Light dependence of carboxylation capacity for C₃ photosynthesis models

J. A. Bunce

Photosynthetica 2016, 54(4):484-490 | DOI: 10.1007/s11099-016-0215-9

C₃ photosynthesis at high light is often modeled by assuming limitation by the maximum capacity of Rubisco carboxylation (V_Cmax) at low CO₂ concentrations, by electron transport capacity (J_max) at higher CO₂ concentrations, and sometimes by triose-phosphate utilization rate at the highest CO₂ concentrations. Net photosynthetic rate (P _N) at lower light is often modeled simply by assuming that it becomes limited by electron transport (J). However, it is known that Rubisco can become deactivated at less than saturating light, and it is possible that P _N...

Photosynthetic and growth responses of two mustard cultivars differing in phytocystatin activity under cadmium stress

T. S. Per, S. Khan, M. Asgher, B. Bano, N. A. Khan

Photosynthetica 2016, 54(4):491-501 | DOI: 10.1007/s11099-016-0205-y

Cadmium inhibits photosynthetic capacity of plants by disturbing protein conformations, whereas phytocystatins prevent degradation of target proteins and are involved in abiotic stress tolerance. Two mustard (Brassica juncea L.) cultivars, Ro Agro 4001 and Amruta, were grown with Cd (50 µM) in order to study physiological and biochemical basis of differences in Cd tolerance. Amruta accumulated higher Cd and H₂O₂ concentrations in leaves than that of Ro Agro 4001. Cd significantly decreased photosynthesis and growth of plants in both cultivars by reducing a chlorophyll content, gas exchange parameters, and activity...

Cultivar variation in cotton photosynthetic performance under different temperature regimes

W. T. Pettigrew

Photosynthetica 2016, 54(4):502-507 | DOI: 10.1007/s11099-016-0208-8

Cotton (Gossypium hirsutum L.) yields are impacted by overall photosynthetic production. Factors that influence crop photosynthesis are the plants genetic makeup and the environmental conditions. This study investigated cultivar variation in photosynthesis in the field conditions under both ambient and higher temperature. Six diverse cotton cultivars were grown in the field at Stoneville, MS under both an ambient and a high temperature regime during the 2006-2008 growing seasons. Mid-season leaf net photosynthetic rates (P _N) and dark-adapted chlorophyll fluorescence variable to maximal ratios (F_v/F_m)...

Rearrangement of leaf traits with changing source-sink relationship in blueberry (Vaccinium corymbosum L.) leaves

E. Jorquera-Fontena, M. Alberdi, M. Reyes-Díaz, N. Franck

Photosynthetica 2016, 54(4):508-516 | DOI: 10.1007/s11099-016-0207-9

The source-sink relationship is one of major determinants of plant performance. The influence of reproductive sink demand on light-saturated photosynthesis (P _max), dark respiration (R _D), stomatal conductance (g _s), intrinsic water-use efficiency (WUE_i), contents of soluble sugar (SSC), nitrogen, carbon, and photosynthetic pigments was examined in blueberry (Vaccinium corymbosum L. cv. 'Brigitta') during the final stage of rapid fruit growth. Measurements were performed three times per day on developed, sun-exposed leaves of girdled shoots with 0.1, 1, and 10 fruit per leaf (0.1F:L,...

In silico, in vitro and in vivo approach in understanding the functional relationship between ergosterol and Rubisco

J. Mitra, P. Narad, P. K. Paul

Photosynthetica 2016, 54(4):517-523 | DOI: 10.1007/s11099-016-0211-0

Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco; EC 4.1.1.39) is one of the key enzymes involved in assimilation of CO₂ in chloroplasts. Phylloplane microfungi and their metabolites have been reported to affect the physiology of host plants, particularly, their photosynthesis. However, information is lacking on the effect of these microflora on the physiology of chloroplasts. The current study emphasized the impact of two dominant phylloplane fungi, Aspergillus niger and Fusarium oxysporum, on activity of Rubisco in tomato chloroplasts. Ergosterol, which is a component of only fungal cell membranes and is not synthesized...

Effects of drought stress on growth and chlorophyll fluorescence of Lycium ruthenicum Murr. seedlings

Y. Y. Guo, H. Y. Yu, D. S. Kong, F. Yan, Y. J. Zhang

Photosynthetica 2016, 54(4):524-531 | DOI: 10.1007/s11099-016-0206-x

The present study aimed to determine effects of drought stress on Lycium ruthenicum Murr. seedlings. Our results showed that mild drought stress was beneficial to growth of L. ruthenicum seedlings. Their height, basal diameter, crown, leaf number, stem dry mass, leaf and root dry mass increased gradually when the soil water content declined from 34.7 to 21.2%. However, with further decrease of the soil water content, the growth of L. ruthenicum seedlings was limited. After 28 d of treatment, the seedlings were apparently vulnerable to drought stress, which resulted in significant leaf shedding and slow growth. However, growth was...

Physiological and ultrastructural responses of sour orange (Citrus aurantium L.) clones to water stress

A. Ben Salem-Fnayou, I. Belghith, M. Lamine, A. Mliki, A. Ghorbel

Photosynthetica 2016, 54(4):532-541 | DOI: 10.1007/s11099-016-0221-y

Water stress is a major abiotic constraint leading to serious crop losses. Recently, in the Mediterranean region, water stress has become markedly sensed, especially in Citrus orchards. This study investigated the physiological responses of local sour orange (Citrus aurantium L.) clones to severe water stress. Water stress was applied by withholding irrigation during weeks, followed by a rewatering phase during three months. Under water stress, sour orange clones decreased their stomatal conductance, net photosynthetic rate, and transpiration rate. On the contrary, biomass was stable, especially in the Kliaa clone. In addition, reduced...

Improving photosynthetic performance and some fruit quality traits in mango trees by shading

K. Jutamanee, S. Onnom

Photosynthetica 2016, 54(4):542-550 | DOI: 10.1007/s11099-016-0210-1

Excess solar radiation under hot climate can lead to decline in photosynthetic activity with detrimental effects on growth and yield. The aim of this study was to evaluate the use of a transparent plastic roof as shading for diurnal changes in photosynthetic gas exchange, chlorophyll fluorescence, fruit set and quality of mango (Mangifera indica L.) cv. 'Nam Dok Mai' growth in the field conditions. Fully expanded leaves were examined either shaded by the plastic roof or sunlit under natural conditions. Leaf temperature and leaf-to-air vapour pressure deficit of the shaded leaves measured on the clear day were lowered compared to those of the...

Increased water supply promotes photosynthesis, C/N ratio, and plantamajoside accumulation in the medicinal plant Plantago depressa Willd

Z. Li, W. Bai, L. Zhang, L. Li

Photosynthetica 2016, 54(4):551-558 | DOI: 10.1007/s11099-016-0222-x

Anthropogenic activities are changing global precipitation regimes and result in many middle latitude arid and semiarid regions experiencing less precipitation and more extreme weather events. However, little is known about the response of active ingredient accumulation in the medicinal herb Plantago depressa Willd. Therefore, we carried out a greenhouse experiment in order to study effect of control (CK, normal water supply equal to 309 mm per four months), -30 (-WS) and +30% (+WS) of the control water supply on the photosynthesis (P _N), C/N ratio, and plantamajoside accumulation in P. depressa. Our results showed that...

A novel method for the estimation of soybean chlorophyll content using a smartphone and image analysis

J. P. G. Rigon, S. Capuani, D. M. Fernandes, T. M. Guimarães

Photosynthetica 2016, 54(4):559-566 | DOI: 10.1007/s11099-016-0214-x

The development of smartphones, specifically their cameras, and imaging technologies has enabled their use as sensors/measurement tools. Here we aimed to evaluate the applicability of a fast and noninvasive method for the estimation of total chlorophyll (Chl), Chl a, Chl b, and carotenoids (Car) content of soybean plants using a smartphone camera. Single leaf disc images were obtained using a smartphone camera. Subsequently, for the same leaf discs, a Chl meter was used to obtain the relative index of Chl and the photosynthetic pigments were then determined using a classic method. The RGB, HSB and CIELab color models were extracted from...

Image analysis of the leaf vascular network: physiological considerations

M. Pagano, P. Corona, P. Storchi

Photosynthetica 2016, 54(4):567-571 | DOI: 10.1007/s11099-016-0238-2

The study of leaf vascular systems is important in order to understand the fluid dynamics of water movement in leaves. Recent studies have shown how these systems can be involved in the performance of photosynthesis, which is linked to the density of the vascular network per unit of leaf area. The aim of the present study was to highlight the correlation between a leaf vein density (V_D) and net photosynthetic rate (P _N), which was undertaken using a digital camera, a stereoscopic microscope, and a light source. The proposed hypothesis was tested, for the first time, on the leaves of two cultivars of Vitis vinifera...

The altitudinal effects on photosynthesis of Rosa platyacantha from the Tianshan Mountains in Northwestern China

S. H. Yang, J. J. Wei, H. Ge

Photosynthetica 2016, 54(4):572-580 | DOI: 10.1007/s11099-016-0649-0

The altitudinal effects on photosynthesis were measured on progenies of three populations of Rosa platyacantha Schrenk from altitudes of 1,170 (L); 1,580 (M); and 1,920 (H) m a. s. l. During the day, net photosynthetic rate (P _N) decreased in all populations due to the high air temperature in the summer. The H population showed a significantly lower P _N at noon compared to other populations. The midday depression of P _N occurred in L and M populations due to stomatal limitations, while P _N inhibition was associated with PSII activity decline in the H population. In order...

Relationship of photosynthetic efficiency and seed-setting rate in two contrasting rice cultivars under chilling stress

L. Z. Wang, L. M. Wang, H. T. Xiang, Y. Luo, R. Li, Z. J. Li, C. Y. Wang, Y. Meng

Photosynthetica 2016, 54(4):581-588 | DOI: 10.1007/s11099-016-0648-1

Low temperature during the vegetative stage affects rice (Oryza sativa L.) seed-setting rate in Heilongjiang province at Northeast China. However, little is known about changes of the photosynthetic rate and physiological response in contrasting rice cultivars during chilling periods. In this study, two rice cultivars with different chilling tolerance were treated with 15°C from June 27 to July 7. The chilling-susceptive cultivar, Longjing11 (LJ11), showed a significant decrease in a ripening rate and seed-setting rate after being treated for four days, whilst chilling-tolerant cultivar, Kongyu131 (KY131), was only slightly affected after 4-d...

Girdling interruption between source and sink in Quercus pubescens does not trigger leaf senescence

V. Holland, L. Fragner, T. Jungcurt, W. Weckwerth, W. Brüggemann

Photosynthetica 2016, 54(4):589-597 | DOI: 10.1007/s11099-016-0646-3

Metabolite changes and senescence behaviour after mechanical phloem girdling were studied in leaf tissue of Quercus pubescens. Sugar accumulation is not only considered to be an important part of several developmental signalling pathways, but is also seen as one of the basic triggers for senescence induction, or at least an obligatory accessory phenomenon. Our survey showed that an accumulation of the soluble sugars, glucose and fructose, was not on its own obligatorily connected with the induction of leaf senescence, since no indication or even an onset of senescence could be observed during the course of the experiment. Instead, we observed...

Ecophysiological responses of Cunninghamia lanceolata to nongrowing-season warming, nitrogen deposition, and their combination

L. Yu, T. F. Dong, Y. B. Lu, M. Y. Song, B. L. Duan

Photosynthetica 2016, 54(4):598-610 | DOI: 10.1007/s11099-016-0647-2

Warming winter and atmospheric nitrogen (N) deposition are expected to have effects on net primary production (NPP) of Chinese fir (Cunninghamia lanceolata) plantation and implications for plantation carbon sequestration. The effects of nongrowing-season warming on plant morphological and physiological traits were investigated in a greenhouse experiment with two-year-old C. lanceolata seedlings. Elevated temperature (ET) during the nongrowing season significantly increased the net photosynthetic characteristics. The strongest effects occurred during warming period from 1 December 2014 to 1 February 2015 (W1). Moreover, the carbohydrate...

Effects of long-term action of high temperature and high light on the activity and energy interaction of both photosystems in tomato plants

A. Faik, A. V. Popova, M. Velitchkova

Photosynthetica 2016, 54(4):611-619 | DOI: 10.1007/s11099-016-0644-5

The acclimation to high light, elevated temperature, and combination of both factors was evaluated in tomato (Solanum lycopersicum cv. M82) by determination of photochemical activities of PSI and PSII and by analyzing 77 K fluorescence of isolated thylakoid membranes. Developed plants were exposed for six days to different combinations of temperature and light intensity followed by five days of a recovery period. Photochemical activities of both photosystems showed different sensitivity towards the heat treatment in dependence on light intensity. Elevated temperature exhibited more negative impact on PSII activity, while PSI was slightly stimulated....

Exogenous Ca²⁺ alleviates waterlogging-caused damages to pepper

B. Z. Yang, Z. B. Liu, S. D. Zhou, L. J. Ou, X. Z. Dai, Y. Q. Ma, Z. Q. Zhang, W. C. Chen, X. F. Li, C. L. Liang, S. Yang, X. X. Zou

Photosynthetica 2016, 54(4):620-629 | DOI: 10.1007/s11099-016-0200-3

Ca²⁺ has been considered as a necessary ion for alleviation of stress-induced damages in plants. We investigated effects of exogenous Ca²⁺ on waterlogging-induced damage to pepper and its underlying mechanisms. Pepper seedlings under stress were treated by spraying of 10 mM CaCl₂. Applying exogenous Ca²⁺ increased the biomass of pepper leaves and roots, improved photosynthetic characteristics, membrane permeability, root activity, osmotic substance contents, antioxidant enzyme and alcohol dehydrogenase activities, while it reduced lactate dehydrogenase activity. It maintained hydroxide radical contents and...

Photosynthesis and yield traits in different soybean lines in response to salt stress

Y. He, Y. Chen, C. L. Yu, K. X. Lu, Q. S. Jiang, J. L. Fu, G. M. Wang, D. A. Jiang

Photosynthetica 2016, 54(4):630-635 | DOI: 10.1007/s11099-016-0217-7

To evaluate utility of different salt-tolerant lines, three soybean lines with different resistance to salt were planted in the field under control and salt-stress conditions for two years. The results showed that net photosynthetic rate (P _N) was significantly different among lines at the anthesis stage and decreased on average by 13.6-34.1% under conditions of salt stress. The stomatal conductance was a primary limiting factor for the reduction of P _N under salt stress. Meanwhile, the grain yield (GY) decreased on average by 14.0-35.3% among lines under salt stress. The salt-tolerant lines S111-9 and S113-6 showed...

Morphological and photosynthetic response of waxy corn inbred line to waterlogging

M. Zhu, F. H. Li, Z. S. Shi

Photosynthetica 2016, 54(4):636-640 | DOI: 10.1007/s11099-016-0203-0

This study aimed to investigate the effects of waterlogging on the growth and photosynthetic characteristics of paired near-isogenic lines of waterlogging-tolerant (Zz-R) and waterlogging-sensitive (Zz-S) waxy corn inbred line seedlings. All plants were grown until the fifth leaves were fully expanded. Subsequently the plants in the pots were submerged in water for 4 d. During the waterlogging period, morphological and photosynthetic parameters related to waterlogging tolerance were examined. After 4 d, a significant decrease was observed in shoot and root fresh mass, net photosynthetic rate, stomatal conductance, transpiration, water-use efficiency,...

Prof. RNDr. Danuše Sofrová, CSc.

Helena Synková, Jirí Masojídek, Josef Komenda, Jirí Wilhelm, Nada Wilhelmová, František Vácha

Photosynthetica 2016, 54(4):481-483 | DOI: 10.1007/s11099-016-0664-1