Hartmut Lichtenthaler

Karlsruhe Institute of Technology | KIT · Botanical Institute

The method of remote sensing of forest decline via the airborne determination of reflectance signatures of forests has been applied with reat success in recent years in USA and in the Federal Repubfic of Germany. These classifications of tree damage were due to an increased reflectance in the visible range (around 550 and 680 nm a blue shift of the...

1. INTRODUCTION The Operation of the highlight induced xanthophyll/zeaxanthin cycle in the chloroplasts of higber plants, as detected by Sapozhnikov (1), has long been established by several research groups (1, 2, 3, 4). At a high irradiance the photosynthetic apparatus de-epoxidizes the xanthophyll viola,canthin v (2 hydroxy, 2 epoxy groups) via a...

A 50-year-old solitary, sun-exposed ginkgo tree had strongly been pruned in the fall of 2021. Very few buds for the formation of new leaves, twigs, and branches were left over. In spring 2022, these few remaining buds responded with the formation of a different leaf type. These leaves were 2.7 times larger and also thicker than in the years before....

Govindjee is a prolific and influential writer in the arena of oxygenic photosynthesis. He is internationally revered as one of the most prominent plant scientists of the 21st century, who enhanced 'Emerson Enhancement'. He is widely regarded for extensive collaborations with hundreds of scientists from around the World and moreover, his solely aut...

This Critical Review deals with all basic aspects of chlorophyll fluorescence signatures in plants: the fluorescence rise and decrease kinetics, the fluorescence emission spectra, the different kinds of Chl fluorescence ratios and their application in the detection of stress conditions in plants. It also demonstrates the detection of the photosynth...

The content of chlorophylls (Chl) (a+b), total carotenoids (x+c), and the pigment ratios of Chl a/b and Chls to carotenoids (a+b)/(x+c) of green leaves of five C4 plants were determined and compared to those of C3 plants. The C4 plants were: Pacific and Chinese silvergrass (Miscanthus floridulus and Miscanthus sinensis), sugar cane (Saccharum offic...

Imaging the four fluorescence bands of leaves, the red (F690) and far-red (F740) chlorophyll (Chl) fluorescence as well as the blue (F440) and green (F520) fluorescence of leaves and the corresponding fluorescence ratios is a fast and excellent nondestructive technique to detect the photosynthetic activity and capacity of leaves, of gradients over...

Govindjee and Hartmut Lichtenthaler have a very similar curriculum vitae. Both chose photosynthesis as research field and actively applied chlorophyll fluorescence. Their research was overlapping and complementary. On the occasion of Govindjee's 88th anniversary in 2020, Hartmut Lichtenthaler gives a short retrospective on interactions and joint ac...

Melvin Calvin (1911–1997) was the recipient of the 1961 Nobel Prize in Chemistry for the discovery of the canonical photosynthetic carbon reduction cycle. We present here a very brief glimpse of this extraordinary American scientist, who in his time was a preeminent force in physical and organic chemistry. Besides natural photosynthesis, Calvin’s p...

On November 4, 2018, Roland Douce, Professor Emeritus at the University of Grenoble, France, died at the age of 79. In Grenoble, where he spent most of his scientific career, Roland Douce created a world-renowned school of plant science, studying the structure, functions, and interactions of plant organelles involved in photosynthesis, respiration,...

For the first time, the adaptive role of the rolling leaf trait for tolerance of wheat plants (Triticum aestivum L.) to the main factor of drought, high temperature, was demonstrated. Cv. Otan with high degree of this trait expression was more tolerant to temperature stress (40°C, 4 h during 2 days (2h/day)). Changes in parameters of chlorophyll fl...

On August 30, 2018, Professor Emeritus Martin Bopp, an internationally highly regarded botanist and former director of the Botanical Institute at the University of Heidelberg, died in Wuppertal, Germany, at the age of 95 years. His scientific career, his valuable contributions to the progress of plant science and his manifold activities as editor a...

On the occasion of the 50th anniversary of the international journal Photosynthetica in 2017 we briefly report on the establishment of this journal and on Dr. Zdeněk Šesták, the renowned researcher of photosynthesis processes who, in cooperation with the Czechoslovak Academy of Sciences, founded this essential science journal in Prague in 1967.

On October 22, 2015, Professor Peter Heinrich Böger, an excellent and internationally highly regarded plant scientist, died in Constance, Germany, at the age of 80 years. He was a broadly oriented researcher of photosynthetic processes, with emphasis on the mode of action of herbicides in chloroplasts and on the biodiversity of nitrogen-fixing cyan...

In the past 55 years, enormous scientific progress was made in many fields of plant physiology and plant biochemistry. Throughout these years, our knowledge on the photosynthetic light processes, the chemical composition and biosynthesis of the photosynthetic apparatus, the ultrastructure of chloroplasts, and their large adaptation capacity to high...

Unlabelled: On January 16, 2015, Professor Andrew Alm Benson, one of the leading plant biochemists of the twentieth century, died in La Jolla, California, at the age of 97; he was born on September 24, 1917. Benson was known especially for his pioneering studies on photosynthesis (CO2 assimilation, carbon reduction cycle) and plant lipids (phospho...

Higher plants and several photosynthetic algae contain the plastidic 1-deoxy-D-xylulose 5-phosphate/2-C-methyl-D-erythritol 4-phosphate pathway (DOXP/MEP pathway) for isoprenoid biosynthesis. The first four enzymes and their genes are known of this novel pathway. All of the ca. 10 enzymes of this isoprenoid pathway are potential targets for new cla...

The fungal metabolite mevinolin, known to be a potent hypocholesterolemic agent, exerts in vitro a strong inhibitory effect on microsomal HMG-CoA reductase from etiolated radish seedlings at a concentration of about three magnitudes lower than the Km towards the natural substrate (S)-HMG-CoA (I50 = 2.5 x 10(-9)M). Beside this, mevinolin significant...

1) In kinetic studies, mevinolin proved to be a highly specific inhibitor of partially purified yeast HMG-CoA reductase (K i = 3.5 nᴍ towards HMG-CoA) and of microsomal HMG-CoA reductase from etiolated radish seedlings (Ki = 2.2 nᴍ). At low concentrations of NADPH, the inhibitor counteracts the sigmoidal response of plant HMG-CoA reductase activity...

The effect of a prolonged darkness (48 h) with a following re-illumination on the prenyllipid metabolism of chloroplasts is tested in green Hordeum seedlings. Continuous darkness induces thylakoid and prenyllipid breakdown and changes the remaining lipoquinone and carotenoid metabolism of chloroplasts to that of etioplasts. Re-illumination, in turn...

The Hill-activity (reduction of DCPIP or methylviologen) and the concentration of P700 were studied in chloroplasts isolated from cotyledons of radish seedlings (R aphanus sativu s L. Saxa Treib), which had been grown with the addition of β-indoleacetic acid (IAA), kinetin, or gibberellic acid. 1) The photosynthetic activity of young chloroplasts f...

Short pulses of red light induce in etiolated barley seedlings an enhanced synthesis of plastidic benzoquinones and vitamin K1, which can be reverted by subsequent irradiation with short pulses of far-red. As compared to the dark there is more formation of plastoquinone-9 than alpha-tocopherol. The enhanced formation of vitamin K1 is coupled with a...

Short time red pulses, given 6 times for 5 min within 36 h, induce in etiolated barley seedlings an enhanced synthesis of the main chloroplast carotenoids beta-carotene, violaxanthine, lutein and neoxanthine. The level of antheraxanthine and zeaxanthine decreases by red light treatment. These red light effects are reverted by subsequent short time...

Reflectance spectra allow the early detection of stressors causing differences in pigment content as well as changes of leaf tissue structure and photosynthetic activity. The reflectance decreased with increasing Chl content in greening bean leaves. In stressed leaves, in turn, the reflectance increased with decreasing Chl content. This also caused...

The synthesis of plastidquinones was studied from leaf development until autumnal leaf degeneration in sun and shade leaves of Fagus silvatica and compared with chlorophyll and carotinoid synthesis. 1. The lipoquinone content of Fagus chloroplasts increases steadily with increasing age of leaf tissue. This lipoquinone accumulation takes place in su...

The function of the osmiophilic stroma component of plastids - termed plastoglobuli1- has not yet been explained satisfactory. The changing plastoglobuli content during thylakoid-formation in proplastids of etiolated barley seedlings gives some evidence on their function. Before thylakoiddifferentiation proplastids of barley seedlings contain great...

The electromicroscopical structure and quinone composition of the osmiophilic, globular, lipiderich plastid inclusions were investigated in several plants. The localisation of the osmiophilic globuli in the plastid stroma and their behaviour toward fixation agents are described. The isolated globuli - here termed plastoglobuli - contain high amount...

The changes in quinone and pigment composition of isolated spinach chloroplasts were investigated after treatment with UV-light of 254 mμ, which is known to decrease the Hill- reaction activity. The plastidquinones are more UV-sensitive than carotenoids (except neoxanthin) and chlorophylls. Neoxanthin, reduced plastoquinone 45 and α-tocopherol func...

The synthesis of plastidquinones was studied during the development through the degeneration of Ficus leaves and compared with chlorophyll and carotenoid synthesis. 1. The plastidquinone content of Ficus chloroplasts increases steadily with increasing age of leaf tissue. The augmentation of the plastidquinone level is mainly due to the synthesis of...

Various bacterial and plastidic plant terpenoids are synthesized via the non-mevalonate 1-deoxy-D-xylulose-5-phosphate (DOXP) pathway. The antibiotic and herbicidal compound fosmidomycin is known to inhibit growth of several bacteria and plants, but so far its mode of action was unknown. Here we present data which demonstrate that the DOXP pathway...

The activity of the plastidic pyruvate dehydrogenase complex (pPDHC) is one source of acetyl-CoA in plastids of higher plants needed for de novo fatty acid biosynthesis. This plastidic enzyme reaction is specifically inhibited by acetylmethylphosphinate (AMPI), a com ­ pound which had hitherto been known only as an inhibitor of the mitochondrial py...

The incorporation of deuterium labeled 1-deoxy-D-xylulose into isoprene, emitted by three higher plants upon illumination, was analysed by headspace GC-MS. A high extent of incorporation into isoprene was found, indicating that isoprene is synthesized in higher plants via the novel isopentenyl pyrophosphate pathway, of which 1-deoxy-D-xylulose-5-ph...

The uneven distribution of carotenoids and chlorophylls between several chlorophyll- carotenoid-proteins isolated from radish chloroplasts by SDS-polyacrylamide-gel electrophoresis is described. Lutein and neoxanthin are enriched in the light-harvesting chlorophyll a/b-protein LHCP 3 , which exhibits low chlorophyll a/b ratios (1.1-1.3) and high va...

Chloroplast Biogenesis, Inhibition of Chloroplast Replication, Sethoxydim. Sun-Type Chloroplast Sethoxydim not only blocks leaf growth and development of barley seedlings but also inhibits chloroplast biogenesis at all stages of development from proplastids to prochloroplasts, young and mature chloroplasts. Not only thylakoid synthesis, thylakoid m...

The effect of the three cyclohexane-1,3-dione derivatives cycloxydim, sethoxydim and clethodim on the incorporation of l4C-labelled acetate, malonate, acetyl-C oA or malonyl-CoA into fatty acids was studied in an enzyme preparation isolated from barley chloroplasts (H ordeum vulgare L. var. “A lexis”). The herbicides cycloxydim, clethodim and setho...

Adaptation In saturating light radish seedlings grown in high-light growth conditions (90 W · m ⁻² ) possess a much higher photosynthetic capacity on a chlorophyll and leaf area basis than the low-light grown plants (10 W · m ⁻² ). The higher CO 2 -fixation rate of HL-plants is due to the presence of HL-chloroplasts which possess a different ultras...

The effect of the herbicides and aryloxy-phenoxy-propionic acid derivatives diclofop, fenoxaprop, fluazifop and haloxyfop and their ethyl, methyl or butyl esters on the de novo fatty-acid biosynthesis of isolated chloroplasts was investigated with intact chloroplasts isolated from sensitive grasses (Poaceae) and tolerant dicotyledonous plants (Pisu...

The partition of phylloquinone (vitamin K 1 ), of chlorophylls a and b and of the two main carotenoids, β-carotene and lutein, in subthylakoid particles (digitonin treatment) and chlorophyll protein complexes (sodium dodecylsulfate polyamide-gel electrophoresis) isolated from tobacco chloroplasts (Nicotiana tabacum L.) is described. 1. The “light p...

The pyridazinone herbicide San 6706 blocks chlorophyll and carotenoid formation simultaneously in a correlated way in both Raphanus and Hordeum seedlings. With decreasing carotenoid content the carotenoid precursor phytoene appears in San 6706-treated plants. The accumulation of the chloroplast prenylquinones (plastoquinone-9, α-tocopherol, α-tocoq...

The mode of action of cyclohexane-l,3-dione-type (cycloxydim, clethodim, sethoxydim, tralkoxydim) and aryloxyphenoxypropanoate-type herbicides (diclofop, fenoxaprop, haloxyfop, fluazifop) is summarized in this review. Both herbicide classes, though structurally completely different, specifically block the same target enzyme i.e. the plastid acetyl-...

Illumination of 3 day old etiolated radish seedlings with continuous white light results in a progressive accumulation of chlorophyll a and b. Both pigments are bound in a different way to the thylakoid chlorophyll-proteins, which appear parallel to the formation of chlorophylls. By applying the SDS-PAGE method to SDS-digested chloroplasts, it was...

The influence of two biocides (bentazone, triadimefon) on the growth-response of radish seedlings (Raphanus sativus L.) was investigated with special emphasis on the development of sun or shade-type chloroplasts. 1. The fungicid e triadimefon causes strong-light growth-response and the formation of sun-type chloroplasts as seen from the changed chl...

The structure of plastids, as well as size and frequency of the osmiophilic plastoglobuli were studied from the development of Ficus leaves until the degeneration of older leaves and compared with the accumulation of excess plastid-quinones. 1. The plastids on the young, light green Ficus leaves still rolled up in the buds already contain thylakoid...

Biogenesis and development of chloroplasts are sum m arized in the light of new findings; the interactions of different groups of photosynthetic herbicides with chloroplast developm ent are indicated. The effect of two new active ingredients, m evinolin and sethoxydim, on chloroplast modification and biogenesis are described. M evinolin blocks the...

The influence of the photosystem II-herbicide bentazon on the ultrastructure of chloroplasts of radish seedlings (Raphanus sativus L.) was investigated with special emphasis on thylakoid development and grana formation. Bentazon application (10 ⁻³ ᴍ) induces the formation of broader and higher grana stacks (grana width: 0.5-0.6 μm; greatest frequen...

The cyclohexanedione derivatives sethoxydim and alloxydim block leaf growth and inhibit the accumulation of photosynthetic pigments (chlorophylls, carotenoids) in expanding leaves of oat seedlings, but do not affect the rate of photosynthesis in the primary or secondary leaves. In isolated intact oat chloroplasts the incorporation of [2 -14C]acetat...

In the test system of isolated oat chloroplasts various structurally different cyclohexan e-1.3- dione derivatives were investigated for their inhibitory effect on de novo fatty-acid biosynthesis. Cycloxydim proved to be the most efficient inhibitor in the group of the tested cycloh exane- 1,3-diones. The alkoxyimino side-chain appears to be essent...

Two natural antibiotics, cerulenin and thiolactomycin, were tested for their inhibitory efficacy on de novo fatty-acid biosynthesis of chloroplasts isolated from oat and spinach seedlings and compared with that of known herbicides. With both antibiotics a strong dose-dependent inhibition of the incorporation of [1-14C]acetate into the fatty-acid fr...

It is demonstrated that — similar to chloroplasts — etioplasts isolated from leaves of pea (Pisum sativum L.) and oat seedlings (Avena sativa L.) also possess a high capacity for de novo fatty acid biosynthesis starting from [1-14C]acetate. The etioplast system proved to be a suitable test system for inhibitors of de novo fatty acid biosynthesis su...

Thiolactomycin was shown to be a potent inhibitor of de novo fatty acid biosynthesis in intact isolated chloroplasts (measured as [14C]acetate incorporation into total fatty acids). In our attempt to further localize the inhibition site we confirmed the inhibition with a fatty acid synthetase preparation, measuring the incorporation of [14C]malonyl...

Red light induces in etioplasts of dark-grown barley seedlings (H ordeum vulgare L.) parallel to the formation of chlorophyll an increased synthesis of carotenoids, lipophilic benzoquinones and of vitamin K 1 . 1. Among the carotenoids red light initiates an enhanced synthesis of β-carotene, lutein, violaxanthine and neoxanthine whereas the pools o...

In higher plants the biosynthetic machinery of de novofatty acid biosynthesis, measured as [14C]acetate incorporation intofatty acids, is predominantly located in plastids. A key enzyme in this pathway is the biotin-containing acetyl-CoA carboxylase (ACC, EC 6.4.1.2) which catalyzes the ATP-dependent carboxylation of acetyl-CoA to malonyl-CoA. The...

The plant acetyl-CoA synthetase (ACS) is bound to the plastids and provides acetyl-CoA, the starting substrate for de novo fatty acid biosynthesis in plastids. This enzymic reaction, which consumes ATP and releases A M P, can be inhibited by different alkyladenylates such as ethyl-, isopropyl-, propyl- or allyl-adenylates as is shown here. The inhi...

Two new headspace methods for the analysis of isoprene emission from detached plant leaves are described. The first method is based on the UV-absorption of isoprene emitted by leaves inside quartz cuvettes and can be used for the quantitative spectrophotometric determination of isoprene production. The second technique is a micro-extraction method...

The inhibition of photosynthetic CO 2 -assimilation and of the variable chlorophyll fluorescence as well as uptake and transport of ¹⁴ C-labelled bentazon and the possibilities for a herbicideinduced shade-type modification of the photosynthetic apparatus were investigated in bentazonsensitive weeds (Galium, Sinapis, Raphanus) and in the tolerant c...

Halogenated naphthoquinones act as inhibitors of photosynthetic electron flow. I50 concentration for inhibition of methylviologen reduction were found to range between 2 × 10⁻⁵ M to 2 × 10⁻⁶ M. Comparing their effects on several partial reactions of electron flow, the inhibition site of the naphthoquinones was found to be at the reducing site of PS...

Within a dark period of 24 hours green Hordeum plants change their lipoquinone and carotenoid metabolism to that of etiolated plants. A longer darkness induces degeneration of chloroplasts with a concomitant destruction of pigments and lipoquinones which is similar to that of the natural chloroplast degeneration in leaves. 1. The chlorophyll and vi...

The antibiotic cerulenin was shown to be a potent dose-dependent inhibitor of de novo fatty-acid biosynthesis in intact isolated chloroplasts of different plants (measured as [¹⁴C]acetate incorporation into the total fatty-acid fraction). Various chemical derivatives of cerulenin were synthesized and tested in the chloroplast assay-system of oat, s...

Blue light induces in etioplasts of Hordeum seedlings parallel to the formation of chlorophyll an increased synthesis of carotenoids, plastidic benzoquinones and vitamin K 1 . 1. Blue light induces an enhanced synthesis of β-carotene, lutein, violaxanthin, and neoxanthin, while the levels of antheraxanthin and zeaxanthin are decreased. 2. In contra...

We have studied in intact radish seedlings the effects of mevinolin (at concentrations of 0.25 to 5 μᴍ), a specific inhibitor of HMG-CoA reductase, and, therefore, of mevalonate biosynthesis, on the production of various isopentenoids and prenyllipids. Whereas the content of free desmethyl sterols was decreased steadily, only depending on the conce...

The principles of the chlorophyll (Chl) fluorescence induction kinetics (known as Kautsky effect) and their change by the photosystem II herbicide diuron are presented together with the Chl fluorescence emission spectra of a normal and diuron-inhibited leaf. By imaging the Chl fluorescence emission of green leaves the successive uptake of diuron an...

The chlorophyll (Chl) fluorescence induction kinetics, net photosynthetic CO2 fixation rates P N, and composition of photosynthetic pigments of differently light exposed leaves of several trees were comparatively measured to determine the differences in photosynthetic activity and pigment adaptation of leaves. The functional measurements were carri...

The overview provides basic information on the appearance and biosynthesis of thylakoids and osmiophilic plastoglobuli and their association with chloroplast development and senescence. The light-induced formation of sun chloroplasts at high irradiation with a different thylakoid arrangement, grana stacking and plastoglobuli content as compared to...

Reflectance images of various intact leaves were taken in four selected bands at 440, 550, 690, and 800 nm and compared with their reflectance spectra in the visible to near infra-red (range: 400 to 800 nm). The images showed high local resolution over the leaf surface (0.025 mm2 per pixel) with a low spectral resolution, whereas the reflectance sp...

With a multicolor fluorescence imaging system the fluorescence images of freshly harvested light-green apples were measured in the four major fluorescence bands of green plant tissue, i.e., the fluorescence bands F440 (blue), F520 (green), F690 (red), and F740 (far-red). By a pixel-to-pixel division of the fluorescence images we also determined the...

The biosynthesis of the tetraterpenoid carotenoids (carotenes and xanthophylls) in plants via the plastidic plastidic 1-deoxy-D-xylulose-4-phosphate/2-C-methylerythritol 5-phosphate pathway of isopentenyl and isoprenoid formation is described together with the different enzymatic steps (and genes) that lead from the active isoprenoid C5 diphosphate...

Fluorescence images of leaves of sugar beet plants (Beta vulgaris L. cv. Patricia) grown on an experimental field with different fertilisation doses of nitrogen [0, 3, 6, 9, 12, 15 g(N) m−2] were taken, applying a new multicolour flash-lamp fluorescence imaging system (FL-FIS). Fluorescence was excited by the UV-range (280–400 nm, λmax = 340 nm) of...

An overview is given on the fluorescence imaging of plants. Emphasis is laid upon multispectral fluorescence imaging in the maxima of the fluorescence emission bands of leaves, i.e., in the blue (440 nm), green (520 nm), red (690 nm), and far-red (740 nm) spectral regions. Details on the origin of these four fluorescence bands are presented includi...

With a flash-lamp chlorophyll (Chl) fluorescence imaging system (FL-FIS) the photosynthetic activity of several thousand image points of intact shade and sun leaves of beech were screened in a non-destructive way within a few seconds. The photosynthetic activity was determined via imaging the Chl fluorescence at maximum Fp and steady state fluoresc...

Some vascular angiosperm plants, which are sometimes addressed as “resurrection plants,” can survive severe drought periods and regain full physiological function in the subsequent rainy season. These desiccation-tolerant (DT) plants are poikilohydric and capable of surviving the loss of at least 80–95% of their cell water content for shorter or lo...

For the first time, the adaptive role of the rolling leaf trait for tolerance of wheat plants (Triticum aestivum L.) to the main factor of drought, high temperature, was demonstrated. Cv. Otan with high degree of this trait expression was more tolerant to temperature stress (40°C, 4 h during 2 days (2h/day)). Changes in parameters of chlorophyll fl...

The plastidic pathway for isopentenyl diphosphate (IPP) and isoprenoid biosynthesis, the DOXP/MEP pathway, possesses an essential function in the biosynthesis of thylakoidal prenylllipids chlorophylls (phytyl side-chain), carotenoids, plastoquinone-9, phylloquinone K1 and α-tocopherol, as well as for monoterpenes and diterpenes. Here we review its...

The world population is expected to increase to 9 billion by the year 2050 which will generate food and fuel shortages. Since it will be difficult to increase the land area under cultivation without serious environmental consequences, higher productivity for biomass is required. Improvement in photosynthetic efficiency would require increased knowl...

The objective of this study is to determine the potential of photosynthesis for the detection of heat stress in three wheat genotypes 'Grekum 476', 'Otan' and 'Alba', which are known to differ in their leaf rolling ability. The results of measurements of gas-exchange, stomatal conductance and pigment determination indicate that the use of a tempera...

The winter photosynthetic activity (quantified by net CO2 assimilation rates and chlorophyll (Chl) a fluorescence parameters) of 20 plant species (including two lichens and two mosses) of a Hungarian temperate semi-desert sand grassland was determined on one occasion per year in 1984, 1989 and 1994. Throughout winter, the overwintering green shoots...

We tested the hypothesis that leaf age affects photosynthetic induction, because conductance to CO2 diffusion usually decreases with increasing leaf age. Photosynthetic inductions, primarily determined by the light modulation of Rubisco activity and stomatal opening, were investigated in both young and mature leaves, as defined by leaf plastochron...

There are specific differences between red and blue light greening of etiolated seedlings of Hordevm vulgare L. Blue light results in a different prenyl lipid composition of chloroplast as compared to red light of equal quanta density. This is documented by a much higher prenylquinone content, higher chlorophyll a/b ratios, and lower values for the...

Abstract— Depending on the light intensity that they received during growth, radish seedlings altered not only the pigment and quinone composition of the thylakoid membrane but also the chloroplast ultrastructure. In strong light, sun chloroplasts of radish were very similar to those from sun leaves of beech trees, while those developed under under...

Abstract— The dependency of cytokinin effects upon irradiance was studied with radish seedlings (Raphanus sativus L. cv. Saxa Treib). Kinetin (6-furfurylamino-purine) or BAP (6-benzylamino-purine) were applied via the roots of plants growing either in continuous darkness or under high (90 Wm-2) or low intensity white light (10Wm-2). Apart from the...

In this section, we present the current knowledge on the blue-green fluorescence and redþfar-red chlorophyll fluorescence signals of plant tissues, give an introduction to the multicolor fluorescence imaging technique, and provide examples for its application in the assessment of agrofood.

Rising atmospheric carbon dioxide (CO(2)) concentration and air temperature are of major concern when considering the possible effects of global climate change on vegetations. Although production has been found to increase in many cases, other experiments have also indicated increased hazards for plant growth because of the increased frequency of w...

The differential pigment composition and photosynthetic activity of sun and shade leaves of deciduous (Acer pseudoplatanus, Fagus sylvatica, Tilia cordata) and coniferous (Abies alba) trees was comparatively determined by studying the photosynthetic rates via CO(2) measurements and also by imaging the Chl fluorescence decrease ratio (R(Fd)), which...

We examined the principal differences in photosynthetic characteristics between sun and shade foliage and determined the relative importance of biochemical and stomatal limitations during photosynthetic induction. Temperate-zone broadleaf and conifer tree species, ranging widely in shade tolerance, were investigated from one locality in the Czech R...

The differences in pigment levels, photosynthetic activity and the chlorophyll fluorescence decrease ratio R Fd (as indicator of photosynthetic rates) of green sun and shade leaves of three broadleaf trees (Platanus acerifolia Willd., Populus alba L., Tilia cordata Mill.) were compared. Sun leaves were characterized by higher levels of total chloro...