Concentration and Function of Membrane-Bound Cytochromes in Cyanobacterial Heterocysts

Houchins, Jeffrey P.; Hínd, Geoffrey

doi:10.1104/pp.76.2.456

Cited by 42 publications

(7 citation statements)

References 17 publications

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“…The contents of cyt b 559HP , b 559LP , b 563 , and f were measured according to Houchins and Hind (1984). Values were obtained at 545 nm, using the isosbestic wavelengths of 545 and 568 nm for cyt b 559 .…”

Section: Methodsmentioning

confidence: 99%

Mechanisms of energy dissipation in peanut under water stress

Lauriano¹,

Ramalho²,

Lidon³

et al. 2006

Photosynt.

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Effect of drought on the mechanisms of energy dissipation was evaluated in two-month-old Arachis hypogaea cvs. . Plants were submitted to three treatments: control (C), mild water stress (S1), and severe water stress (S2). Photosynthetic performance was evaluated as the Hill and Mehler reactions. These activities were correlated with the contents of the low and high potential forms of cytochrome (cyt) b 559, plastoquinone, cyt b 563 , and cyt f. Additionally, the patterns of carotenoids and chlorophylls (Chls), as well as the alterations of Chl a fluorescence parameters were studied. Under mild water stress the regulatory mechanism at the antennae level was effective for 57-422 and GC 8-35, while in the cv. 73-30 an overcharge of photosynthetic apparatus occurred. Relative to this cv., under S1 the stability of carotene and the dissipative cycle around photosystem (PS) 2 became an important factor for the effective protection of the PS2 reaction centres. The cyclic electron flow around PS1 was important for energy dissipation under S1 only for the cvs. 57-422 and 73-30.

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Section: Methodsmentioning

confidence: 99%

Mechanisms of energy dissipation in peanut under water stress

Lauriano¹,

Ramalho²,

Lidon³

et al. 2006

Photosynt.

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“…7 g FW, from 3 plants (in triplicate), following the procedures of Spiller and Terry (1980) with modifications for coffee leaves (Ramalho et al, 1999). The concentrations of cytochromes (Cyt) b 559LP , b 559HP , b 563 and f were obtained using a spectrophotometer (UV-Vis Shimadzu UV-1800, Japan) with readings at 545 nm, with isosbest wavelengths of 528 and 568 nm for cytochrome b 559 , and 552 and 572 nm for cytochrome b 563 (Houchins and Hind, 1984), An extinction coefficient of 20 mmol L -1 cm -1 was assumed. For Cyt f concentration, readings were performed at 554 nm, and an extinction coefficient of 19.7 mmol L -1 cm -1 was used.…”

Section: Thylakoid Electron Carriersmentioning

confidence: 99%

Resilient and Sensitive Key Points of the Photosynthetic Machinery of Coffea spp. to the Single and Superimposed Exposure to Severe Drought and Heat Stresses

et al. 2020

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This study unveils the single and combined drought and heat impacts on the photosynthetic performance of Coffea arabica cv. Icatu and C. canephora cv. Conilon Clone 153 (CL153). Well-watered (WW) potted plants were gradually submitted to severe water deficit (SWD) along 20 days under adequate temperature (25/20°C, day/night), and thereafter exposed to a gradual temperature rise up to 42/30°C, followed by a 14-day water and temperature recovery. Single drought affected all gas exchanges (including A max) and most fluorescence parameters in both genotypes. However, Icatu maintained F v /F m and RuBisCO activity, and reinforced electron transport rates, carrier contents, and proton gradient regulation (PGR5) and chloroplast NADH dehydrogenase-like (NDH) complex proteins abundance. This suggested negligible non-stomatal limitations of photosynthesis that were accompanied by a triggering of protective cyclic electron transport (CEF) involving both photosystems (PSs). These findings contrasted with declines in RuBisCO and PSs activities, and cytochromes (b 559 , f, b 563) contents in CL153. Remarkable heat tolerance in potential photosynthetic functioning was detected in WW plants of both genotypes (up to 37/28°C or 39/30°C), likely associated with CEF in Icatu. Yet, at 42/30°C the tolerance limit was exceeded. Reduced A max and increased C i

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“…The chloroplast pellet was resuspended in 40 mM Hepes (pH 7.5) and the concentrations of high and low potential forms of Cyt b 559 as well as b 563 were determined by measuring reduced-minus-oxidised difference spectra according to Houchins and Hind (1984). Absorbance changes were measured at 545 nm by considering a straight line drawn through the following isobests: Cyt b 559 , 548-568; Cyt b 563 , 552-572.…”

Section: Photosynthetic Electron Carriersmentioning

confidence: 99%