Change in salicylic acid and antioxidants during induced thermo tolerance in mustard seedlings. Plant Physiol (original) (raw)
Related papers
Changes in Salicylic Acid and Antioxidants during Induced Thermotolerance in Mustard Seedlings
Plant Physiology, 1998
Heat-acclimation or salicylic acid (SA) treatments were previously shown to induce thermotolerance in mustard (Sinapis alba L.) seedlings from 1.5 to 4 h after treatment. In the present study we investigated changes in endogenous SA and antioxidants in relation to induced thermotolerance. Thirty minutes into a 1-h heat-acclimation treatment glucosylated SA had increased 5.5-fold and then declined during the next 6 h. Increases in free SA were smaller (2-fold) but significant. Changes in antioxidants showed the following similarities after either heat-acclimation or SA treatment. The reduced-to-oxidized ascorbate ratio was 5-fold lower than the controls 1 h after treatment but recovered by 2 h. The glutathione pool became slightly more oxidized from 2 h after treatment. Glutathione reductase activity was more than 50% higher during the first 2 h. Activities of dehydroascorbate reductase and monodehydroascorbate reductase decreased by at least 25% during the first 2 h but were 20% to ...
Plant physiology, 1998
Spraying mustard (Sinapis alba L.) seedlings with salicylic acid (SA) solutions between 10 and 500 &mgr;m significantly improved their tolerance to a subsequent heat shock at 55 degreesC for 1.5 h. The effects of SA were concentration dependent, with higher concentrations failing to induce thermotolerance. The time course of thermotolerance induced by 100 &mgr;m SA was similar to that obtained with seedlings acclimated at 45 degreesC for 1 h. We examined the hypothesis that induced thermotolerance involved H2O2. Heat shock at 55 degreesC caused a significant increase in endogenous H2O2 and reduced catalase activity. A peak in H2O2 content was observed within 5 min of either SA treatment or transfer to the 45 degreesC acclimation temperature. Between 2 and 3 h after SA treatment or heat acclimation, both H2O2 and catalase activity significantly decreased below control levels. The lowered H2O2 content and catalase activity occurred in the period of maximum thermoprotection. It is sugg...
Plant Physiology, 1998
Spraying mustard (Sinapis alba L.) seedlings with salicylic acid (SA) solutions between 10 and 500 μm significantly improved their tolerance to a subsequent heat shock at 55°C for 1.5 h. The effects of SA were concentration dependent, with higher concentrations failing to induce thermotolerance. The time course of thermotolerance induced by 100 μm SA was similar to that obtained with seedlings acclimated at 45°C for 1 h. We examined the hypothesis that induced thermotolerance involved H2O2. Heat shock at 55°C caused a significant increase in endogenous H2O2 and reduced catalase activity. A peak in H2O2 content was observed within 5 min of either SA treatment or transfer to the 45°C acclimation temperature. Between 2 and 3 h after SA treatment or heat acclimation, both H2O2 and catalase activity significantly decreased below control levels. The lowered H2O2 content and catalase activity occurred in the period of maximum thermoprotection. It is suggested that thermoprotection obtained...
Salicylic Acid Enhanced Low Temperature Stress Tolerance in Vegetables: A Review
Low temperature stress adversely affects growth, productivity and triggers a series of morphological, physiological and biochemical changes in plants. It is a major environmental cue that limits the vegetable productivity of plants, particularly in hilly areas. Development of procedures to enhance low temperature stress tolerance in plants is crucial and attracts considerable attention. The tolerance to low temperature stress is an intricate process that involves morphological, physiological and biochemical modifications. Salicylic acid is a vital signalling molecule for modulating plant response to various abiotic stresses. Salicylic acid induced alleviation of low temperature stress has been reported in vegetables. In this review, the aim is to emphasise the ameliorative effects of SA on growth, physiological, biochemical changes, yield and quality of plants growing under low temperature stress. On the basis of different studies, it has been concluded that SA enhanced the low temperature stress tolerance significantly and increased plant growth, photosynthetic pigments, accumulations of osmoprotectants and activity of antioxidant enzymes. It also increased production and quality of vegetables under low temperature stress.
Plant Science, 2006
To investigate importance of salicylic acid (SA) and SA biosynthesis pathway in the development of plant thermotolerance, the research tested the effects of heat acclimation on pea plants (Pisum sativun L.) at 37 8C for 2 h and examined in vivo pretreatments of the plants in a medium containing either SA or SA biosynthesis inhibitors before heat treatment. The results showed that both heat acclimation and SA application could reduce leaf injury caused by subsequent heat stress and induce the synthesis of heat shock proteins (Hsp 70 and Hsp 17.6). Further, membrane lipid peroxidation caused by the heat stress was found to decrease, suggesting that plant's thermotolerance developed as a result of heat acclimation and SA application. A rapid transient increase of endogenous free SA and a subsequent enrichment in Hsp 70 were both elevated by heat acclimation. Changes of phenylalanine ammonia lyase (PAL) and benzoic acid 2-hydroxylase (BA2H) activities roughly paralleled those of free SA. In addition, pretreatment with the inhibitors of either PAL or BA2H effectively blocked SA accumulation and Hsp 70 enrichment in the plants subjected to heat acclimation, thus reduced plant tolerance to heat stress. This finding indicates that inhibition of SA biosynthesis during heat acclimation can annul the development of plant thermotolerance and that SA synthesized by BA2H participates in the acquisition of heat acclimation-induced thermotolerance. #
Brazilian Journal of Plant Physiology, 2009
Pots holding 7 day-old seedlings of Indian mustard (Brassica juncea L.) were subjected to differential temperature stress by exposing plants to 30 or 40ºC for 24 h. Seedlings were sprayed with double distilled water (DDW) or 10-5M salicylic acid (SA) at the 8-day stage and were sampled at 30 DAS. The plants exposed to temperature stress exhibited a significant (p < 0.05) decline in growth, and in levels of chlorophyll, nitrate reductase and carbonic anhydrase activities and photosynthetic parameters. A follow-up treatment with SA protected against the stress generated by temperature and significantly improved the above parameters. Antioxidative enzymes and levels of proline significantly increased in response to SA as well as to temperature stress.
Pakistan Journal of Agricultural Research, 2020
M aize (Zea mays L.) is an important cereal crop and cultivated under divergent climatic conditions of spring and summer seasons in Pakistan (Tariq et al., 2002). Being monoecious crop and very much sensitive to high temperatures (Ullah et al., 2020) which causes severe irreversible changes in Abstract | Temperature is a very important factor that affects crop yield. Maize, a monoecious plant, is adversely affected by high temperature during anthesis. Asynchronous fertilization and pollen desiccation reduce maize yield by reducing grain number and their size. Spray of hydrogen peroxide (H 2 O 2), salicylic acid (SA) and ascorbic acid (AsA) may induce heat stress tolerance. Spray of SA, AsA, and H 2 O 2 increased chlorophyll, relative water and nutrient contents, membrane stability index (MSI) and antioxidants activities in heat stress. Moreover, foliar application of chemicals during normal and late planting improved the grain yield by increasing both the grain number and size. Foliar spray of SA, AsA and H 2 O 2 may induce heat tolerance by improving antioxidant activities which stabilized membrane and maintaining relative water, chlorophyll and nutrient content in ear leaves of maize during heat stress.
Frontiers in bioscience, 2022
In the present era of climate change and global warming, high temperatures have increased considerably, posing a threat to plant life. Heat stress affects the biochemistry, physiology and molecular makeup of the plant by altering the key processes, i.e., photosynthesis, respiration and reproduction which reduces its growth and development. There is a dire need to manage this problem sustainably for plant conservation as well as the food security of the human population. Use of phytohormones to induce thermotolerance in plants can be a sustainable way to fight the adversities of heat stress. Phytohormone-induced thermotolerance proves to be a compelling approach to sustainably relieve the damaging effects of heat stress on plants. Salicylic acid (SA) is an essential molecule in biotic and abiotic defense response signal transduction pathways. When supplied externally, it imparts heat stress tolerance to the plants by different means, viz., increased Heat Shock Proteins (HSP) production, Reactive oxygen species (ROS) scavenging, protection of the reproductive system and enhancing photosynthetic efficiency. The effect of SA on plants is highly dependent on the concentration applied, plant species, plant age, type of tissues treated, and duration of the treatment. The present review paper summarizes the mechanism of thermotolerance induced by salicylic acid in plants under heat stress conditions. It includes the regulatory effects of SA on heat shock proteins, antioxidant metabolism, and maintenance of Ca 2+ homeostasis under heat stress. This review combines the studies conducted to elucidate the role of SA in the modulation of different mechanisms which lead to heat stress tolerance in plants. It discusses the mechanism of SA in protecting the photosynthetic machinery and reproductive system during high-temperature stress.
Plant signaling & behavior, 2015
Ascorbate (AsA)-glutathione (GSH) cycle metabolism has been regarded as the most important defense mechanism for the resistance of plants under stress. In this study the influence of salicylic acid (SA) was studied on ascorbate-glutathione pathway, S-assimilation, photosynthesis and growth of mustard (Brassica juncea L.) plants subjected to 100 mM NaCl. Treatment of SA (0.5 mM) alleviated the negative effects of salt stress and improved photosynthesis and growth through increase in enzymes of ascorbate-glutathione pathway which suggest that SA may participate in the redox balance under salt stress. The increase in leaf sulfur content through higher activity of ATP sulfurylase (ATPS) and serine acetyl transferase (SAT) by SA application was associated with the increased accumulation of glutathione (GSH) and lower levels of oxidative stress. These effects of SA were substantiated by the findings that application of SA-analog, 2,6, dichloro-isonicotinic acid (INA) and 1 mM GSH treatmen...
Plants
In the era of global warming, heat stress, particularly at the seedling stage, is a major problem that affects the production and productivity of crops such as mustard that are grown in cooler climates. Nineteen mustard cultivars were exposed to contrasting temperature regimes—20 °C, 30 °C, 40 °C and a variable range of 25–40 °C—and evaluated for changes in physiological and biochemical parameters at the seedling stage to study their role in heat-stress tolerance. Exposure to heat stress showed detrimental effects on seedling growth as revealed by reduced vigor indices, survival percentages, antioxidant activity and proline content. The cultivars were grouped into tolerant, moderately tolerant and susceptible based on the survival percentage and biochemical parameters. All the conventional and three single-zero cultivars were found to be tolerant and moderately tolerant, respectively, while double-zero cultivars were reckoned to be susceptible except for two cultivars. Significant i...