Comparison of thermostability of PSII between the chromatic and green leaf cultivars of Amaranthus tricolor L.

Title:

Comparison of thermostability of PSII between the chromatic and green leaf cultivars of Amaranthus tricolor L.

Creator:

Shu, Z., Shao, L., Huang, H.-Y., Zeng, X.-Q., Lin, Z.-F., Chen, G.-Y., and Peng, C.-L.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:446dd57a-d6da-4959-b459-4f1935fd87c4
uuid:446dd57a-d6da-4959-b459-4f1935fd87c4
issn:0300-3604
doi:10.1007/s11099-009-0080-x

Subject:

Amaranthus tricolor L., betacyanins accumulation, circadian oscillation, high temperature, and thermal stability of PSII

Type:

model:article and TEXT

Format:

bez média and svazek

Description:

In the present study, we investigated the antioxidative potential in leaves of the chromatic (CC) versus green (GC) Amaranthus tricolor L. under moderate high-temperature stress at 45°C. Before heat stress, CC had significantly higher levels of betacyanins [about 3.2 mg g-1(FM)] than the green [1.8 mg g-1(FM) (p<0.01), while similar chlorophyll (Chl) content [about 2 mg g-1(FM)] was observed between both cultivars. After exposure to high temperature (45°C) for 6 days, betacyanins in leaves of CC were remarkably increased (about 2 times of that in control samples grown at 30°C). In contrast, betacyanins in GC significantly decreased by 56% in comparison with that of the control. Chl level in CC was higher than that in GC after heat stress for 6 days. Flavonoids and total phenolics in both cultivars were increased, but much more in CC. Significantly less H2O2 accumulation was observed in the leaves and stems of CC than in those of GC under heat stress. Interestingly, much stronger circadian oscillation in fluorescence was observed in both cultivars after treatment at 45°C, which suggested that heat stress stimulates endogenous rhythms of photosystem II (PSII). Under moderate high-temperature stress, Chl fluorescence parameters Fv/Fm (maximum quantum yield of PSII), qP (coefficient of photochemical quenching), ΦPSII (effective PSII quantum yield), and ETR (electron transport rate) exhibited a gradual decrease, NPQ (nonphotochemical quenching) showed a slight increase followed by a gradual decline, whereas Fo (minimum fluorescence of a dark-adapted leaf) increased continuously. In contrast to GC, after 120 h of high-temperature treatment, CC exhibited significantly lower Fo level, and higher levels of Fv/Fm and NPQ. It is clear that PSII in CC was more stable than that in GC. The results indicate that betacyanins are an effective antioxidant, and probably contribute greatly to the higher thermal stability of PSII and higher tolerance to heat stress. and Z. Shu ... [et al.].

Language:

Multiple languages

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Coverage:

548-558

Source:

Photosynthetica | 2009 Volume:47 | Number:4

Harvested from:

CDK

Metadata only:

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