Photosynthetica - Ahead of Print
Silicon improves the photosynthetic performance of black pepper plants inoculated with Fusarium solani f. sp. piperis
V. DꞌADDAZIO, J.V.G. SILVA, A.S. JARDIM, L.L. LONGUE, R.A.A. SANTOS, A.A. FERNANDES, M.B. SILVA, D.M. SILVA, T.A. SANTOS, E.R. SCHMILDT, L.H. PFENNING, A.R. FALQUETO
Photosynthetica X:X | DOI: 10.32615/ps.2019.182
This study evaluated the effect of silicon (Si)-supplementation in controlling the fusariosis in two Piper nigrum cultivars (Bragantina and Kottanadan). We hypothesized that susceptible cultivar improves the photosynthetic performance with Si-supplementation. Under greenhouse conditions, six-month-old plants were treated with silicon 30 and 15 d before inoculation with Fusarium solani f. sp. piperis and compared with untreated plants and with healthy control plants. All samples remained photosynthetically active after infection. Chlorophyll content, chlorophyll a fluorescence, and leaf gas-exchange parameters were less affected...
Ultrasonic seed treatment and Cu application modulate photosynthesis, grain quality, and Cu concentrations in aromatic rice
Z. MO, Q. LIU, W. XIE, U. ASHRAF, M. ABRAR, S. PAN, M. DUAN, H. TIAN, S. WANG, X. TANG
Photosynthetica X:X
The present study investigated the effects of ultrasonic seed treatment and Cu application on grain yield, photosynthesis, grain quality, and Cu contents of aromatic rice. The ultrasonic treated and nontreated seeds of two aromatic rice cultivars, i.e., Nongxiang 18 and Meixiangzhan 2, were sown in Cu-contaminated soil with 1.5 and 3.0 g(Cu) m-2 whereas the soil without Cu application was taken as control (CK). Ultrasonic seed treatment and Cu application increased grain yield by 2.7-33.5% in Nongxiang 18 and by 12.9-20.2% in Meixiangzhan 2 owing to substantial improvements in morphophysiological and yield-related traits. Both ultrasonic...
Photosynthetic characteristics and growth performance of lettuce (Lactuca sativa L.) under different light/dark cycles in mini plant factories
J. ZHOU, J.Z. WANG, T. HANG, P.P. LI
Photosynthetica X:X | DOI: 10.32615/ps.2020.013
We investigated the photosynthesis and growth of lettuce (Lactuca sativa L.) grown under three light/dark cycles in a mini plant factory with artificial illumination. A relative longer light cycle [12/12 h (light/dark)] increased not only light-response curve parameters, such as light-saturated net photosynthetic rate, light-saturation point, light-compensation point, dark respiration rate, but also upregulated CO2-response curves parameters, such as CO2-saturated net photosynthetic rate, initial carboxylation efficiency, and photorespiration rate, compared to those of the shorter light cycles [6/6 h and 3/3 h (light/dark)]....
Effects of exogenous zinc on the photosynthesis and carbonic anhydrase activity of millet (Setaria italica L.)
M.L. CAO, Y.X. LI, H.L. DU
Photosynthetica X:X | DOI: 10.32615/ps.2020.018
This study aimed to evaluate the effects of Zn on the growth safety and activity of carbonic anhydrase (CA) in foxtail millet (Setaria italica L.). The photosynthetic characteristics, CA activity, and relative gene expression of different varieties of millet at the seedling stage were studied by spraying Zn solution under pot experiment and indoor culture conditions. Results showed that spraying low-concentration Zn solution (20, 40, and 60 mg L-1) reduced malondialdehyde content and intercellular CO2 concentration (Ci) but increased antioxidant enzyme activity, pigment content, and photosynthetic...
Light stability of the isolated CP43 studied by infrared and terahertz spectroscopy
Y.G. QU, X.L. WANG, T.Y. KUANG
Photosynthetica X:X
Here, the light-induced changes of the core antenna complex chlorophyll protein 43 (CP43) isolated from PSII of spinach were assessed using infrared and terahertz (THz) spectroscopy. We found that the collective vibrational modes at low frequencies and the secondary structures of CP43 were altered upon illumination. The helix changed more than any other secondary structure. CP43 is more easily damaged by illumination than PSII. Infrared and THz spectroscopy have different functions in protein studies. THz spectroscopy has potential in evaluating the stability of proteins.
Transcription analysis of chlorophyll biosynthesis in wildtype and chlorophyll b-lacking rice (Oryza sativa L.)
M.K. NGUYEN, T.H. SHIH, S.H. LIN, W.D HUANG, C.M. YANG
Photosynthetica X:X | DOI: 10.32615/ps.2020.022
The aim of the present study was to investigate the photosynthetic properties and transcriptomic profiles of wildtype and chlorophyll (Chl) b-lacking rice (Oryza sativa L.). The plastid ultrastructure of the Chl b-lacking rice (i.e., loss of starch granules, abundant vesicles, and abundant plastoglobuli) indicated abnormal plastid development, whereas the analysis of transcriptome profiles and differentially expressed genes revealed that gene encoding PsbR (PSII core protein) was downregulated in the mutant, thereby reducing the Chl accumulation of the mutant. Meanwhile, in regards to Chl biosynthesis and degradation pathways,...
Neodymium improves the activity of ascorbate-glutathione cycle and chloroplast function of wheat seedlings under chromium stress
N.H. LU, L.M. WU, R. YANG, H. LI, C.J. SHAN
Photosynthetica X:X | DOI: 10.32615/ps.2020.024
We investigated the roles of neodymium trichloride (NdCl3) in regulating ascorbate-glutathione (AsA-GSH) cycle and chloroplast function of chromium (Cr)-stressed wheat seedlings. The findings showed that Cr stress markedly increased malondialdehyde (MDA) content, electrolytic leakage (EL), nonphotochemical quenching, and the activities of enzymes in AsA-GSH cycle, compared with control. However, Cr stress markedly reduced the ratios of reduced ascorbate to dehydroascorbate and reduced glutathione to oxidized glutathione, net photosynthetic rate, the contents of chlorophylls and carotenoids, maximum photochemical efficiency of PSII, photochemical...
Endogenous ascorbic acid delays ethylene-induced leaf senescence in Arabidopsis thaliana
X.T. ZHENG, Z.C. YU, X.F. CHEN, M.L. CAI, Y.Z. WANG, C.L. PENG
Photosynthetica X:X | DOI: 10.32615/ps.2020.028
Leaf senescence is an important event in the plant life cycle. Ethylene and ascorbic acid (AsA) both regulate the leaf senescence process. The role of endogenous AsA in ethylene-induced leaf senescence was explored in two independent endogenous AsA changing Arabidopsis thaliana mutants. The line vtc2-1 with a single base change in VTC was AsA-deficient mutant; the GLDH-overexpressing line (GLDHOE) driven by the CaMV 35S promoter was AsA-overaccumulating mutant. After spraying 600 μM ethephon for 6 d, vtc2-1 showed the most serious leaf chlorosis, reactive oxygen species (ROS) accumulation, chlorophyll breakdown,...
Light reacclimatization of lower leaves in C4 maize canopies grown at two planting densities
T. YABIKU, S. AKAMATSU, O. UENO
Photosynthetica X:X | DOI: 10.32615/ps.2020.029
C4 plants have high photosynthetic capacity but are inefficient under low light. In a canopy, lower leaves developed under high light are progressively shaded. To elucidate how lower leaves in a C4 canopy reacclimatize to low light, we investigated maize canopies differing in light environment grown at standard and low planting densities (SPD, LPD). Although upper leaves at SPD and both upper and lower leaves at LPD had light-response curves of photosynthesis of sun leaves, lower leaves at SPD had that of shade leaves. All leaves at both densities had anatomical framework of sun leaves, but the chloroplast content in mesophyll...