(116) Floral Competence of Primocane-fruiting Blackberries Prime-Jan™ and Prime-Jim™ Grown at Three Temperature Regimes

We investigated the response of staminate and pistillate floral components of Prime-Jan™ and Prime-Jim™ primocane-fruiting blackberry (Rubus L. subgenus Rubus Watson) to three different growth chamber temperature regimes, 35.0/23.9 °C (HT), 29.4/18.3 °C (MT), and 23.9/12.8 °C (LT). Temperature was negatively related to flower size and morphological abnormalities in floral structures were evident in 41% and 98% of the MT- and HT-grown plants, respectively. The viability (stainability) of pollen from LT- and MT-grown Prime-Jan™ flowers exceeded 70%; that of Prime-Jim™ pollen was significantly reduced (<40%) by the MT regime. Pollen in-vitro germinability was negatively influenced by temperature but was unaffected by cultivar. LT-grown pollen held at 23.9 °C retained 63% of its original germinability over a 32-hour period; the germinability of LT-grown pollen held at 35.0 °C was decreased by 97% from its original level after 16 hours. Virtually all flowers cultured under HT conditions were male-sterile, exhibiting structural and/or sporogenous class abnormalities including petaloidy, malformation of tapetal cells, and microspores or failure of dehiscence. The duration of stigma receptivity, pistil density, and drupelet set were also negatively influenced by increasing temperature; values for these parameters of floral competency among control plants were reduced by 51%, 39%, and 76%, respectively, in flowers cultured under HT conditions. Herein, flowering and fruiting parameters and presumably the yield potential of Prime-Jan™ and Prime-Jim™ were adversely affected by increased temperature. However, assessment of their adaptative response to heat stress under field conditions awaits experimentation.

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Floral Competence of Primocane-fruiting Blackberries Prime-Jan and Prime-Jim Grown at Three Temperature Regimens

HortScience ◽

10.21273/hortsci.42.3.508 ◽

2007 ◽

Vol 42 (3) ◽

pp. 508-513 ◽

Cited By ~ 7

Author(s):

Michele A. Stanton ◽

Joseph C. Scheerens ◽

Richard C. Funt ◽

John R. Clark

Keyword(s):

Adaptive Response ◽

Yield Potential ◽

Male Sterile ◽

Stigma Receptivity ◽

Increased Temperature ◽

Tapetal Cells ◽

Pollen Germinability ◽

Chamber Temperature ◽

Useful Life

We investigated the responses of staminate and pistillate floral components of Prime-Jan and Prime-Jim primocane-fruiting blackberry (Rubus L. subgenus Rubus Watson) to three different growth chamber temperature regimens, 35.0/23.9 °C (HT), 29.4/18.3 °C (MT), and 23.9/12.8 °C (LT). Temperature was negatively related to flower size, and morphologically abnormal floral structures were evident in 41% and 98% of the MT- and HT-grown plants, respectively. Anthers of LT- and MT-grown plants dehisced. The viability of pollen (as deduced through staining) from Prime-Jan grown at LT or MT exceeded 70%, whereas that of Prime-Jim pollen was significantly reduced (<40%) by the MT regimen. In vitro pollen germinability (typically <50%) was negatively influenced by temperature but was unaffected by cultivar. Pollen useful life was diminished under HT conditions; LT-grown pollen held at 23.9 °C retained 63% of its original germinability over a 32-h period, while the germinability of that held at 35.0 °C for 16 hours decreased by 97%. Virtually all flowers cultured under HT conditions were male sterile, exhibiting structural or sporogenous class abnormalities including petaloidy and malformation of tapetal cells or microspores; HT anthers that were present, failed to dehisce. Stigma receptivity, pistil density, and drupelet set were also negatively influenced by increased temperature; values for these parameters of floral competency among control plants were reduced by 51%, 39%, and 76%, respectively, in flowers cultured under HT conditions. In this study, flowering and fruiting parameters, and presumably the yield potential of Prime-Jan and Prime-Jim, were adversely affected by increased temperature. However, their adaptive response to heat stress under field conditions awaits assessment.

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The Heat-Shock Response and Expression of Heat-Shock Proteins in Wheat Under Diurnal Heat Stress and Field Conditions

Functional Plant Biology ◽

10.1071/pp9940857 ◽

1994 ◽

Vol 21 (6) ◽

pp. 857 ◽

Cited By ~ 14

Author(s):

HT Nguyen ◽

CP Joshi ◽

N Klueva ◽

J Weng ◽

KL Hendershot ◽

...

Keyword(s):

Heat Stress ◽

Heat Shock ◽

Heat Shock Proteins ◽

Heat Tolerance ◽

Heat Shock Response ◽

Field Conditions ◽

Shock Response ◽

Heat Tolerant ◽

Shock Proteins

The occurrence of heat-shock proteins (HSPs) in response to high temperature stress is a universal phenomenon in higher plants and has been well documented. However, in agriculturally important species, less is known about the expression of HSPs under natural environments. A review of the heat-shock response in wheat (Triticum aestivum L.) is presented and recent results on the expression of wheat HSPs under diurnal stress and field conditions are reported. In the field experiment, flag leaf blade temperatures were obtained and leaf blades collected for northern blot analysis using HSP 16.9 cDNA as a probe. Temperatures of leaf blades ranged from 32 to 35�C under the tested field conditions at New Deal near Lubbock, Texas. Messenger RNAs encoding a major class of low molecular weight HSPs, HSP 16.9, were detected in all wheat genotypes examined. The results suggested that HSPs are synthesised in response to heat stress under agricultural production, and furthermore, that HSPs are produced in wheats differing in geographic background. In the controlled growth chamber experiment, HSP expression in two wheat cultivars, Mustang (heat tolerant) and Sturdy (heat susceptible) were analysed to determine if wheat genotypes differing in heat tolerance differ in in vitro HSP synthesis (translatable HSP mRNAs) under a chronic, diurnal heat-stress regime. Leaf tissues were collected from seedlings over a time-course and poly (A)+RNAs were isolated for in vitro translation and 2-D gel electrophoresis. The protein profiles shown in the 2-D gel analysis revealed that there were not only quantitative differences of individual HSPs between these two wheat lines, but also some unique HSPs which were only found in the heat tolerant line. This data provides evidence of a correlation between HSP synthesis and heat tolerance in wheat under a simulated field environment and suggests that further genetic analysis of HSPs in a segregating population is worthy of investigation. In conclusion, the results of this study provide an impetus for the investigation of the roles of HSP genes in heat tolerance in wheat.

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Effects of temperature and day length on cytoplasmic male sterility in cotton (Gossypium)

Australian Journal of Agricultural Research ◽

10.1071/ar9740443 ◽

1974 ◽

Vol 25 (3) ◽

pp. 443 ◽

Cited By ~ 11

Author(s):

DR Marshall ◽

NJ Thompson ◽

GH Nicholls ◽

CM Patrick

Keyword(s):

Male Sterility ◽

Cotton Seed ◽

Day Length ◽

Male Sterile ◽

Temperature Regimes ◽

Minor Degree ◽

Tropical Areas ◽

Effects Of Temperature ◽

Increasing Temperature ◽

B Lines

Temperature and day length were shown to affect, to a major and minor degree respectively, the expression of male sterility in G. hirsutum stocks carrying G. anomalum or G. arboreum cytoplasms. Generally, sterility increased with increasing temperature and day length. Day temperatures above 33°C were required for the consistent expression of male sterility in the sterile A lines tested, while the maintainer, or B, lines became completely sterile at day temperatures above 36�. It was concluded that while the production of hybrid cotton seed by means of the sterile A lines currently available may be feasible in some tropical areas of Australia, it would be desirable to develop genotypes in which the cytoplasmic male sterile character is stable under a much wider set of temperature regimes.

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Suppression of cellular immune response of chickens following in vivo and in vitro heat stress

Egyptian Journal of Animal Production ◽

10.21608/ejap.1996.115945 ◽

1996 ◽

Vol 33 (1) ◽

pp. 71-77

Keyword(s):

Immune Response ◽

Heat Stress ◽

Cellular Immune Response ◽

Cellular Immune

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Cytoprotective Effects of Taurine on Heat-Induced Bovine Mammary Epithelial Cells In Vitro

Cells ◽

10.3390/cells10020258 ◽

2021 ◽

Vol 10 (2) ◽

pp. 258

Author(s):

Hui Bai ◽

Tingting Li ◽

Yan Yu ◽

Ningcong Zhou ◽

Huijuan Kou ◽

...

Keyword(s):

T Cells ◽

Heat Stress ◽

Heat Shock ◽

T Antigen ◽

Mammary Epithelial ◽

Epithelial Cell Line ◽

Heat Shock Factor 1 ◽

Alveolar Cells ◽

Bovine Mammary Epithelial Cells

It is a widely known that heat stress induces a reduction in milk production in cows and impairs their overall health. Studies have shown that taurine protects tissues and organs under heat stress. However, there have yet to be studies showing the functions of taurine in mammary alveolar cells-large T antigen (MAC-T) (a bovine mammary epithelial cell line) cells under heat shock. Therefore, different concentrations of taurine (10 mM, 50 mM, and 100 mM) were tested to determine the effects on heat-induced MAC-T cells. The results showed that taurine protected the cells against heat-induced damage as shown by morphological observations in conjunction with suppressed the translocation and expression of heat shock factor 1 (HSF1). Moreover, taurine not only reversed the decline in antioxidase (superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX)) activities but also attenuated the accumulation of malondialdehyde (MDA). Meanwhile, mitochondrial damage (morphology and complex I activity) resulting from heat exposure was mitigated. Taurine also alleviated the rates of cell apoptosis and markedly depressed the mRNA expressions of BCL2 associated X, apoptosis regulator (BAX) and caspase3. Furthermore, compared with the heat stress (HS) group, the protein levels of caspase3 and cleaved caspase3 were decreased in all taurine groups. In summary, taurine improves the antioxidant and anti-apoptosis ability of MAC-T cells thereby alleviates damage of cells due to heat insults.

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Heat stress lowers yields, alters nutrient uptake and changes seed quality in quinoa grown under Mediterranean field conditions

Journal of Agronomy and Crop Science ◽

10.1111/jac.12495 ◽

2021 ◽

Author(s):

Javier Matías ◽

María José Rodríguez ◽

Verónica Cruz ◽

Patricia Calvo ◽

María Reguera

Keyword(s):

Heat Stress ◽

Nutrient Uptake ◽

Seed Quality ◽

Field Conditions

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Assessing the Potential of Extra-Early Maturing Landraces for Improving Tolerance to Drought, Heat, and Both Combined Stresses in Maize

Agronomy ◽

10.3390/agronomy10030318 ◽

2020 ◽

Vol 10 (3) ◽

pp. 318 ◽

Cited By ~ 5

Author(s):

Charles Nelimor ◽

Baffour Badu-Apraku ◽

Antonia Yarney Tetteh ◽

Ana Luísa Garcia-Oliveira ◽

Assanvo Simon-Pierre N’guetta

Keyword(s):

Heat Stress ◽

Abiotic Stress ◽

Field Experiments ◽

Yield Loss ◽

Yield Potential ◽

Genetic Base ◽

Maize Varieties ◽

Early Maturing ◽

Maize Landraces ◽

Landrace Accessions

Maize landrace accessions constitute an invaluable gene pool of unexplored alleles that can be harnessed to mitigate the challenges of the narrowing genetic base, declined genetic gains, and reduced resilience to abiotic stress in modern varieties developed from repeated recycling of few superior breeding lines. The objective of this study was to identify extra-early maize landraces that express tolerance to drought and/or heat stress and maintain high grain yield (GY) with other desirable agronomic/morpho-physiological traits. Field experiments were carried out over two years on 66 extra-early maturing maize landraces and six drought and/or heat-tolerant populations under drought stress (DS), heat stress (HS), combined both stresses (DSHS), and non-stress (NS) conditions as a control. Wide variations were observed across the accessions for measured traits under each stress, demonstrating the existence of substantial natural variation for tolerance to the abiotic stresses in the maize accessions. Performance under DS was predictive of yield potential under DSHS, but tolerance to HS was independent of tolerance to DS and DSHS. The accessions displayed greater tolerance to HS (23% yield loss) relative to DS (49% yield loss) and DSHS (yield loss = 58%). Accessions TZm-1162, TZm-1167, TZm-1472, and TZm-1508 showed particularly good adaptation to the three stresses. These landrace accessions should be further explored to identify the genes underlying their high tolerance and they could be exploited in maize breeding as a resource for broadening the genetic base and increasing the abiotic stress resilience of elite maize varieties.

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Effects of Temperature on Leaf Expansion in Sunflower

Functional Plant Biology ◽

10.1071/pp9820209 ◽

1982 ◽

Vol 9 (2) ◽

pp. 209 ◽

Cited By ~ 19

Author(s):

HM Rawson ◽

JH Hindmarsh

Keyword(s):

Field Studies ◽

Leaf Expansion ◽

Photon Flux ◽

Photon Flux Density ◽

Leaf Position ◽

Leaf Emergence ◽

Temperature Regimes ◽

Effects Of Temperature ◽

Increasing Temperature ◽

Relative Change

Five commercial cultivars of sunflower were grown in cabinets at three temperature regimes, 32/22, 27/17 and 22/12°C, and with 15-h and 11-h photoperiods, and expansion of leaves 5-15 was followed. Leaves appeared faster with increasing temperature (0.022 leaves day-1 °C-1) and with increasing daylength. Areas of individual leaves increased linearly up the plant profile and, although final area per leaf (Amax) decreased with increasing temperature, the relative change was similar for each leaf position. Cultivars maintained their ranking for Amax across temperatures, and these rankings agreed with those in previous field studies. Within each temperature regime, both the expansion rate of leaves and the duration of expansion increased with leaf position. As temperature increased, leaves grew for shorter periods with a change of 1.04 days °C-1, but under the photon flux density used (500 �mol m-2 s-1, or about 25% full sunlight) expansion rates were greatest at the lowest temperature. Expansion rates were only one-third of those in field studies at comparable temperatures, but durations were similar. Cultivars that achieved the largest Amax did so via faster rates of expansion and not via longer durations: only one cultivar differed from the mean (20 days) duration of leaf expansion. All cultivars reached floral initiation progressively earlier with extension of photoperiod from 10 to 15 h, with the change for the most sensitive cultivars being 8 days and for the least sensitive 5 days. Rates of leaf emergence were linked with this sensitivity.

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