Photoperiodism of diapause induction in the mothThyrassia penangae: Measuring day length rather than night length

2016 ◽  
Author(s):  
Haimin He
Keyword(s):  
Diapause Induction ◽  
Day Length

A method for induction and quantification of diapause entry in the swede midge (Diptera: Cecidomyiidae)

2012 ◽  
Vol 144 (6) ◽  
pp. 792-800 ◽  
Author(s):  
Lauren E. Des Marteaux ◽  
Marc B. Habash ◽  
Jonathan M. Schmidt ◽  
Rebecca H. Hallett
Keyword(s):  
Diapause Induction ◽  
Day Length ◽  
Retrieval Method ◽  
Short Day ◽  
Long Day ◽  
Rearing Conditions ◽  
Swede Midge ◽  
Pupal Mortality ◽  
Contarinia Nasturtii ◽  
Cool Conditions

AbstractInduction of diapause under laboratory conditions is a valuable tool for the study of dormancy in economic pests such as the swede midge, Contarinia nasturtii Kieffer (Diptera: Cecidomyiidae). In the present study, diapause in larval swede midge was achieved via manipulation of rearing photoperiod and temperature. Frequency of diapause was assessed by sieve separation of diapause cocoons from pre-sifted peat substrate following emergence of pupating individuals. Mean diapause frequency for swede midge larvae reared under cool conditions with short day length or cool conditions with decreasing day lengths were 45.2% and 19.5%, respectively. Only 1.2% of swede midge reared under warm, long day length conditions entered diapause. A small percentage of larvae neither pupated nor entered diapause and remained in substrate long after other individuals had emerged as adults. This behaviour was more prevalent under cool and short or decreasing day length rearing conditions. Approximately 76% of the larvae used for diapause induction were recovered with the present larval and cocoon retrieval method, and premature (larval and pupal) mortality averaged 18.2%. Although diapause occurred in the present study, conditions resulting in higher diapause frequencies should be investigated and attempts should be made to improve survival and recovery of individuals.

scholarly journals The expression of circadian clock genes in Daphnia magna diapause

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Anke Schwarzenberger ◽  
Luxi Chen ◽  
Linda C. Weiss
Keyword(s):  
Gene Expression ◽  
Circadian Clock ◽  
Daphnia Magna ◽  
Seasonal Changes ◽  
Clock Genes ◽  
Diapause Induction ◽  
Day Length ◽  
Circadian Clock Genes ◽  
Short Days ◽  
Gene Expression Levels

AbstractDiapause is a mechanism necessary for survival in arthropods. Often diapause induction and resurrection is light-dependent and therefore dependent on the photoperiod length and on the number of consecutive short-days. In many organisms, including the microcrustacean Daphnia magna, one functional entity with the capacity to measure seasonal changes in day-length is the circadian clock. There is a long-standing discussion that the circadian clock also controls photoperiod-induced diapause. We tested this hypothesis in D. magna, an organism which goes into a state of suspended animation with the shortening of the photoperiod. We measured gene expression of clock genes in diapause-destined embryos of D. magna in the initiation, resting and resurrection phases and checked it against gene expression levels of continuously developing embryos. We demonstrate that some genes of the clock are differentially expressed during diapause induction but not during its maintenance. Furthermore, the photoreceptor gene cry2 and the clock-associated gene brp are highly expressed during induction and early diapause, probably in order to produce excess mRNA to prepare for immediate resurrection. After resurrection, both types of embryos show a similar pattern of gene expression during development. Our study contributes significantly to the understanding of the molecular basis of diapause induction, maintenance and termination.

Cyclamen Leaf Unfolding Rate in Response to Temperature

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 447d-447
Author(s):  
Meriam Karlsson ◽  
Jeffrey Werner
Keyword(s):  
Day Length ◽  
Leaf Number ◽  
Cyclamen Persicum ◽  
Flower Buds ◽  
Flower Bud ◽  
Leaf Unfolding ◽  
Significant Difference ◽  
Number Of Leaves ◽  
Growth Chambers ◽  
Response To Temperature

Nine-week-old plants of Cyclamen persicum `Miracle Salmon' were transplanted into 10-cm pots and placed in growth chambers at 8, 12, 16, 20, or 24 °C. The irradiance was 10 mol/day per m2 during a 16-h day length. After 8 weeks, the temperature was changed to 16 °C for all plants. Expanded leaves (1 cm or larger) were counted at weekly intervals for each plant. The rate of leaf unfolding increased with temperature to 20 °C. The fastest rate at 20 °C was 0.34 ± 0.05 leaf/day. Flower buds were visible 55 ± 7 days from start of temperature treatments (118 days from seeding) for the plants grown at 12, 16, or 20 °C. Flower buds appeared 60 ± 6.9 days from initiation of treatments for plants grown at 24 °C and 93 ± 8.9 days for cyclamens grown at 8 °C. Although there was no significant difference in rate of flower bud appearance for cyclamens grown at 12, 16, or 20 °C, the number of leaves, flowers, and flower buds varied significantly among all temperature treatments. Leaf number at flowering increased from 38 ± 4.7 for plants at 12 °C to 77 ± 8.3 at 24 °C. Flowers and flower buds increased from 18 ± 2.9 to 52 ± 11.0 as temperature increased from 12 to 24 °C. Plants grown at 8 °C had on average 6 ± 2 visible flower buds, but no open flowers at termination of the study (128 days from start of treatments).

scholarly journals Geographic Variation in Diapause Induction: The Grape Berry Moth (Lepidoptera: Tortricidae)

2010 ◽  
Vol 39 (6) ◽  
pp. 1751-1755 ◽  
Author(s):  
Jody Timer ◽  
Patrick C. Tobin ◽  
Michael C. Saunders
Keyword(s):  
Geographic Variation ◽  
Grape Berry ◽  
Diapause Induction

scholarly journals Cytochrome c Deficiency Differentially Affects the In Vivo Mitochondrial Electron Partitioning and Primary Metabolism Depending on the Photoperiod

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 444
Author(s):  
Igor Florez-Sarasa ◽  
Elina Welchen ◽  
Sofia Racca ◽  
Daniel H. Gonzalez ◽  
José G. Vallarino ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Tca Cycle ◽  
Day Length ◽  
Primary Metabolism ◽  
Stress Signaling ◽  
Alternative Pathways ◽  
Tca Cycle Intermediates ◽  
Growth Adaptation ◽  
Plant Respiration

Plant respiration provides metabolic flexibility under changing environmental conditions by modulating the activity of the nonphosphorylating alternative pathways from the mitochondrial electron transport chain, which bypass the main energy-producing components of the cytochrome oxidase pathway (COP). While adjustments in leaf primary metabolism induced by changes in day length are well studied, possible differences in the in vivo contribution of the COP and the alternative oxidase pathway (AOP) between different photoperiods remain unknown. In our study, in vivo electron partitioning between AOP and COP and expression analysis of respiratory components, photosynthesis, and the levels of primary metabolites were studied in leaves of wild-type (WT) plants and cytochrome c (CYTc) mutants, with reduced levels of COP components, under short- and long-day photoperiods. Our results clearly show that differences in AOP and COP in vivo activities between WT and cytc mutants depend on the photoperiod likely due to energy and stress signaling constraints. Parallel responses observed between in vivo respiratory activities, TCA cycle intermediates, amino acids, and stress signaling metabolites indicate the coordination of different pathways of primary metabolism to support growth adaptation under different photoperiods.

scholarly journals FLOWERING HTH1 is involved in CONSTANS-mediated flowering regulation in Arabidopsis

2019 ◽  
Vol 62 (1) ◽  
Author(s):  
Soon Ae Sim ◽  
Su Gyeong Woo ◽  
Dae Yeon Hwang ◽  
Jin-Hong Kim ◽  
Seung Sik Lee ◽  
...  
Keyword(s):  
Subcellular Location ◽  
Day Length ◽  
Interacting Protein ◽  
Photoperiodic Flowering ◽  
Family Protein ◽  
Flowering Regulation ◽  
Delayed Flowering ◽  
The Right ◽  
Two Hybrid ◽  
Repression Domain

Abstract Flowering at the right time is essential for maximum reproductive fitness. In Arabidopsis thaliana, the CONSTANS (CO) protein facilitates the transition from the vegetative phase to the reproductive phase under long-day conditions. The formation of heterodimeric complexes between CO and DNA binding domain-containing transcription factors is important for the induction of day length-dependent flowering. Here, we report a myb-like helix turn helix (HTH) transcriptional regulator family protein as a new modulator of floral transition, which we have named FLOWERING HTH1 (FHTH1). We isolated FHTH1 as a CO-interacting protein by a yeast two-hybrid screen using an Arabidopsis transcription factor library. Our analysis showed that FHTH1 presented in the nucleus and the FHTH1-CO complex was formed in the same subcellular location. We also observed the expression of a FHTH1:GUS construct in the leaf vasculature, where CO exists. Transgenic plants overexpressing FHTH1 fused with the plant-specific repression domain SRDX showed a delayed flowering phenotype in long days, resembling the phenotype of the co mutant. Our results suggest that FHTH1 may contribute to CO-mediated photoperiodic flowering regulation.

Plasticity of nutrient accumulation patterns in diapausing fall webworm pupae

2021 ◽  
pp. 1-8
Author(s):  
Lvquan Zhao ◽  
Wei Wang ◽  
Ying Qiu ◽  
Alex S. Torson
Keyword(s):  
The Body ◽  
Diapause Induction ◽  
Energy Reserve ◽  
Short Photoperiod ◽  
Induction Phase ◽  
Energy Reserves ◽  
Hyphantria Cunea ◽  
Survival And Reproduction ◽  
Fall Webworm ◽  
Diapause Incidence

Abstract The accumulation of nutrients during diapause preparation is crucial because any lack of nutrition will reduce the likelihood of insects completing diapause, thereby decreasing their chances of survival and reproduction. The fall webworm, Hyphantria cunea, diapause as overwintering pupae and their diapause incidence and diapause intensity are regulated by the photoperiod. In this study, we test the hypothesis that photoperiod influences energy reserve accumulation during diapause preparation in fall webworm. We found that the body size and mass, lipid and carbohydrate content of pupae with a short photoperiod during the diapause induction phase were significantly greater than those of pupae with a relatively short photoperiod, and the efficiency of converting digested food and ingested food into body matter was greater in the short-photoperiod diapause-destined larvae than the relatively short-photoperiod diapause-destined larvae. We also observed higher lipase and amylase activities in short-photoperiod diapause-destined larvae relative to the counterparts. However, no obvious difference was found in protein and protease in the pupae with a short photoperiod during the diapause induction phase and short-photoperiod diapause-destined larvae compared with the counterparts. Therefore, we conclude that the energy reserve patterns of diapausing fall webworm pupae are plastic and that short-photoperiod diapause-destined larvae increase their energy reserves by improving their feeding efficiency and increase their lipid and carbohydrate stores by increasing the lipase and amylase activities in the midgut.

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