Flowering responses to vernalization and photoperiod in annual medics (Medicago spp.)

1975 ◽  
Vol 26 (5) ◽  
pp. 831 ◽  
Author(s):  
NM Clarkson ◽  
JS Russell
Keyword(s):  
High Temperature ◽  
Flowering Time ◽  
Vernalization Requirement ◽  
Vernalization Response ◽  
The Third ◽  
Long Day ◽  
Temperature Requirement ◽  
New Finding ◽  
Annual Medics

The three processes thought to control flowering times in annual medics (Medicago spp.) are a vernalization requirement, a long day requirement and a high temperature requirement. To examine the first two processes, seed of seven cultivars of six species was vernalized at 1�C for periods of up to 11 weeks, then grown to flowering under three photoperiods in a glasshouse. To study the third process, the time to flowering of selected treatments from this expcrirnent was compared with flowering data from plants grown in the field at a range of temperatures lower than in the glasshouse. Vernalization and photoperiod caused large shifts in flowering time but the effects varied widely among species. M. scutellata was almost insensitive to both factors but in M. rugosa acceleration of up to 91 days was caused by treatment. Vernalization and short dark periods were additive in accelerating flowering and largely able to substitute for each other. Species flowered almost simultaneously when given their most favourable conditions for flowering. High temperature accelerated flowering in all species studied. However, in species other than M. scutellata it was necessary for a vernalization requirement to be met before this effect was observed. A new finding was that the vernalization response in M. truncatula and M. littoralis was largely reversed after more than 7 weeks of vernalization. This suggests a previously undetected flowering mechanism in these species.

scholarly journals The third form electric organ discharge of electric eels

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jun Xu ◽  
Xiang Cui ◽  
Huiyuan Zhang
Keyword(s):  
High Voltage ◽  
Low Voltage ◽  
Electric Organ Discharge ◽  
Electric Organ ◽  
The Third ◽  
Electric Organs ◽  
Electric Eel ◽  
New Finding ◽  
Discharge Behavior ◽  
Unique Species

AbstractThe electric eel is a unique species that has evolved three electric organs. Since the 1950s, electric eels have generally been assumed to use these three organs to generate two forms of electric organ discharge (EOD): high-voltage EOD for predation and defense and low-voltage EOD for electrolocation and communication. However, why electric eels evolved three electric organs to generate two forms of EOD and how these three organs work together to generate these two forms of EOD have not been clear until now. Here, we present the third form of independent EOD of electric eels: middle-voltage EOD. We suggest that every form of EOD is generated by one electric organ independently and reveal the typical discharge order of the three electric organs. We also discuss hybrid EODs, which are combinations of these three independent EODs. This new finding indicates that the electric eel discharge behavior and physiology and the evolutionary purpose of the three electric organs are more complex than previously assumed. The purpose of the middle-voltage EOD still requires clarification.

Host choice, settling and folding leaf behaviors of the larval rice leaf folder under heat stress

2016 ◽  
Vol 106 (6) ◽  
pp. 809-817 ◽  
Author(s):  
M.A. Bodlah ◽  
A.-X. Zhu ◽  
X.-D. Liu
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Host Choice ◽  
Cnaphalocrocis Medinalis ◽  
Behavioral Traits ◽  
The Third ◽  
Rice Leaf ◽  
Rice Leaf Folder ◽  
Extreme High Temperature ◽  
Third Instar Larvae

AbstractExtreme high-temperature events are the key factor to determine population dynamics of the rice leaf folder,Cnaphalocrocis medinalis(Guenée), in summer. Although we know that adult of this insect can migrate to avoid heat stress, the behavioral response of larva to high temperature is still unclear. Therefore, impacts of high temperature on behavioral traits ofC. medinalisincluding host choice, settling and folding leaf were observed. The results revealed that these behavioral traits were clearly influenced by high temperature. The larvae preferred maize leaves rather than rice and wheat at normal temperature of 27°C, but larvae experienced a higher temperature of 37 or 40°C for 4 h preferred rice leaves rather than maize and wheat. Capacity of young larvae to find host leaves or settle on the upper surface of leaves significantly reduced when they were treated by high temperature. High temperature of 40°C reduced the leaf-folding capacity of the third instar larvae, but no effects were observed on the fourth and fifth instar larvae. Short-term heat acclimation could not improve the capacity of the third instar larvae to make leaf fold under 40°C.

scholarly journals The crystal structure of Mycobacterium tuberculosis high-temperature requirement A protein reveals an autoregulatory mechanism

2018 ◽  
Vol 74 (12) ◽  
pp. 803-809
Author(s):  
Arvind Kumar Gupta ◽  
Debashree Behera ◽  
Balasubramanian Gopal
Keyword(s):  
Crystal Structure ◽  
Mycobacterium Tuberculosis ◽  
High Temperature ◽  
Catalytic Domain ◽  
Pdz Domain ◽  
Regulatory Pathways ◽  
Inactive Conformation ◽  
Temperature Requirement ◽  
Autoregulatory Mechanism

The crystal structure of Mycobacterium tuberculosis high-temperature requirement A (HtrA) protein was determined at 1.83 Å resolution. This membrane-associated protease is essential for the survival of M. tuberculosis. The crystal structure reveals that interactions between the PDZ domain and the catalytic domain in HtrA lead to an inactive conformation. This finding is consistent with its proposed role as a regulatory protease that is conditionally activated upon appropriate environmental triggers. The structure provides a basis for directed studies to evaluate the role of this essential protein and the regulatory pathways that are influenced by this protease.

Distribution and variability in development of the genus Trigonella in Asia Minor and its possible use in Australian environments

1981 ◽  
Vol 32 (5) ◽  
pp. 793 ◽  
Author(s):  
GM Halloran ◽  
AL Pennell
Keyword(s):  
Flowering Time ◽  
Subterranean Clover ◽  
Asia Minor ◽  
Vernalization Response ◽  
Developmental Patterns ◽  
Late Flowering ◽  
Commercial Cultivars ◽  
Wide Variability ◽  
Upper Level ◽  
Autumn Sowing

A number of Trigonella species were examined for their possible use in Australian environments. There was a wide variability in flowering time in Trigonella. Under an outdoor autumn sowing the range in flowering time was comparable with that found within early- to late-flowering Australian commercial cultivars of subterranean clover. The upper level of vernalization response was much lower in Trigonella than in subterranean clover. Good prospects exist within Trigonella for selecting genotypes with close adaptation (in terms of appropriate developmental patterns) to a range of Australian environments, a range at least as wide as that now occupied by subterranean clover and annual medic.

scholarly journals High-Temperature Requirement A1 (Htra1) - A Novel Regulator of Canonical Wnt Signaling

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Oriane Globus ◽  
Tamar Evron ◽  
Michal Caspi ◽  
Ronen Siman-Tov ◽  
Rina Rosin-Arbesfeld
Keyword(s):  
High Temperature ◽  
Wnt Signaling ◽  
Canonical Wnt Signaling ◽  
Temperature Requirement ◽  
Canonical Wnt

The crystal structure of an essential high-temperature requirement protein HtrA1 (Rv1223) from Mycobacterium tuberculosis reveals its unique features

2018 ◽  
Vol 74 (9) ◽  
pp. 906-921 ◽  
Author(s):  
Khundrakpam Herojit Singh ◽  
Savita Yadav ◽  
Deepak Kumar ◽  
Bichitra Kumar Biswal
Keyword(s):  
Crystal Structure ◽  
Amino Acids ◽  
Mycobacterium Tuberculosis ◽  
High Temperature ◽  
Protein Quality ◽  
Pdz Domain ◽  
Survival Strategies ◽  
Dimensional Structure ◽  
Protease Domain ◽  
Temperature Requirement

High-temperature requirement A (HtrA) proteins, which are members of the heat-shock-induced serine protease family, are involved in extracytoplasmic protein quality control and bacterial survival strategies under stress conditions, and are associated with the virulence of several pathogens; they are therefore major drug targets. Mycobacterium tuberculosis possesses three putative HtrAs: HtrA1 (Rv1223), HtrA2 (Rv0983) and HtrA3 (Rv0125). Each has a cytoplasmic region, a transmembrane helix and a periplasmic region. Here, the crystal structure of the periplasmic region consisting of a protease domain (PD) and a PDZ domain from an M. tuberculosis HtrA1 mutant (mHtrA1S387A) is reported at 2.7 Å resolution. Although the mHtrA1S387A PD shows structural features similar to those of other HtrAs, its loops, particularly L3 and LA, display different conformations. Loop L3 communicates between the PDs of the trimer and the PDZ domains and undergoes a transition from an active to an inactive conformation, as reported for an equivalent HtrA (DegS). Loop LA, which is responsible for higher oligomer formation owing to its length (50 amino acids) in DegP, is very short in mHtrA1S387A (five amino acids), as in mHtrA2 (also five amino acids), and therefore lacks essential interactions for the formation of higher oligomers. Notably, a well ordered loop known as the insertion clamp in the PDZ domain interacts with the protease domain of the adjacent molecule, which possibly aids in the stabilization of a trimeric functional unit of this enzyme. The three-dimensional structure of mHtrA1S387A presented here will be useful in the design of enzyme-specific antituberculosis inhibitors.

Tagesperiodische antagonistische Schwankungen der Blauviolett- und Gelbrot-Empfindlichkeit als Grundlage der photoperiodischen Diapause-Induktion bei Pieris brassicae

1960 ◽  
Vol 15 (4) ◽  
pp. 205-213 ◽  
Author(s):  
Erwin Bünning ◽  
Gabriele Joerrens
Keyword(s):  
Dark Period ◽  
Red Light ◽  
Pieris Brassicae ◽  
Light Period ◽  
Measuring Process ◽  
The Third ◽  
Long Day ◽  
Critical Daylength ◽  
Qualitative Responses ◽  
Short Days

In Pieris brassicae, diapause is inhibited if long-day conditions are imposed during and immediately after the third molting. The critical daylength is approximately 14 hours. Under short-day conditions with a main light period of 6 or 12 hours’ duration, supplementary light given in the period from 14 to 16 hours after the beginning of the main light period will inhibit diapause. In contrast to this effect of late exposures to light, light given from 1 to 12 hours after the beginning of the main light period promotes diapause. Experiments with extremely long light periods (10—35 hours), but always with a dark period of 10 hours, show that these diurnal fluctuations in quantitative and qualitative responses to light can continue endogenously for several days. Thus, this time-measuring process operates through the mechanism of endogenous diurnal oscillations in just the same way as do photoperiodic reactions in plants.The inhibition of diapause by light in the second half of the diurnal oscillation (under long days or by light interruptions in the dark period) and the promotion by light in the first half (under short days) occur only with light of short wavelengths: ultraviolet, violet, and blue up to about 550 mμ. Yellow and red light act in the opposite fashion, giving diapause inhibition in the first half of the cycle and promotion in the second half. In white light the violet reaction predominates, so that diapause is promoted by short days and inhibited by long days.

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