Physiological Adaptation of Habitat by Ion Distribution in the Leaves of Four Ecotypes of Reed (Phragmites australis)

The ion levels in the epidermal bulliform cells of epidermis, mesophyll cells and cells of the vascular bundle sheath of four ecotypes of reed (Phragmites australis (Cav.) Trin. ex Steud.) were determined by means of X_ray microanalysis. The results indicated that higher K +, Na +, Ca 2+ , Mg 2+ and Cl - were distributed in the vascular bundle sheath cells than in mesophyll cells and epidermal bulliform cells of the swamp ecotype. Higher Ca 2+ was found in the bulliform cells than in mesophyll cells and vascular bundle sheath cells, higher Mg 2+ in the mesophyll cells and higher K +, Na + and Cl - in the vascular bundle sheath cells of the dune ecotype. Higher Na + and Mg 2+ was determined in the mesophyll cells than in the bulliform cells and vascular bundle sheath cells, and higher K +, Ca 2+ and Cl - in the vascular bundle sheath cells of the light salt meadow ecotype. In the heavy salt meadow ecotype, higher Na + and Mg 2+ were accumulated in the bulliform cells than in mesophyll cells and vascular bundle sheath cells, but higher K +, Ca 2+ and Cl - in the mesophyll cells. Furthermore, the distributional conditions of the above five ions in leaf cells of the four ecotypes and their significance in the physiological adaptation of reed to habitat were discussed in detail.

Effects of Low Temperature on Physiological Responses of Two White Clover Cultivars

In order to explore the effects of low temperature on the two different genotypes of white clover, electrical conductivity （EC）, soluble sugar, malondialdehyde （MDA） and some other physiological indexes of plants were compared under laboratory conditions. Seedlings of Longping No.1 and Koala were undergone a series of degrading temperatures set in turn 25℃, 10℃, 5℃, 0℃, –5℃ and –10℃. The results showed that the activities of superoxide dismutase （SOD）, electrical conductivity, soluble sugar, free proline and MDA increased obviously with the decrease of stress temperature, while the content of starch decreased, and the content of soluble protein increased first and then decreased during the process. Comprehensive assessments on physiological responses to low temperature stress indicated that the cultivar Longping No.1 had stronger cold resistance than that of cultivar Koala.

Exercise sustains the hallmarks of health

Exercise has long been known for its active role in improving physical fitness and sustaining health.Regular moderate-intensity exercise improves all aspects of human health and is widely accepted as a preventative and therapeutic strategy for various diseases.It is well-documented that exercise maintains and restores homeostasis at the organismal,tissue,cellular,and molecular levels to stimulate positive physiological adaptations that consequently protect against various pathological conditions.Here we mainly summarize how moderate-intensity exercise affects the major hallmarks of health,including the integrity of barriers,containment of local perturbations,recycling and turnover,integration of circuitries,rhythmic oscillations,homeostatic resilience,hormetic regulation,as well as repair and regeneration.Furthermore,we summarize the current understanding of the mechanisms responsible for beneficial adaptations in response to exercise.This review aimed at providing a comprehensive summary of the vital biological mechanisms through which moderate-intensity exercise maintains health and opens a window for its application in other health interventions.We hope that continuing investigation in this field will further increase our understanding of the processes involved in the positive role of moderate-intensity exercise and thus get us closer to the identification of new therapeutics that improve quality of life.

Mitochondrial energy metabolism in diabetic cardiomyopathy:Physiological adaption,pathogenesis,and therapeutic targets

Diabetic cardiomyopathy is defined as abnormal structure and function of the heart in the setting of diabetes,which could eventually develop heart failure and leads to the death of the patients.Although blood glucose control and medications to heart failure show beneficial effects on this disease,there is currently no specific treatment for diabetic cardiomyopathy.Over the past few decades,the pathophysiology of diabetic cardiomyopathy has been extensively studied,and an increasing number of studies pinpoint that impaired mitochondrial energy metabolism is a key mediator as well as a therapeutic target.In this review,we summarize the latest research in the field of diabetic cardiomyopathy,focusing on mitochondrial damage and adaptation,altered energy substrates,and potential therapeutic targets.A better understanding of the mitochondrial energy metabolism in diabetic cardiomyopathy may help to gain more mechanistic insights and generate more precise mitochondria-oriented therapies to treat this disease.

Improvement of Wheat Water Use Efficiency in Semiarid Area of China

The greatest fear of global climate change is drought since in most areas where wheat is grown water is the most important factor influencing wheat yield. Average wheat yield throughout the world is only 30-60% of the attainable yield potential because water shortage is the major factor preventing the realization of maximum yield. Periods of drought alternating with short periods of available water are common conditions to influence wheat productivity. Such conditions include variable frequency of dry and wet periods, intensity of drought, rate of drought onset and patterns of soil water deficit and/or atmospheric water deficit. It is this deficit and variable water conditions in semiarid environments that influence wheat productivity variously. This paper reviewed the physiological adaptation and benefits associated with deficit and variable water conditions. In addition, it also highlights the compensative effect of limited irrigation and breeding of new varieties for high water use efficiency (WUE) that could improve wheat productivity under water-limited environments in the semiarid regions. Considerable potential for further improvement in wheat WUE and productivity in semiarid environments seems to depend on effective conservation of moisture and efficient use of this limited water such as soil fertility improvement, conservation tillage, residues and film mulch, rain water harvesting for limited irrigation, and breeding for water saving varieties. Different crop, soil and water management strategies should be adjusted according to the conditions that prevail in various semiarid areas. By combining soil and water conservation approaches and adjusting the cropping system by growing drought-tolerant and water-saving cultivars, increase in wheat WUE and productivity could be achieved.

Effect of bowel rehabilitative therapy on structural adaptation of remnant small intestine: animal experiment

AIM: To investigate the individual and the combined effects of glutamine, dietary fiber, and growth hormone on the structural adaptation of the remnant small bowel. METHODS: Forty-two adult male Sprague-Dawley rats underwent 85% mid-small bowel resection and received total parenteral nutrition (TPN) support during the first three postoperational days.From the 4th postoperational day, animals were randomly assigned to receive 7 different treatments for 8 days: TPNcon group, receiving TPN and enteral 20 g x L(-1) glycine perfusion; TPN+Gln group, receiving TPN and enteral 20 g x L(-1) glutamine perfusion; ENcon group, receiving enteral nutrition (EN) fortified with 20 g x L(-1) glycine; EN+Gln group, enteral nutrition fortified with 20 g x L(-1) glutamine; EN+Fib group, enteral nutrition and 2 g x d(-1) oral soybean fiber; EN+GH group, enteral nutrition and subcutaneous growth hormone (GH) (0.3 IU) injection twice daily; and ENint group, glutamine-enriched EN, oral soybean fiber, and subcutaneous GH injection. RESULTS: Enteral glutamine perfusion during TPN increased the small intestinal villus height (jejunal villus height 250 microm +/- 29 microm in TPNcon vs 330 microm +/- 54 microm in TPN+Gln, ileal villus height 260 microm +/- 28 microm in TPNcon vs 330 microm +/- 22 microm in TPN+Gln, P【0.05) and mucosa thickness (jejunal mucosa thickness 360 microm +/- 32 microm in TPNcon vs 460 microm +/- 65 microm in TPN+Gln, ileal mucosa thickness 400 microm +/- 25 microm in TPNcon vs 490 microm +/- 11 microm in TPN+Gln,P【 0.05) in comparison with the TPNcon group. Either fiber supplementation or GH administration improved body mass gain (end body weight 270 g +/- 3.6g in EN+Fib, 265.7 g +/- 3.3 g in EN+GH, vs 257 g +/- 3.3 g in ENcon, P【 0.05), elevated plasma insulin-like growth factor (IGF-I) level (880 microg x L(-1). 52 microg x L-(-1) in EN+Fib,1200 microg x L(-1). 96 microg x L-(-1) in EN +/- GH, vs 620 microg x L(-1).43 microg x L-(-1) in ENcon, P【 0.05), and increased the villus height (jejunum 560 microm +/- 44 microm in EN +/- Fib, 530 microm +/- 30 microm in EN +/- GH, vs 450 microm +/- 44 microm in ENcon, ileum 400 microm +/- 30 microm in EN+Fib, P【0.05) and the mucosa thickness (jejunum 740 microm +/- 66 microm in EN +/- Fib, 705 microm +/- 27 microm in EN +/- GH, vs 608 microm +/- 58 microm in ENcon, ileum 570 microm +/- 27 microm in EN +/- Fib, 560 microm +/- 56 microm in remnant jejunum and ileum. Glutamine-enriched EN produced little effect in body mass, plasma IGF-I level, and remnant small bowel mucosal structure. The ENint group had greater body mass (280 g +/- 2.2g), plasma IGF-I level (1450 microg x L(-1). 137 microg x L-(-1)), and villus height (jejunum 620 microm +/- 56 microm, ileum 450 microm +/- 31 microm) and mucosal thickness (jejunum 800 microm +/- 52 microm, ileum 633 microm +/- 33 microm) than those in ENcon, EN+Gln (jejunum villus height and mucosa thickness 450 microm +/- 47 microm and 610 +/- 63 microm, ileum villus height and mucosa thickness 330 microm +/- 39 microm and 500 microm +/- 52 microm), EN+GH groups (P【0.05), and than those in EN+Fib group although no statistical significance was attained. CONCLUSION: Both dietary fiber and GH when used separately can enhance the postresectional small bowel structural adaptation. Simultaneous use of these two gut-trophic factors can produce synergistic effects on small bowel structural adaptation. Enteral glutamine perfusion is beneficial in preserving small bowel mucosal structure during TPN, but has little beneficial effect during EN.

HAL1 mediate salt adaptation in Arabidopsis thaliana

The yeast HAL1 gene was introduced into Arabidopsis thaliana by Agrobacterium tumefaciens-mediated transformation with vacuum infiltration under the control of CaMV 35S promoter. Thirty-three individual kanamycin resistant plants were obtained from 75,000 seeds. Southern blotting analysis indicated that HAL1 gene had been integrated into all of the transgenic plants’ genomes. The copy number of HAL1 gene in transgenic plants was mostly 1 to 3 by Southern analysis. Phenotypes of transgenic plants have no differences with wild type plants. several samples of transformants were self-pollinated, and progenies from transformed and non-transformed plants (controls) were evaluated for salt tolerance and gene expression. Measurement of concentrations of intracellular K+ and Na+ showed that transgenic lines were able to retain less Na+ than that of the control under salt stress. Results from different tests indicated the expression of HAL1 gene promotes a higher level of salt tolerance in vivo in the transgenic Arabidopsis plants.

The behavioral and antioxidant response of the bivalve Gomphina veneriformis to sediment burial effect

A laboratory-based microcosm experiment was carried out to examine both the behavioral and antioxidant response of the clam Gomphina veneriformis under the conditions of 3 types of burial material(sand,silt,silt-sand mixture)with 3 burial depths(5 cm,15 cm,30 cm).The concentration of dissolved oxygen decreased significantly after 3 d of burial in all experimental groups.In silt and sand-silt mixture groups,the interstitial water quality became worsened with lower pH,and higher NH4^(+)-N concentration,where clam mortality occurred simultaneously.However,clam samples in all sand groups and 5 cm,15 cm sand-silt mixture groups survived well for 8 d.Obviously fewer individuals left in the bottom sand in the 15 cm,30 cm silt groups and 30 cm sand-silt mixture groups than in the 5 cm groups.Therefore,it suggests that adding silt and increasing burial depth could stimulate the vertical movement of organisms and cause lethal effects.It was found that the burial depth was the key factor that influenced the activities of antioxidant enzymes,such as superoxide dismutase(SOD)and catalase(CAT).The SOD and CAT activities in the gills and hepatopancreases of organisms both showed significant upregulation in 30 cm burial depth after buried for 8 d.Higher enzyme activities were found in gills than in hepatopancreases,which indicated that the gills of the bivalve G.veneriformis were more susceptible to burial effects than hepatopancreases.Overall,this study shows that sediment burial could cause effects on the biological behavior and antioxidant enzyme activities.

Temperature relations of aerial and aquatic physiological performance in a mid-intertidal limpet Cellana toreuma: Adaptation to rapid changes in thermal stress during emersion

The physiological performance of a mid-intertidal limpet Cellana toreuma was determined to study the physiological adaptation of intertidal animals to rapid changes and extreme temperatures during emersion.The relationship between the Arrhenius breakpoint temperature(ABT)and in situ operative body temperature was studied to predict the possible impact of climate change on the species.The temperature coefficient(Q10)of emersed animals was higher than that of submersed animals and the ratio of aerial:aquatic heart rate rose with increasing temperature.The ABTs of submersed and emersed animals were 30.2 and 34.2°C,respectively.The heart rate and levels of molecular biomarkers(hsps,ampkα,ampkβand sirt1 mRNA)were determined in 48 h simulated semi-diurnal tides.There were no obvious changes of heart rate and gene expression during the transition between emersion and submersion at room temperature,although expressions of hsp70 and hsp90 were induced significantly after thermal stress.These results indicate that C.toreuma can effectively utilize atmospheric oxygen,and the higher Q10 and ABT of emersed animals are adaptations to the rapid change and extreme thermal stress during emersion.However,the in situ operative body temperature frequently exceeds the aerial ABT of C.toreuma,indicating the occurrence of large-scale mortality of C.toreuma in summer,and this species should be sensitive to increasing temperature in the scenario of climate change.

OBSERVATIONS ON BAIJI(LIPOTES VEXILLIFER) AND FINLESS PORPOISE(NEOPHOCAENA ASIAEORIENTALIS)IN THE LOWER REACHES OF THE CHANG JIANG——WITH REMARKS ON PHYSIOLOGICAL ADAPTATIONS OF BAIJI TO THE ENVIRONMENTS

Lipotes usually occurs in pairs or in small loose groups. The calves are born in March-April.The Finless porpoises are usually seen in groups of five or six individuals.The blowof Lipotes lasts 0.2--0.6 sec and that of Neophocaena 0.2--0.5 sec. In Lipotes,a short divewould take 10--20 sec and a long dive up to 1--2 min (average value being 31 sec). InNeophocaena a long dive would reach a maximum of 65 sec with an average of 17.5 sec.Lipotes has a pair of functional eyes. The selective secondary atrophy of a number of eyemuscles and nerves and the position of the eyes in the head correspond with the physical con-ditions of the environments so that the field of vision is directed forwards and upwards. When pursued by motor boat, both species react with a long dive and a change of direc-tion under water. With the Baiji this would occasionally cause fatal injuries by thepropeller of the ship. Such a case seems much less often with Neophocaena. The populationof Lipotes is at present very small.In the stretch of the river (between Nanjing andTaiyangzhou) under exploration, we found scarcely more than one dolphin per 4 km. Thecause for its scarcity is mostly due to accidents or wounds caused by propellers.

Adaptive alterations of elastic fibers in the bilaminar zone of rabbit temporomandibular joint following disc displacement

OBJECTIVE: To study the adaptive alterations of elastic fibers in the bilaminar zone (BZ) of rabbit temporomandibular joint (TMJ) following disc displacement. METHODS: Twenty-eight Japanese white rabbits were used in this study. The right temporomandibular joints of 20 of 28 rabbits were subjected to the surgical procedure of anterior disc displacement (ADD). Four rabbits in the surgical group were sacrificed at 2, 4, 6, 8 and 12 weeks after operation. Their temporomandibular joints were studied histochemically. RESULTS: Elastic fibers were reduced in number and ran irregularly in the superior lamina of BZ from ADD rabbits. The jungly elastic fibers (EFs) could still be seen at 2 weeks after operation. At 4 weeks, the number of EFs decreased significantly; EFs lost their jungly arrangement and were shaped like rough dots, of which the arrangement and the lengths were different. Six weeks after operation, many EFs were replaced by distorted, uneven, non-oriented fine EFs, distributed unevenly and some thick or fine EFs that ran irregularly. The number of EFs decreased further and their arrangement was more deranged at 8 weeks. At 10 and 12 weeks, EFs in the superior lamina of BZ were similar to those at 8 weeks. CONCLUSION: Our results show that EFs lost their function as well as their distribution and arrangement after disc displacement.