Photosynthetica - Ahead of Print
Phosphate fertilizers increase CO2 assimilation and yield of soybean in a shaded environment
W. ZHAO, B. ZHENG, T.H. REN, X.H. ZHANG, T.Y. NING, G. LI
Photosynthetica X:X | DOI: 10.32615/ps.2021.063 
Two light treatments [ambient sunlight (L1) during the entire growth period and 40% shade (L2) from 40 d after sowing until 24 d after flowering] and two phosphate fertilizer treatments [no phosphate fertilizer application (P0) and a conventional phosphate fertilizer application (P1)] were used to determine how phosphate fertilizer regulates soybean [Glycine max (L.) Merr.] photosynthesis under shading. We showed that phosphorus significantly increased chlorophyll content and grain yield under shading. The light-saturated net photosynthetic rate, apparent quantum yield, maximum electron transport rate, and maximum Rubisco carboxylation rate...
Partial shade improved the photosynthetic capacity and polysaccharide accumulation of the medicinal plant Bletilla ochracea Schltr.
X.F. YU, X.Y. MING, M. XIONG, C. ZHANG, L.J. YUE, L. YANG, C.Y. FAN
Photosynthetica X:X | DOI: 10.32615/ps.2021.064
To study the light intensity suitable for Bletilla ochracea Schltr., morphology, photosynthetic parameters, and polysaccharide content of seedlings were evaluated under different light intensities. All shade treatments promoted plant growth and net photosynthetic rate while having no significant effect on transpiration rate. The maximum photochemical efficiency and potential photochemical efficiency reached the lowest values under full sunlight. The electron transport rate and photochemical quenching under shade were significantly higher than those under full light, while nonphotochemical quenching was the highest under full light. This indicated...
Effect of short-term combined alkaline stress on antioxidant metabolism, photosynthesis, and leaf-air temperature difference in sorghum
J.J. GUO, X.X. XU, R.D. ZHANG, X.F. CHEN, Y.F. XING, B. LI, C. LIU, Y.F. ZHOU
Photosynthetica X:X | DOI: 10.32615/ps.2021.067
Alkaline stress is important abiotic stress that restricts the growth and physiological activity of sorghum (Sorghum bicolor L. Moench). We aimed to investigate the effects of alkaline stress on alkali-tolerant SX44B and alkali-sensitive 262B sorghum inbred lines. The results showed that alkaline stress decreased the content of chlorophyll, activity of photosystem II, net photosynthetic rate, and destroyed chloroplast morphology. These changes were less pronounced in SX44B, possibly owing to its higher antioxidant enzyme activity and nonphotochemical quenching. Alkaline stress decreased water content, transpiration rate, and stomatal conductance...
Effects of source-sink alteration by pruning on physiological parameters and fruit production of Rosa roxburghii Tratt. on the Yunnan-Guizhou Plateau in China
C. ZHANG, K. YAN, L.Z. LIN, Y.M. FANG, X.Y. ZHANG
Photosynthetica X:X | DOI: 10.32615/ps.2022.001
The formation of economic yield and fruit quality of Roxburgh rose (Rosa roxburghii Tratt.) depends essentially on its source-sink interaction. Thus, a pruning experiment was conducted to assess the effects of source-sink regulation on photosynthetic physiology and fruit yield of Roxburgh rose, which was of great significance to production. Cutting off vegetative branches reduced physiological fruit loss and malformed fruits but increased single fruit quality and yield. Results revealed that the stomatal characteristics, the composition of mesophyll tissue, and photosynthesis of leaves on reproductive branches were significantly affected by...
Nitrogen rate and plant density interaction enhances grain yield by regulating the grain distribution of secondary branches on the panicle axis and photosynthesis in japonica rice
Y.L. GONG, Y. LEI, X.P. ZHANG, B.C. YAN, X.T. JU, X.Y. CHENG, J.D. ZHANG, X.Y. SUN, H. XU, W.F. CHEN
Photosynthetica X:X | DOI: 10.32615/ps.2022.002
Two japonica rice cultivars with different panicle trait index (PTI), HP917 (a high-PTI cultivar) and DP128 (a low-PTI cultivar) were used to investigate the effects of the nitrogen (N) rate and plant density on the grain distribution of secondary branches on the panicle axis, leaf photosynthetic characteristics, and grain yield by a split plot design. The main plots were assigned to four N rates (0, 140, 200, and 260 kg ha-1), and the subplots were assigned to two plant densities: (D20, 15 plants m-2; D10, 30 plants m-2). Results showed that the grain yield was increased by increasing N rate...
Chloroplast protease/chaperone AtDeg2 holds γ1 subunit of ATP synthase in an unaggregated state under high irradiance conditions in Arabidopsis thaliana
P. JAGODZIK, G. JACKOWSKI
Photosynthetica X:X | DOI: 10.32615/ps.2022.004
Little data on the role played in vivo by chloroplast protein AtDeg2 as a chaperone is available. Therefore, we sought for chloroplast proteins protected from high irradiance-induced interprotein aggregation via disulphide bridges by AtDeg2 acting as a holdase. To reach this goal, we performed analyses which involved comparative diagonal electrophoreses of lysates of chloroplasts isolated from wild type (WT) plants and transgenic plants 35S:AtDEG2ΔPDZ1-GFP which expressed AtDeg2 lacking its chaperone activity but retaining the protease activity. The results of the analyses indicate that AtDeg2 acting...
Transgenerational effect of UV-B priming on photochemistry and associated metabolism in rice seedlings subjected to PEG-induced osmotic stress
A. SEN, J.T. PUTHUR, D. CHALLABATHULA, M. BRESTIČ
Photosynthetica X:X | DOI: 10.32615/ps.2022.006
Rice being the major food crop for more than half of the world population is severely affected by drought stress starting from the establishment of the seedling. We focused on the UV-B priming mediated transgenerational drought tolerance of a drought-tolerant rice variety (Vaisakh) towards polyethylene glycol (PEG) 6,000 (20%)-induced drought. Results showed that priming in F0 generation and re-priming in F1 generation with UV-B enhanced the PEG stress tolerance potential of rice seedlings with increased expression of genes encoding antioxidant enzymes and stress-related proteins offering better protection to primed plants. UV-B...
Chlorophyll measurements in Alstroemeria sp. using SPAD-502 meterand the color space CIE L*a*b*, and its validation in foliar senescence
I. VILLEGAS-VELÁZQUEZ, H.A. ZAVALETA-MANCERA, M.L. ARÉVALO-GALARZA, J. SUAREZ-ESPINOSA, C. GARCIA-OSORIO, D. PADILLA-CHACON, I.G. GALVAN-ESCOBEDO, J.F. JIMENEZ-BREMONT
Photosynthetica X:X | DOI: 10.32615/ps.2022.007
Our research aimed to study the correlation between the SPAD-502 readings and the color space CIE L*a*b* values in two cultivars of Alstroemeria sp. during leaf senescence and to evaluate the statistical criteria used in the selection of the best fit calibration functions. We demonstrate the importance of the Akaike information criterion and the parsimonious function besides the coefficient of determination. The reliability of the functions was tested by Student's t-test comparison between the chlorophyll (Chl) estimated from SPAD readings and their chemical concentrations. Polynomial and Hoerl function described well the...
Vertical profile of photosynthetic CO2 response within rice canopy
Y.P. LV, Y. PAN
Photosynthetica X:X | DOI: 10.32615/ps.2022.011
Leaf-specific Farquhar-von Caemmerer-Berry (FvCB) model was fitted to characterize the vertical profile of photosynthetic CO2 response within rice canopy. Leaf-position-specific and canopy average FvCB models were fitted to study a suitable leaf representing photosynthetic parameters at the canopy scale. The results showed that leaf photosynthesis was limited by Rubisco activity or ribulose-1,5-bisphosphate regeneration under field conditions. The maximum rate of carboxylation, maximum rate of electron transport, rate of triose phosphates utilization, and light respiration rate in the FvCB model reached the highest values for the top second...
Leaf structure and photosynthesis in Populus alba under naturally fluctuating environments
X.Y. LIN, X.X. WANG, Q.Y. ZENG, Q. YANG
Photosynthetica X:X | DOI: 10.32615/ps.2022.012
The ability to modulate photosynthesis is essential for plants to adapt to fluctuating growing conditions. Populus species show high tolerance to various and highly variable environments. To understand their response strategies against fluctuating environments, this study investigated the morphological and physiological differences of white poplar (Populus alba) leaves when grown in a phytotron, glasshouse, and field. Our results show that the palisade cells were elongated in the field, which would enhance intercellular CO2 exchange. Photosynthetic capacity was the highest in the field leaves, as shown by higher electron transport...
The role of photosynthetic activity in the regulation of flg22-induced local and systemic defence reaction in tomato
Z. Czékus, P. Koprivanacz, A. Kukri, N. Iqbal, A. Ördög, P. Poór
Photosynthetica X:X | DOI: 10.32615/ps.2022.015
Flagellin (flg22) induces rapid and long-lasting defence responses. It may also affect the photosynthetic activity depending on several internal and external factors, such as the phytohormone ethylene or the day/night time. Based on the results, flg22 treatment, neither in the light phase nor in the evening, caused any significant change in chlorophyll fluorescence induction parameters in the leaves of wild-type and ethylene-receptor mutant Never ripe tomato plants measured the next morning. However, flg22 in the light phase decreased the effective quantum yield and the photochemical quenching both locally and systemically in guard cells. In...
Upregulation of the mitochondrial alternative oxidase pathway improves PSII function and photosynthetic electron transport in tomato seedlings under chilling stress
J.J. ZENG, W.H. HU, X.H. HU, H.M. TAO, L. ZHONG, L.L. LIU
Photosynthetica X:X | DOI: 10.32615/ps.2022.019
The aim of this study was to explore how the mitochondrial alternative oxidase (AOX) pathway alleviates photoinhibition in chilled tomato (Solanum lycopersicum) seedlings. Chilling induced photoinhibition in tomato seedlings despite the increases in thermal energy dissipation and cyclic electron flow around PSI (CEF-PSI). Chilling inhibited the function of PSII and blocked electron transport at the PSII acceptor side, however, it did not affect the oxygen-evolving complex on the donor side of PSII. Upregulation of the AOX pathway protects against photoinhibition by improving PSII function and photosynthetic electron transport in tomato seedlings...