Regeneration and Endogenous Phytohormone Responses to High-Temperature Stress Drive Recruitment Success in Hemiepiphytic Fig Species

Exposure to high-temperature stress (HTS) during early regeneration in plants can profoundly shape seed germination, seedling growth, and development, thereby providing stress resilience. In this study, we assessed how the timing of HTS, which was implemented as 8 h in 40°C, could affect the early regeneration stages and phytohormone concentration of four hemiepiphytic (Hs) and four non-hemiepiphytic (NHs) Ficus species. Their seed germination, seedling emergence, and seedling survival probabilities and the concentrations of three endogenous phytohormones, abscisic acid (ABA), indole-3-acetic acid (IAA), and salicylic acid (SA) were assessed after HTS imposed during imbibition, germination, and emergence. In both groups, seeds were more sensitive to HTS in the early regeneration process; stress experienced during imbibition affected emergence and survival, and stress experienced during germination affected subsequent emergence. There was no effect from HTS when received after emergence. Survival was highest in hemiepiphytes regardless of the HTS treatment. The phytohormones showed growth form- and regeneration stage-specific responses to HTS. Due to the HTS treatment, both SA and ABA levels decreased in non-hemiepiphytes during imbibition and germination; during germination, IAA increased in hemiepiphytes but was reduced in non-hemiepiphytes. Due to the HTS treatment experienced during emergence ABA and IAA concentrations were greater for hemiepiphytes but an opposite effect was seen in the two growth forms for the SA concentration. Our study showed that the two growth forms have different strategies for regulating their growth and development in the early regeneration stages in order to respond to HTS. The ability to respond to HTS is an ecologically important functional trait that allows plant species to appropriately time their seed germination and seedling development. Flexibility in modulating species regeneration in response to HTS in these subtropical and tropical Ficus species could provide greater community resilience under climate change.

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Emergence of seedlings from different depths following high temperature stress

The Journal of Agricultural Science ◽

10.1017/s0021859600052746 ◽

1975 ◽

Vol 84 (3) ◽

pp. 525-528 ◽

Cited By ~ 8

Author(s):

I. C. Onwueme ◽

S. A. Adegoroye

Keyword(s):

Heat Stress ◽

High Temperature ◽

Temperature Stress ◽

Seedling Emergence ◽

High Temperature Stress ◽

Moist Soil ◽

Different Depths

SUMMARYSeeds of Amaranthus, melon, cowpea and tomato were planted in moist soil at 1, 4 or 7·5 cm depth and subjected to a heat stress of 45 °C for 10 h on the day of sowing (day 0), 1 day after sowing or 2 days after sowing. Seedling emergence was retarded by heat stress, the most drastic retardation being due to heat stress on day 1 for cowpea and tomato, day 2 for melon, and day 0 for Amaranthus. Emergence also decreased with increasing depth of sowing. The interaction of depth and heat stress was also significant in all cases, such that the delay in emergence due to heat stress tended to be greater with increasing depth of sowing. The agronomic significance of the results is discussed.

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Effects of salicylic acid on seed germination and biochemical properties in seedlings ofLactuca sativaL. under high temperature stress

Acta Horticulturae ◽

10.17660/actahortic.2016.1123.16 ◽

2016 ◽

pp. 117-122

Author(s):

J.T. Gu ◽

J. Kang ◽

J. Lian ◽

X.C. Zhang ◽

T.T. Zhang ◽

...

Keyword(s):

Salicylic Acid ◽

High Temperature ◽

Seed Germination ◽

Temperature Stress ◽

High Temperature Stress ◽

Biochemical Properties

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Untangling the Influence of Heat Stress on Crop Phenology, Seed Set, Seed Weight, and Germination in Field Pea (Pisum sativum L.)

Frontiers in Plant Science ◽

10.3389/fpls.2021.635868 ◽

2021 ◽

Vol 12 ◽

Author(s):

Amrit Lamichaney ◽

Ashok K. Parihar ◽

Kali K. Hazra ◽

Girish P. Dixit ◽

Pradip K. Katiyar ◽

...

Keyword(s):

Heat Stress ◽

High Temperature ◽

Seed Germination ◽

Temperature Stress ◽

Seed Weight ◽

Seed Set ◽

High Temperature Stress ◽

Field Pea ◽

Maximum Temperature ◽

100 Seed Weight

The apparent climatic extremes affect the growth and developmental process of cool-season grain legumes, especially the high-temperature stress. The present study aimed to investigate the impacts of high-temperature stress on crop phenology, seed set, and seed quality parameters, which are still uncertain in tropical environments. Therefore, a panel of 150 field pea genotypes, grouped as early (n = 88) and late (n = 62) maturing, were exposed to high-temperature environments following staggered sowing [normal sowing time or non-heat stress environment (NHSE); moderately late sowing (15 days after normal sowing) or heat stress environment-I (HSE-I); and very-late sowing (30 days after normal sowing) or HSE-II]. The average maximum temperature during flowering was about 22.5 ± 0.17°C for NHSE and increased to 25.9 ± 0.11°C and 30.6 ± 0.19°C in HSE-I and HSE-II, respectively. The average maximum temperature during the reproductive period (RP) (flowering to maturity) was in the order HSE-II (33.3 ± 0.03°C) > HSE-I (30.5 ± 0.10°C) > NHSE (27.3 ± 0.10°C). The high-temperature stress reduced the seed yield (24–60%) and seed germination (4–8%) with a prominent effect on long-duration genotypes. The maximum reduction in seed germination (>15%) was observed in HSE-II for genotypes with >115 days maturity duration, which was primarily attributed to higher ambient maximum temperature during the RP. Under HSEs, the reduction in the RP in early- and late-maturing genotypes was 13–23 and 18–33%, suggesting forced maturity for long-duration genotypes under late-sown conditions. The cumulative growing degree days at different crop stages had significant associations (p < 0.001) with seed germination in both early- and late-maturing genotypes; and the results further demonstrate that an extended vegetative period could enhance the 100-seed weight and seed germination. Reduction in seed set (7–14%) and 100-seed weight (6–16%) was observed under HSEs, particularly in HSE-II. The positive associations of 100-seed weight were observed with seed germination and germination rate in the late-maturing genotypes, whereas in early-maturing genotypes, a negative association was observed for 100-seed weight and germination rate. The GGE biplot analysis identified IPFD 11-5, Pant P-72, P-1544-1, and HUDP 11 as superior genotypes, as they possess an ability to produce more viable seeds under heat stress conditions. Such genotypes will be useful in developing field pea varieties for quality seed production under the high-temperature environments.

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The effect of time of harvest, irrigation treatments and kilning temperature on Eucalyptus globulus seed germination response to high temperature stress

Seed Science and Technology ◽

10.15258/sst.2012.40.2.04 ◽

2012 ◽

Vol 40 (2) ◽

pp. 185-199 ◽

Cited By ~ 1

Author(s):

K.D. Rix ◽

A.J. Gracie ◽

B.M. Potts ◽

P.H. Brown ◽

C.J. Spurr ◽

...

Keyword(s):

High Temperature ◽

Seed Germination ◽

Temperature Stress ◽

Eucalyptus Globulus ◽

High Temperature Stress ◽

Germination Response ◽

Irrigation Treatments ◽

Time Of Harvest

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Effects of elevated CO2and temperature on seed quality

The Journal of Agricultural Science ◽

10.1017/s0021859612000263 ◽

2012 ◽

Vol 151 (2) ◽

pp. 154-162 ◽

Cited By ~ 26

Author(s):

J. G. HAMPTON ◽

B. BOELT ◽

M. P. ROLSTON ◽

T. G. CHASTAIN

Keyword(s):

High Temperature ◽

Seed Germination ◽

Temperature Stress ◽

Crop Production ◽

Seed Quality ◽

Environmental Changes ◽

Crop Yields ◽

Seed Mass ◽

High Temperature Stress ◽

Seed Vigour

SUMMARYSuccessful crop production depends initially on the availability of high-quality seed. By 2050 global climate change will have influenced crop yields, but will these changes affect seed quality? The present review examines the effects of elevated carbon dioxide (CO2) and temperature during seed production on three seed quality components: seed mass, germination and seed vigour.In response to elevated CO2, seed mass has been reported to both increase and decrease in C3plants, but not change in C4plants. Increases are greater in legumes than non-legumes, and there is considerable variation among species. Seed mass increases may result in a decrease of seed nitrogen (N) concentration in non-legumes. Increasing temperature may decrease seed mass because of an accelerated growth rate and reduced seed filling duration, but lower seed mass does not necessarily reduce seed germination or vigour.Like seed mass, reported seed germination responses to elevated CO2have been variable. The reported changes in seed C/N ratio can decrease seed protein content which may eventually lead to reduced viability. Conversely, increased ethylene production may stimulate germination in some species. High-temperature stress before developing seeds reach physiological maturity (PM) can reduce germination by inhibiting the ability of the plant to supply the assimilates necessary to synthesize the storage compounds required for germination.Nothing is known concerning the effects of elevated CO2on seed vigour. However, seed vigour can be reduced by high-temperature stress both before and after PM. High temperatures induce or increase the physiological deterioration of seeds. Limited evidence suggests that only short periods of high-temperature stress at critical seed development stages are required to reduce seed vigour, but further research is required.The predicted environmental changes will lead to losses of seed quality, particularly for seed vigour and possibly germination. The seed industry will need to consider management changes to minimize the risk of this occurring.

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Dampak Suhu Tinggi terhadap Pertumbuhan dan Hasil Tanaman Padi

Jurnal Agronomi Indonesia (Indonesian Journal of Agronomy) ◽

10.24831/jai.v47i3.24892 ◽

2020 ◽

Vol 47 (3) ◽

pp. 248-254

Author(s):

Usamah Jaisyurahman ◽

Desta Wirnas ◽

Trikoesoemaningtyas ◽

Dan Heni Purnamawati

Keyword(s):

High Temperature ◽

Temperature Stress ◽

Growth And Development ◽

Rice Variety ◽

Grain Filling ◽

High Temperature Stress ◽

High Temperature Treatment ◽

Tolerance Index ◽

Grain Number ◽

Grain Number Per Panicle

Global warming becomes a pressure in food production sustainability because it affected crop growth and development. The purpose of this study was to obtain information on the effect of high-temperature stress on the growth and development phase of rice and to evaluate the genotype for tolerance to high-temperature stress. Two environment conditions were used in the field and greenhouse of IPB Cikabayan experimental field, IPB University from August 2016 until February 2017. The study used varieties of IPB 4S, IPB 6R, Mekongga, and Situ Patenggang. High-temperature treatment was done by transferring the rice plants to the greenhouse at 50 days after transplanting. Observations were made on the generative phase in two different environmental conditions. The results showed that the total tillers number, filled grain number per panicle, unfilled grain number per panicle, total grain number per panicle, grain filling rate, percentage of filled grain and filled grain weight per plant had different responses among rice genotypes due to high-temperature stress. High-temperature decreased pollen fertility in all genotypes, which classified IPB 4S as a sensitive genotype and Mekongga as a tolerant genotype. This information could be useful for development and improving rice variety to anticipate high-temperature stress. Keywords: Climate change, fertility, pollen, stress tolerance index

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Preventing Thermodormancy in Lettuce Seeds by Fluridone Treatment

HortScience ◽

10.21273/hortsci.30.4.777b ◽

1995 ◽

Vol 30 (4) ◽

pp. 777B-777

Author(s):

Anwar A Khan

Keyword(s):

Abscisic Acid ◽

High Temperature ◽

Temperature Stress ◽

Seedling Emergence ◽

High Temperature Stress ◽

Lettuce Seeds ◽

Grand Rapids ◽

Supraoptimal Temperatures

Fluridone (FL), a catotenoid biosynthesis inhibitory herbicide, prevented supraoptimal temperatures from inducing thermodormancy in seeds and permitted seedling emergence in several lettuce cultivars. A 48-h dark soak at 35C with 23 μM FL completely prevented the induction of thermodormancy in `Mesa 659' and `Emperor' lettuce seeds as more than 90% of the seeds germinated on transfer to water in darkness at 25C. Abscisic acid (100 μM) applied with FL did not prevent FL from acting. Dormancy was released completely in the naturally dormant `Garnet' and `Grand Rapids' lettuce seeds at 25C in darkness by 1 μM FL. FL applied following thermodormancy induction at 35C in `Mesa 659' lettuce seeds had little effect on releasing the induced dormancy. A 2-h presoak of `Mesa 659' lettuce seeds with 0.47 μM FL followed by washing, drying, and sowing in a peatlite mix at 25C/35C (12 h/12 h), permitted 80% seedling emergence. Higher concentrations resulted in the emergence of albino seedlings. Similar results were obtained with seeds of other lettuce cultivars (`Prizehead', `Emperor', `Ithaca', and `Empress'). A 6-h matriconditioning (MC) (A.A. Khan, Hort. Rev. 13:131–181, 92) of `Mesa 659' lettuce seeds in 7.5 μM FL enhanced the emergence to a greater extent than by MC alone at 25C/35C. The FL procedure in alleviating high-temperature stress in lettuce and other seeds is being tested further.

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Effects of Pre-sowing High Temperature Stress on Seedling Emergence and Yield of Seed Cotton

Experimental Agriculture ◽

10.1017/s0014479700023619 ◽

1973 ◽

Vol 9 (1) ◽

pp. 9-14 ◽

Cited By ~ 2

Author(s):

Riaz A. Khan ◽

S. Ahmad ◽

S. Hussain

Keyword(s):

High Temperature ◽

Temperature Stress ◽

Thermal Injury ◽

Seedling Emergence ◽

High Temperature Stress ◽

Seed Cotton ◽

Subsequent Performance ◽

Cotton Plants

SUMMARYThe seed of American Cotton, Var. 134, was stressed at 50, 60, 70, 80 and 90°C for 24 or 48 hours before seeding. Stresses at 50 to 70°C had a stimulatory effect on seedling emergence and subsequent performance of the cotton plants, but higher temperatures caused thermal injury or killed the seed.

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