous Spm in plants and exogenous application of Spm improves the plants’ ability to tolerate drought stress. Spm’s role in enhancing antioxidant defense mechanisms, glyoxalase systems, methylglyoxal (MG) detoxification, and creating tolerance for drought-induced oxidative stress is well documented in plants. However, the influences of enzyme activity and osmoregulation on Spm biosynthesis and metabolism are variable. Spm interacts with other molecules like nitric oxide (NO) and phytohormones such as abscisic acid, salicylic acid, brassinosteroids, and ethylene, to coordinate the reactions necessary for developing drought tolerance. This review focuses on the role of Spm in plants under severe drought stress. We have proposed models to explain how Spm interacts with existing defense mechanisms in plants to improve drought tolerance.


2021 ◽  
Vol 13 (12) ◽  
pp. 6582
Author(s):  
Syeda Fasiha Amjad ◽  
Nida Mansoora ◽  
Samia Yaseen ◽  
Afifa Kamal ◽  
Beenish Butt ◽  
...  

On a global scale, wheat (Triticum aestivum L.) is a widely cultivated crop among all cereals. Increasing pollution, population expansion, socio-economic development, ecological and industrial policies have induced changes in overall climatic attributes. The impact of these factors on agriculture dynamics has led to various biotic and abiotic stresses, i.e., significant decline in rainfall, directly affect sustainable agriculture. Increasing abiotic stresses have a direct negative effect on worldwide crop production. More promising and improved stress-tolerant strategies that can help to feed the increasing global population are required. A laboratory experiment was performed on two of the latest wheat (Triticum aestivum L.) genotypes (Akbar 2019 and Anaj 2017) from Punjab Pakistan, to determine the influence of seed priming with thiamine (vitamin B1) along with soil inoculation of Endophytic bacterial strains to mitigate the effects of drought stress at different degrees. Results revealed that thiamine helped in the remote germination; seeds of Anaj 2017 germinated within 16 hours while Akbar 2019 germinated after one day. Overall growth parameters of Anaj 2017 were negatively affected even under higher levels of drought stress, while Akbar 2019 proved to be a susceptible cultivar. A significant increase in RFW (54%), SFW (85%), RDW (69%), SDW (67%) and TChl (136%) validated the effectiveness of D-T3 compared to C-T0 in drought stress. Significant decrease in MDA, EL and H2O2 signified the imperative function of D-T3 over C-T0 under drought stress. In conclusion and recommendation, we declare that farmers can get better wheat growth under drought stress by application of D-T3 over C-T0.


Author(s):  
Benjamin D. Elder ◽  
Kyriacos A. Athanasiou

It has previously been demonstrated that hydrostatic pressure (HP) enhances the biochemical properties of self-assembled articular cartilage constructs [1]. However, studies that systematically assess the effects of HP magnitude and frequency are lacking. Additionally, studies examining the combined effects of hydrostatic pressure and growth factors are limited. To this end, this study sought to test the hypotheses that static HP will have the greatest enhancement of construct biomechanical and biochemical properties, and that there will be additive or synergistic effects when combining growth factors and HP stimulation.


2018 ◽  
Vol 427 ◽  
pp. 434-445 ◽  
Author(s):  
Jaroslav Holuša ◽  
Jan Lubojacký ◽  
Vladislav Čurn ◽  
Tomáš Tonka ◽  
Karolina Lukášová ◽  
...  

2014 ◽  
Vol 174 (2) ◽  
pp. 693-707 ◽  
Author(s):  
Adnan Zahir ◽  
Bilal Haider Abbasi ◽  
Muhammad Adil ◽  
Sumaira Anjum ◽  
Muhammad Zia ◽  
...  

2020 ◽  
Vol 66 (No. 4) ◽  
pp. 175-182 ◽  
Author(s):  
Tri Handayani ◽  
Kazuo Watanabe

Several research groups have examined the effects of drought stress and heat stress on potato, but few investigations of the effects of combined drought-heat stress have been reported. Using five potato lines, the potato plants’ responses to drought stress, heat stress, as well as combined drought-heat stress were studied, to get the insight in phenotypic shift due to abiotic stresses. The experiment was conducted as a growth room experimental under non-stress and abiotic stresses (drought, heat, and combined drought-heat) conditions. The results demonstrated that potato plants responded to the abiotic stresses by decreasing their plant height, leaf size, cell membrane stability, and relative water content (RWC). However, increasing their leaf chlorophyll content under drought and combined drought-heat stresses. Generally, the combined drought-heat stress had a greater effect on the tested traits. The potato line L1 (84.194.30) showed the lowest level of wilting in all three types of abiotic stress, supported by a small RWC change compared to the control condition; L1 is thus considered relatively tolerant to abiotic stress. The potato lines’ different responses to each type of abiotic stress indicate that the potato lines have different levels of sensitivity to each abiotic stress.


2020 ◽  
Vol 11 ◽  
Author(s):  
Suzhen Huang ◽  
Junying Zhu ◽  
Lu Zhang ◽  
Xue Peng ◽  
Xinyi Zhang ◽  
...  

Polyphenols are allelochemicals secreted by aquatic plants that effectively control cyanobacteria blooms. In this study, sensitive response parameters (including CFPs) of Microcystis aeruginosa were explored under the stress of different polyphenols individually and their combination. The combined effects on M. aeruginosa were investigated based on the most sensitive parameter and cell densities. For pyrogallic acid (PA) and gallic acid (GA), the sensitivity order of parameters based on the EC50 values (from 0.73 to 3.40 mg L–1 for PA and from 1.05 to 2.68 mg L–1 for GA) and the results of the hierarchical cluster analysis showed that non-photochemical quenching parameters [NPQ, qN, qN(rel) and qCN] > photochemical quenching parameters [YII, qP, qP(rel) and qL] or others [Fv/Fm, F’v/F’m, qTQ and UQF(rel)] > cell densities. CFPs were not sensitive to ellagic acid (EA) and (+)-catechin (CA). The sensitivity order of parameters for M. aeruginosa with PA-GA mixture was similar to that under PA and GA stress. The quantitative (Toxicity Index, TI) and qualitative (Isobologram representation) methods were employed to evaluate the combined effects of PA, GA, and CA on M. aeruginosa based on cell densities and NPQ. TI values based on the EC50 cells suggested the additive effects of binary and multiple polyphenols, but synergistic and additive effects according to the EC50 NPQ (varied from 0.16 to 1.94). In terms of NPQ of M. aeruginosa, the binary polyphenols exhibited synergistic effects when the proportion of high toxic polyphenols PA or GA was lower than 40%, and the three polyphenols showed a synergistic effect only at the ratio of 1:1:1. Similar results were also found by isobologram representation. The results showed that increasing the ratio of high toxic polyphenols would not enhance the allelopathic effects, and the property, proportion and concentrations of polyphenols played an important role in the combined effects. Compared with cell densities, NPQ was a more suitable parameter as evaluating indicators in the combined effects of polyphenols on M. aeruginosa. These results could provide a method to screen the allelochemicals of polyphenols inhibiting cyanobacteria and improve the inhibitory effects by different polyphenols combined modes.


2017 ◽  
pp. 19-24
Author(s):  
Basal Oqba

Abiotic stresses are one of the most limiting factors inhibit plant's growth, leading to a serious production loss. Drought stress is one of the most destructive abiotic stresses and is still increasing year after year resulting in serious yield losses in many regions of the world,consequently, affecting world’s food security for the increasing world population. Soybean is an important grain legume. It is one of the five major crops in the world, an essential source of oil, protein, macronutrients and minerals, and it is known as the main source of plant oil and protein. Harvested area of soybean is increasing globally year after year. However, soybean is the highest drought stress sensitive crop, the water deficit influences the physiology, production and seed composition of this crop. We introduce a review for literatures concerning the changes of the above traits of soybean exposed to drought stress, with past explanations for these changes.


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