Shading Reduces Water Deficit in Strawberry (Fragaria × ananassa Duch.) Plants during Vegetative Growth

Strawberry (Fragaria × ananassa Duch.) is a commercially important crop with high water requirements, for which it is necessary to find strategies that mitigate the influence of water deficit on plant growth. This study was aimed to evaluate the effects of shading on the vegetative growth of strawberry cv. Sweet Ann under water deficit. The treatments consisted of the combination of two levels of shading (light intensity reduced on 47% vs. non-shaded plants) and two levels of water availability (water deficit vs. well-watered plants). The water deficit reduced the leaf water potential from -1.52 to -2.21 MPa, and diminished stomatal conductance, net photosynthetic rate (from 9.13 to 2.5 μmol m-2 s-1), photosystem II photochemical efficiency (from 0.79 to 0.67), and biomass accumulation, while increased the electrolyte leakage. The shading allowed the water-deficient plants to maintain water potential (-1.58 MPa) and photosystem II efficiency (0.79) and to increase water use efficiency (from 14.80 to 86.90 μmol CO2/mmol H2O), net photosynthetic rate (from 2.40 to 9.40 μmol m-2 s-1) and biomass of leaves, crowns, and roots compared to non-shaded plants without water limitation. These results suggest that a reduction in incident light intensity attenuates the effects of stomatic and non-stomatic limitations caused by water deficit during vegetative growth of strawberry.

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The Role of D 1* in Light-Induced D 1 Protein Turnover in Leaves

Zeitschrift für Naturforschung C ◽

10.1515/znc-1993-3-421 ◽

1993 ◽

Vol 48 (3-4) ◽

pp. 246-250

Author(s):

Anna J. Syme ◽

Harald R . Bolhàr-N ordenkampf ◽

Christa Critchley

Keyword(s):

Chlorophyll Fluorescence ◽

Photosystem Ii ◽

Light Intensity ◽

Protein Turnover ◽

Photochemical Efficiency ◽

Light Conditions ◽

Ps Ii ◽

Light Intensities ◽

Intact Leaves

Abstract Light-induced degradation of the D 1 protein of photosystem II (PS II) was determined by radioactive pulse-chase labelling experiments in intact leaves of Schefflera polybotrya. PS II photochemical efficiency was monitored by measuring chlorophyll fluorescence. A significant and consistent decline in the Fv/ Fm ratio was taken to indicate photoinhibition. The formation and degradation of a modified form of the D 1 protein, D 1*, was different under photoinhibi-tory or non-photoinhibitory light conditions. At photoinhibitory irradiance greater amounts of D 1 * were formed relative to D 1, and the degradation of D 1* was slower when compared with non-photoinhibitory irradiance. The formation and degradation of D 1* were therefore shown to be at least partly light intensity dependent. Higher light intensities appeared to slow D 1* degradation, which suggests a modification in PS II turnover properties.

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Effect of Water Stress on Photosynthetic Parameters of Soybean (Glycine max) and Velvetleaf (Abutilon theophrasti)

Weed Science ◽

10.1017/s0043174500026722 ◽

1987 ◽

Vol 35 (1) ◽

pp. 15-21 ◽

Cited By ~ 16

Author(s):

Philip H. Munger ◽

James M. Chandler ◽

J. Tom Cothren

Keyword(s):

Glycine Max ◽

Water Stress ◽

Stomatal Conductance ◽

Water Potential ◽

Net Photosynthetic Rate ◽

Photosynthetic Rate ◽

Transpiration Rate ◽

Abutilon Theophrasti ◽

Leaf Water ◽

Photosynthetic Parameters

Greenhouse experiments were conducted to elucidate the effects of water stress on photosynthetic parameters of soybean [Glycine max(L.) Merr. ‘Hutton′] and velvetleaf (Abutilon theophrastiMedik. # ABUTH). Stomatal conductance of both species responded curvilinearly to reductions in leaf water potential. At leaf water potentials less negative than −2.5 MPa, stomatal conductance, net photosynthetic rate, and transpiration rate were greater in velvetleaf than in soybean. Soybean photosynthetic rate was linearly related to stomatal conductance. Velvetleaf photosynthetic rate increased linearly with stomatal conductances up to 1.5 cm s–1; however, no increase in photosynthetic rate was observed at stomatal conductances greater than 1.5 cm s–1, indicating nonstomatal limitations to photosynthesis. As water stress intensified, stomatal conductance, photosynthetic rate, and transpiration of velvetleaf declined more rapidly than in soybean.

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Evaluation of Photosynthetic Characters and Regulation Pattern of Photosynthesis Associated Gene in Two Mulberry Varieties

International Journal of Agriculture and Biology ◽

10.17957/ijab/15.1740 ◽

2021 ◽

Vol 25 (04) ◽

pp. 863-872

Author(s):

Yong Li

Keyword(s):

Net Photosynthetic Rate ◽

Photosynthetic Rate ◽

Metabolic Pathways ◽

Carbon Fixation ◽

Expression Patterns ◽

Photochemical Efficiency ◽

High Yield ◽

Photochemical Quenching ◽

Chlorophyll Metabolism ◽

Photosynthetic Organisms

Photosynthetic characteristics and expression patterns of the photosynthesis-related genes in the high-yield mulberry variety E’Sang 1 (E1) and normal mulberry variety Husang 32 (H32) were investigated in this study. The observation of daily variation of photosynthesis in E1 and H32 indicated that the peak of net photosynthetic rate(Pn)inE1 variety was significantly higher than that inH32 (P <0.05). Meanwhile, the Pn-PAR and Pn-Ci responses of E1 and H32 were evaluated, and the results showed that the carboxylation efficiency and compensation saturation point were much higher in E1 rather thanH32. Importantly, the photosystem II actual photochemical efficiency and photochemical quenching coefficient in the leaves of E1 were significantly higher than those in H32 (P<0.05). Also, the activity of RuBP in E1 was higher than that in H32 (P >0.05). Based on the RNA-seq data, a total of 3,356 differentially expressed genes (DEGs) were detected among different time points between E1 and H32. Of these, 1,136 DEGs were involved in the metabolic pathways, including three main photosynthesis-related metabolic pathways (i.e., carbon fixation in photosynthetic organisms, carbon metabolism, and porphyrin and chlorophyll metabolism). Meanwhile, 10 novel DEGs related to photosynthesis were detected, and four potential key genes of them could account for the differences in net photosynthetic rate and yield betweenH32 and E1.This study could provide important insights into the molecular breeding of mulberry varieties with high photosynthetic efficiency and contribute to understanding the genetic mechanism of photosynthesis.© 2021 Friends Science Publishers

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Accumulation of End Products in Source Leaves Affects Photosynthetic Rate in Peach via Alteration of Stomatal Conductance and Photosynthetic Efficiency

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.134.6.667 ◽

2009 ◽

Vol 134 (6) ◽

pp. 667-676 ◽

Cited By ~ 21

Author(s):

Jieshan Cheng ◽

Peige Fan ◽

Zhenchang Liang ◽

Yanqiu Wang ◽

Ning Niu ◽

...

Keyword(s):

Stomatal Conductance ◽

Photosystem Ii ◽

Photosynthetic Rate ◽

Prunus Persica ◽

Photochemical Efficiency ◽

Feedback Regulation ◽

Light Period ◽

Photochemical Quenching ◽

Fruit Removal ◽

End Products

In ‘Beijing 24’ peach [Prunus persica (L.) Batch] trees, a series of source leaves with differing levels of end products were created by retaining fruit (“+fruit”), removing fruit (“−fruit”), or reducing the light period. To alter the light period, leaves were covered with a bag made of brown inner paper and outer silver paper, which was then removed at different times the next day. The highest level of end products were obtained by fruit removal, while reducing the light period resulted in a lower level than “+fruit.” Net photosynthetic rate (Pn) and stomatal conductance (gs) decreased, but leaf temperatures (Tleaf) increased, following an increase in end product levels in leaves. After the “−fruit” treatment, reduced Pn was correlated with lower gs, and Tleaf increase was concomitant with decreases in maximal quantum yield of photosystem II (Fv/Fm), actual photochemical efficiency of photosystem II (ΦPSII), and photochemical quenching, and with an increase in nonphotochemical quenching. However, there were no significant differences in chlorophyll fluorescence between “+fruit” and the two treatments reducing the light period. The ΦPSII decreased following an increase in foliar sorbitol level, and it linearly decreased as sucrose and starch increased. Although fruit removal resulted in a significant accumulation of sucrose, sorbitol, and starch in leaves throughout the day, the extractable activities of several important enzymes involved in carbohydrate leaf storage and translocation did not decrease. Therefore, instead of feedback regulation by the accumulation of end products in source leaves, a high Tleaf induced by decreased stomatal aperture may play a key role in regulation of photosynthesis by limiting the photochemical efficiency of the PSII reaction centers under high levels of the end products in peach leaves.

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Physiological Advantages of Grafted Watermelon (Citrullus lanatus) Seedlings under Low-temperature Storage in Darkness

HortScience ◽

10.21273/hortsci.46.7.993 ◽

2011 ◽

Vol 46 (7) ◽

pp. 993-996 ◽

Cited By ~ 8

Author(s):

Ming Ding ◽

Beibei Bie ◽

Wu Jiang ◽

Qingqing Duan ◽

Hongmei Du ◽

...

Keyword(s):

Low Temperature ◽

Net Photosynthetic Rate ◽

Photosynthetic Rate ◽

Citrullus Lanatus ◽

Soluble Sugar ◽

Photochemical Efficiency ◽

Chlorophyll Contents ◽

Low Temperature Storage ◽

Short Period ◽

Temperature Storage

Low-temperature storage in darkness is usually used for preserving seedlings for a short period. To investigate whether grafted watermelon [Citrullus lanatus (Thunb.) Matsum. and Nakai] seedlings are superior to non-grafted ones under low-temperature storage in darkness and to study their physiological differences during storage, watermelon (‘Zaojia 84-24’) scions were grafted to pumpkin (Cucurbita moschata Duch. ‘Zhuangshi’) rootstocks. Carbohydrate levels; chlorophyll and malondialdehyde contents; the activities of superoxide dismutase, catalase, and peroxidase; and photochemical efficiency were assayed during 6 days of storage at 15 °C in darkness. After that, seedlings were transplanted into an artificial climate chamber. The net photosynthetic rate and stomatal conductance (gS) were measured on the first and third days after transplanting. The results showed that the grafted watermelon seedlings had more soluble sugar and chlorophyll contents, higher activities of antioxidant enzymes, and less malondialdehyde content than the non-grafted ones after 6 days of storage. In addition, low-temperature storage in darkness damaged the photosystem II of non-grafted watermelon seedlings more than that of grafted ones. After transplanting, grafted seedlings had a higher net photosynthetic rate. The results suggest that grafted watermelon seedlings were more suitable for the low-temperature storage in darkness than the non-grafted ones.

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Effect of Atrazine and Mesotrione on Centipedegrass Growth, Photochemical Efficiency, and Establishment

Weed Technology ◽

10.1614/wt-07-109.1 ◽

2009 ◽

Vol 23 (1) ◽

pp. 67-72 ◽

Cited By ~ 7

Author(s):

J. Scott McElroy ◽

Robert H. Walker

Keyword(s):

Photosystem Ii ◽

Maximum Rate ◽

Photochemical Efficiency ◽

Ground Cover ◽

Rate Range ◽

Photosystem Ii Efficiency ◽

Greenhouse Trial ◽

Time Period

Centipedegrass is tolerant of both atrazine and mesotrione when applied separately to established turf. However, no information is available regarding the use of mesotrione or the synergistic mixture of atrazine plus mesotrione applied to centipedegrass during seeded establishment. Research was conducted to evaluate centipedegrass tolerance to various rates and combinations of atrazine plus mesotrione when applied 14 d after emergence (DAE). Experiment 1 evaluated centipedegrass tolerance to atrazine and mesotrione in a broad rate-range screen in a greenhouse environment. Variations were observed between greenhouse trial runs with respect to injury and biomass with less injury and decrease in biomass observed in run 2. Overall, atrazine alone and atrazine plus mesotrione were more injurious for a greater time period and decreased biomass more than mesotrione alone. In fact, although mesotrione alone initially reduced centipedegrass photosystem II efficiency, an overall increase in efficiency was observed 28 d after treatment (DAT). Based on experiment 1, atrazine at 0.28 kg ai/ha was the maximum rate that could be applied to seedling centipedegrass when tank mixed with mesotrione. Experiment 2 evaluated atrazine at 0.28 kg/ha plus mesotrione at 0.03 to 0.28 kg/ha on centipedegrass field establishment. Although all atrazine plus mesotrione treatments reduced centipedegrass ground cover 28 DAT; no treatment reduced centipedegrass ground cover 49 DAT.

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Photosynthesis, Chlorophyll Fluorescence, and Yield of Peanut in Response to Biochar Application

Frontiers in Plant Science ◽

10.3389/fpls.2021.650432 ◽

2021 ◽

Vol 12 ◽

Author(s):

Shujun Wang ◽

Junlin Zheng ◽

Yujia Wang ◽

Qingfeng Yang ◽

Taotao Chen ◽

...

Keyword(s):

Chlorophyll Fluorescence ◽

Net Photosynthetic Rate ◽

Photosynthetic Rate ◽

Leaf Gas Exchange ◽

Photochemical Efficiency ◽

Photochemical Quenching ◽

Nitrogen Accumulation ◽

Leaf Nitrogen Content ◽

Chlorophyll Fluorescence Parameters ◽

Plant Nitrogen

The effect of biochar application on photosynthetic traits and yield in peanut (Arachis hypogaea L.) is not well understood. A 2-year field experiment was conducted in Northwest Liaoning, China to evaluate the effect of biochar application [0, 10, 20, and 40 t ha−1 (B0, B10, B20, and B40)] on leaf gas exchange parameters, chlorophyll fluorescence parameters, and yield of peanut. B10 improved photochemical quenching at flowering and pod set and reduced non-photochemical quenching at pod set, relative to B0. B10 and B20 increased actual photochemical efficiency and decreased regulated energy dissipated at pod set, relative to B0. B10 significantly increased net photosynthetic rate, transpiration rate, stomatal conductance, and water use efficiency at flowering and pod set, relative to B0. Compared with B0, B10 significantly improved peanut yield (14.6 and 13.7%) and kernel yield (20.2 and 14.4%). Biochar application increased leaf nitrogen content. B10 and B20 significantly increased plant nitrogen accumulation, as compared to B0. The net photosynthetic rate of peanut leaves had a linear correlation with plant nitrogen accumulation and peanut yield. The application of 10 t ha−1 biochar produced the highest peanut yield by enhancing leaf photosynthetic capacity, and is thus a promising strategy for peanut production in Northwest Liaoning, China.

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Photoperiod has a stronger impact than irradiance on the source–sink relationships in the sink-limited species Erythronium americanum

Botany ◽

10.1139/b11-061 ◽

2011 ◽

Vol 89 (11) ◽

pp. 763-770 ◽

Cited By ~ 6

Author(s):

Anthony Gandin ◽

Pierre Dizengremel ◽

Line Lapointe

Keyword(s):

Feedback Control ◽

Net Photosynthetic Rate ◽

Photosynthetic Rate ◽

Feedback Inhibition ◽

Photochemical Efficiency ◽

Biomass Accumulation ◽

Growth Season ◽

Erythronium Americanum ◽

Source Sink ◽

Long Photoperiod

Under sink-limited conditions, source activity is modulated to remain in balance with the use of carbohydrates by the sink, but this feedback control has been studied in only a few systems so far. Sink and source activities were investigated throughout the season. Plants were subjected to two photoperiod regimes combined with two irradiance levels to produce three different daily amounts of photons. Net photosynthetic rate and the photochemical efficiency of photosynthesis were initially higher under a long photoperiod, but decreased early in the growth season, whereas they remained fairly constant until a few days before leaf senescence under a short photoperiod. The rates of starch and biomass accumulation in the bulb were also faster under a long photoperiod at the beginning of the season but reached similar levels under both short and long photoperiods later on. Response to photoperiod cannot be explained by changes in daily amounts of photons, as none of the variables reported were affected by instantaneous or daily irradiance. It appears that the total amount of carbohydrate synthesized under a long photoperiod was in excess compared to the ability of the sink to store or use them, inducing a feedback inhibition of net photosynthetic rate to restore the source–sink balance.

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Leaf Hairs of Olive (Olea europaea) Prevent Stomatal Closure by Ultraviolet-B Radiation

Functional Plant Biology ◽

10.1071/pp9940293 ◽

1994 ◽

Vol 21 (3) ◽

pp. 293 ◽

Cited By ~ 26

Author(s):

G Grammatikopoulos ◽

G Karabourniotis ◽

A Kyparissis ◽

Y Petropoulou ◽

Y Manetas

Keyword(s):

Photosystem Ii ◽

Water Vapour ◽

Photosynthetic Rate ◽

White Light ◽

Photochemical Efficiency ◽

Ultraviolet B ◽

Hair Removal ◽

Leaf Hairs ◽

Ultraviolet B Radiation ◽

Leaf Resistance

In olive (Olea europaea L.), hair removal had no effect on the photosynthetic rate and the apparent leaf resistance to water vapour diffusion in leaves illuminated with white light (900 μmol m-2 s-1 photosynthetically active radiation) devoid of ultraviolet-B radiation. In addition, intact and dehaired leaves showed no significant differences in absorptance in the visible spectral region, while leaf temper- ature was independent of hair removal. These results indicate that leaf hairs of O. europaea may play only a marginal role in leaf energy balance and transpiration. When the white light was supplemented with ultraviolet-B radiation (5.89 W m-2), however, there was a considerable decrease in the photo- synthetic rate, and a simultaneous increase in leaf resistance to water vapour in dehaired leaves. Photochemical efficiency of photosystem II, evaluated from chlorophyll fluorescence emitted from the illuminated side, was reduced in all cases, but the reduction in dehaired, ultraviolet-B treated leaves was more pronounced and irreversible, indicating that the reduction of the photosynthetic rate may result from both stomatal limitation and electron flow inhibition. Photosynthetic capacity of dehaired leaves, measured at 5% CO2, however, was not influenced by ultraviolet-B radiation. We suggest, therefore, that ultraviolet-B radiation reduces photosynthetic rates by closing the stomata, while the observed reduction in photosystem II photochemical efficiency may concern only a superficial chloroplast population, contributing negligibly to whole leaf photosynthesis. Under the conditions of our experi- ments, the protective function of the indumentum against ultraviolet-B radiation predominates over the water conservation function.

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