Vegetative desiccation tolerance of Tripogon spicatus (Poaceae) from the tropical semiarid region of northeastern Brazil

2017 ◽  
Vol 44 (11) ◽  
pp. 1124 ◽  
Author(s):  
Saulo de T. Aidar ◽  
Agnaldo R. de M. Chaves ◽  
Paulo I. Fernandes Júnior ◽  
Melquisedec de S. Oliveira ◽  
Benjamim P. da Costa Neto ◽  
...  

The vegetative desiccation tolerance of Tripogon spicatus (Nees) Ekman was confirmed by its ability to recover the physiological functionality of intact plants previously subjected to extreme dehydration. Photosynthesis became undetectable when leaf relative water content (RWCleaf) achieved ~60%, whereas photochemical variables showed a partial decrease. Until the minimum RWCleaf of 6.41%, total chl decreased by 9%, and total carotenoids increased by 29%. Superoxide dismutase (SOD) activity decreased by 57%, on average, during dehydration, but catalase (CAT) and peroxidase (APX) activities showed no significant differences throughout the experiment. Malondialdehyde (MDA) content increased by 151%, total leaf and root amino acids decreased by 62% and 77%, respectively, whereas leaf and root proline decreased by 40% and 61%, respectively, until complete desiccation. After rehydration, leaves completely recovered turgidity and total chl contents. Carotenoids and MDA remained high, whereas SOD was 60% lower than the measured average measured before dehydration. With the exception of root amino acid contents, total amino acids and proline concentrations recovered completely. Gas exchange and photochemical variables remained substantially higher 4 days after rehydration, compared with the control. Besides increasing MDA, the overall physiological results showed that membrane functionality was preserved, leading to the vegetative desiccation tolerance of T. spicatus during the dehydration–rehydration cycle.

2020 ◽  
Vol 11 ◽  
pp. e3303
Author(s):  
Daíse Souza Reis Lima ◽  
Welson Lima Simões ◽  
José Aliçandro Bezerra da Silva ◽  
Magno do Nascimento Amorim ◽  
Alessandra Monteiro Salviano ◽  
...  

The objective of this work was to evaluate physiological and biochemical responses of Pele de sapo melon to different irrigation depths (ID) and bioestimulant rates (BTM) to improve its production efficiency. The experiment was conducted in an experimental field in Juazeiro, BA, Brazil. A randomized block design in split split-plot arrangement was used, with four ID (60, 80, 100, and 120% of crop evapotranspiration – ETc) in the plots; five (BTM) (Stimulate® at 0, 0.6, 1.2, 2.4, and 4.8 L ha-1 applied via irrigation system during the flowering stage and after the fruiting stage) in the subplots; and two crop seasons (hot season, 23 to 39 °C; and cold season, 15 to 30 °C) in the sub-subplots. The plants were under daily drip irrigation and spacing of 2.0 × 0.3 m. The variables evaluated were: gas exchange, water use efficiency, chlorophyll a and b, relative water, sugar, and amino acid contents, and fruit yield. The results showed that the ID of 60% ETc resulted in water deficit, denoted by increases in solute concentrations, whereas the ID of 80% and 100% resulted in plants with good performance for biochemical, physiological, and production parameters in both crop seasons. The hot season, ID of 120% ETc, and BTM of 2.4 L ha-1 are recommended for Pele de sapo melon crops, since they result in the best physiological responses and fruit yields.


2024 ◽  
Vol 84 ◽  
Author(s):  
M. Javed ◽  
M. Iqbal ◽  
H. Bano ◽  
N. Hussain ◽  
A. Ghaffar ◽  
...  

Abstract Growth of plants is severely reduced due to water stress by affecting photosynthesis including photosystem II (PSII) activity and electron transport. This study emphasised on comparative and priority targeted changes in PSII activity due to progressive drought in seven populations of Panicum antidotale (P. antidotale) collected from Cholistan Desert and non-Cholistan regions. Tillers of equal growth of seven populations of P. antidotale grown in plastic pots filled with soil were subjected progressive drought by withholding water irrigation for three weeks. Progressive drought reduced the soil moisture content, leaf relative water content, photosynthetic pigments and fresh and dry biomass of shoots in all seven populations. Populations from Dingarh Fort, Dingarh Grassland and Haiderwali had higher growth than those of other populations. Cholistani populations especially in Dingarh Grassland and Haiderwali had greater ability of osmotic adjustment as reflected by osmotic potential and greater accumulation of total soluble proteins. Maximum H2O2 under water stress was observed in populations from Muzaffargarh and Khanewal but these were intermediate in MDA content. Under water stress, populations from Muzaffargarh and Dingarh Fort had greater K+ accumulation in their leaves. During progressive drought, non-Cholistani populations showed complete leaf rolling after 23 days of drought, and these populations could not withstand with more water stress condition while Cholistani populations tolerated more water stress condition for 31 days. Moreover, progressive drought caused PSII damages after 19 days and it became severe after 23 days in non-Cholistani populations of P. antidotale than in Cholistani populations.


2011 ◽  
Vol 23 (2) ◽  
pp. 123-130 ◽  
Author(s):  
Gabriela B. Arcoverde ◽  
Bruno M. Rodrigues ◽  
Marcelo F. Pompelli ◽  
Mauro G. Santos

Stomatal conductance (g s), transpiration (E), relative water content (RWC), superoxide dismutase activity (SOD), malondialdehyde (MDA), leaf carbohydrate soluble (LCS), free amino acids (FAA) and total protein (TP) content were measured under mild and severe drought stress in young potted Jatropha curcas L. in the greenhouse. The plants were kept for 12 days under three different water regimes, control (well hydrated), 50% irrigation control (mild stress) and 25% (severe stress), after rehydration were measured on the second and fourth day. Both mild and severe stress decreased g s and E; however, only severe stress reduced LCS, FAA and TP content and increased SOD activity (70%) and MDA content (60%) compared with the control. Moreover, under these conditions the plants showed severe leaf senescence. These results show that only severe drought stress decrease foliar metabolism in potted plants. These results show that severe drought decreased metabolism and leaf RWC, in potted plants. However, 48 h under a moderate stress is enough to drive the stomatal control is the main barrier against water loss. Finally, in the fourth day after rehydration the plants under a moderate and severe drought even had a g s and E reduced in both evaluation periods.


2018 ◽  
Author(s):  
Yiming Liu ◽  
Guofu Hu ◽  
Guoqiang Wu ◽  
Guodao Liu ◽  
Hengfu Huan ◽  
...  

AbstractDrought stress is a major limiting factor for plant growth and development in many regions of the world. This study was designed to investigate antioxidant metabolism and dehydrin expression responses to drought stress in two switchgrass cultivars (drought tolerant Alamo, and drought sensitive Dacotah) contrasting in drought tolerance. The plants were subjected to well-watered [100% evapotranspiration (ET)] or drought stress (30%-50% ET) conditions for up to 24 d in growth chambers. Drought stress decreased leaf relative water content (RWC), increased leaf electrolyte leakage (EL), leaf malondialdehyde (MDA) content in two cultivars, but Alamo exhibited higher leaf RWC level, lower leaf EL and MDA when compared to Dacotah at 24 d of drought treatment. Drought stress also increased superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) activities in two cultivars, Alamo had relatively higher SOD, CAT and APX activities and greater abundance of SOD and APX isozymes than Dacotah at 24 d of drought treatment. Alamo had higher abundance of 55 KDa and 18 KDa dehydrin accumulation than Dacotah under drought treatment. Relative genes expression level of PvCAT1, PvAPX2, PvERD and PvPIP1;5 in Alamo were significantly higher than Dacotah at 24 d of drought treatment. These results suggest that increase in antioxidant enzymes and accumulation of dehydrin were highly related with switchgrass drought tolerance. Antioxidant enzyme activity, isozyme expression and dehydrin abundance could provide a useful screening tool to identify relative drought tolerance in switchgrass cultivars.


2008 ◽  
Vol 38 (7) ◽  
pp. 1877-1887 ◽  
Author(s):  
Xiaoxia Huang ◽  
Chunying Yin ◽  
Baoli Duan ◽  
Chunyang Li

The morphological and physiological responses of two contrasting Populus cathayana Rehd. populations to three light regimes, full sunlight (control), 33% full sunlight (moderate shade), and 12% full sunlight (severe shade), were investigated under well-watered and drought conditions. The populations were from Hanyuan (relatively more annual rainfall and less annual solar radiation) and Ledu (less annual rainfall and more annual solar radiation) in western China. In both populations, drought-treated plants exhibited reduced growth, leaf relative water content, net photosynthesis, and maximal efficiency of photosystem II (PSII); increased levels of chlorophyll, carotenoid, abscisic acid, and carbon isotope composition; and a greater accumulation of malondialdehyde (MDA) than did well-watered plants. There was an apparent alleviation of drought effects by moderate shade, especially in the Hanyuan population, as indicated by the higher leaf relative water content, net photosynthesis, stomatal conductance, and maximal efficiency of PSII and the lower MDA content. On the other hand, an apparent aggravation of drought effects by severe shade was also observed, especially in the Ledu population, as indicated by the lower total biomass and net photosynthesis and the higher MDA content. Moreover, the Hanyuan population was more shade tolerant and drought sensitive than the Ledu population.


Author(s):  
Hatice Tunca ◽  
Ali Doğru ◽  
Feray Köçkar ◽  
Burçin Önem ◽  
Tuğba Ongun Sevindik

Azadirachtin (Aza) used as insecticide due to inhibiting growth of insects and preventing them from feeding on plants. To understand the effects of contamination of this insecticide on phototrophs, and to determine the responses of these organisms against these insecticides are extremely important in understanding how the ecosystem is affected. In this study, chlorophyll-a amount, OD 560 and antioxidant parameters (total SOD, APX, GR, Proline, MDA and H2O2) were determined in order to understand the effect of Aza on Arthrospira platensis Gomont. Aza was applied between 0–20 μg mL−1 concentrations for 7 days in the study. Enzyme analysis was conducted at the end of the 7th day. There was a statistically significant decrease in the absorbance of OD560 and the chlorophyll-a content in A. platensis cultures exposed to the Aza (0–20 μg mL−1) during 7 days due to the increase in pesticide levels. SOD activity decreased at 8, 16 and 20 μg mL−1 concentrations; GR enzyme activity showed a significant decrease compared to the control at a concentration of 20 μg mL−1. APX activity did not change significantly compared to control. The MDA content increased significantly at 16 and 20 μg mL−1 concentrations. The H2O2 content significantly increased at 12, 16 and 20 μg mL−1 concentrations (p < 0.05) while the free proline content decreased at 4 μg mL−1 concentration (p < 0.05). As a result, regarding the Aza concentrations used in this study may be a step to prevent pesticide pollution in the environment.


Author(s):  
S. E. Dubenko ◽  
T. V. Mazhaeva ◽  
G. M. Nasybullina

Th e authors reviewed literature on methodic evaluations of human requirements of protein, based on Russian and foreign data bases (Scopus, Web of Science, MedLine, RINTs, eLIBRA RY) via key words in article headings, and evaluated quality and quantity of protein in diets of workers exposed to occupational hazards. Average requirements of amino acids and their additional intake for bett er health state in certain occupational groups remains a topical problem. Th e article covers list of methods for quantitative and qualitative evaluation of proteins in foods and diets. Findings are diff erences in approaches to protein quantity regulation in Russian Federation and WHO/FAO/UNU (protein normal level in RF is higher, depends on physical exertion, with lower quantity of amino acids with branched chain in structure of essential amino acids). Th erapeutic and prophylactic diet corresponding to Order N46 of Russian Health Ministry for main occupations of metallurgic workshops can be considered as high-proteous and balanced in amino acid contents. Necessity is to study adequate intake of amino acids in workers exposed to occupational hazards, for improving protective and adaptative body mechanisms, and prevention of occupational and occupationally conditioned diseases.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adam Yousif Adam Ali ◽  
Muhi Eldeen Hussien Ibrahim ◽  
Guisheng Zhou ◽  
Nimir Eltyb Ahmed Nimir ◽  
Aboagla Mohammed Ibrahim Elsiddig ◽  
...  

AbstractSalinity one of environmental factor that limits the growth and productivity of crops. This research was done to investigate whether GA3 (0, 144.3, 288.7 and 577.5 μM) and nitrogen fertilizer (0, 90 and 135 kg N ha−1) could mitigate the negative impacts of NaCl (0, 100, and 200 mM NaCl) on emergence percentage, seedling growth and some biochemical parameters. The results showed that high salinity level decreased emergence percentage, seedling growth, relative water content, chlorophyll content (SPAD reading), catalase (CAT) and peroxide (POD), but increased soluble protein content, superoxide dismutase (SOD) activity and malondialdehyde (MDA) content. The SOD activity was decreased by nitrogen. However, the other measurements were increased by nitrogen. The interactive impact between nitrogen and salinity was significant in most parameters except EP, CAT and POD. The seedling length, dry weight, fresh weight, emergence percentage, POD, soluble protein and chlorophyll content were significantly affected by the interaction between GA3 and salinity. The GA3 and nitrogen application was successful mitigating the adverse effects of salinity. The level of 144.3 and 288.7 μm GA3 and the rate of 90 and 135 kg N ha−1 were most effective on many of the attributes studied. Our study suggested that GA3 and nitrogen could efficiently protect early seedlings growth from salinity damage.


2017 ◽  
Vol 45 (08) ◽  
pp. 1613-1629 ◽  
Author(s):  
Yan-Jiao Xu ◽  
Zao-Qin Yu ◽  
Cheng-Liang Zhang ◽  
Xi-Ping Li ◽  
Cheng-Yang Feng ◽  
...  

The present study was designed to assess the effects and potential mechanisms of ginsenosides on 17[Formula: see text]-ethynyelstradiol (EE)-induced intrahepatic cholestasis (IC). Ginsenoside at doses of 30, 100, 300[Formula: see text]mg/kg body weight was intragastrically (i.g.) given to rats for 5 days to examine the effect on EE-induced IC. Serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and total bile acid (TBA) were measured. Hepatic malondialdehyde (MDA) content and superoxide dismutase (SOD) activity were determined. Protein expression of proinflammatory cytokines TNF-[Formula: see text], IL-6 and IL-1[Formula: see text] was analyzed by immunohistochemistry and Western blot. Results indicated that ginsenosides remarkably prevented EE-induced increase in the serum levels of AST, ALT, ALP and TBA. Moreover, the elevation of hepatic MDA content induced by EE was significantly reduced, while hepatic SOD activities were significantly increased when treated with ginsenosides. Histopathology of the liver tissue showed that pathological injuries were relieved after treatment with ginsenosides. In addition, treatment with ginsenosides could significantly downregulate the protein expression of TNF-[Formula: see text], IL-6 and IL-1[Formula: see text] compared with EE group. These findings indicate that ginsenosides exert the hepatoprotective effect on EE-induced intrahepatic cholestasis in rats, and this protection might be attributed to the attenuation of oxidative stress and inflammation.


2012 ◽  
Vol 152 (1) ◽  
pp. 104-118 ◽  
Author(s):  
M. DE A. SILVA ◽  
J. L. JIFON ◽  
J. A. G. DA SILVA ◽  
C. M. DOS SANTOS ◽  
V. SHARMA

SUMMARYThe relationships between physiological variables and sugarcane productivity under water deficit conditions were investigated in field studies during 2005 and 2006 in Weslaco, Texas, USA. A total of 78 genotypes and two commercial varieties were studied, one of which was drought-tolerant (TCP93-4245) and the other drought-sensitive (TCP87-3388). All genotypes were subjected to two irrigation regimes: a control well-watered treatment (wet) and a moderate water-deficit stress (dry) treatment for a period of 90 days. Maximum quantum efficiency of photosystem II (Fv/Fm), estimated chlorophyll content (SPAD index), leaf temperature (LT), leaf relative water content (RWC) and productivity were measured. The productivity of all genotypes was, on average, affected negatively; however, certain genotypes did not suffer significant reduction. Under water deficit, the productivity of the genotypes was positively and significantly correlated with Fv/Fm, SPAD index and RWC, while LT had a negative correlation. These findings suggest that genotypes exhibiting traits of high RWC values, high chlorophyll contents and high photosynthetic radiation use efficiency under low moisture availability should be targeted for selection and variety development in programmes aimed at improving sugarcane for drought prone environments.


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