scholarly journals Effects of Salicylic Acid and Calcium Chloride on Heat Tolerance in Rhododendron ‘Fen Zhen Zhu’

2016 ◽  
Vol 141 (4) ◽  
pp. 363-372 ◽  
Author(s):  
Huifei Shen ◽  
Bing Zhao ◽  
Jingjing Xu ◽  
Xizi Zheng ◽  
Wenmei Huang

Rhododendrons (Rhododendron) are ornamental plants that exhibit poor thermotolerance. Salicylic acid (SA) and Ca2+ regulate the physiological and biochemical mechanisms in plants adapted to adverse environmental conditions. This study investigated the role of SA and CaCl2 in managing heat tolerance of Rhododendron ‘Fen Zhen Zhu’. Plants of the triennial Rhododendron ‘Fen Zhen Zhu’ were pretreated with SA and CaCl2, alone and combined. Following this pretreatment, the plants were subjected to 38/30 °C (day/night) incubation for 6 days, and then allowed to recover for 20 days under 25/17 °C (day/night) in a chamber. Changes in morphology were observed and recorded. Data were collected on plant chlorophyll content, malondialdehyde (MDA) content, H2O2 level, antioxidant enzyme activity, and total soluble protein content. The results revealed that the plant growth was considerably affected by heat stress, the leaves became brown and withered, and the plant defoliated. Under heat stress, chlorophyll content and total soluble protein levels decreased. Peroxidase (POD) activity and superoxide dismutase (SOD) also decreased, whereas the H2O2 and MDA content increased. Individual or combined application of SA and CaCl2 had a positive effect on plant growth, chlorophyll content, total soluble protein levels, and enzymatic antioxidant activity under heat stress. In general, the effect of the combined application of SA and CaCl2 was superior to individual application. In addition, treatment with high CaCl2 concentrations effectively alleviated the decrease in chlorophyll content. However, at low SA and CaCl2 concentrations, SOD and POD activity and total soluble protein accumulation increased whereas MDA and H2O2 levels decreased. These results suggest that SA and CaCl2 may interact to alleviate heat stress.

2017 ◽  
Vol 9 (3) ◽  
pp. 1338-1342
Author(s):  
Amarjeet Kumar ◽  
Swati Swati ◽  
N. K. Singh ◽  
Birendra Prasad ◽  
Anil Kumar

To estimate the level of heat tolerance for different genotypes of bread wheat with respect to morphological characters under studied grains/ spike, grain weight/spike, grain filling duration (duration between the anthesis stage and the physiological maturity), 1000-kernel weight and grain yield/plant for yield. Physiological traits like relative injury (RI %), chlorophyll content, canopy temperature depression (CTD), were used in present investigation to contribute toward capability of plants to tolerate heat stress of the yield contributing traits during heat stress.The findings of present investigation had clearly explained that influences of environments on morpho physiological characters i.e. grain yield per plant (14886.15) and its attributing traits i.e. spike length (459.7), tillers per plant (622.34), spikelets per spike (278.1), 1000 kernel weight (13262.39), grain weight per spike (177.89) and number of grains per spike (2898.44) in wheat were highly significant and positive. Among the parent and their crosses had handsome amount of variations across the environment. The results of interaction for environments with parents, lines, testers and their crosses with respect to morpho physiological characters in wheat was found significant for some characters while variation was absent for other characters studied. Physiological traits like relative injury per cent, chlorophyll content and CTD were vital parameters to quantify the degree of heat stress to develop tolerant genotypes which is urgent and present need under changing climate scenario.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6743 ◽  
Author(s):  
Anna Wyrwicka ◽  
Magdalena Urbaniak ◽  
Mirosław Przybylski

Background The increasing production of sewage sludge (SS) engenders the problem of its responsible utilization and disposal. Likewise, urban sediments (SED) are deposited at the bottom of urban reservoirs and sedimentation ponds, and these require periodical dredging and utilization. However, while the SS and SED deposits often contain nutrients such as nitrogen and phosphorus; however, they also contain a variety of hazardous compounds including heavy metals, Persistent Organic Pollutants (POPs) and microbial pollutants. Fortunately, some species of Cucurbitaceae can accumulate high levels of POPs, such as polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF) and polychlorinated biphenyls (PCB), in their tissues. Methods SS was collected from the Lodz Municipal Wastewater Treatment Plant and SED from the Sokołówka Sequential Biofiltration System. The SS and SED samples were added to soil in flower pots at three concentrations (1.8 g, 5.4 g and 10.8 g per flower pot), and one pot was left as an unamended control (C). Soil PCB concentrations were determined before cucumber planting, and after five weeks of growth. Also, total soluble protein, total chlorophyll content, chlorophyll a/b ratio and degree of lipid peroxidation (TBARS) were examined in the leaves of the cucumber plants (Cucumis sativus L.) cv. Cezar after five weeks. Antioxidative response was assessed by ascorbate peroxidase (APx) and catalase (CAT) assay. Results The initial PCB concentration in soil after application of SS or SED was dependent on the applied dose. After five weeks, PCB concentration fell significantly for all samples and confirmed that the dose of SS/SED had a strong effect. Soil remediation was found to be more effective after SS application. Total soluble protein content in the cucumber leaf tissues was dependent on both the type and the dose of the applied amendments, and increased with greater SS doses in the soil. The total chlorophyll content remained unchanged, and the chlorophyll a/b ratio was slightly elevated only after the application of the highest SS and SED dose. The use of SS and SED did not significantly affect TBARS content. APx activity fell after SS or SED application; however, CAT activity tended to increase, but only in the leaves of plants grown in SS-amended soil. Discussion The cultivation of cucumber plants reduces PCB concentration in soil amended with SS or SED; however, this effect is more evident in the case of SS. SS application also induced more intensive changes in the activity of enzymes engaged in antioxidative response and oxidative stress markers in plant tissues than SED. The levels of PCB in the SS may have triggered a more severe imbalance between pro- and antioxidative reactions in plants. Cucumber plants appear to be resistant to the presence of toxic substances in SS and SED, and the addition of SS and SED not only acts as a fertilizer, but also protects against accelerated aging.


HortScience ◽  
2019 ◽  
Vol 54 (3) ◽  
pp. 499-504 ◽  
Author(s):  
Kuan-Hung Lin ◽  
Shao-Bo Huang ◽  
Chun-Wei Wu ◽  
Yu-Sen Chang

Exogenous application of either salicylic acid (SA) or calcium chloride (CaCl2) to alleviate heat stress has been extensively studied. However, the effects of combined SA and CaCl2 treatment on the heat tolerance of poinsettia have been poorly studied. This study investigated the role of a foliar spray comprising SA and CaCl2 in managing heat tolerance of three poinsettia (Euphorbia pulcherrima Willd.) cultivars, Noel, Winter Rose (WR), and Ice Punch’ (IP). Plants were pretreated with SA, CaCl2, or combined SA and CaCl2 and then exposed to a temperature of 42 °C for 1 hour. Changes in the relative injury (RI) percentage, malondialdehyde (MDA) content, and antioxidant enzyme activities were determined. All plants were then placed in an environment-controlled greenhouse for 14 days and evaluated. Lateral bud sprouting (%), new leaf numbers, and phenotypic appearance were recorded. Results revealed that the three poinsettia cultivars varied in their appearance, morphological growth patterns, and ability to tolerate high-temperature stress. Plant growth of ‘Noel’ was more robust than that of ‘WR’ and ‘IP’, which were considerably affected by heat stress, resulting in brown, withered leaves and defoliation. In general, the effects of the combined application of SA and CaCl2 on heat-tolerant ‘Noel’ were superior to those of individual applications and no treatment (for control groups) in terms of the RI percentage, lateral bud sprouting (%), and appearance under heat stress. Application of combined SA and CaCl2 for ‘Noel’ plants was more beneficial for enhancing catalase activity and resulted in the effective alleviation of decreased malondialdehyde content under heat stress. Treatment including 200 μΜ SA and 10 mm CaCl2 may alleviate heat stress and may prove useful in breeding programs focused on improving poinsettia cultivars.


Plants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2110
Author(s):  
Kuan-Hung Lin ◽  
Tse-Yen Lin ◽  
Chun-Wei Wu ◽  
Yu-Sen Chang

High-temperature stress is a major risk to fresh-market Salvia production, and heat intolerance is a major constraint in sage cultivation, particularly during the hot summer season. Previously, we investigated heat tolerance in five common-market cultivars of sage plants using leaf relative injury (RI) values and found that S. elegans Vahl (SE) and S. officinalis L. (SO) were the most and least heat-tolerant species, respectively. The exogenous applications of salicylic acid (SA) and calcium chloride (CaCl2) to alleviate heat stress in various species have been extensively studied, but reports of the effects of SA and CaCl2 treatments on the heat tolerance of sage plants are scarce. The objective of this study was to investigate how SA and CaCl2 affect the physiology and morphology of SE and SO plants under high-temperature conditions. Potted plants were pretreated with SA (0, 100, 200, 400, and 800 μM) and CaCl2 (0, 5, 10, and 15 mM), alone and combined, exposed to 55 °C and 80% humidity for 30 min, then placed in an environment-controlled chamber at 30°C for three days and evaluated for changes in phenotypic appearance, RI, spectral reflectance, and chlorophyll fluorescence indices at different time intervals. Plants watered without chemical solutions were used as controls. Our results show that the growth of SO plants pretreated with SA and CaCl2 was more robust, compared with control plants, which were considerably affected by heat stress, resulting in brown, withered leaves and defoliation. The effects of the combined applications of SA (100 μM) and CaCl2 (5 mM) to SO plants were superior to control plants in increasing values of soil-plant analysis development (SPAD), normalized difference vegetation index (NDVI), and the maximal quantum yield of photosystemII photochemistry (Fv/Fm), while reducing RI%. Furthermore, SO plants exhibited higher SPAD and Fv/Fm values and lower RI% than SE plants in combined treatments at all time intervals after heat stress, implying that different genotypes displayed variations in their SPAD, Fv/Fm, and RI%. Thus, a combined treatment of 100 μM of SA and 5 mM of CaCl2 is effective and beneficial to plant appearance and ability to ameliorate heat stress. These indices can be used as indicators to characterize the physiology of these plants and applied on a commercial scale for informing the development of rapid and precise management practices on bedded sage plants grown in plant factories to achieve maximum market benefit.


2017 ◽  
Vol 5 (1) ◽  
pp. 81-87
Author(s):  
Vishnuveni Murugan ◽  
Sivakumar Rathinavelu ◽  
Nandhitha Krishnadevaraj ◽  
Chandrasekaran Perumal

An experiment was conducted to study the effect of PGRs { gibberellic acid (10 ppm), brassinolide (0.5 ppm), salicylic acid (100 ppm), ascorbic acid (100 ppm), benzyl amino purine (5 ppm)} and nutrients { K2SO4 (0.5%) + FeSO4 (0.5%) + Borax (0.3%) mixture and 19:19:19 (1%) mixture} on growth, NR enzyme activity, proline, soluble protein content and yield of bhendi hybrid (COBh H 1) under saline condition. The treatments were given at 25 and 45 DAS as foliar spray. The results showed that, nitrate reductase activity, soluble protein and plant growth were reduced under saline condition where as proline content was increased compared to absolute control. Foliar application of PGRs and nutrients enhanced the NR activity, proline, soluble protein and plant growth under saline condition. Among the PGRs and nutrients, foliar application of salicylic acid (100 ppm) and brassinolide (0.5 ppm) showed the better performance to mitigate the effect of salinity.


2022 ◽  
Vol 147 (1) ◽  
pp. 18-24
Author(s):  
Stephanie Rossi ◽  
Bingru Huang

Heat stress symptoms in cool-season plants are characterized by loss of chlorophyll (Chl) and membrane stability, as well as oxidative damage. The objectives of this study were to determine whether foliar application of β-sitosterol, a naturally occurring plant metabolite, may promote heat tolerance by suppressing heat-induced leaf senescence as indicated by the maintenance of healthy turf quality (TQ), and Chl and membrane stability; and to determine its roles in regulating antioxidant metabolism in creeping bentgrass (Agrostis stolonifera). ‘Penncross’ plants were exposed to heat stress (35/30 °C day/night) optimal temperature conditions (nonstressed control, 22/17 °C day/night) for a duration of 28 days in environment-controlled growth chambers. Plants were foliar-treated with β-sitosterol (400 µM) or water only (untreated control) before heat stress, and at 7-day intervals through 28 days of heat stress. Plants treated with β-sitosterol had significantly greater TQ and Chl content, and significantly less electrolyte leakage (EL) than untreated controls at 21 and 28 days of heat stress. Application of β-sitosterol reduced malondialdehyde (MDA) content significantly at 21 and 28 days of heat stress, and promoted the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) from 14 through 28 days of heat stress. β-Sitosterol effectively improved heat tolerance through suppression of leaf senescence in creeping bentgrass exposed to heat stress in association with the alleviation of membrane lipid peroxidation and activation of the enzymatic antioxidant system.


2022 ◽  
Author(s):  
Shikha Yashveer ◽  
Neeru Redhu ◽  
Vikram Singh ◽  
Sonali Sangwan ◽  
Hembade Laxman ◽  
...  

Abiotic stresses like heat, drought, and salinity are among the major threats to sustainable crop production. These stresses induce numerous adverse effects in plants by impairing biochemical, physiological and molecular processes, eventually affecting plant growth, development and productivity. The rising temperature is one of the major causes of heat stress in agriculture. The variation in temperature during crop development has led to devastating agricultural losses in terms of yield. To adapt and mitigate these effects, germplasm scientists and agronomists aim to develop heat-tolerant varieties or cultivars. These efforts generally include the identification of alleles responsible for heat tolerance and their introgression into breeding populations through conventional or biotechnological methods. However, heat tolerance is a very complex physio-biochemical response of plants governed by a number of genes positioned at different loci. The accumulation of various additive gene effects into a single genotype is an extremely tedious and time-consuming process in both plant breeding and biotechnology. Recent advancements in agricultural nanotechnology have raised expectations for sustainable productivity without altering the genetic make-up of plants. In this milieu, the application of biologically active nanoparticles (NPs) could be a novel approach to enhance heat tolerance in crops. Recently, the NPs from silver, silicon, titanium and selenium have been proven valuable for plants to combat heat stress by altering their physiological and biochemical responses. Due to nano-scale size and the high surface area along with their slow and steady release, the NPs exert positive effects in plants through their growth-promoting and antioxidant capabilities. In this review, various technologies used for NPs characterization and their applications in agriculture have been discussed. The review further elaborates the uptake mechanism of NPs and their translocation in different plant parts along with the factors affecting them. This article also describes the role of metal or metal oxide NPs, as well as nano, encapsulated plant growth regulators and signal molecules in heat stress tolerance. The review will provide an insight to the scientists working in the area of agricultural sciences to explore new NPs to encounter different types of biotic and abiotic stresses.


HortScience ◽  
2005 ◽  
Vol 40 (3) ◽  
pp. 874d-874
Author(s):  
Seenivasan Natarajan ◽  
Jeff S. Kuehny ◽  
James E. Board

One of the greatest impediments to production of marketable ornamental herbaceous plants in southern U.S. is high temperature stress. Exposure of plants to sub-lethal temperature (heat preconditioning) before sustained heat stress helps some plants to tolerate subsequent heat stress a phenomenon often referred as acquired thermotolerance. The objective of this research was to examine various morphological, physiological and anatomical responses of `Vista red' (heat tolerant) and `Sizzler red'(heat sensitive) cultivars of Salvia splendens to heat preconditioning (HC) and subsequent heat stress treatments (challenging temperatures, CT). Cultivars of Salvia were subjected to short duration HC of 35 °C for 3 hours every third day until 5 weeks after germination and subsequent exposure to two CT treatments 30/23 °C and 35/28 °C (D/N) cycles in growth chambers for the next five weeks. Plant growth, marketable quality, stomatal conductance and net photosynthesis declined for Sizzler Red without HC treatment. Compared with nonpreconditioned plants, heat preconditioned Sizzler Red had 38.28% higher root dry weight, 95% greater leaf thickness, 50% higher marketable quality at 35/28 °C heat stress condition. Heat preconditioning helped both Vista Red and Sizzler to survive in both the heat stress treatments. Vista Red had greater heat tolerant traits than Sizzler Red, these traits exacerbated with heat preconditioning treatment. The results demonstrated that heat preconditioning enhanced heat tolerance in cultivars of Salvia, which could be related to maintenance of dense plant growth with shorter internodes, thicker stems, greater stomatal conductance, extensive root growth that compensated the transpirational water loss and overall cooling of plants.


2015 ◽  
Vol 52 (1-2) ◽  
pp. 19-36 ◽  
Author(s):  
Roya Razavizadeh

Abstract The effect of salicylic acid (SA) on the salt (NaCl) tolerance mechanism was studied in canola plants (oilseed rape, Brassica napus L.) by molecular and physiological experiments in plant tissue culture. Seeds of B. napus ‘Ocapy’ were germinated at 0, 50, and 100 mM NaCl on Murashige and Skoog (MS) medium containing different levels (0, 2, and 5 μM) of SA for 4 weeks. Total chlorophyll, carotenoid, and flavonoid content increased in response to interactive effects of SA and NaCl treatments at some concentrations. Proline content was increased under salt and SA treatments in shoot and root tissues. Salt alone and in combination with SA increased the total soluble protein content of shoots only, while the different concentrations of SA in the culture media affected variously the total soluble protein content. Protein patterns of shoots and roots showed some remarkable differences, based on gel electrophoresis and the consequent analysis of bands by ImageJ program. The relative expression of 15 and 12 protein bands in shoots and roots, respectively, differed under the applied treatments. In addition, the protein profile indicated that salinity and SA regulate the expression of salt-stress-inducible proteins as well as induced de novo synthesis of specific polypeptides. The findings may help to explain the salt tolerance mechanisms and to produce salt-tolerant canola plants.


Author(s):  
P. Kuchlan ◽  
M.K. Kuchlan

Background: Salicylic acid (SA) is an endogenous plant growth regulator plays a vital role in plant growth, ion uptake, transport, interaction with other organisms and in the responses to environmental stress. The aim of the study was to find the effect of salicylic acid on chlorophyll content, superoxide dismutase and malondialdehyde level of leaves and seed yield parameters of soybean.Methods: Field trials were conducted during kharif 2018 and 2019 at ICAR-Indian Institute of Soybean Research, Indore farm (22.78oN, 75.88oE), India. Salicylic acid applied as foliar spray with (50,100 and 200 ppm) concentrations at vegetative stage (22-25 days after sowing) and at pod filling stage (57-60 days after sowing). Chlorophyll content, lipid peroxidation activity and superoxide dismutase enzyme, plant height, number of pod per plant, seed yield and seed index were determined.Result: Chlorophyll content, antioxidant enzyme were enhanced and the level of lipid peroxidation of leaves was reduced as compared to untreated plant when salicylic acid applied at critical stage of crop growth. Significant increase in soybean seed yield was observed both with concentration of 100 and 200 ppm salicylic acid. Foliar spray with salicylic acid @ 100 ppm at vegetative and at pod filling stage was very effective for better seed production programme to improve quantity as well as quality of soybean seeds.


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