Light-Related Photosynthetic Characteristics of Lotic Macroalgae

Necchi, Orlando

doi:10.1023/b:hydr.0000038861.18999.7b

Cited by 33 publications

(46 citation statements)

References 33 publications

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“…This result could help to explain the presence, sometimes predominant, of this algal group in lotic environments with different degrees of shading (Necchi et al, 2008) and can be related to the indifferent response of their photosynthetic apparatus to different light levels (Necchi, 2004). Tetraspora lubrica, however, presented a clear development of percent cover under higher light intensity, which is typical for Chlorophyta (Richardson et al, 1983;Necchi, 2004). The pigment composition of Chlorophyta limits them to predominately high irradiance sections of streams (DeNicola and Hoagland, 1992).…”

Section: Discussionmentioning

confidence: 95%

“…However, algal taxa differ in ability to acclimatize to different levels of irradiance (Necchi, 2004), which aids their success in specific environments (Branco and Necchi, 1996).…”

Section: Introductionmentioning

confidence: 99%

“…Research on the influence of light conditions on lotic macroalgae has mostly concerned physiological aspects (Falkowski and LaRoche, 1991;Necchi, 2004) that help understanding of cellular processes, but contributed less to ecological understanding. Nevertheless, there is some evidence for a strong relationship between irradiance and spectral composition with the ecological response of these communities.…”

Section: Introductionmentioning

confidence: 99%

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Effects of irradiance and spectral composition on the establishment of macroalgae in streams in southern Brazil

Tonetto

Branco

Peres

2012

Ann. Limnol. - Int. J. Lim.

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-The relative effects of irradiance and spectral composition on the colonization and development of macroalgal communities were examined in four streams exposed to full sunlight in southern Brazil. A set of solar filters surrounded the artificial substrata to provide various quantitative and qualitative light conditions. In addition to the control, the conditions were full sunlight attenuated by 50, 70 and 90%, blue light (filter transmitting 430-500 nm), green light (500-600 nm) and red light ( > 600 nm). Macroalgal percent cover was determined three times during the colonization period (15, 39 and 70 days). Significant differences occurred in the mean values for macroalgal community percent cover between treatments at 15 and 39 days, suggesting that early and intermediate stages of the colonization were directly influenced by irradiance. There was an almost complete absence of macroalgae with 90% attentuation, but progressive increases with 70 and 50% attenuation. However, the mean values for macroalgal community percent cover did not differ significantly between color treatments, suggesting that the effects of irradiance on macroalgal colonization were stronger than those of spectral composition at similar intensity. The quantitative responses differed among the taxa.

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Section: Discussionmentioning

confidence: 95%

“…However, algal taxa differ in ability to acclimatize to different levels of irradiance (Necchi, 2004), which aids their success in specific environments (Branco and Necchi, 1996).…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Effects of irradiance and spectral composition on the establishment of macroalgae in streams in southern Brazil

Tonetto

Branco

Peres

2012

Ann. Limnol. - Int. J. Lim.

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“…PI curves were generated on the basis of ETR and the respective parameters were calculated by the equation of Jassby and Platt (1976): photosynthetic efficiency (αETR), maximum photosynthetic rate (P max = ETR max ) and saturation parameter (I k ). The values of αETR were determined by linear fitting using the three first points of the ETR versus irradiance curve (Necchi, 2004).…”

Section: Condition/datesmentioning

confidence: 99%

Photoacclimation in a tropical population of Cladophora glomerata (L.) Kützing 1843 (Chlorophyta) from southeastern Brazil

Bautista

Necchi-Júnior

2008

Braz. J. Biol.

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Photoacclimation of photosynthesis was investigated in a tropical population of C. glomerata (São Paulo State, southeastern Brazil, 20° 48' 24" S and 49° 22' 24" W) by chlorophyll fluorescence parameters and chlorophyll a content. Plants were acclimated to two levels of irradiance: low (65 ± 5 mmol.m -2 .s -1 ) and high (300 ± 10 mmol.m -2.s -1 ) and exposed short-term (4 days) and long-term (28 days) under a light-dark cycle of 12:12 hours. Photosynthesis-irradiance (PI) curves revealed distinct strategies of photoacclimation. In long-term exposure, plants acclimated by altering the photosynthetic units (PSU) number and keeping fixed the PSU size, revealed by increased rates of maximum photosynthesis (P max ), lower photosynthetic efficiency (alpha) and higher values of the saturation parameter (I k ) under high irradiance. The short-term acclimation strategy consisted of changing the PSU size, with a fixed number of PSUs, as revealed by similar P max but higher alpha and lower I k under low irradiance. Chlorophyll a contents followed the general pattern reported in green algae of higher concentrations under lower irradiance. Dark/light induction curves revealed consistently higher values of potential quantum yield under low irradiance. Initial and final values showed a higher recovery capacity in the short (84.4-90.6%) term exposure than in the long-term case (81.4-81.5%). ETR (electron transport rate) and NPQ (non-photochemical quenching) values were consistently higher under low irradiance. ETR showed a continuous and steady increase along the light exposure period in the short and long-term experiments, whereas NPQ values revealed a rapid increase after 15 seconds of light exposure, kept a slightly increasing trend and stabilized in most treatments. Lower photosynthetic performance (ETR) and recovery capacity of potential quantum yield were observed, particularly in long-term exposure, suggesting that this population is constrained by the typical high light environment of tropical regions.Keywords: acclimation, Cladophora, light, macroalgae, photosynthesis, tropical. ) e expostas a curto período (4 dias) e longo período (28 dias) em fotoperíodo de 12 horas. Curvas de fotossíntese-irradiância (FI) revelaram estratégias distintas de fotoaclimatação. Plantas expostas a longo período aclimataram pela alteração do número de unidades fotossintéticas (UF) e mantiveram fixo o tamanho das UF. Estas características foram reveladas por menores taxas de fotossíntese máxima (F max ), menor eficiência fotossintética (alfa) e valores mais altos do parâmetro de saturação (I k ) em alta irradiância. A estratégia de aclimatação em curto período consistiu em mudança no tamanho das UF, com número fixo de UF, conforme revelado por taxas semelhantes de fotossíntese máxima (F max ), maiores valores de alfa e menores de I k em baixa irradiância. Os conteúdos de clorofila a seguiram o padrão geral reportado para algas verdes de maiores concentrações em baixa irradiância. Curvas de indução escuro/luz revelaram valores consi...

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“…Incubation lengths were of 30 min for each irradiance level. Parameters from the PI curves were calculated by the equation proposed by Platt et al (1980) that includes a photoinhibition parameter because some charophyte species exhibited photoinhibition in previous studies Necchi, 2004b).…”

Section: Methodsmentioning

confidence: 99%

Photosynthetic characteristics of a tropical population of Nitella cernua (Characeae, Chlorophyta)

Vieira

Necchi

2006

Braz. J. Plant Physiol.

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Photosynthetic characteristics (assessed by chlorophyll fluorescence and O 2 evolution) were analysed monthly during one year in a tropical population of Nitella cernua from southeastern Brazil (20 o 50 32" S, 49 o 26 15" W). Parameters derived from photosynthesis-irradiance (PI) curves by fluorescence (high values of the photosynthetic parameter, I k , and lack or low values of photoinhibition, β) suggested adaptation to high irradiance, whereas those by O 2 evolution showed a different pattern (low values of I k and compensation irradiance, I c , high values of photosynthetic efficiency, α, and photoinhibition). Parameters from PI curves by O 2 evolution suggested light acclimation: I k and maximum photosynthetic rate, P max (as rETR, relative electron transfer rate) increased, whereas α became significantly lower under higher irradiance (winter). This pattern is an adjustment of both number and size of photosynthetic units. Photosynthetic performance assessed by fluorescence revealed two seasonal periods: higher values of P max (rETR), I k and nonphotochemical quenching from October to March (rainy season), and lower values from April to October (dry season). Temperature responses were observed only in summer, but temperature optima were different between methods: peaks of net photosynthesis occurred at 20 o C, whereas rETR increased towards higher temperatures (up to 30 o C). Dark respiration increased with higher temperatures. Current velocity had a stimulatory effect on photosynthetic rates, as suggested by positive correlations with P max (rETR) and α. pH experiments revealed highest net photosynthetic rates under pH 4.0, suggesting higher affinity for CO 2 than HCO 3 -. This broad range of responses of photosynthetic characteristics of this N. cernua population to irradiance, temperature, and pH/inorganic carbon reflects a wide tolerance to variations in these environmental variables, which probably contribute to the wide distribution of this species. Key words: charophytes, irradiance, Nitella, pH, photosynthesis, seasonal dynamics, temperature Características fotossintéticas de uma população tropical de Nitella cernua (Characeae, Chlorophyta): Foram analisadas mensalmente, durante um ano, as características fotossintéticas (por meio de fluorescência da clorofila e evolução de O 2 ) de uma população tropical de Nitella cernua do sudeste do Brasil (20 o 50 32" S, 49 o 26 15" W). Parâmetros derivados das curvas fotossíntese-irradiância (FI) por fluorescência (alto valor do parâmetro de saturação de luz, I k , e ausência ou baixa fotoinibição, β) sugeriram adaptação a alta irradiância, enquanto aqueles por evolução de oxigênio mostraram adaptações à sombra (baixo valores de I k e de irradiância de compensação, I c , altos valores de eficiência fotossintética, α, e β). Parâmetros das curvas FI por oxigênio sugeriram aclimatação à luz: I k e taxa fotossintética máxima, F max (analisada como rETR, taxa relativa de transporte de elétrons) aumentaram e α foi significativamente menor sob irradiância mais alta (i...

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Light-Related Photosynthetic Characteristics of Lotic Macroalgae

Cited by 33 publications

References 33 publications

Effects of irradiance and spectral composition on the establishment of macroalgae in streams in southern Brazil

Effects of irradiance and spectral composition on the establishment of macroalgae in streams in southern Brazil

Photoacclimation in a tropical population of Cladophora glomerata (L.) Kützing 1843 (Chlorophyta) from southeastern Brazil

Photosynthetic characteristics of a tropical population of Nitella cernua (Characeae, Chlorophyta)

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