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Start Over Coverage 529-537

1. Decline of photosynthetic pigments, ribulose-1,5-bisphosphate carboxylase and soluble protein contents, nitrate reductase and photosynthetic activities, and changes in thylakoid membrane protein pattern in canopy shade grapevine (Vitis vinifera L. cv. Moscato giallo) leaves

Creator:
Bertamini, M. and Nedunchezhian, N.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
carotenoids, chlorophyll, donor side, electron transport, fluorescence, nitrate reductase, and photosystems 1 and 2
Language:
Multiple languages
Description:
In canopy shade leaves of grapevine (Vitis vinifera L. cv. Moscato giallo) grown in the field the contents of chlorophyll (Chl), carotenoids (Car), and soluble protein per fresh mass were lower than in sun leaves. RuBPC activity, in vivo nitrate reductase activity (indicator of nitrate utilisation), apparent electron transport rate, and photochemical fluorescence quenching were also significantly reduced in canopy shade leaves. When various photosynthetic activities were followed in isolated thylakoids, canopy shade leaves exerted a marked inhibition of whole chain and photosystem (PS) 2 activity. Smaller inhibition of PS1 activity was observed even in high-level canopy shade (HS) leaves. The artificial exogenous electron donors, DPC and NH2OH, significantly restored the loss of PS2 activity in HS leaves. Similar results were obtained when Fv/Fm was evaluated by Chl fluorescence measurements. The marked loss of PS2 activity in canopy shade leaves was due to the loss of 47, 43, 33, 28-25, 23, 17, and 10 kDa polypeptides. and M. Bertamini, N. Nedunchezhian.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2. Monitoring cashew seedlings during interactions with the fungus Lasiodiplodia theobromae using chlorophyll fluorescence imaging

Creator:
Muniz, C. R., Freire, F. C. O., Viana, F. M. P., Cardoso, J. E., Sousa, C. A. F., Guedes, M. I. F., Van der Schoor, R., and Jalink, H.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fotosyntéza, photosynthesis, Brazílie severovýchodní, Brasil, North-eastern, kešu, Anacardium occidentale, gummosis, plant disease detection, high-throughput screening, cashew, 2, and 581
Language:
Multiple languages
Description:
The chlorophyll (Chl) fluorescence imaging technique was applied to cashew seedlings inoculated with the fungus Lasiodiplodia theobromae to assess any disturbances in the photosynthetic apparatus of the plants before the onset of visual symptoms. Two-month-old cashew plants were inoculated with mycelium of L. theobromae isolate Lt19 or Lt32. Dark-adapted and light-acclimated whole plants or previously labelled, single, mature leaf from each plant were evaluated weekly for Chl fluorescence parameters. From 21 to 28 days, inoculation with both isolates resulted in the significantly lower maximal photochemical quantum yield of PSII (Fv/Fm) than those for control samples, decreasing from values of 0.78 to 0.62. In contrast, the time response of the measured fluorescence transient curve from dark-acclimated plants increased in both whole plants and single mature leaves in inoculated plants compared with controls. The Fv/Fm images clearly exhibited photosynthetic perturbations 14 days after inoculation before any visual symptoms appeared. Additionally, decays in the effective quantum yield of PSII photochemistry and photochemical quenching coefficient were also observed over time. However, nonphotochemical quenching increased during the evaluation period. We conclude that Fv/Fm images are the effective way of detecting early metabolic perturbations in the photosynthetic apparatus of cashew seedlings caused by gummosis in both whole plants and single leaves and could be potentially employed in larger-scale screening systems., C. R. Muniz, F. C. O. Freire, F. M. P. Viana, J. E. Cardoso, C. A. F. Sousa, M. I. F. Guedes, R. van der Schoor, H. Jalink., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3. Photosynthetic apparatus performance and anatomical modulations of Alcantarea imperialis (Bromeliaceae) exposed to selenium during in vitro growth

Creator:
Martins, J.P.R., Moreira, S.W., Braga, P.C.S., Conde, L.T., Cipriano, R., Falqueto, A.R., and Gontijo, A.B.P.L.
Format:
počítač and online zdroj
Type:
model:article and TEXT
Subject:
bromeliad, chlorophyll a fluorescence, electron transport, plant anatomy, and plant tissue culture
Language:
Multiple languages
Description:
Elements not usually included in culture medium formulations, such as selenium (Se), may have beneficial effects on micropropagated plants. We evaluated the effects of Se on the physiological and anatomical responses of Alcantarea imperialis during in vitro culture. Plants were cultured in a medium containing a gradient of Se concentrations (0, 4, 8, 16, or 32 µM Se). After 56 d, the growth traits, chlorophyll a fluorescence, and root and leaf anatomy were analyzed. The fresh mass declined at the highest Se concentration. Higher Se concentrations induced bigger stomata, while the stomatal density decreased. Plants cultured with Se had improved PSII and PSI electron transport. This led to higher values of the total performance index. Thus, Se-induced plants showed a higher electron transport dynamics and energy conservation from water to PSI and developed anatomical traits that can favor tolerance to water deficit.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public