EDITORIAL

M. LANDI, M. BRESTIC, S. KATARIA, S.I. ALLAKHVERDIEV

Photosynthetica 2023, 61(2):135-137 | DOI: 10.32615/ps.2023.024  

Influence of phytochromes on microRNA expression, phenotype, and photosynthetic activity in A. thaliana phy mutants under light with different spectral composition

P. PASHKOVSKIY, V. KRESLAVSKI, A. KHUDYAKOVA, A. KOSOBRYUKHOV, Vl.V. KUZNETSOV, S.I. ALLAKHVERDIEV

Photosynthetica 2023, 61(2):138-147 | DOI: 10.32615/ps.2022.036  

Light-induced changes in miRNAs, morphogenesis, and photosynthetic processes in phytochrome-deficient mutant plants grown under different light qualities were studied. miRNA activity in many processes is regulated by phytochromes and phytochrome-interacting factors (PIFs). The reduced content of photoreceptors in phytochrome mutants affects the PIF-microRNA interaction. In plants grown under red light (RL) and white light (WL), the phenotype of phyb mutant was distorted; however, under blue light (BL) conditions, the phyb phenotype was normalized. The photosynthetic rates of both the mutants and wild type were higher under BL than under...

Effects of abiotic stress on photosystem II proteins

M. LANDI, L. GUIDI

Photosynthetica 2023, 61(2):148-156 | DOI: 10.32615/ps.2022.043  

Photosystem II (PSII) represents the most vulnerable component of the photosynthetic machinery and its response in plants subjected to abiotic stress has been widely studied over many years. PSII is a thylakoid membrane-located multiprotein pigment complex that catalyses the light-induced electron transfer from water to plastoquinone with the concomitant production of oxygen. PSII is rich in intrinsic (PsbA and PsbD, namely D1 and D2, CP47 or PsbB and CP43 or PsbC) but also extrinsic proteins. The first ones are more largely conserved from cyanobacteria to higher plants while the extrinsic proteins are different among species. It has been found that...

Changes in ultrastructure, photosynthetic abilities, and secondary metabolite due to individual and interactive effects of chromium and ultraviolet-B radiation in Adhatoda vasica

A. PANDEY, D. JAISWAL, M. AGRAWAL, S.B. AGRAWAL

Photosynthetica 2023, 61(2):157-167 | DOI: 10.32615/ps.2022.042  

The study was executed to assess individual and interactive effects of elevated ultraviolet-B (eUV-B) radiation and chromium (Cr) on a medicinal plant Adhatoda vasica Nees. The experiment was conducted under field conditions involving control, Cr, eUV-B, and Cr+eUV-B treatments. The results showed that Cr content was the highest in roots as compared to other parts under Cr+eUV-B. Significant reductions in photosynthetic rate, intercellular CO₂ concentration, and stomatal conductance were observed under all treatments with maximum under Cr+eUV-B. Chlorophyll (Chl) fluorescence parameters showed variable responses under Cr and Cr+eUV-B....

Light intensity affects tolerance of pyrene in Chlorella vulgaris and Scenedesmus acutus

R.S. TOMAR, R. ATRE, D. SHARMA, P. RAI-KALAL, A. JAJOO

Photosynthetica 2023, 61(2):168-176 | DOI: 10.32615/ps.2022.044  

The impact of light intensity on the toxicity of pyrene, a 4-ring polycyclic aromatic hydrocarbon (PAH), was studied in Chlorella vulgaris and Scenedesmus acutus. Both species were cultured under low light, LL [50-60 µmol(photon) m^-2 s^-1], and high light, HL [100-110 µmol(photon) m^-2 s^-1] conditions to study the effects of pyrene (PYR) toxicity on growth parameters, the content of biomolecules, chlorophyll content, and photosynthetic efficiency. In the presence of PYR, S. acutus could grow well in LL and HL intensity. On the other hand, C. vulgaris showed a drastic...

Moderate photoinhibition of PSII and oxidation of P700 contribute to chilling tolerance of tropical tree species in subtropics of China

V.S.J. SUNOJ, Y. WEN, A. JAJOO, A.W. SHORT, W.H. ZENG, N.I. ELSHEERY, K.F. CAO

Photosynthetica 2023, 61(2):177-189 | DOI: 10.32615/ps.2022.039  

In the subtropics, a few tropical tree species are distributed and planted for ornamental and horticultural purposes; however, the photosynthesis of these species can be impaired by chilling. This study aimed to understand how these species respond to chilling. Light-dependent and CO₂ assimilation reactions of six tropical tree species from geographically diverse areas, but grown at a lower subtropical site in China, were monitored during a chilling (≤ 10°C). Chilling induced stomatal and nonstomatal effects and moderate photoinhibition of PSII, with severe effect in Ixora chinensis. Woodfordia fruticosa was little affected...

Changes in the photosynthetic performance, the activity of enzymes of nitrogen metabolism, and proline content in the leaves of wheat plants after exposure to low CO₂ concentration

A. IVANOV, A. KOSOBRYUKHOV, V. KRESLAVSKI, S.I. ALLAKHVERDIEV

Photosynthetica 2023, 61(2):190-202 | DOI: 10.32615/ps.2022.047  

The changes in photosynthetic activity, as well as the activity of nitrogen-metabolism enzymes, the intensity of lipid peroxidation, and proline content were studied in Triticum aestivum L. plants after their incubation at a low CO₂ concentration in a sealed chamber for 10 d. CO₂ deficiency (-CO₂) compared to normal CO₂ concentration (control) led to a decrease in the rate of O₂ gas exchange at the plateau of the light curve and quantum yield of photosynthesis. The maximum and effective quantum photochemical yields also decreased. CO₂ deficiency reduced the activity of nitrate...

Intraspecific variation in photosynthetic efficiency in soybean (Glycine max L.) varieties towards solar ultraviolet radiations

S.S. BARONIYA, K. JUMRANI, M. BARONIYA, K.N. GURUPRASAD, M. LANDI, S. KATARIA

Photosynthetica 2023, 61(2):203-214 | DOI: 10.32615/ps.2022.048  

In the current study, we used four soybean varieties PK-1029, PK-472, NRC-7, and Hardee to examine the effect of exclusion of solar UV radiation on photosynthetic efficiency and to test possible variety-dependent sensitivity to ambient UV (280-400 nm). Plants that were grown under UV exclusion filters had higher chlorophyll a and b, efficiencies of PSII and more active reaction centers indicated that PSII were substantially affected by solar UV radiation. The significant increase in net photosynthesis was linked to increased stomatal conductance and lower intercellular concentration of CO₂ in UV-excluded plants. The exclusion...

Impact of additional green light and deficit in cryptochrome 1 on photosynthetic activity and pro-/antioxidant balance in Arabidopsis thaliana

V. KRESLAVSKI, A. KHUDYAKOVA, A. KOSOBRYUKHOV, P. PASHKOVSKIY, M. VERESHCHAGIN, T. BALAKHNINA, H.F. ALHARBY, S.I. ALLAKHVERDIEV

Photosynthetica 2023, 61(2):215-224 | DOI: 10.32615/ps.2023.009  

The light spectral composition acting through a set of photoreceptors, such as cryptochromes and phytochromes, plays an important role in maintaining sustainable photosynthesis. An impact of cryptochrome 1 deficiency and additions of green light (GL) against the background of red (RL) and blue (BL) (different ratios of RL:BL:GL) on the activity of the photosynthetic apparatus, the content of photosynthetic pigments, pro-/antioxidant balance, and expression of some genes in the leaves of 23-d-old Arabidopsis thaliana hy4 mutant plants was studied. The deficiency of cryptochrome 1 at RL/BL ratio of 4:1 led to a decrease in the rate of...

Variation in leaf mesophyll anatomy of fern species imposes significant effects on leaf gas exchange, light capture, and leaf hydraulic conductance

S. FUJII, K. NISHIDA, T.K. AKITSU, A. KUME, Y.T. HANBA

Photosynthetica 2023, 61(2):225-235 | DOI: 10.32615/ps.2023.017  

The mesophyll anatomical traits are essential factors for efficient light capture, CO₂ diffusion, and hydraulics in leaves. At the same time, leaf hydraulics are governed by the xylem anatomical traits. Thus, simultaneous analyses of the mesophyll and xylem anatomy will clarify the links among light capture, CO₂ capture, and water use. However, such simultaneous analyses have been scarcely performed, particularly on non-seed plants. Using seven fern species, we first showed that fern species with a large mesophyll thickness had a high photosynthetic rate related to high light capture, high drought tolerance, and low leaf hydraulic...

Effect of UV exclusion and AMF inoculation on photosynthetic parameters of Glycine max

P. LAAD, P. PATEL, K.N. GURUPRASAD, M.P. SHARMA, S. KATARIA, M. BRESTIC

Photosynthetica 2023, 61(2):236-243 | DOI: 10.32615/ps.2023.014  

The study aims to understand the effect of UV exclusion and arbuscular mycorrhizal fungi (AMF) inoculation on the photosynthetic parameters of soybean. The study was conducted in nursery bags and plants were grown under iron mesh covered with UV cut-off filters. The plants grown under the exclusion of UV with AMF inoculation (I) showed higher photosynthetic pigments, carbonic anhydrase activity, reduced internal CO₂ concentration, enhanced transpiration rate, and stomatal conductance as well as improved photosynthetic rate over uninoculated plants. Moreover, -UVB+I and -UVAB+I plants exhibited an increased performance index, the activity...

The basalt dust deposition on leaves does not influence the measurement of ecophysiological traits in grapevine

F. PETRACCA, C. ARENA, C. CIRILLO, V. DE MICCO

Photosynthetica 2023, 61(2):244-249 | DOI: 10.32615/ps.2023.013  

In many crops, including grapevine, the distribution of reflecting dust on foliage is a practice potentially leading to the mitigation of environmental stresses such as excessive light and limited water supply. This study aimed to evaluate whether the presence of dust on the leaves may affect PSII photochemical efficiency and gas-exchange measurements, thus leading to biased results. The study was conducted in a winery located at Benevento (Italy) on Vitis vinifera L. subsp. vinifera 'Falanghina' where the application of basalt dust was tested on the canopy to alleviate the effects of water stress. The results showed that there is no...

Photosystems under high light stress: throwing light on mechanism and adaptation

N. SHARMA, S. NAGAR, M. THAKUR, P. SURIYAKUMAR, S. KATARIA, A.K. SHANKER, M. LANDI, A. ANAND

Photosynthetica 2023, 61(2):250-263 | DOI: 10.32615/ps.2023.021  

High light stress decreases the photosynthetic rate in plants due to photooxidative damage to photosynthetic apparatus, photoinhibition of PSII, and/or damage to PSI. The dissipation of excess energy by nonphotochemical quenching and degradation of the D1 protein of PSII and its repair cycle help against photooxidative damage. Light stress also activates stress-responsive nuclear genes through the accumulation of phosphonucleotide-3'-phosphoadenosine- 5'-phosphate, methylerythritol cyclodiphosphate, and reactive oxygen species which comprise the chloroplast retrograde signaling pathway. Additionally, hormones, such as abscisic acid, cytokinin, brassinosteroids,...