Demyristoylation of the Cytoplasmic Redox Protein Trx-h2 Is Critical for Inducing a Rapid Cold Stress Response in Plants

In Arabidopsis, the cytosolic redox protein thioredoxin h2 (Trx-h2) is anchored to the cytoplasmic endomembrane through the myristoylated second glycine residue (Gly2). However, under cold stress, the cytosolic Trx-h2 is rapidly translocated to the nucleus, where it interacts with and reduces the cold-responsive C-repeat-binding factors (CBFs), thus activating cold-responsive (COR) genes. In this study, we investigated the significance of fatty acid modification of Trx-h2 under cold conditions by generating transgenic Arabidopsis lines in the trx-h2 mutant background, overexpressing Trx-h2 (Trx-h2OE/trx-h2) and its point mutation variant Trx-h2(G/A) [Trx-h2(G/A)OE/trx-h2], in which the Gly2 was replaced by alanine (Ala). Due to the lack of Gly2, Trx-h2(G/A) was incapable of myristoylation, and a part of Trx-h2(G/A) localized to the nucleus even under warm temperature. As no time is spent on the demyristoylation and subsequent nuclear translocation of Trx-h2(G/A) under a cold snap, the ability of Trx-h2(G/A) to protect plants from cold stress was greater than that of Trx-h2. Additionally, COR genes were up-regulated earlier in Trx-h2(G/A)2OE/trx-h2 plants than in Trx-h2OE/trx-h2 plants under cold stress. Consequently, Trx-h2(G/A)2OE/trx-h2 plants showed greater cold tolerance than Col-0 (wild type) and Trx-h2OE/trx-h2 plants. Overall, our results clearly demonstrate the significance of the demyristoylation of Trx-h2 in enhancing plant cold/freezing tolerance.

Digitization of analog signals

We live in the world of digital technologies – everyone has a digital phone, television has switched to a digital broadcasting format as it is more noise-immune, digital processes are literally in every household appliance, from the iron to the computer on which this article was written. Digital technologies simplify our lives, some operations performed by humans require large material costs, for example, writing text on a typewriter and computer vary greatly. The gain of the computer is especially evident when editing the test. They brought us comfort – how nice it is when the processor that monitors the temperature in the house increased the heat supply during a cold snap or reduced it in order to save money in the absence of people in the house.But in order for the digital system to perform this or that action, it needs a command coming from the sensor. It can be a temperature, humidity, pressure sensor. Or maybe a microphone used in voice control systems. All these sensors, without which the operation of a digital system is impossible, give an analog signal that changes its value over time. The digital system is not sensitive to such a signal. It “does not understand” the signal. The problem is solved by ADC (analog-to-digital converters). They have a different structure, varying degrees of complexity, the device, depending on the parameters of the digitized signal. For example, the temperature in the house changes very slowly, even when warming up or when the heating is turned off in frost, the temperature rises or, accordingly, does not fall faster than one degree per hour. The ADC speed requirements for the temperature sensor are very low. Instead, a microphone is used to receive voice commands. In order to distinguish the voices of people and to carry out the commands of some people and not to carry out commands from others, processing of the signal spectrum with a width of kilohertz is required - which means that the signal level will change at a frequency of thousands of times per second. This is a very high demand. The different types of ADCs, their design and application will be discussed in this article.

Meteorological considerations of grapevine damage due to temperature variations: the 2019 late spring frost and summer heat wave events in Burgundy

<p><strong><span>Meteorological considerations of grapevine damage due to temperature variations:</span> <span>t</span><span>he 2019 late spring frost and summer heat wave events </span>in Burgundy </strong></p><p>During 2019, <span>the occurrence of two contrasting weather events, a cold snap and a heat wave, caused extensive damage to the vineyards</span> of Northern Burgundy. <span>The late spring cold snap, that </span><span>occurred</span><span> from May 5</span><sup><span>th</span></sup><span> to 7</span><sup><span>th</span></sup><span>, generated frost like conditions across the northern and north-western areas of the Côte-d'Or department.</span> The weather stations of the Northern Auxois area, where the three observation and study sites are located, recorded minimum temperatures <span>ranging </span>between -1 and -2°C. <span>On the 24</span><sup><span>th</span></sup><span> and the 25</span><sup><span>th</span></sup><span> of July vineyards were exposed, yet again, to an extreme temperature variation.</span> <span>A brief but unusually intense heat wave increased daily maximum temperatures up to 42°C in the department’s far north. Landforms such as plateaus were less exposed to the increase in temperatures due the limiting effect of higher elevations. This led to temperatures not exceeding 40°C above 300 m, elevation at which the vineyard sites of this study are located.</span></p><p>Weather conditions that caused the early May frost event were related to a northern circulation <span>present </span>over Western Europe <span>that persisted </span>from <span>the 28</span><sup><span>th</span></sup><span> of April </span><span>to</span><span> the 6</span><sup><span>th</span></sup><span> of May</span>. <span>The strong anticyclonic ridge stretching from Greenland to the Iberian Peninsula directed an air mass of arctic origin towards France.</span> <span>On July 24</span><sup><span>th</span></sup><span> and 25</span><sup><span>th</span></sup><span>, the presence of a surface high pressure system above Scandinavia, associated with a low-pressure center located near the Atlantic Ocean, generated an influx of a very hot air mass from the northern part of the African continent through France and neighbouring countries.</span></p><p>The local impact of these two weather events was modulated by the topographical features specific to the study area: a limestone plateau strongly dissected by parallel valleys <span>of S.E. / N.W. orientations</span>. <span>The three observation sites have similar soil characteristics and are located on south facing slopes.</span> <span>However, damage to vegetation was uneven across sites as well as within each site.</span> These observations rise up the question of the influence of very fine-scale environmental conditions <span>and the impact they might have on the different vegetative growth stages.</span> <span>Lastly, the variation in physiological response among grapevines and its effect on their sensitivity to the occurrence of different weather hazards is also to be considered.</span></p>

Geosystems of the Barguzin Ridge

The study of geosystems of geodynamically active territories and their mapping is one of the urgent tasks of modern geographical research. The long period of formation and development of the Barguzin ridge determined the specifics of geosystems and their components. The conducted research allowed us to identify five physical and geographical areas, each of which has its own unique features. Within the large tectonic faults, which are characterized by an influx of endogenous heat and hot mineral springs are common, there is the largest accumulation of Miocene-Pliocene relics that have been preserved here since the Pleistocene cold snap. The development of the dark coniferous taiga is confined to the areas of distribution of acidic granites. Currently, pyrogenic impact is of great importance in the development of geosystems of the Barguzin ridge, which is reflected in the spread of derived forests that have arisen in the places of large fires. Frequent fires can cause the disappearance of dark coniferous taiga, as the process of restoring geosystems will be replaced by their transformation. The specifics of geosystems and their current state are reflected in the medium-scale map of geosystems of the central part of the western macroslope of the Barguzin ridge, which is presented in the article. The map was made for the first time at a scale of 1: 200000 to the level of facies groups.

Long-term monitoring provides insight into estuarine top predator (Carcharhinus leucas) resilience following an extreme weather event

Chronic environmental change threatens biodiversity, but acute disturbance events present more rapid and immediate threats. In 2010, a cold snap across south Florida had wide-ranging impacts, including negative effects on recreational fisheries, agriculture, and ecological communities. Here, we use acoustic telemetry and historical longline monitoring to assess the long-term implications of this event on juvenile bull sharks Carcharhinus leucas in the Florida Everglades. Despite the loss of virtually all individuals (ca. 90%) within the Shark River Estuary during the cold snap, the catch per unit effort (CPUE) of age 0 sharks on longlines recovered through recruitment within 6-8 mo of the event. Acoustic telemetry revealed that habitat use patterns of age 0-2 sharks reached an equilibrium in 4-6 yr. In contrast, the CPUE and habitat use of age 3 sharks required 5-7 yr to resemble pre-cold snap patterns. Environmental conditions and predation risk returned to previous levels within 1 yr of the cold snap, but abundances of some prey species remained depressed for several years. Reduced prey availability may have altered the profitability of some microhabitats after the cold snap, leading to more rapid ontogenetic shifts to marine waters among sharks for several years. Accelerated ontogenetic shifts coupled with inter-individual behavioral variability of bull sharks likely led to a slower recovery rate than predicted based on overall shark CPUE. While intrinsic variation driven by stochasticity in dynamic ecosystems may increase the resistance of species to chronic and acute disturbance, it may also increase recovery time in filling the diversity of niches occupied prior to disturbance if resistive capacity is exceeded.