Synergistic and antagonistic effects of arbuscular mycorrhizal fungi and Azospirillum and Rhizobium nitrogen-fixers on the photosynthetic activity of alfalfa, probed by the polyphasic chlorophyll a fluorescence transient O-J-I-P

Tsimilli‐Michael, Merope; Eggenberg, P.; Bíró, Borbála; Köves-Péchy, K.; Vörös, I.; Strasser, Reto J.

doi:10.1016/s0929-1393(00)00093-7

Cited by 121 publications

(81 citation statements)

References 28 publications

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Section: Psii Activity Under Growth Light Conditionsmentioning

confidence: 95%

“…S5; Strasser et al, 1996;Tsimilli-Michael et al, 2000). The shape of the curve, the values obtained for the relative variable fluorescence at the J-step (F J ) between 0.36 and 0.47, and the initial slope (M 0 ) between 0.78 and 1.26 are typical for healthy plants (Tsimilli-Michael et al, 2000). The analysis of the O-J-I-P curves allows the determination of the fate of the absorbed energy (parameter ABS): part of the excitation energy is dissipated in the antenna of the light-harvesting complex II (LHCII; parameter DI 0 ) as heat and/or fluorescence, and the remaining is channeled to the reaction centers (parameter TR 0 ).…”

Section: Psii Activity Under Growth Light Conditionsmentioning

confidence: 99%

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Role of Thylakoid ATP/ADP Carrier in Photoinhibition and Photoprotection of Photosystem II in Arabidopsis

et al. 2010

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The chloroplast thylakoid ATP/ADP carrier (TAAC) belongs to the mitochondrial carrier superfamily and supplies the thylakoid lumen with stromal ATP in exchange for ADP. Here, we investigate the physiological consequences of TAAC depletion in Arabidopsis (Arabidopsis thaliana). We show that the deficiency of TAAC in two T-DNA insertion lines does not modify the chloroplast ultrastructure, the relative amounts of photosynthetic proteins, the pigment composition, and the photosynthetic activity. Under growth light conditions, the mutants initially displayed similar shoot weight, but lower when reaching full development, and were less tolerant to high light conditions in comparison with the wild type. These observations prompted us to study in more detail the effects of TAAC depletion on photoinhibition and photoprotection of the photosystem II (PSII) complex. The steady-state phosphorylation levels of PSII proteins were not affected, but the degradation of the reaction center II D1 protein was blocked, and decreased amounts of CP43-less PSII monomers were detected in the mutants. Besides this, the mutant leaves displayed a transiently higher nonphotochemical quenching of chlorophyll fluorescence than the wild-type leaves, especially at low light. This may be attributed to the accumulation in the absence of TAAC of a higher electrochemical H + gradient in the first minutes of illumination, which more efficiently activates photoprotective xanthophyll cycle-dependent and independent mechanisms. Based on these results, we propose that TAAC plays a critical role in the disassembly steps during PSII repair and in addition may balance the trans-thylakoid electrochemical H + gradient storage.In plants, the chloroplast thylakoid membrane is the site of light-driven photosynthetic reactions coupled to ATP synthesis. There are four major protein complexes involved in these reactions, namely, PSI, PSII, the cytochrome b 6 f, and the H + -translocating ATP synthase (for review, see Nelson and Ben-Shem, 2004). The photosystems and the cytochrome b 6 f complex also contain redox components and pigments bound to protein subunits. Their synthesis, assembly, optimal function, and repair during normal development and stress require a number of transport and regulatory mechanisms. In this context, the water-oxidizing PSII complex composed of more than 25 integral and peripheral proteins attracts special attention since its reaction center D1 subunit is degraded and replaced much faster than the other subunits under excess and even growth light conditions (for review, see Aro et al., 2005). Thus, the D1 protein turnover is the major event in the repair cycle of the PSII complex and occurs subsequently to the inactivation of PSII electron transport. D1 degradation is most likely performed by thylakoid FtsH and Deg proteases, operating on both sides of the thylakoid membrane (Lindahl et al., 2000;Haussü hl et al., 2001;Silva et al., 2003;Kapri-Pardes et al., 2007). The PSII repair cycle is regulated by reversible phosphorylation of sever...

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Section: Psii Activity Under Growth Light Conditionsmentioning

confidence: 95%

Section: Psii Activity Under Growth Light Conditionsmentioning

confidence: 99%

Role of Thylakoid ATP/ADP Carrier in Photoinhibition and Photoprotection of Photosystem II in Arabidopsis

et al. 2010

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“…The JIP transient rise reflects the successive but overlapping reduction of the electron acceptor pool of PS II [50] and can be used to obtain information on the redox state of the photosynthetic electron transport chain, on the stoichiometry of its components and on the relative PS II antenna size [51]. This transient has been found to be very sensitive to stress caused by changes in different biotic and abiotic conditions, presenting alterations even before visible symptoms could be detected on the plants [52][53][54][55][56][57]. Albeit some information may be obtained from the application of the JIP test to pre-illuminated leaves, the most used protocols require a dark-adaptation period [58].…”

Section: Passive Fluorescencementioning

confidence: 99%

Monitoring Photosynthesis by In Vivo Chlorophyll Fluorescence: Application to High-Throughput Plant Phenotyping

Silva¹

2016

Applied Photosynthesis - New Progress

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In spite of the decrease in the rate of population growth, world population is expected to rise from the current figure (slightly above to 7.2 billion) to reach 9.6 billion in 2050. There is therefore a pressing need to increase food production. Since most of the best arable lands are already under production, expanding the agricultural areas would have negative impacts on important natural areas. Thereby, increasing the productivity of the current agricultural areas is the chief objective of agronomical planners, and planting more productive and better adapted plant varieties is crucial to achieve it. In fact, plant breeding is at the forefront of concern of both agronomists and plant biologists. Plant breeding is a millenary activity that deeply changed our world. However, the use of molecular biology techniques jointly with informatics capabilities-giving rise to the omics techniquesdeeply accelerated plant breeding, providing new and better plant varieties at an increased pace. The advances in genomics, though, far by-passed the advances in phenomics, and so there is a rising consensus among plant breeders that plant phenotyping is a bottleneck to advancing plant breeding. Therefore, a range of international initiatives in highthroughput plant phenotyping (HTPP) are at course, and new automated equipment is being developed. Phenotyping plants, however, is not a simple matter. To begin with, it has to be decided which parameters to measure in order to extrapolate to the desired goals, plant resistance and plant productivity. For this, as well as for plant breeding, an indepth knowledge of plant physiology is required. Photosynthesis has been considered as a good indicator of overall plant performance. It is the only energy input in plants and thereby impacts all aspects of plant metabolism and physiology. The cumulative rate of photosynthesis over the growing season is the primary determinant of crop biomass. It largely determines the redox state of plant cells, and therefore, it is at the core of regulatory networks. Therefore, assessing photosynthesis and the photosynthetic apparatus plays a core role on plant phenotyping. Nevertheless, high-throughput phenotyping demands very rapid measurements, and consequently the most common method of photosynthesis measurement-the infra-red gas analysis-is not well suited for this purpose. On the contrary, the techniques based on in vivo chlorophyll (Chl) a fluorescence measurements are perfectly fit. In this chapter, an historical perspective on the development of in vivo Chl a measurement is briefly addressed. Then, the state of the art of the fluorescence-based techniques of photosynthesis assessment is presented, and their potential use in HTPP is evaluated. Finally, the current use of these techniques in the main systems of phenotyping is surveyed.

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“…quantificam o comportamento dos fotossistemas II e I (FSII e FSI). [8][9][10][11][12][13] Essa metodologia fornece informações do comportamento do aparato fotossintético, estrutura, conformação e funcionalização em qualquer estado fisiológico. 14 A técnica está baseada em três suposições básicas: os centros reativos (RCs) de FSII são unicamente definidos pelo processo redox do aceptor primário do FSII, a quinona A (Q A ); quando Q A é reduzida em um RC, o mesmo se encontra fechado e a fluorescência da Chl a é alta; enquanto Q A está no estado oxidado, o RC está aberto e o sinal da fluorescência da antena é atenuado; à temperatura ambiente, a presença da clorofila a em plantas, algas e cianobactérias se encontra na região de 680 e 740 nm e é estimulada principalmente pelo FSII.…”

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“…14 A técnica está baseada em três suposições básicas: os centros reativos (RCs) de FSII são unicamente definidos pelo processo redox do aceptor primário do FSII, a quinona A (Q A ); quando Q A é reduzida em um RC, o mesmo se encontra fechado e a fluorescência da Chl a é alta; enquanto Q A está no estado oxidado, o RC está aberto e o sinal da fluorescência da antena é atenuado; à temperatura ambiente, a presença da clorofila a em plantas, algas e cianobactérias se encontra na região de 680 e 740 nm e é estimulada principalmente pelo FSII. 8,9,14 Os dados de fluorescência podem oferecer informações de outros parâmetros também envolvidos na avaliação da eficiência do aparato fotossintético. Todas as variáveis avaliadas são cálculos quânticos baseados nos quatro acontecimentos principais da fotossíntese [absorção da energia (ABS), aprisionamento da energia (TR), transporte de elétrons (ET) e receptor final (RE)].…”

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Avaliação de furanocumarinas como inibidores da fotossíntese através de ensaios de fluorescência da clorofila a

Sampaio¹,

Silva²,

Veiga³

et al. 2012

Quím. Nova

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Recebido em 15/5/12; aceito em 18/9/12; publicado na web em 26/10/12 EVALUATION OF FUROCOUMARINS AS PHOTOSYNTHETIC INHIBITOR BY CHLOROPHYLL a FLUORESCENCE ASSAY. The evaluations of Chorophyll a fluorescence emitted by superior plants carry structural information and photosynthetic apparatus function. Quantitative analysis apparatus of fluorescence kinetic were measured by energy flows (ABS), (TR), (ET) and (DI), known as phenomenological phenomena of OJIP test. Four furocoumarins were isolated from Ruta graveolens (Rutaceae), and chorophyll a (Chl a) fluorescence assays were performed with these compounds to evaluate the photosynthesis inhibition potential. This test was realized in spinach`s leaf discs and in Lolium perenne leaves. The results indicated the herbicide potential mainly for bergapten and chalepin.Keywords: Chl a fluorescence; furocoumarins; "JIP-test". INTRODUÇÃOEvolução e pressão de seleção são processos que as espécies vegetais suportam constantemente ao redor do mundo. Muitas plantas, especialmente as daninhas, apresentam uma ampla variabilidade genética, que lhes permite sobreviver em uma diversidade de condições ambientais. Nos últimos anos, o controle das plantas daninhas tem sido realizado basicamente pelo uso de herbicidas. 1,2Além dos perigos aos seres humanos, nos aspectos ocupacionais, alimentares e de saúde pública, sabe-se que a introdução de agrotó-xicos no ambiente pode provocar efeitos indesejáveis, tendo como consequência mudanças no funcionamento do ecossistema afetado. O Brasil é um país altamente agrícola, e o consumo anual de agrotó-xicos no país tem sido superior a 300 mil t de produtos comerciais. 2Os herbicidas inibidores da fotossíntese são amplamente empregados na agricultura brasileira nas culturas de Zea mays (milho), Saccharum officinarum (cana-de-açúcar), Glycine max (soja), na cultura de frutas, hortaliças, entre outras. Esta classe de herbicidas é uma das mais importantes em todo o mundo. A taxa de fixação de CO 2 declina poucas horas após o tratamento com este tipo de herbicida e eles não possuem problemas de volatilização e apresentam baixa toxicidade para mamíferos. 1,2Os pigmentos, as proteínas e outras substâncias químicas envolvidas na reação da fotossíntese estão localizados nos cloroplastos. Em condições normais, sem a interferência de inibidores fotossinté-ticos, durante a fase fotoquímica, a energia luminosa capturada pelos pigmentos (clorofila e carotenoides) é transferida para um "centro de reação" especial (P680), gerando um elétron "excitado". Este elétron é transferido para uma molécula de quinona localizada na membrana tilacoide do cloroplasto (Q A ). A quinona A transfere o elétron para outra molécula de plastoquinona (PQ), que se reduz a plastoquinol, chegando no citocromo b 6 f, em seguida, até a plastocianina (PC), localizadas na mesma proteína.3 A captura de dois prótons a partir do estroma é também requerida para a formação do plastoquinol. A difusão do platoquinol ocorre através da camada lipídica da membrana tilacoidal ao complexo citocromo b...

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Synergistic and antagonistic effects of arbuscular mycorrhizal fungi and Azospirillum and Rhizobium nitrogen-fixers on the photosynthetic activity of alfalfa, probed by the polyphasic chlorophyll a fluorescence transient O-J-I-P

Cited by 121 publications

References 28 publications

Role of Thylakoid ATP/ADP Carrier in Photoinhibition and Photoprotection of Photosystem II in Arabidopsis

Role of Thylakoid ATP/ADP Carrier in Photoinhibition and Photoprotection of Photosystem II in Arabidopsis

Monitoring Photosynthesis by In Vivo Chlorophyll Fluorescence: Application to High-Throughput Plant Phenotyping

Avaliação de furanocumarinas como inibidores da fotossíntese através de ensaios de fluorescência da clorofila a

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