scholarly journals Heat-tolerant Hot Pepper Exhibits Constant Photosynthesis Via Increased 4 Transpiration Rate, High Proline Content and Fast Recovery in Heat Stress 5 Condition

2021 ◽  
Author(s):  
Sherzod Rajametov ◽  
Eun Young Yang ◽  
Myeong Cheoul Cho ◽  
Soo Young Chae ◽  
Hyo Bong Jeong ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Heat Stress ◽  
Photosynthetic Rate ◽  
Heat Tolerance ◽  
Transpiration Rate ◽  
Proline Content ◽  
Hot Pepper ◽  
Fast Recovery ◽  
Heat Damage ◽  
Heat Tolerant

Understanding the mechanism for heat tolerance is important for the hot pepper breeding program to develop heat-tolerant cultivars in changing climate. This study was conducted to investigate physiological and biochemical parameters related to heat tolerance and to determine leaf heat damage levels critical for selecting heat-tolerant genotypes. Seedlings of two commercial cultivars, heat-tolerant ‘NW Bigarim’ (NB) and susceptible ‘Chyung Yang’ (CY), were grown in 42 °C for ten days. Photosynthesis, electrolyte conductivity, proline content were measured among seedlings during heat treatment. Photosynthetic rate was significantly reduced in ‘CY’ but not in ‘NB’ seedlings in 42 °C. Stomatal conductivity and transpiration rate was significantly higher in ‘NB’ than ‘CY’. Proline content was also significantly higher in ‘NB’. After heat treatment, leaf heat damages were determined as 0, 25, 50 and 75% and plants with different leaf heat damages were moved to a glasshouse (30–32/22–24 °C in day/night). The growth and developmental parameters were investigated until 70 days. ‘NB’ was significantly affected by leaf heat damages only in fruit yield while ‘CY’ was in fruit set, number and yield. ‘NB’ showed fast recovery after heat stress compared to ‘CY’. These results suggest that constant photosynthetic rate via increased transpiration rate as well as high proline content in heat stress condition confer faster recovery from heat damage of heat-tolerant cultivars in seedlings stages.

scholarly journals Heat-tolerant hot pepper exhibits constant photosynthesis via increased transpiration rate, high proline content and fast recovery in heat stress condition

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sherzod Nigmatullayevich Rajametov ◽  
Eun Young Yang ◽  
Myeong Cheoul Cho ◽  
Soo Young Chae ◽  
Hyo Bong Jeong ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Heat Stress ◽  
Heat Tolerance ◽  
Transpiration Rate ◽  
Stress Condition ◽  
Proline Content ◽  
Hot Pepper ◽  
Fast Recovery ◽  
Heat Stress Condition ◽  
Heat Tolerant

AbstractUnderstanding the mechanism for heat tolerance is important for the hot pepper breeding program to develop heat-tolerant cultivars in changing climate. This study was conducted to investigate physiological and biochemical parameters related to heat tolerance and to determine leaf heat damage levels critical for selecting heat-tolerant genotypes. Seedlings of two commercial cultivars, heat-tolerant ‘NW Bigarim’ (NB) and susceptible ‘Chyung Yang’ (CY), were grown in 42 °C for ten days. Photosynthesis, electrolyte conductivity, proline content were measured among seedlings during heat treatment. Photosynthetic rate was significantly reduced in ‘CY’ but not in ‘NB’ seedlings in 42 °C. Stomatal conductivity and transpiration rate was significantly higher in ‘NB’ than ‘CY’. Proline content was also significantly higher in ‘NB’. After heat treatment, leaf heat damages were determined as 0, 25, 50 and 75% and plants with different leaf heat damages were moved to a glasshouse (30–32/22–24 °C in day/night). The growth and developmental parameters were investigated until 70 days. ‘NB’ was significantly affected by leaf heat damages only in fruit yield while ‘CY’ was in fruit set, number and yield. ‘NB’ showed fast recovery after heat stress compared to ‘CY’. These results suggest that constant photosynthetic rate via increased transpiration rate as well as high proline content in heat stress condition confer faster recovery from heat damage of heat-tolerant cultivars in seedlings stages.

Effects of exogenous application of abscisic acid on membrane stability, osmotic adjustment, photosynthesis and hormonal status of two lucerne (Medicago sativa L.) genotypes under high temperature stress and drought stress

2014 ◽  
Vol 65 (3) ◽  
pp. 274 ◽  
Author(s):  
Yuan An ◽  
Peng Zhou ◽  
Jinfeng Liang
Keyword(s):  
Heat Stress ◽  
Photosynthetic Rate ◽  
Electrolyte Leakage ◽  
Physiological Responses ◽  
Proline Content ◽  
Water Conditions ◽  
Medicago Sativa L ◽  
Heat Tolerant ◽  
Soil Water Conditions ◽  
Aba Content

This study was designed to examine effects of high temperature, drought and exogenous abscisic acid (ABA) on membrane stability, osmotic adjustment, photosynthesis and the hormone status of two lucerne (alfalfa, Medicago sativa L.) genotypes contrasting in heat tolerance: Ameristand 801S (AS801) (heat-tolerant), and Aohan (heat-sensitive), The results showed that AS801 had lower electrolyte leakage, but higher chlorophyll content, net photosynthetic rate, stomatal conductance, proline content, ABA content and zeatin riboside (ZR) content than Aohan during 72 h of heat stress under well-watered conditions. Under drought conditions, however, only proline content and ZR content in roots, electrolyte leakage in leaves and roots, net photosynthetic rate, and ABA content were significantly different between the two genotypes. A foliar application of ABA to heat-stressed plants significantly decreased electrolyte leakage and stomatal conductance, and increased recovery in growth and leaf water potential in the two genotypes under both watering conditions. The other physiological responses measured differed under drought or well-watered conditions, and appeared to be genotype-specific. These results suggest that the physiological responses of heat-sensitive and heat-tolerant lucerne to heat stress under different soil-water conditions varied. The heat-induced changes in proline accumulation in roots, electrolyte leakage in leaves and roots, and photosynthetic rate could serve as early instant stress indicators for evaluating the tolerance of lucerne genotypes to heat stress under different soil water conditions.

scholarly journals Evaluation of seedling proline content of wheat genotypes in relation to heat tolerance

1970 ◽  
Vol 40 (1) ◽  
pp. 17-22 ◽  
Author(s):  
JU Ahmed ◽  
MA Hassan
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Heat Tolerance ◽  
Negative Correlation ◽  
Significant Negative Correlation ◽  
Proline Content ◽  
Membrane Injury ◽  
Wheat Genotypes ◽  
Membrane Thermostability ◽  
Heat Tolerant

Seedling of 20 wheat genotypes were grown in Phytotron at about 25 and 35°C for measuring membrane injury in per cent and seedling proline content to investigate seedling proline as screening criterion against heat stress. The wheat genotypes (Bijoy, Sufi, Kanchan, Fang 60, BAW 1059, BL 1883, BL 1022, IVT 7, IVT 8, IVT 9, IVT 10 and BAW 917) showing < 50% membrane injury were grouped as heat tolerant (HT) and the genotypes (Shatabdi, Prodip, BAW 1064, Gourab, Pavon 76, Sonora, Kalyansona and IVT 6) showing ≥ 50% membrane injury were classified as heat sensitive (HS). At high temperature (35°C) the HT genotypes produced more than double (> 200%) proline than that of 25°C but the HS genotypes produced less quantity of proline at 35°C compared to that in HT genotypes. The seedling proline content at 35°C and membrane injury (%) maintained a significant negative correlation (r = – 0.619**) across the 20 wheat genotypes tested. Key words: Membrane thermostability; Seedling proline; Heat tolerance; Wheat DOI: http://dx.doi.org/10.3329/bjb.v40i1.7991 Bangladesh J. Bot. 40(1): 17-22, 2011 (June)

The effect of duration of heat stress during grain filling on two wheat varieties differing in heat tolerance: grain growth and fractional protein accumulation

1998 ◽  
Vol 25 (1) ◽  
pp. 13 ◽  
Author(s):  
P.J. Stone ◽  
M.E. Nicolas
Keyword(s):  
Heat Treatment ◽  
Heat Stress ◽  
High Temperature ◽  
Heat Tolerance ◽  
Grain Filling ◽  
Protein Accumulation ◽  
Tolerant Variety ◽  
Heat Tolerant ◽  
Very High ◽  
Individual Kernel

Two varieties of wheat differing in heat tolerance were exposed to very high temperature (40/19°C day/night) for periods of 1–10 days duration. Responses of grain dry matter, water and fractional protein accumulation to high temperature were monitored throughout grain filling in the heat- sensitive variety, and at maturity only in the heat-tolerant variety. Results are compared with controls maintained at 21/16°C day/night. As little as 1 day of heat treatment reduced kernel mass by 14% in the heat-sensitive variety (Oxley), but by only 5% in the heat-tolerant variety (Egret). In both varieties, the reduction of individual kernel mass due to high temperature increased linearly with increased duration of heat treatment, such that after the first day of heat stress, each additional day of treatment reduced mature individual kernel mass by a further 1.6%. For a given duration of heat treatment, the difference in response of the two varieties was constant (9%), indicating that the varietal difference in heat tolerance was maintained for both brief and extended periods of very high temperature. Responses of grain water content and fractional protein accumulation to duration of heat stress are discussed.

scholarly journals Effect of Heat Treatment on Physiological and Recovery Growth Status of Two Tomato Cultivars With Different Heat Susceptibility

2021 ◽  
Author(s):  
Sherzod Nigmatullayevich Rajametov ◽  
Eun Young Yang ◽  
Hyo Bong Jeong ◽  
Myeong Cheoul Cho ◽  
Soo-Young Chae ◽  
...  
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Stress Tolerance ◽  
Heat Tolerance ◽  
Fruit Set ◽  
Fruit Size ◽  
Seedling Stage ◽  
Screening Methods ◽  
Tomato Cultivars ◽  
Heat Tolerant

High temperature seriously effects on plant vegetative and reproductive development and reduces productivity of plants, while to increase crop yield is the main target in most crop heat stress tolerance improvement breeding programs, not just survival, under high temperature. Our aim was to compare temperature stress tolerance in two commercial tomato cultivars &ldquo;Dafnis&rdquo; (big fruit size) and &ldquo;Minichal&rdquo; (cherry fruit size) to develop early screening methods and find out survival rate and physiological responses of tomato cultivars on high temperature (40&deg;C and within 70% RH, day/night) in 4-5 true leaf seedling stage- (4LS) and identifies the linkage of heat tolerance with fruit set and leaf heat damage rates (LHD) in seedling stage with subsequent vegetative traits at recovery. Results showed that heat stress significantly affected on physiological-chemical and vegetative parameters of seedlings regardless of tomato cultivars. Survival and the threshold level of high temperature tolerance in the seedlings of cv. &ldquo;Dafnis&rdquo; and &ldquo;Minichal&rdquo; were identified on days 7 and 9, respectively. Our findings revealed that photosynthesis (PN, Gs, Ci, Tr) parameters were increased and CHL content persisted steady value in cv. &ldquo;Minichal&rdquo; during heat stress period, however EC and RPL rates were lower than cv. &ldquo;Dafnis&rdquo;. Heat stress reduced the SFW in both cultivars in seedling stage, but PH and RFW were significantly decreased in the heat tolerant cv. &ldquo;Minichal&rdquo;, whereas this parameters were not significantly ranged in the heat susceptible cv. &ldquo;Dafnis&rdquo;. Additionally, there no found linkage between vegetative parameters with decreasing of PN and CHL rates during HT of seedlings. In plants of cv. &ldquo;Minichal&rdquo; with LHD-25, 50 and 75% were no found significant differences in PH, whereas in cv. &ldquo;Dafnis&rdquo; significant differences were determined in plants with LHD-75%, and the significant differences in rates of SFW and RFW were observed in plants of cv. &ldquo;Dafnis&rdquo; having LHD-75% for 28 days of recovery at NT condition. Taken together, we concluded that heat stress affected on physiological parameters regardless of tolerance level, and to identify heat tolerant genotype in tomato breeding program, screening and selection genotypes have to be evaluated at the vegetative and reproductive stages with consideration fruit size types. Since we could not find linkage between heat tolerances in seedling stage with fruit set at the reproductive stage and fruit set cannot be used as a general predictor of heat tolerance.

scholarly journals Patatesin Kısa Süreli Kuraklık Uygulamasına Fizyolojik Tepkileri

2016 ◽  
Vol 4 (7) ◽  
pp. 618
Author(s):  
İlknur Tındaş ◽  
Ufuk Demirel
Keyword(s):  
Stomatal Conductance ◽  
Photosynthetic Rate ◽  
Transpiration Rate ◽  
Tuber Yield ◽  
Russet Burbank ◽  
Significant Decline ◽  
Proline Content ◽  
Drought Treatment ◽  
H2o2 Accumulation ◽  
Tuber Bulking

The study aimed to identify physiological response of potato to drought. For this aim, a drought experiment was carried out by using two different potato varieties, cv. Desiree and Russet Burbank, under environmentally controlled greenhouse conditions. Drought treatment was initiated at 45 days after emergence (early tuber bulking period) by withholding irrigation for 10 days. Physiological traits such as stomatal conductance, transpiration rate, photosynthetic rate, chlorophyll index, leaf temperature, proline content, malondialdehyde (MDA) accumulation and hydrogen peroxide (H2O2) accumulation, in addition, some yield components average tuber weight, number of tubers and plant tuber yield were evaluated in the study. While the first significant decline in stomatal conductance, transpiration rate, and photosynthetic rate of both varieties was occurred at the 5th day of withholding irrigation, the highest decline was observed at 9th and 10th days of withholding irrigation. Proline content in both varieties increased two times at 10th day of withholding irrigation, however, H2O2 accumulation was not changed significantly by drought treatment. Even though MDA accumulation was increased in both varieties under drought stress conditions, the increase was significant in Desiree whereas, it was not significant in Russet Burbank. In addition, while drought treatment did not change the plant tuber yield in both varieties, it caused to a significant decline in average tuber yield of Russet Burbank, being an important trait for marketable tuber yield.

Agronomic, physiological and molecular characterisation of rice mutants revealed the key role of reactive oxygen species and catalase in high-temperature stress tolerance

2020 ◽  
Vol 47 (5) ◽  
pp. 440 ◽  
Author(s):  
Syed Adeel Zafar ◽  
Amjad Hameed ◽  
Muhammad Ashraf ◽  
Abdus Salam Khan ◽  
Zia-ul- Qamar ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Heat Stress ◽  
High Temperature ◽  
Grain Yield ◽  
Temperature Stress ◽  
Heat Tolerance ◽  
High Temperature Stress ◽  
Oxygen Species ◽  
Selection Indices ◽  
Heat Tolerant

Climatic variations have increased the occurrence of heat stress during critical growth stages, which negatively affects grain yield in rice. Plants adapt to harsh environments, and particularly high-temperature stress, by regulating their physiological and biochemical processes, which are key tolerance mechanisms. The identification of heat-tolerant rice genotypes and reliable selection indices are crucial for rice improvement programs. Here, we evaluated the response of a rice mutant population for high-temperature stress at the seedling and reproductive stages based on agronomic, physiological and molecular indices. Estimates of variance components revealed significant differences (P &lt; 0.001) among genotypes, treatments and their interactions for almost all traits. The principal component analysis showed significant diversity among genotypes and traits under high-temperature stress. The mutant HTT-121 was identified as the most heat-tolerant mutant with higher grain yield, panicle fertility, cell membrane thermo-stability (CMTS) and antioxidant enzyme levels under heat stress. Various seedling-based morpho-physiological traits (leaf fresh weight, relative water contents, malondialdehyde, CMTS) and biochemical traits (superoxide dismutase, catalase and hydrogen peroxide) explained variations in grain yield that could be used as selection indices for heat tolerance in rice during early growth. Notably, heat-sensitive mutants accumulated reactive oxygen species, reduced catalase activity and upregulated OsSRFP1 expression under heat stress, suggesting their key roles in regulating heat tolerance in rice. The heat-tolerant mutants identified in this study could be used in breeding programs and to develop mapping populations to unravel the underlying genetic architecture for heat-stress adaptability.

scholarly journals Effect of Heat Stress on Growth and Physiological Traits of Alfalfa (Medicago sativa L.) and a Comprehensive Evaluation for Heat Tolerance

Agronomy ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 597 ◽  
Author(s):  
Misganaw Wassie ◽  
Weihong Zhang ◽  
Qiang Zhang ◽  
Kang Ji ◽  
Liang Chen
Keyword(s):  
Heat Stress ◽  
Medicago Sativa ◽  
Membership Function ◽  
Heat Tolerance ◽  
Comprehensive Evaluation ◽  
Soluble Sugar ◽  
Fluorescence Analysis ◽  
Relative Water ◽  
Medicago Sativa L ◽  
Heat Tolerant

Alfalfa (Medicago sativa L.) is a valuable forage legume, but its production is largely affected by high temperature. In this study, we investigated the effect of heat stress on 15 alfalfa cultivars to identify heat-tolerant and -sensitive cultivars. Seedlings were exposed to 38/35 °C day/night temperature for 7 days and various parameters were measured. Heat stress significantly reduced the biomass, relative water content (RWC), chlorophyll content, and increased the electrolyte leakage (EL) and malondialdehyde (MDA) content of heat-sensitive alfalfa cultivars. However, heat-tolerant cultivars showed higher soluble sugar (SS) and soluble protein (SP) content. The heat tolerance of each cultivar was comprehensively evaluated based on membership function value. Cultivars with higher mean membership function value of 0.86 (Bara310SC) and 0.80 (Magna995) were heat tolerant, and Gibraltar and WL712 with lower membership function value (0.24) were heat sensitive. The heat tolerance of the above four cultivars were further evaluated by chlorophyll a fluorescence analysis. Heat stress significantly affected the photosynthetic activity of heat-sensitive cultivars. The overall results indicate that Bara310SC and WL712 are heat-tolerant and heat-sensitive cultivars, respectively. This study provides basic information for understanding the effect of heat stress on growth and productivity of alfalfa.

scholarly journals Expression of Target Gene Hsp70 and Membrane Stability Determine Heat Tolerance in Chili Pepper

2015 ◽  
Vol 140 (2) ◽  
pp. 144-150 ◽  
Author(s):  
Magaji G. Usman ◽  
Mohd Y. Rafii ◽  
Mohd Razi Ismail ◽  
Mohammad Abdul Malek ◽  
Mohammad Abdul Latif
Keyword(s):  
Heat Stress ◽  
Heat Shock ◽  
Heat Tolerance ◽  
Membrane Integrity ◽  
Temperature Treatment ◽  
Chili Pepper ◽  
High Temperature Treatment ◽  
Experimental Plant ◽  
Membrane Thermostability ◽  
Heat Tolerant

Experiments were carried out to study the mechanisms for heat tolerance in chili pepper (Capsicum annuum). To assess these mechanisms, six genotypes were evaluated for cellular membrane thermostability (CMT) and for HSP70 gene expression. The plants were grown in an experimental plant growth chamber. The mean value of CMT indicates that membrane integrity was not damaged by the high temperature treatment (50 °C) in most of the genotypes. The genotypes were classified as follows: heat-tolerant (greater than 60%), moderately tolerant (30% to 60%), and susceptible (less than 30%). The heat-tolerant plants recorded the highest CMTs at 89.27%, 88.03%, and 85.10% for AVPP0702, AVPP0116, and AVPP9905, respectively, which might be the reason for the change in their cell membrane thermostability. AVPP9703 and AVPP0002 showed CMTs of 15.87% and 18.43%, which might indicate their sensitivity to heat stress. Heat shock protein 70 kDa was identified and found to be differentially expressed under the heat stress. Under heat stress, significantly increased levels of the HSP70 gene were detected after 2 h of temperature treatment at 42 °C, which indicated that this gene is quickly and sharply induced by heat shock. This was true for all genotypes tested, which were significantly up-regulated by more than 36.9-, 7.10-, 3.87-, and 3-fold for AVPP0702, AVPP0116, AVPP0002, and AVPP9703, respectively. The HSP70 gene was found to be significantly down-regulated under heat stress in ‘Kulai’. AVPP0702, AVPP9905, and AVPP0116 could be considered as heat-tolerant genotypes, whereas ‘Kulai’ and AVPP9703 were found to be heat-sensitive genotypes in this investigation.

scholarly journals Inheritance of Heat Tolerance during Reproductive Development in Snap Bean (Phaseolus vulgaris L.)

2005 ◽  
Vol 130 (5) ◽  
pp. 700-706 ◽  
Author(s):  
Katy M. Rainey ◽  
Phillip D. Griffiths
Keyword(s):  
Heat Stress ◽  
Common Bean ◽  
Heat Tolerance ◽  
Recessive Gene ◽  
Reproductive Development ◽  
Reproductive Organs ◽  
High Rate ◽  
Snap Bean ◽  
Heat Tolerant ◽  
Pod Number

The genetic basis for heat tolerance during reproductive development in snap bean was investigated in a heat-tolerant × heat-sensitive common bean cross. Parental, F1, F2, and backcross generations of a cross between the heat-tolerant snap bean breeding line `Cornell 503' and the heat-sensitive wax bean cultivar Majestic were grown in a high-temperature controlled environment (32 °C day/28 °C night), initiated prior to anthesis and continued through plant senescence. During flowering, individual plants of all generations were visually rated and scored for extent of abscission of reproductive organs. The distribution of abscission scores in segregating generations (F2 and backcrosses) indicated that a high rate of abscission in response to heat stress was controlled by a single recessive gene from `Majestic'. Abscission of reproductive organs is the primary determinant of yield under heat stress in many annual grain legumes; this is the first known report of single gene control of this reaction in common bean or similar legumes. Generation means analysis indicated that genetic variation among generations for pod number under heat stress was best explained by a six-parameter model that includes nonallelic interaction terms, perhaps the result of the hypothetical abscission gene interacting with other genes for pod number in the populations. A simple additive/dominance model accounted for genetic variance for seeds per pod. Dominance [h] and epistatic dominance × dominance [l] genetic parameters for yield components under high temperatures were the largest in magnitude. Results suggest `Cornell 503' can improve heat tolerance in sensitive cultivars, and heat tolerance in common bean may be influenced by major genes.

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