scholarly journals Species-specific responses to drought, salinity and their interactions in Populus euphratica and P. pruinosa seedlings

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 53 (2) ◽  
pp. 233-242
Author(s):  
A. AHMADI SHADMEHRI ◽  
A. KHATIBY

Salicylic acid (SA) is a well-known signaling molecule that plays an important role in resistance against pathogens, as well as adaptation to some abiotic stress factors, such as drought, heavy metal toxicity, chilling, heat and osmotic stress and can be a factor effective treatment for plants. The impact of SA on different plant processes under optimal environmental conditions is controversial. Also, SA as a plant growth regulator may have a positive effect on the regulation of physiological and biochemical processes of different plant species, such as seed germination, seed production, respiration, vegetative growth, flower formation and photosynthesis. In addition, SA as a regulator of cell growth, could contribute to maintaining cellular redox homeostasis by induction of the alternative respiratory pathway and the regulation of antioxidant enzymes activity and to regulating gene expression by inducing a RNA-dependent RNA polymerase. However, SA may act as a stressor, and may have a negative impact on different plant processes. Recent results indicate that the exogenous application of SA to plants have affect several on many physiological processes, such as control of ion absorption, stomatal closure and transport, reducing of stress and stimulation of growth and differentiation of plants, and also the controlled levels of SA in plants are important for improving performance and adaptation to environmental stimuli and emphasize its important role in plant health and protection. The present study investigated the effect of SA on different plant processes.


Author(s):  
Ramazan Beyaz ◽  
Mustafa Yıldız

Background: Drought is one of the important abiotic stress factors that restrict plant development. Sainfoin is known to be relatively tolerant of drought. However, there are limited reports on the effects of drought stress on antioxidant components of Onobrychis species and/or ecotypes. Methods: To determine drought stress effects on antioxidant components of 4 sainfoin ecotypes (“Koçaþ”, “Malya”, “Altýnova” and “Ulaþ”), callus tissue was grown on MS medium enriched with 200 g l-1 PEG-6000. Result: Callus of the sainfoin ecotypes, cultured on a medium having 200 g l-1 PEG-6000, showed significant increases in antioxidant enzyme activities (SOD, CAT, GR (except in “Ulaþ” ecotype) and APX). However, the PEG induced increase in the accumulation of MDA and proline in callus tissue of all sainfoin ecotypes. The findings of the present study show that in terms of the increasing rate of antioxidant components under drought stress, the “Koçaþ” ecotype seemed to be the best.


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 ◽  
Author(s):  
Mustafa Yildiz ◽  
İrem Poyraz ◽  
Aslinur Çavdar ◽  
Yasin Özgen ◽  
Ramazan Beyaz

Salt stress is one of the harmful abiotic stress factors. It makes agricultural lands especially in arid and semi-arid regions useless despite the efforts. More than six percent of total world agricultural lands are on the edge of vanishing due to salt stress. Salinity in soil occurs as a result of the factors such as lack of drainage, improper irrigation, excessive accumulation of soluble salts. Salinity limits the growth of plants. Despite the main results, some results of plants due to these limitations vary from species to species. The negative effects get morphological, biochemical and physiological reactions from plants. Slowed or stopped growth of roots and shoots, closuring of stomata, germination slowing, decreased or stopped development of seedling, deterioration of photosynthetic activity are the main reactions of plants to stress. On the other hand, plants also develop tolerance mechanisms as a result of some auxiliaries for surviving under adverse conditions. Plants have tendency to protect themselves from salinity with osmotic protectants synthesized by them such as sugars, proline, amino acids, glycine betaine. In this review, the responses of plants to salt stress were investigated and gathered.


2020 ◽  
Author(s):  
Raziye Kul ◽  
Melek Ekinci ◽  
Metin Turan ◽  
Selda Ors ◽  
Ertan Yildirim

Roots are generally subject to more abiotic stress than shoots. Therefore, they can be affected by such stresses as much as, or even more, than above ground parts of a plant. However, the effect of abiotic stresses on root structure and development has been significantly less studied than above ground parts of plants due to limited availability for root observations. Roots have functions such as connecting the plant to the environment in which it grows, uptaking water and nutrients and carrying them to the above-ground organs of the plant, secreting certain hormones and organic compounds, and thus ensuring the usefulness of nutrients in the nutrient solution. Roots also send some hormonal signals to the body in stress conditions such as drought, nutrient deficiencies, salinity, to prevent the plant from being damaged, and ensure that the above-ground part takes the necessary precautions to adapt to these adverse conditions. Salinity, drought, radiation, high and low temperatures, heavy metals, flood, and nutrient deficiency are abiotic stress factors and they negatively affect plant growth, productivity and quality. Given the fact that impending climate change increases the frequency, duration, and severity of stress conditions, these negative effects are estimated to increase. This book chapter reviews to show how abiotic stress conditions affect growth, physiological, biochemical and molecular characteristics of plant roots.


2017 ◽  
Vol 78 (2) ◽  
pp. 159-164
Author(s):  
Monika Skwarek ◽  
Jacek Patykowski ◽  
Adrian Witczak

Abstract Plants are constantly exposed to the influence of biotic and abiotic stress factors that significantly affect the induction of resistance responses. Biotic factors include bacteria, fungi and insects such as the common cockchafer (Melolontha melolontha) that harm many tree species, including pine and larch. The adult beetles damage needles, while the larvae (grubs) feed on roots. The aim of the experiment was to determine how plants cope with the damage caused by these insects. The activity of antioxidant enzymes such as peroxidase (POD) and superoxide dismutase (SOD) were determined three and six weeks after the insect-induced damage and the results show that the peroxidase activity, as measured with guaiacol (GPOD), was higher in the damaged roots of larch. The POD activity measured with syringaldazine (SPOD) was slightly higher in damaged pine needles as well as pine roots. SOD activity was higher in the damaged roots of both species as compared to the needles. It is believed that changes in the activity of POD and SOD as well as the presence of another form of SOD in the roots of larch, indicate direct involvement of these enzymes in the plants’ response to damage caused by M. melolontha.


Author(s):  
Nham Phong Tuan ◽  
Nguyen Ngoc Quy ◽  
Nguyen Thi Thanh Huyen ◽  
Hong Tra My ◽  
Tran Nhu Phu

The objective of this study is to investigate the impact of seven factors causing academic stress on students of University of Economics and Business - Vietnam National University: Lack of leisure time, Academic performance, Fear of failure, Academic overload, Finances, Competition between students, Relationships with university faculty. Based on the results of a practical survey of 185 students who are attending any courses at the University of Economics and Business - Vietnam National University, the study assesses the impact of stress factors on students. The thesis focuses on clarifying the concept of "stress" and the stress level of students, while pointing out its negative effects on students. This study includes two cross-sectional questionnaire surveys. The first survey uses a set of 16 questions to assess students’ perceptions and attitudes based on an instrument to measure academic stress - Educational Stress Scale for Adolescents (ESSA). The second survey aims to test internal consistency, the robustness of the previously established 7-factor structure. Henceforth, the model was brought back and used qualitatively, combined with Cronbach’s Alpha measurement test and EFA discovery factor analysis. This study was conducted from October 2019 to December 2019. From these practical analyzes, several proposals were made for the society, the school and the students themselves.


Author(s):  
Dorin Sora ◽  
Mădălina Doltu

This study aimed to identification of an ecological alternative for the chemical disinfection of soil in the greenhouses from Romania. Tomato (Solanum lycopersicum L.) is one of the most popular vegetable crops in the world. The carbohydrate, vitamins, salts of important mineral elements and organic acids content of tomato fruits is very important. Tomato crops are very sensitive to climatic vagaries, so fluctuation in climatic parameters at any phase of growth can affect the yield and the fruit quality. Grafting on Solanaceae is a method which has improved and spread quickly during the past years, a similar approach to crop rotation, a practice meant to increase productivity, resistance or tolerance to biotic and abiotic stress factors and at increasing fruit quality. The research was conducted in a glass greenhouse of the Horting Institute, Bucharest, Romania. The biological material used was a Romanian tomato hybrid (Siriana F1), a Dutch tomato hybrid (Abellus F1) and four rootstocks, a Dutch tomato hybrid (Emperador F1) and three Romanian tomato cultivars (L542, L543 and L544) obtained from the Research and Development Station for Vegetable Growing, Buzău, Romania. The rootstocks have had resistance to biotic stress factors (soil diseases and pests) and the chemical disinfection of soil has was eliminated. The result of this research are presented in this paper.


2021 ◽  
Vol 22 (6) ◽  
pp. 2950
Author(s):  
Beatrycze Nowicka ◽  
Agnieszka Trela-Makowej ◽  
Dariusz Latowski ◽  
Kazimierz Strzalka ◽  
Renata Szymańska

Plant prenyllipids, especially isoprenoid chromanols and quinols, are very efficient low-molecular-weight lipophilic antioxidants, protecting membranes and storage lipids from reactive oxygen species (ROS). ROS are byproducts of aerobic metabolism that can damage cell components, they are also known to play a role in signaling. Plants are particularly prone to oxidative damage because oxygenic photosynthesis results in O2 formation in their green tissues. In addition, the photosynthetic electron transfer chain is an important source of ROS. Therefore, chloroplasts are the main site of ROS generation in plant cells during the light reactions of photosynthesis, and plastidic antioxidants are crucial to prevent oxidative stress, which occurs when plants are exposed to various types of stress factors, both biotic and abiotic. The increase in antioxidant content during stress acclimation is a common phenomenon. In the present review, we describe the mechanisms of ROS (singlet oxygen, superoxide, hydrogen peroxide and hydroxyl radical) production in chloroplasts in general and during exposure to abiotic stress factors, such as high light, low temperature, drought and salinity. We highlight the dual role of their presence: negative (i.e., lipid peroxidation, pigment and protein oxidation) and positive (i.e., contribution in redox-based physiological processes). Then we provide a summary of current knowledge concerning plastidic prenyllipid antioxidants belonging to isoprenoid chromanols and quinols, as well as their structure, occurrence, biosynthesis and function both in ROS detoxification and signaling.


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