Antibacterial activity of Artemisia nilagirica leaf extracts against clinical and phytopathogenic bacteria

<p>Abstract</p> <p>Background</p> <p>The six organic solvent extracts of <it>Artemisia nilagirica </it>were screened for the potential antimicrobial activity against phytopathogens and clinically important standard reference bacterial strains.</p> <p>Methods</p> <p>The agar disk diffusion method was used to study the antibacterial activity of <it>A. nilagirica </it>extracts against 15 bacterial strains. The Minimum Inhibitory Concentration (MIC) of the plant extracts were tested using two fold agar dilution method at concentrations ranging from 32 to 512 μg/ml. The phytochemical screening of extracts was carried out for major phytochemical derivatives in <it>A. nilagirica</it>.</p> <p>Results</p> <p>All the extracts showed inhibitory activity for gram-positive and gram-negative bacteria except for <it>Klebsiella pneumoniae, Enterococcus faecalis </it>and <it>Staphylococcus aureus</it>. The hexane extract was found to be effective against all phytopathogens with low MIC of 32 μg/ml and the methanol extract exhibited a higher inhibition activity against <it>Escherichia coli, Yersinia enterocolitica, Salmonella typhi</it>, <it>Enterobacter aerogenes</it>, <it>Proteus vulgaris</it>, <it>Pseudomonas aeruginosa </it>(32 μg/ml), <it>Bacillus subtilis </it>(64 μg/ml) and <it>Shigella flaxneri </it>(128 μg/ml). The phytochemical screening of extracts answered for the major derivative of alkaloids, amino acids, flavonoids, phenol, quinines, tannins and terpenoids.</p> <p>Conclusion</p> <p>All the extracts showed antibacterial activity against the tested strains. Of all, methanol and hexane extracts showed high inhibition against clinical and phytopathogens, respectively. The results also indicate the presence of major phytochemical derivatives in the <it>A. nilagirica </it>extracts. Hence, the isolation and purification of therapeutic potential compounds from <it>A. nilagirica </it>could be used as an effective source against bacterial diseases in human and plants.</p

DDT, epigenetic harm, and transgenerational environmental justice

Although the environmentally harmful effects of widespread dichlorodiphenyltrichloroethane (DDT) use became well-known following Rachel Carson’s Silent Spring (1962), its human health effects have more recently become clearer. A ban on the use of DDT has been in place for over 30 years, but recently DDT has been used for malaria control in areas such as Africa. Recent work shows that DDT has transgenerational effects in progeny and generations never directly exposed to DDT. These effects have health implications for individuals who are not able to have any voice in the decision to use the pesticide. The transgenerational effects of DDT are considered in light of some widely accepted ethical principles. We argue that this reframes the decision to use DDT, requiring us to incorporate new considerations, and new kinds of decision making, into the deliberative process that determines its ongoing use. Ethical considerations for intergenerational environmental justice are presented that include concern and respect for autonomy, nonmaleficence, and justice. Here, we offer a characterization of the kinds of ethical considerations that must be taken into account in any satisfactory decisions to use DDT

Frequently asked questions about chlorophyll fluorescence, the sequel

[EN] Using chlorophyll (Chl) a fluorescence many aspects of the photosynthetic apparatus can be studied, both in vitro and, noninvasively, in vivo. Complementary techniques can help to interpret changes in the Chl a fluorescence kinetics. Kalaji et al. (Photosynth Res 122: 121-158, 2014a) addressed several questions about instruments, methods and applications based on Chl a fluorescence. Here, additionalChl a fluorescence-related topics are discussed again in a question and answer format. Examples are the effect of connectivity on photochemical quenching, the correction of F-V/F-M values for PSI fluorescence, the energy partitioning concept, the interpretation of the complementary area, probing the donor side of PSII, the assignment of bands of 77 K fluorescence emission spectra to fluorescence emitters, the relationship between prompt and delayed fluorescence, potential problems when sampling tree canopies, the use of fluorescence parameters in QTL studies, the use of Chl a fluorescence in biosensor applications and the application of neural network approaches for the analysis of fluorescence measurements. The answers draw on knowledge fromdifferent Chl a fluorescence analysis domains, yielding in several cases new insights.Kalaji, H.; Schansker, G.; Brestic, M.; Bussotti, F.; Calatayud, A.; Ferroni, L.; Goltsev, V.... (2017). Frequently asked questions about chlorophyll fluorescence, the sequel. Photosynthesis Research. 132(1):13-66. https://doi.org/10.1007/s11120-016-0318-yS13661321Adams WW III, Demmig-Adams B (1992) Operation of the xanthophyll cycle in higher plants in response to diurnal changes in incident sunlight. Plant 186:390–398Adams WW III, Demmig-Adams B (2004) Chlorophyll fluorescence as a tool to monitor plant response to the environment. In: Papageorgiou GC, Govindjee (eds) Advances in photosynthesis and respiration series chlorophyll fluorescence: a signature of photosynthesis, vol 19. Springer, Dordrecht, pp 583–604Adams WW III, Demmig-Adams B, Winter K, Schreiber U (1990a) The ratio of variable to maximum chlorophyll fluorescence from photosystem II, measured in leaves at ambient temperature and at 77 K, as an indicator of the photon yield of photosynthesis. Planta 180:166–174Adams WW III, Winter K, Schreiber U, Schramel P (1990b) Photosynthesis and chlorophyll fluorescence characteristics in relationship to changes in pigment and element composition of leaves of Platanus occidentalis L. during autumnal senescence. Plant Physiol 93:1184–1190Alfonso M, Montoya G, Cases R, Rodriguez R, Picorel R (1994) Core antenna complexes, CP43 and CP47, of higher plant photosystem II. Spectral properties, pigment stoichiometry, and amino acid composition. Biochemistry 33:10494–10500Allakhverdiev SI (2011) Recent progress in the studies of structure and function of photosystem II. J Photochem Photobiol B Biol 104:1–8Allakhverdiev SI, Klimov VV, Carpentier R (1994) Variable thermal emission and chlorophyll fluorescence in photosystem II particles. Proc Natl Acad Sci USA 491:281–285Allakhverdiev SI, Los DA, Mohanty P, Nishiyama Y, Murata N (2007) Glycinebetaine alleviates the inhibitory effect of moderate heat stress on the repair of photosystem II during photoinhibition. Biochim Biophys Acta 1767:1363–1371Allen JF (1992) Protein phosphorylation in regulation of photosynthesis. Biochim Biophys Acta 1098:275–335Allen JF, Bennett J, Steinback KE, Arntzen CJ (1981) Chloroplast protein phosphorylation couples platoquinone redox state to distribution of excitation energy between photosystems. Nature 291:21–25Amesz J, van Gorkom HJ (1978) Delayed fluorescence in photosynthesis. Annu Rev Plant Physiol 29:47–66Ananyev GM, Dismukes GC (1996) Assembly of the tetra-Mn site of photosynthetic water oxidation by photoactivation: Mn stoichiometry and detection of a new intermediate. Biochemistry 35:4102–4109Anderson JM, Chow WS, Goodchild DJ (1988) Thylakoid membrane organization in sun/shade acclimation. Aust J Plant Physiol 15:11–26Andrizhiyevskaya EG, Chojnicka A, Bautista JA, Diner BA, van Grondelle R, Dekker JP (2005) Origin of the F685 and F695 fluorescence in photosystem II. Photosynth Res 84:173–180Anithakumari AM, Nataraja KN, Visser RGF, van der Linden G (2012) Genetic dissection of drought tolerance and recovery potential by quantitative trait locus mapping of a diploid potato population. Mol Breed 30:1413–1429Antal TK, Krendeleva TE, Rubin AB (2007) Study of photosystem 2 heterogeneity in the sulfur-deficient green alga Chlamydomonas reinhardtii. Photosynth Res 94:13–22Antal TK, Matorin DN, Ilyash LV, Volgusheva AA, Osipov A, Konyuhow IV, Krendeleva TE, Rubin AB (2009) Probing of photosynthetic reactions in four phytoplanktonic algae with a PEA fluorometer. Photosynth Res 102:67–76Araus JL, Amaro T, Voltas J, Nakkoul H, Nachit MM (1998) Chlorophyll fluorescence as a selection criterion for grain yield in durum wheat under Mediterranean conditions. Field Crops Res 55:209–223Argyroudi-Akoyunoglou J (1984) The 77 K fluorescence spectrum of the Photosystem I pigment-protein complex CPIa. FEBS Lett 171:47–53Arnold WA (1991) Experiments. Photosynth Res 27:73–82Arnold WA, Thompson J (1956) Delayed light production by blue-green algae, red algae and purple bacteria. J Gen Physiol 39:311–318Aro EM, Hundal T, Carlberg I, Andersson B (1990) In vitro studies on light-induced inhibition of PSII and D1-protein degradation at low temperatures. Biochim Biophys Acta 1019:269–275Aro EM, Virgin I, Andersson B (1993) Photoinhibition of photosystem II. Inactivation protein damage and turnover. Biochim Biophys Acta 1143:113–134Arsalane W, Parésys G, Duval JC, Wilhelm C, Conrad R, Büchel C (1993) A new fluorometric device to measure the in vivo chlorophyll a fluorescence yield in microalgae and its use as a herbicide monitor. Eur J Phycol 28:247–252Asada K (1999) The water-water cycle in chloroplasts: scavenging of active oxygens and dissipation of excess photons. Annu Rev Plant Physiol Plant Mol Biol 50:601–639Ashraf M, Harris PJC (2004) Potential biochemical indicators of salinity tolerance in plants. Plant Sci 166:3–16Bailey S, Walters RG, Jansson S, Horton P (2001) Acclimation of Arabidopsis thaliana to the light environment: the existence of separate low light and high light responses. Planta 213:794–801Baker NR (2008) Chlorophyll fluorescence: a probe of photosynthesis in vivo. Annu Rev Plant Biol 59:659–668Baker NR, Rosenqvist E (2004) Applications of chlorophyll fluorescence can improve crop production strategies: an examination of future possibilities. J Exp Bot 55:1607–1621Ballottari M, Dall’Osto L, Morosinotto T, Bassi R (2007) Contrasting behavior of higher plant photosystem I and II antenna systems during acclimation. J Biol Chem 282:8947–8958Barbagallo RP, Oxborough K, Pallett KE, Baker NR (2003) Rapid, noninvasive screening for perturbations of metabolism and plant growth using chlorophyll fluorescence imaging. Plant Physiol 132:485–493Barber J, Malkin S, Telfer A (1989) The origin of chlorophyll fluorescence in vivo and its quenching by the photosystem II reaction centre. Philos Trans R Soc Lond B 323:227–239Barra M, Haumann M, Loja P, Krivanek R, Grundmeier A, Dau H (2006) Intermediates in assembly by photoactivation after thermally accelerated disassembly of the manganese complex of photosynthetic water oxidation. Biochemistry 45:14523–14532Baumann HA, Morrison L, Stengel DB (2009) Metal accumulation and toxicity measured by PAM-chlorophyll fluorescence in seven species of marine macroalgae. Ecotoxicol Environ Safe 72:1063–1075Bauwe H, Hagemann M, Fernie A (2010) Photorespiration: players, partners and origin. Trends Plant Sci 15:330–336Beck WF, Brudvig GW (1987) Reactions of hydroxylamine with the electron-donor side of photosystem II. Biochemistry 26:8285–8295Belgio E, Kapitonova E, Chmeliov J, Duffy CDP, Ungerer P, Valkunas L, Ruban AV (2014) Economic photoprotection in photosystem II that retains a complete light-harvesting system with slow energy traps. Nat Commun 5:4433. doi: 10.1038/ncomms5433Bell DH, Hipkins MF (1985) Analysis of fluorescence induction curves from pea chloroplasts: photosystem II reaction centre heterogeneity. Biochim Biophys Acta 807:255–262Bellafiore S, Barneche F, Peltier G, Rochaix J-D (2005) State transitions and light adaptation require chloroplast thylakoid protein kinase STN7. Nature 433:892–895Belyaeva NE, Schmitt F-J, Paschenko VZ, Riznichenko GY, Rubin AB (2015) Modeling of the redox state dynamics in photosystem II of Chlorella pyrenoidosa Chick cells and leaves of spinach and Arabidopsis thaliana from single flash-induced fluorescence quantum yield changes on the 100 ns–10 s time scale. Photosynth Res 125:123–140Bennett J (1977) Phosphorylation of chloroplast membrane polypeptides. Nature 269:344–346Bennett J (1983) Regulation of photosynthesis by reversible phosphorylation of the light-harvesting chlorophyll a/b protein. Biochem J 212:1–13Bennett J, Shaw EK, Michel H (1988) Cytochrome b6f complex is required for phosphorylation of light-harvesting chlorophyll a/b complex II in chloroplast photosynthetic membranes. Eur J Biochem 171:95–100Bennoun P (2002) The present model for chlororespiration. Photosynth Res 73:273–277Bennoun P, Li Y-S (1973) New results on the mode of action of 3,-(3,4-dichlorophenyl)-1,1-dimethylurea in spinach chloroplasts. Biochim Biophys Acta 292:162–168Berden-Zrimec M, Drinovec L, Zrimec A (2011) Delayed fluorescence. In: Suggett DJ, Borowitzka M, Prášil O (eds) Chlorophyll a fluorescence in aquatic sciences: methods and applications, developments in applied phycology, vol 4. Springer, The Netherlands, pp 293–309Berger S, Sinha AK, Roitsch T (2007) Plant physiology meets phytopathology: plant primary metabolism and plant-pathogen interactions. J Exp Bot 58:4019–4026Bernacchi CJ, Leakey ADB, Heady LE, Morgan PB, Dohleman FG, McGrath JM, Gillespie GM, Wittig VE, Rogers A, Long SP, Ort DR (2006) Hourly and seasonal variation in photosynthesis and stomatal conductance of soybean grown at future CO2 and ozone concentrations for 3 years under fully open-air field conditions. Plant Cell Environ 29:2077–2090Betterle N, Ballotari M, Zorzan S, de Bianchi S, Cazzaniga S, Dall’Osto L, Morosinotto T, Bassi R (2009) Light-induced dissociation of an antenna hetero-oligomer is needed for non-photochemical quenching induction. J Biol Chem 284:15255–15266Bielczynski LW, Schansker G, Croce R (2016) Effect of light acclimation on the organization of photosystem II super and sub-complexes in Arabidopsis thaliana. Front Plant Sci. doi: 10.3389/fpls.2016.00105Björkman O, Demmig-Adams B (1995) Regulation of photosynthetic light energy capture, conversion, and dissipation in leaves of higher plants. In: Schulze ED, Caldwell MM (eds) Ecophysiology of photosynthesis. Springer, Berlin, pp 17–47Blubaugh DJ, Cheniae GM (1990) Kinetics of photoinhibition in hydroxylamine-extracted photosystem II membranes: relevance to photoactivation and site of electron donation. Biochemistry 29:5109–5118Bock A, Krieger-Liszkay A, Ortiz de Zarate IB, Schönknecht G (2001) Cl—channel inhibitors of the arylaminobenzoate type act as photosystem II herbicides: a functional and structural study. Biochemistry 40:3273–3281Bode S, Quentmeier CC, Liao P-N, Hafi N, Barros T, Wilk L, Bittner F, Walla PJ (2009) On the regulation of photosynthesis by excitonic interactions between carotenoids and chlorophylls. Proc Natl Acad Sci USA 106:12311–12316Boekema EJ, Van Roon H, Van Breemen JFL, Dekker JP (1999) Supramolecular organization of photosystem II and its light-harvesting antenna in partially solubilized photosystem II membranes. Eur J Biochem 266:444–452Bolhar-Nordenkampf HR, Long SP, Baker NR, Öquist G, Schreiber U, Lechner EG (1989) Chlorophyll fluorescence as a probe of the photosynthetic competence of leaves in the field: a review of current Instrumentation. Funct Ecol 3:497–514Bonaventura C, Myers J (1969) Fluorescence and oxygen evolution from Chlorella pyrenoidosa. Biochim Biophys Acta 189:366–383Bonfig KB, Schreiber U, Gabler A, Roitsch T, Berger S (2006) Infection with virulent and avirulent P. syringae strains differentially affects photosynthesis and sink metabolism in Arabidopsis leaves. Planta 225:1–12Bouges-Bocquet B (1980) Kinetic models for the electron donors of photosystem II of photosynthesis. Biochim Biophys Acta 594:85–103Bradbury M, Baker NR (1981) Analysis of the slow phases of the in vivo chlorophyll fluorescence induction curve; changes in the redox state of photosystem II electron acceptors and fluorescence emission from photosystem I and II. Biochim Biophys Acta 635:542–551Brestič M, Živčák M (2013) PSII fluorescence techniques for measurement of drought and high temperature stress signal in crop plants: protocols and applications. In: Das AB, Rout GR (eds) Molecular stress physiology of plants. Springer, New Dehli, pp 87–131Brestič M, Cornic G, Fryer MJ, Baker NR (1995) Does photorespiration protect the photosynthetic apparatus in French bean leaves from photoinhibition during drought stress? Planta 196:450–457Brestič M, Živčák M, Kalaji HM, Allakhverdiev SI, Carpentier R (2012) Photosystem II thermo-stability in situ: environmentally induced acclimation and genotype-specific reactions in Triticum aestivum L. Plant Physiol Biochem 57:93–105Brody SS, Rabinowitch E (1957) Excitation lifetime of photosynthetic pigments in vitro and in vivo. Science 125:555–563Brudvig GW, Casey JL, Sauer K (1983) The effect of temperature on the formation and decay of the multiline EPR signal species associated with photosynthetic oxygen evolution. Biochim Biophys Acta 723:366–371Bukhov NG, Boucher N, Carpentier R (1997) The correlation between the induction kinetics of the photoacoustic signal and chlorophyll fluorescence in barley leaves is governed by changes in the redox state of the photosystem II acceptor side; a study under atmospheric and high CO2 concentrations. Can J Bot 75:1399–1406Bukhov N, Egorova E, Krendeleva T, Rubin A, Wiese C, Heber U (2001) Relaxation of variable chlorophyll fluorescence after illumination of dark-adapted barley leaves as influenced by the redox states of electron carriers. Photosynth Res 70:155–166Buschmann C, Koscányi L (1989) Light-induced heat production correlated with chlorophyll fluorescence and its quenching. Photosynth Res 21:129–136Bussotti F (2004) Assessment of stress conditions in Quercus ilex L. leaves by O-J-I-P chlorophyll a fluorescence analysis. Plant Biosystems 13:101–109Bussotti F, Agati G, Desotgiu R, Matteini P, Tani C (2005) Ozone foliar symptoms in woody plants assessed with ultrastructural and fluorescence analysis. New Phytol 166:941–955Bussotti F, Desotgiu R, Cascio C, Pollastrini M, Gravano E, Gerosa G, Marzuoli R, Nali C, Lorenzini G, Salvatori E, Manes F, Schaub M, Strasser RJ (2011a) Ozone stress in woody plants assessed with chlorophyll a fluorescence. A critical reassessment of existing data. Environ Exp Bot 73:19–30Bussotti F, Pollastrini M, Cascio C, Desotgiu R, Gerosa G, Marzuoli R, Nali C, Lorenzini G, Pellegrini E, Carucci MG, Salvatori E, Fusaro L, Piccotto M, Malaspina P, Manfredi A, Roccotello E, Toscano S, Gottardini E, Cristofori A, Fini A, Weber D, Baldassarre V, Barbanti L, Monti A, Strasser RJ (2011b) Conclusive remarks. Reliability and comparability of chlorophyll fluorescence data from several field teams. Environ Exp Bot 73:116–119Butler WL (1978) Energy distribution in the photochemical apparatus of photosynthesis. Annu Rev Plant Physiol 29:345–378Byrdin M, Rimke I, Schlodder E, Stehlik D, Roelofs TA (2000) Decay kinetics and quantum yields of fluorescence in photosystem I from Synechococcus elongatus with P700 in the reduced and oxidized state: Are the kinetics of excited state decay trap-limited or transfer-limited? Biophys J 79:992–1007Caffarri S, Croce R, Cattivelli L, Bassi R (2004) A look within LHCII: differential analysis of the Lhcb1-3 complexes building the major trimeric antenna complex of higher-plant photosynthesis. Biochemistry 43:9467–9476Calatayud A, Ramirez JW, Iglesias DJ, Barreno E (2002) Effects of ozone on photosynthetic CO2 exchange, chlorophyll a fluorescence and antioxidant systems in lettuce leaves. Physiol Plant 116:308–316Cascio C, Schaub M, Novak K, Desotgiu R, Bussotti F, Strasser RJ (2010) Foliar responses to ozone of Fagus sylvatica L. seedlings grown in shaded and in full sunlight conditions. Environ Exp Bot 68:188–197Cazzaniga S, Dall’Osto L, Kong S-G, Wada M, Bassi R (2013) Interaction between avoidance of photon absorption, excess energy dissipation and zeaxanthin synthesis against photooxidative stress in Arabidopsis. Plant J 76:568–579Ceppi MG, Oukarroum A, Çiçek N, Strasser RJ, Schansker G (2012) The IP amplitude of the fluorescence rise OJIP is sensitive to changes in the photosystem I content of leaves: a study on plants exposed to magnesium and sulfate deficiencies, drought stress and salt stress. Physiol Plant 144:277–288Chaudhary N, Singh S, Agrawal SB, Agrawal M (2013) Assessment of six Indian cultivars of mung bean against ozone by using foliar injury index and changes in carbon assimilation, gas exchange, chlorophyll fluorescence and photosynthetic pigments. Environ Monit Assess 185:7793–7807Chen J, Kell A, Acharya K, Kupitz C, Fromme P, Jankowiak R (2015) Critical assessment of the emission spectra of various photosystem II core complexes. Photosynth Res 124:253–265Cheng L, Fuchigami LH, Breen PJ (2000) Light absorption and partitioning in relation to nitrogen content ‘Fuji’ apple leaves. J Am Soc Hortic Sci 125:581–587Choi CJ, Berges JA, Young EB (2012) Rapid effects of diverse toxic water pollutants on chlorophyll a fluorescence: variable responses among freshwater microalgae. Water Res 46:2615–2626Chow WS, Aro EM (2005) Photoinactivation and mechanisms of recovery. In: Wydrzynski T, Satoh K (eds) Photosystem II: the light-driven water: plastoquinone oxidoreductase, advances in photosynthesis and respiration, vol 22. Springer, Dordrecht, pp 627–648Chow WS, Fan DY, Oguchi R, Jia H, Losciale P, Youn-Il P, He J, Öquist G, Shen YG, Anderson JM (2012) Quantifying and monitoring functional photosystem II and the stoichiometry of the two photosystems in leaf segments: approaches and approximations. Photosynth Res 113:63–74Christensen MG, Teicher HB, Streibig JC (2003) Linking fluorescence induction curve and biomass in herbicide screening. Pest Manag Sci 59:1303–1310Codrea CM, Aittokallio T, Keränen M, Tyystjärvi E, Nevalainen OS (2003) Feature learning with a genetic algorithm for fluorescence fingerprinting of plant species. Pattern Recognit Lett 24:2663–2673Conjeaud H, Mathis P (1980) The effect of pH on the reduction kinetics of P-680 in tris-treated chloroplasts. Biochim Biophys Acta 590:353–359Conrad R, Büchel C, Wilhelm C, Arsalane W, Berkaloff C, Duval JC (1993) Changes in yield of in-vivo fluorescence of chlorophyll a as a tool for selective herbicide monitoring. J Appl Phycol 5:505–516Cornic G, Massacci A (1996) Leaf photosynthesis under drought stress. In: Baker NR (ed) Photosynthesis and the environment. Kluwer Academic Publisher, Dordrecht, pp 347–366Cornic G, Fresneau C (2002) Photosynthetic carbon reduction and carbon oxidation cycles are the main electron sinks for photosystems II during a mild drought. Ann Bot 89:887–894Correia MJ, Chaves MMC, Pereira JS (1990) Afternoon depression in photosynthesis in grapevine leaves—evidence for a high light stress effect. J Exp Bot 41:417–426Cotrozzi L, Remorini D, Pellegrini E, Landi M, Massai R, Nali C, Guidi L, Lorenzini G (2016) Variations in physiological and biochemical traits of oak seedlings grown under drought and ozone stress. Physiol Plant 157:69–84Croce R, Zucchelli G, Garlaschi FM, Bassi R, Jennings RC (1997) Excited state equilibration in the photosystem I-light-harvesting I complex: P700 is almost isoenergetic with its antenna. Biochemistry 35:8572–8579Cser K, Vass I (2007) Radiative and non-radiative charge recombination pathways in photosystem II studied by thermoluminescence and chlorophyll fluorescence in the cyanobacterium Synechocystis 6308. Biochim Biophys Acta 1767:233–243Czyczyło-Mysza I, Tyrka M, Marcińska Skrzypek E, Karbarz M, Dziurka M, Hura T, Dziurka K, Quarrie SA (2013) Quantitative trait loci for leaf chlorophyll fluorescence parameters, chlorophyll and carotenoid contents in relation to biomass and yield in bread wheat and their chromosome deletion bin assignments. Mol Breed 32:189–210D’Haene SE, Sobotka R, Bučinská L, Dekker JP, Komenda J (2015) Interaction of the PsbH subunit with a chlorophyll bound to histidine 114 of CP47 is responsible for the red 77 K fluorescence of Photosystem II. Biochim Biophys Acta 1847:1327–1334Dang NC, Zazubovich V, Reppert M, Neupane B, Picorel R, Seibert M, Jankowiak R (2008) The CP43 proximal antenna complex of higher plant photosystem II revisited: modeling and hole burning study. J Phys Chem B 112:9921–9933Dau H (1994) Molecular mechanisms and quantitative models of variable Photosystem II fluorescence. Photochem Photobiol 60:1–23Dau H, Sauer K (1992) Electric field effect on the picosecond fluorescence of photosystem II and its relation to the energetics and kinetics of primary charge separation. Biochim Biophys Acta 1102:91–106Dau H, Zaharieva I, Haumann M (2012) Recent developments in research on water oxidation by photosystem II. Curr Opin Chem Biol 16:3–10de Wijn R, van Gorkom HJ (2001) Kinetics of electron transfer from QA to QB in photosystem II. Biochemistry 40:11912–11922de Wijn R, van Gorkom HJ (2002) The rate of charge recombination in photosystem II. Biochim Biophys Acta 1553:302–308Debus RJ (1992) The manganese and calcium ions of photosynthetic oxygen evolution. Biochim Biophys Acta 1102:269–352Degl’Innocenti E, Guidi L, Soldatini GF (2002) Characteriz

Prospect and potential of Burkholderia sp. against Phytophthora capsici Leonian: a causative agent for foot rot disease of black pepper

Foot rot disease is a very destructive disease in black pepper in Malaysia. It is caused by Phytophthora capsici Leonian, which is a soilborne pathogenic protist (phylum, Oomycota) that infects aerial and subterranean structures of many host plants. This pathogen is a polycyclic, such that multiple cycles of infection and inoculum production occur in a single growing season. It is more prevalent in the tropics because of the favourable environmental conditions. The utilization of plant growth-promoting rhizobacteria (PGPR) as a biological control agent has been successfully implemented in controlling many plant pathogens. Many studies on the exploration of beneficial organisms have been carried out such as Pseudomonas fluorescens, which is one of the best examples used for the control of Fusarium wilt in tomato. Similarly, P. fluorescens is found to be an effective biocontrol agent against the foot rot disease in black pepper. Nowadays there is tremendous novel increase in the species of Burkholderia with either mutualistic or antagonistic interactions in the environment. Burkholderia sp. is an indigenous PGPR capable of producing a large number of commercially important hydrolytic enzymes and bioactive substances that promote plant growth and health; are eco-friendly, biodegradable and specific in their actions; and have a broad spectrum of antimicrobial activity in keeping down the population of phytopathogens, thus playing a great role in promoting sustainable agriculture today. Hence, in this book chapter, the potential applications of Burkholderia sp. to control foot rot disease of black pepper in Malaysia, their control mechanisms, plant growth promotion, commercial potentials and the future prospects as indigenous PGPR were discussed in relation to sustainable agriculture

Unmasking of tracheomalacia following short-term mechanical ventilation in a patient of adult respiratory distress syndrome

Patients with chronic obstructive pulmonary disease (COPD) are susceptible to airway malacia, which may be unmasked following mechanical ventilation or tracheostomy decannulation. Dynamic imaging of central airways, a non-invasive test as effective as bronchoscopy to diagnose airway malacia, has increased the recognition of this disorder. We describe a 70-year-old woman admitted with adult respiratory distress syndrome. She had cardiorespiratory arrest on admission, from which she was successfully resuscitated. She had obesity, hypertension, diabetes mellitus, recurrent ventricular tachycardia, sarcoidosis with interstitial lung disease and COPD. She received short-term (18 days) mechanical ventilation with tracheostomy and developed respiratory distress following tracheostomy decannulation

First authenticated cases of life-threatening envenoming by the hump-nosed pit viper (Hypnale hypnale) in India.

In Kerala, south-western India, five patients developed systemic envenoming after bites by hump-nosed pit vipers (Hypnale hypnale), proved by identification of the snakes responsible. Two of the dead snakes had been misidentified as saw-scaled vipers (Echis carinatus), while three had remained unidentified. Symptoms of local envenoming were pain, swelling, haemorrhagic blistering, bruising and regional lymphadenopathy. Systemic symptoms included headache, nausea, vomiting and abdominal and chest pain. There was evidence of haemostatic dysfunction (coagulopathy, fibrinolysis, thrombocytopenia or spontaneous systemic haemorrhage) in all cases and of microangiopathic haemolysis in two. Two patients were haemodialysed for acute renal failure, one of whom developed pulmonary oedema requiring mechanical ventilation. In India, H. hypnale has not previously been regarded as a cause of frequent or potentially dangerous envenoming. Its medical importance has been overlooked throughout its geographical range, probably because of confusion with other small species. No specific antivenom exists, yet most patients are treated with non-specific antivenoms, risking reactions without hope of benefit. An effective antivenom is urgently needed in south India and in Sri Lanka, where this species is also a common cause of bites

Not Available

Not AvailableMany countries are engaged in making vaccine against COVID-19 as the world records more than 38 million SARS-CoV-2 infections and more than one million deaths. The infection raging through communities is expected to have evoked some degree of immunity in many asymptomatic and recovered individuals. However, the level of protective immunity and duration of such immunity have not been studied in depth. At the same time, spanning from the conventionalwhole virus vaccine to recombinant vaccines using Adenovirus vectors and first-of-its kind mRNA vaccines are in human trials. Before the effectiveness and safety of such vaccines are established billions of doses have been produced and stockpiled to save time in production and distribution. Antigenic diversity and the potential role of passive surveillance in COVID-19 regulation are explored in this reportNot Availabl