Nonsteroidal anti-inflammatory drugs as antipyretics and modulators of a molecular clock(s) in the appendix of Sauromatum venosum inflorescence

• The appendix of the Sauromatum senosum inflorescence is a striking example of thermogenesis in plants. On the day of opening, the Sauromatum appendix becomes hot, reaching up to 32 °C. Aspirin, salicylic acid and 2,6-dihydroxybenzoic acid, a subclass of NSAIDs, induce a temperature rise from three mitochondrial sources: alternative oxidase, F₁F_O-ATP synthase and adenine nucleotide translocator. This temperature rise is synchronized and compounded under various light/dark regimes. We studied the effect of different subgroups of NSAIDs on the temperature rise.
• Tissue slices of appendix of Sauromatum and Arum italicum inflorescences at a pre-mature stage were treated with the three inducers in combination with one NSAID under constant light or darkness and under different photoperiods.
• Temperature rise generated by the three heat sources in the presence of inducers and different non-selective NSAIDs were not compounded and occurred at three different times. Under constant light, DuP-697, ibuprofen, flurbiprofen, acetaminophen and diclofenac suppressed the temperature rise induced by the three salicylates. Desynchronization and delayed temperature rise were detected with 6/42-h light/ dark and 15/33-h light/dark regimes in the presence of celecoxib and ibuprofen. With a 24/24-h light/dark regime, temperature rise was suppressed in the presence of ibuprofen. There were differences in response to individual NSAIDs between appendix tissue of A. italicum and S. venosum.
• Mitochondrial energy balance is affected by NSAIDs. There is an interaction between light/dark regime and temperature rise and a relationship between timing mechanism and temperature rise.

     

Kinetic analyses of the OJIP chlorophyll fluorescence rise in thylakoid membranes

N,N,N′,N′-tetramethyl-p-phenylenediamine (TMPD) was previously used to study the kinetics of the OJIP chlorophyll fluorescence rise. The present study is an attempt to elucidate the origin of TMPD-induced delay and quenching of the I–P step of fluorescence rise. For this purpose, we analyzed the kinetics of OJIP rise in thylakoid membranes in which electron transport was modified using ascorbate, methyl viologen (MV), and 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone (DBMIB). In the absence of TMPD, the OJIP kinetics of fluorescence induction (FI) was not altered by ascorbate. However, ascorbate eliminated the I–P rise delay caused by high concentrations of TMPD. On the other hand, neither ascorbate nor DBMIB, which blocks the electron release from Photosystem II (PS II) at the cytochrome b₆/f complex, could prevent the quenching of I–P rise by TMPD. In control thylakoids, MV suppressed the I–P rise of FI by about 60. This latter effect was completely removed if the electron donation to MV was blocked by DBMIB unless TMPD was present. When TMPD intercepted the linear electron flow from PS II, re-oxidation of TMPD by photosystem I (PS I) and reduction of MV fully abolished the I–P rise. The above is in agreement with the fact that TMPD can act as an electron acceptor for PS II. With MV, the active light-driven uptake of O₂ during re-oxidation of TMPD by PS I contributes towards an early decline in the I–P step of the OJIP fluorescence rise.     

干旱叠加海平面上升、氮负荷增加对河口潮汐沼泽生态系统净CO2交换的影响

河口潮汐沼泽湿地是全球重要的蓝碳生态系统之一。海平面上升和氮负荷增加是入海河流河口湿地面临的两个主要环境问题。近年来,干旱事件频发,干旱及其与海平面上升、氮负荷增加的叠加将如何影响河口潮汐沼泽湿地生态系统净CO₂交换,目前还未见报道。2020年夏秋,福建沿海经历了数月严重的气象干旱,这为揭示干旱对河口潮汐沼泽湿地生态系统净CO₂交换量(NEE)和生态系统呼吸(ER)的影响提供了一个契机。分别于2019年8—10月(正常天气)和2020年8—10月(干旱天气),在闽江河口微咸水短叶茳芏沼泽湿地运用光合作用测定仪+箱法测定不同处理(对照、模拟海平面上升、模拟氮负荷增加、模拟海平面上升+模拟氮负荷增加)短叶茳芏湿地生态系统NEE和ER,以期揭示气象干旱与海平面上升、氮负荷增加的叠加对河口沼泽湿地生态系统净CO₂交换的影响。与正常天气相比,干旱天气下各处理(包含对照)的NEE均显著降低(P<0.05);对照、海平面上升以及氮负荷增加处理样地的ER显著减少(P<0.05),海平面上升+氮负荷增加处理ER显著增加(P&l...     

The sporophyte of Liagora farinosa lamour

Carpospores of Liagora farinosa from the western Mediterranean in culture gave rise to an Acrochaetium-like phase with filamentous prostrate and sparsely branched erect systems. This phase reproduced readily by tetraspores and monospores. The tetrasporangia were found to go through meiosis and the four haploid spores then gave rise to filamentous protonemal growths on which buds arose that developed into typical (though usually uncalcified) Liagora thalli. The monospores appeared to repeat the Acrochaetium-phase. These observations suggest that Liagora farinosa is another example of those members of the Nemalionales which show a heteromorphic life-history, with the sporophyte generation respresented by a dwarf phase.

Some aspects of the developmental physiology of the species are discussed.     

Analysis of initial chlorophyll fluorescence induction kinetics in chloroplasts in terms of rate constants of donor side quenching release and electron trapping in photosystem II

The fluorescence induction F(t) of dark-adapted chloroplasts has been studied in multi-turnover 1 s light flashes (MTFs). A theoretical expression for the initial fluorescence rise is derived from a set of rate equations that describes the sequence of transfer steps associated with the reduction of the primary quinone acceptor Q _A and the release of photochemical fluorescence quenching of photosystem II (PSII). The initial F(t) rise in the hundreds of μs time range is shown to follow the theoretical function dictated by the rate constants of light excitation (k _L) and release of donor side quenching (k _si ). The bi-exponential function shows sigmoidicity when one of the two rate constants differs by less than one order of magnitude from the other. It is shown, in agreement with the theory, that the sigmoidicity of the fluorescence rise is variable with light intensity and mainly, if not exclusively, determined by the ratio between rate of light excitation and the rate constant of donor side quenching release.     

The effect of weather in modifying the pattern of pasture larval contamination withOstertagia circumcincta

Groups of 3 ewes and 6 lambs were run on each of three paddocks carrying residual pasture larval contamination ofOstertagia circumcincta, pasture larval contamination following the simulated spring rise on both types of infection. On all paddocks a rise in pasture larval contamination occurred in early August. The absence of the usual peak in June on the paddocks contaminated from the spring rise was attributed to the cold weather during April and May which slowed up development of the eggs ofOstertagia circumcincta     

Threshold response of Madagascar's littoral forest to sea-level rise

Aim Coastal biodiversity hotspots are globally threatened by sea‐level rise. As such it is important to understand how ecosystems resist, respond and adapt to sea‐level rise. Using pollen, geochemistry, charcoal and diatom records in conjunction with previously published palaeoclimatic records, we investigated the mechanism, interactions and ecosystem response and resilience of Madagascar's littoral forest to late Holocene sea‐level rise. Location Sediment sequences were collected along the south‐east coast of Madagascar in two adjacent habitats in Mandena; the highly diverse littoral forest fragment and species‐poor Erica‐matrix. Methods We used a multi‐proxy approach to investigate the relative influence of environmental changes on the littoral ecosystem. We reconstructed past vegetation and fire dynamics over the past 6500 years at two sites in the littoral forest using fossil pollen and macrofossil charcoal contained in sedimentary sequences. Alongside these records we reconstructed past marine transgressions from the same sedimentary sequences using geochemical analyses, and a salinity and drought index through the analysis of fossil diatoms. Results Our findings indicated that it was the synergistic effect of sea‐level rise coupled with rainfall deficits that triggered a threshold event with a switch from two types of littoral forest (an open Uapaca forest and a closed littoral forest fragment) to an Erica–Myrica heath/grassland occurring in approximately less than 100 years. Resilience to sea‐level rise differed in the two adjacent habitats, suggesting that the littoral forest fragment was more resilient to the impacts of sea‐level change and aridity than the open Uapaca woodland. Conclusions We demonstrated that the littoral ecosystem was influenced by late Holocene sea‐level rise and climatic desiccation. While climate change‐integrated conservation strategies address the effects of climate change on species distribution and dispersal, our work suggests that more attention should be paid to the impacts of interactive climatic variables that affect ecosystem thresholds.     

Ethylene Production and Respiration of Postharvest Acid Citrus Fruits and Wase Satsuma Mandarin Fruit

Ethylene production and respiratory rate were examined in acid citrus fruits such as yuzu, seedless yuzu and daidai, and wase satsuma mandarin. A large amount of ethylene was produced from four varieties of citrus fruits harvested from May to July but not after September. A rise in ethylene production did not always coincide with a rise in respiratory rate. Excised tissues of fruits contained the ability of ethylene production throughout the developmental stages. The endogenous ethylene level at the ripening stage, reached the maximum when the color changed from green to yellow.     

A preliminary study of the applicability of sweet potatoes for mycological fat production

Summary For mycological fat production,Aspergillus nidulans andPenicillium lilacinum were grown on media made up of crushed and boiled sweet potatoes. Mycelial mats containing a fair amount of fat were obtained, namely, 15 % in case ofAspergillus and 24 % in case ofPenicillium. Media containing an external supply of glucose gave rise to increase in percentage fat in mycelium, but the amount of mycelium and consequently the total fat content decreased.Addition of sodium nitrate gave heavier mycelial mats but the total fat content could not be raised.Addition of potassium phosphate or magnesium sulphate or both to the sweet potato medium gave rise to heavier mycelial mats but with lower fat content.     

CULTURE AND HYBRIDIZATION STUDIES ON PETROCELIS (RHODOPHYTA) FROM ALASKA AND CALIFORNIA1,2

Cultured tetraspores of Petrocelis middendorffii (Ruprecht) Kjellman from Amchitka Island, Alaska, gave rise to foliose, dioecious gametophytes similar to cultured gametophytes of P. franciscana Setchell & Gardner. A 1:1 ratio male:female gametophytes was obtained. Fertilized female plants produced cystocarps and carpospores that gave rise to crustose plants anatomically similar to field-collected Petro-celis sporophytes. Cultured male gametophytes of P. middendorffii were interfertile with cultured female blades of field-collected Gigartina pacifica Kjellman. Cultured P. middendorffii gametophytes from Amchitka were interfertile with cultured gametophytes of P. franciscana from 2 localities in California. Hybrid carpospores gave rise to crustose sporophytes that have not reproduced. Anatomical comparisons of P. middendorffii from Amchitka with P. franciscana from California showed no important differences in the characters originally used to separate these species. The interfertility of cultured Petrocelis gametophytes from california and Amchitka as well as the similarities of the history and anatomy suggests that a single species is involved. P. franciscana is reduced to a synonym of P. middendorfii.     

Stress-induced rise in body temperature is repeatable in free-ranging Eastern chipmunks (<Emphasis Type="Italic">Tamias striatus</Emphasis>)

In response to handling or other acute stressors, most mammals, including humans, experience a temporary rise in body temperature (T _b). Although this stress-induced rise in T _b has been extensively studied on model organisms under controlled environments, individual variation in this interesting phenomenon has not been examined in the field. We investigated the stress-induced rise in T _b in free-ranging eastern chipmunks (Tamias striatus) to determine first if it is repeatable. We predicted that the stress-induced rise in T _b should be positively correlated to factors affecting heat production and heat dissipation, including ambient temperature (T _a), body mass (M _b), and field metabolic rate (FMR). Over two summers, we recorded both T _b within the first minute of handling time (T _b1) and after 5 min of handling time (T _b5) 294 times on 140 individuals. The mean ∆T _b (T _b5 – T _b1) during this short interval was 0.30 ± 0.02°C, confirming that the stress-induced rise in T _b occurs in chipmunks. Consistent differences among individuals accounted for 40% of the total variation in ∆T _b (i.e. the stress-induced rise in T _b is significantly repeatable). We also found that the stress-induced rise in T _b was positively correlated to T _a, M _b, and mass-adjusted FMR. These results confirm that individuals consistently differ in their expression of the stress-induced rise in T _b and that the extent of its expression is affected by factors related to heat production and dissipation. We highlight some research constraints and opportunities related to the integration of this laboratory paradigm into physiological and evolutionary ecology.     

Genetic variation in somatic embryogenic response in open-pollinated families of black spruce

Summary Zygotic embryos from open-pollinated seeds of 20 black spruce (Picea mariana) families were used to investigate the proportion of genotypes that would give rise to embryogenic tissue (ET) and mature somatic embryos. Eighty-five percent of the maternal genotypes gave rise to embryogenic tissue. Within-family rates of ET induction ranged from 0 to 17%, with an average of 8%. The largest proportion of variation was among families, indicating the additive nature of the genetic variation. On a medium with 6% sucrose and 3.7 M ABA, 90% of the embryogenic lines gave rise to abundant (>100/100 mg of ET), well-formed, mature somatic embryos. A medium with 2% sucrose, without 2,4-D, was used to germinate the mature somatic embryos. These were grown in the greenhouse and have now been established in field trials.     

PSII Complexes with Destabilized Primary Quinone Acceptor of Electrons in Dark-Adapted Chlorella

Incubation of the alga Chlorella pyrenoidosa Chick in darkness (at 37°C) for 24 h did not change the initial (F ₀) and maximum (F _m) yield of chlorophyll fluorescence in diuron-treated cells. In dark-incubated alga, the contribution of the slow (rise time 10–15 min) phases to the kinetics of F _m rise and, correspondingly, to variable fluorescence F _v (where F _v = F _m – F ₀) increased twofold. In addition, F _m was attained at higher concentrations of diuron, which inhibits electron transfer between the primary (Q _A) and secondary (Q _B) quinone acceptors of electron in the PSII. Inhibition of photosynthetic electron transfer with o-phenanthroline, which, at high concentrations, competitively replaces both Q _B and Q _A, decreased F _m yield due to selective suppression of the slow phase of fluorescence rise. It was assumed that the slow phase in the kinetics of F _m rise reflects the functioning of PSII complexes with destabilized Q _A. Such destabilization can result from the modification of the major PSII proteins (D1 and D2) in dark-adapted Chlorella cells.     

Derivation of non-acetifying „quasiacetobacters” from a trueAcetobacter strain,andvice versa

Summary A strain ofAcetobacter rancens gave rise to “quasi-acetobacters” which had lost the essential generic character of oxidation of ethanol to acetic acid, whilst retaining all the other characteristics of the genus. Other quasi-acetobacters with other acetobacter properties were also obtained. Conversely a starch-producing quasi-acetobacter gave rise to two trueAcetobacter strains indistinguishable biochemically fromA. pasteurianus andA. rancens respectively. These phenomena were associated with the presence, in the parent strains, of many swollen filaments and large bodies. It is tentatively suggested that the changes from true to quasi-acetobacter, andvice versa, may be correlated with the production of such bodies, and may indicate some heterodox form of reproduction other than simple fission. The advent of “quasi-acetobacters” seems largely to demolish the genusAcetobacter, whilst failing to indicate an alternative under the existing rigid botanical taxonomic conventions.     

Haemogregarina georgianae n. sp., a new haemogregarine parasite from the Antarctic teleost Parachaenichthys georgianus

Haemogregarina georgianae n. sp. occurs frequently in the bathydraconid teleost Parachaenichthys georgianus from the western Antarctic portion of the Southern Ocean. The haemogregarine and its developmental stages in the vertebrate have been found in erythrocytes of the fish: both microschizogony and macroschizogony have been seen in fish caught during the austral summer. Morphological evidence suggests the merozoites from macroschizogony give rise to the microschizont, and that the microschizont merozoites give rise to gametocytes. Comparison of H. georgianae with other haemogregarines known from teleosts shows that it has a previously undescribed morphology.     

Recent CO2 rise has modified the sensitivity of tropical tree growth to rainfall and temperature

Atmospheric CO₂ (c_a) rise changes the physiology and possibly growth of tropical trees, but these effects are likely modified by climate. Such c_a × climate interactions importantly drive CO₂ fertilization effects of tropical forests predicted by global vegetation models, but have not been tested empirically. Here we use tree‐ring analyses to quantify how c_a rise has shifted the sensitivity of tree stem growth to annual fluctuations in rainfall and temperature. We hypothesized that c_a rise reduces drought sensitivity and increases temperature sensitivity of growth, by reducing transpiration and increasing leaf temperature. These responses were expected for cooler sites. At warmer sites, c_a rise may cause leaf temperatures to frequently exceed the optimum for photosynthesis, and thus induce increased drought sensitivity and stronger negative effects of temperature. We tested these hypotheses using measurements of 5,318 annual rings from 129 trees of the widely distributed (sub‐)tropical tree species, Toona ciliata. We studied growth responses during 1950–2014, a period during which c_a rose by 28%. Tree‐ring data were obtained from two cooler (mean annual temperature: 20.5–20.7°C) and two warmer (23.5–24.8°C) sites. We tested c_a × climate interactions, using mixed‐effect models of ring‐width measurements. Our statistical models revealed several significant and robust c_a × climate interactions. At cooler sites (and seasons), c_a × climate interactions showed good agreement with hypothesized growth responses of reduced drought sensitivity and increased temperature sensitivity. At warmer sites, drought sensitivity increased with increasing c_a, as predicted, and hot years caused stronger growth reduction at high c_a. Overall, c_a rise has significantly modified sensitivity of Toona stem growth to climatic variation, but these changes depended on mean climate. Our study suggests that effects of c_a rise on tropical tree growth may be more complex and less stimulatory than commonly assumed and require a better representation in global vegetation models.     

Photosynthesis and water relations of four oak species: impact of flooding and salinity

 As global climate changes, sea level rise and increased frequency of hurricanes will expose coastal forests to increased flooding and salinity. Quercus species are frequently dominant in these forest, yet little is known about their salinity tolerance, especially in combination with flooding. In this study, 1-year-old seedlings of Quercus lyrata Walt. (overcup oak), Q. michauxii Nutt. (swamp chestnut oak), Q. nigra L. (water oak), and Q. nuttallii Palmer (Nuttall oak) were chronically (simulating sea level rise) and acutely (simulating hurricane storm surge) exposed to increased flooding and salinity, individually and in combination. The four species demonstrated two response patterns of photosynthesis (A), conductance, and leaf water potential, apparently related to their relative flood tolerance. In Q. lyrata, Q. nuttallii, and Q. nigra (moderately flood-tolerant), A was not immediately reduced after the initiation of the freshwater flooding, but was reduced as the duration of flooding increased. In the second pattern, demonstrated by the weakly flood-tolerant Q. michauxii, A was immediately reduced by freshwater flooding with an increasing impact over time. Watering with 2 parts per thousand (ppt) saline water did not consistently reduce A, but flooding with 2 ppt reduced A of all species, similar to the response with freshwater flooding. Photosynthesis of all species was reduced by 6 ppt watering or flooding, with the latter treatment killing all species within 8 weeks. When acutely exposed to 30 ppt salinity, A was quickly and severely reduced regardless of whether the seedlings were watered or flooded. Acutely flooded seedlings exposed to high salinity died within 2 weeks, but seedlings watered with 30 ppt saline water recovered and A was not reduced the following spring. As saline flooding of coastal areas increases due to sea level rise, photosynthesis of these species will be differentially affected based primarily on their flood tolerance. This suggests that increased flooding associated with sea level rise will impact these tree species to a greater extent than small increases in soil salinity. High salinity accompanying storm surges will be very harmful to all of these species. Received: 20 October 1997 / Accepted: 2 December 1998     

Effects of climate warming on plant autotoxicity in forest evolution: a case simulation analysis for Picea schrenkiana regeneration

In order to explore how plant autotoxicity changes with climate warming, the autotoxicity of P. schrenkiana needles' water extract, organic extract fractions, and key allelochemical DHAP was systemically investigated at the temperature rising 2 and 4°C based on the data‐monitored soil temperature during the last decade in the stage of Schrenk spruce regeneration (seed germination and seedling growth). The results showed that the criterion day and night temperatures were 12°C and 4°C for seed germination, and 14°C and 6°C for seedling growth, respectively. In the presence of water extract, the temperature rise of 2°C significantly inhibited the germination vigor and rate of P. Schrenkiana seed, and a temperature rise of 4°C significantly increased the inhibition to the seedling growth (P < 0.05). Among the three organic fractions, the low‐polar fraction showed to be more phytotoxic than the other two fractions, causing significant inhibitory effects on the seed germination and growth even at low concentration of 0.1 mg/mL, and the inhibition effect was enhanced as temperature increased. The temperature rise significantly enhanced the promotion effect of DHAP, while the inhibition effect of temperature rise became less important with increasing concentration of DHAP. This investigation revealed that autotoxicity of P. schrenkiana was affected by the climate warming. As expected, it provided an insight into the mechanism and effectiveness of allelopathy in bridging the causal relationship between forest evolution and climate warming.     

Reduced carbon emissions and fishing pressure are both necessary for equatorial coral reefs to keep up with rising seas

A rapid increase in sea-level rise is generating vertical accommodation space on modern coral reefs. Yet increases in sea-surface temperatures (SSTs) are reducing the capacity of coral reefs to keep up with sea-level rise. We use ensemble species distribution models of four coral species (Porites rus, Porites lobata, Acropora hyacinthus and Acropora digitifera) to gauge potential geographic differences in gross carbonate production. Net carbonate production was estimated by considering erosional rates of ocean acidification, increasing cyclone intensity, local pollution, fishing pressure and the projected burdens of increases in SSTs (under Representative Concentration Pathways (RCPs) 4.5, 6.0 and 8.5) through to the year 2100. Our models predict that only 4 ± 0.1% (~60 000 km²) of Indo-Pacific coral reefs are projected to keep up with sea-level rise by the year 2100 under RCP 8.5 – most of which will be located near the Equator. However, with drastic reductions in emissions (under RCPs 4.5 and 6.0 Wm⁻²), we predict that 15 ± 0.3% (~250 000 km²) (under RCP 4.5 Wm⁻²) and 12 ± 0.7% (~200 000 km²) (under RCP 6.0 Wm⁻²) of Indo-Pacific coral reefs, have the potential to keep up with sea-level rise by the year 2100. Yet the burdens of fishing pressure and its cascading effects are projected to be responsible for substantial reef erosion, nearly halving the number of reefs able to keep up with sea-level rise. If action is taken immediately and emissions are drastically reduced to RCPs 4.5 or 6.0 Wm⁻², and reef management reduces the burdens of local pollution and fishing pressure, then our model predicts that 21–27% (~350 000–470 000 km²) of Indo-Pacific coral reefs – most of which will be located near the Equator – would have the potential to keep up with sea-level rise by the year 2100.