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Anatomy Of C3 And C4 Plants Pdf

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However, C3 plants are unable to carry out photosynthesis when the stomata are closed and under very high light concentrations and low CO2 concentrations. Compared to C4 plants, C3 plants are inefficient regarding their photosynthetic mechanism. Material on this page is offered under a Both C3 and C4 plants require 6 molecules of CO2 and 12 molecules of water to synthesis one molecule of glucose.

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An easy and inexpensive method of determining the photosynthetic pathway in grasses using a dye widely used in microscopy. To evaluate the efficiency of a new histochemical test for determination of the photosynthetic pathway in grasses Poacea.

Sections were then mounted between microscopy glass slides and coverslips using water. Grass species showing red staining of the bundle sheath cells were considered C4, and species with translucent bundle sheath were considered C3. The results of the histochemical test were then compared with results from carbon isotope composition analysis and the relevant scientific literature.

The proposed histochemical test proved efficient for characterization of the photosynthetic pathway in the tested grasses; however, the method should be further tested in a greater number of grass species, encompassing, preferably, all Poacea subfamilies. Future studies may elucidate if the proposed method can effectively be used in other botanical families.

Furthermore, additional investigations may determine whether the phenolic compounds indicated by the histochemical test are exclusive to the bundle sheath of C4 grasses and if possible relations exist between these phenolic compounds and the C4 photosynthetic pathway in grasses. The C4 photosynthetic rout evolved in plants tens of millions of years ago in response to environmental changes, characterizing an advantage under high light, hight temperature, or draught conditions Ehleringer et al.

There are 19 botanical families with C4 species Sage et al. Among them, Poaceae is the most diverse with C4 species Christin et al. The distinction between C3 and C4 grasses is not often apparent, although some characteristics can aid in the process, with emphasis on: anatomic characters; carbon isotope composition and CO 2 compensation point; and the activity of specific enzymes.

Many authors have attempted to use anatomical characteristics Hattersley and Watson , ; Hattersley and Browning ; Hattersley ; Prendergast and Hattersley ; Prendergast et al. Other methods were employed for the determination of photosynthetic pathways in plants Edwards and Walker ; Hatch ; Sage et al.

Neto proposed a histochemical method for determination of the photosynthetic pathway in grasses using Safranin O. The test is positive for C4 grasses when cells of the bundle sheath stain strongly red. In C3 grasses, cells of the bundle sheath do not stain red.

Confirmation of the efficiency of the histochemical test would provide an additional—as well as convenient and cheap method for determination of the photosynthetic pathway in grasses. However, validation of the test requires evaluation of its efficiency in a larger number of grass species, as well as confirmation of whether similar results can be obtained among the three types of C4 grasses [NAD-dependent malic enzyme NAD-ME , PEP-Carboxikinase PCK , and NADP-dependent malic enzyme NADP-ME ], comparing the results from the histochemical test with carbon isotope composition analysis and information within the relevant literature.

Afterwards, leaves were ground in liquid nitrogen with a mortar and pestle until a fine powder was obtained. About 2. The acceptable analytical error for carbon concentration determination is 0. Sections were then mounted between microscopy glass slides and coverslips, with a drop of water between them. Results from the histochemical test differed between C3 and C4 grasses. C4 grasses presented bundle-sheath cells stained red, while C3 did not. Results for Arundo donax and Uruchloa brizantha clearly illustrate the distinction Fig.

These results are compatible with those provided in Neto Histochemical test results in Arundo donax a and Urochloa brizantha b. The translucent bundle-sheath cells BS in A. Among the forage grasses, only Festuca aurora , Festuca arundinacea , and Holcus lanatus showed negative results. Among the tested wild grasses, Homolepsis aturensis , H. All other tested species of forage and wild grasses presented a positive result, indicating they have C4 photosynthetic systems.

Safranin O is the least specific histochemical indicator of lignin because it not only stains lignin, but all related phenolic substances Lewis and Yamamoto The red staining exclusively observed in cells from the bundle sheath of C4 grasses indicates the existence of a phenolic substance only in these cells.

Derived from the phenilpropanoid metabolism Ou and Kwok , ferulic acid 4-hydroxymethoxycinnamic is abundant in plant epidermis, xylem, sheath bundle, and sclerenchyma cells Faulds and Williamson ; Lambert et al. The red stain observed in bundle sheath cells may indicate the presence of hydroxicinamic acid.

However, the observation that the phenolic substances revealed by the histochemical test are located in the protoplasts of bundle sheath cells, and not in the cell wall, suggests such substances are likely to perform another important function inside the cells. According to Faulds and Williamson hydroxycinnamic acids, such as ferulic, sinapic, cafeic and p-coumaric acid, are found both covalently attached to the plant cell wall and as soluble forms in the cytoplasm.

The results of the histochemical test of bamboos were expected, given that bamboos are included in the Bambusoideae subfamily, which is composed exclusively of C3 species, distributed between the Bambuseae, Olyreae e Arundinarieae tribes. The genera Festuca and Holcus are included in the Pooideae subfamily, which is composed exclusively by C3 species Sage and Monson Homolepis aturensis , Homolepis isocalycia e Steinchis malaxum are part of the Panicoideae subfamily, Paniceae tribe.

Arundo donax is included in the Arundinoideae subfamily composed of 60 genera, of which five are C4 and within the Arundineae tribe, composed exclusively of C3 species Sage et al. The results from the histochemical test and the carbon isotope composition analysis are in accordance with previous reports concerning the plant genera represented in this study, indicating that the proposed histochemical test can be employed as an additional criterion for the determination of the photosynthetic pathway in grasses.

The convenience and low cost of the proposed method allows its utilization as a first indicator of the photosynthetic pathway in grasses. However, its use is recommended only with fresh samples, given that its performance with dry samples is not feasible. Future studies may confirm the applicability of this method in other botanical families with C4 member species.

In Cyperaceae, preliminary studies did not validate use of the test data not shown. Additionally, the isolation and identification of the phenolic compounds detected by the histochemical test in bundle sheath cells of C4 grasses may elucidate a possible relation between the presence of these substances and the C4 photosynthetic pathway.

Glob Change Biol — Bowes G Facing the inevitable: plant sand increasing atmosferic CO 2. Eur Food Res Technol — Google Scholar. J Agric Food Chem — Cerling T Paleo records of C4 plants and ecosystems.

Academic Press, San Diego, pp — Phytochemistry — Christin PA, Besnard G Two independent C4 origins in Aristidoideae Poaceae revealed by the recruitment of distinct phosphoenolpyruvate carboxylase genes. Am J Bot — Curr Biol — Ann Bot — Blackwell, Oxford. Trends Ecol Evolut — J Sci Food Agric — Nature — Hatch MD C4 photosynthesis: a unique blend of modified biochemistry, anatomy and ultrastructure. Biochem Biophys Acta — Mesophyll: bundle sheath area ratios. Hattersley PW, Browning AJ Occurrence of the suberized lamella in leaves of grasses of different photosynthetic types.

In parenchymatous bundle sheath and PCR kranz sheaths. Protoplasma — Photomorphology — Aust J Bot — Kellogg EA Phylogenetic aspects of the evolution of C4 photosynthesis. Kellogg EA Evolutionary history of the grasses. Plant Physiol — J Sci Food Agric 84 11 — Funct Plant Biol 14 4 — Sage RF The evolution of C 4 photosynthesis.

New Phytol — Academic Press, San Diego. J Exp Bot — Ann Rev Plant Biol — Download references. MAMN analyzed and interpreted the results. All authors read and approved the final manuscript. Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Reprints and Permissions. Neto, M. A new method for determination of the photosynthetic pathway in grasses.

Photosynth Res , 51—56 Download citation. Received : 25 February Accepted : 08 May Published : 15 May Issue Date : October Search SpringerLink Search. Download PDF. Abstract An easy and inexpensive method of determining the photosynthetic pathway in grasses using a dye widely used in microscopy. Introduction The C4 photosynthetic rout evolved in plants tens of millions of years ago in response to environmental changes, characterizing an advantage under high light, hight temperature, or draught conditions Ehleringer et al.

Functional leaf anatomy of plants with crassulacean acid metabolism

An easy and inexpensive method of determining the photosynthetic pathway in grasses using a dye widely used in microscopy. To evaluate the efficiency of a new histochemical test for determination of the photosynthetic pathway in grasses Poacea. Sections were then mounted between microscopy glass slides and coverslips using water. Grass species showing red staining of the bundle sheath cells were considered C4, and species with translucent bundle sheath were considered C3. The results of the histochemical test were then compared with results from carbon isotope composition analysis and the relevant scientific literature. The proposed histochemical test proved efficient for characterization of the photosynthetic pathway in the tested grasses; however, the method should be further tested in a greater number of grass species, encompassing, preferably, all Poacea subfamilies.

A new method for determination of the photosynthetic pathway in grasses

Photosynthesis is the process that plants use to turn light, carbon dioxide, and water into sugars that fuel plant growth, using the primary photosynthetic enzyme Rubisco. The majority of plant species on Earth uses C3 photosynthesis, in which the first carbon compound produced contains three carbon atoms. In this process, carbon dioxide enters a plant through its stomata microscopic pores on plant leaves , where amidst a series of complex reactions, the enzyme Rubisco fixes carbon into sugar through the Calvin-Benson cycle. However, two key restrictions slow down photosynthesis.

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B Corresponding author. Email: nelson botany. In this study, the leaf structure of a phylogenetically diverse assemblage of 18 CAM plants was compared with six C 3 plants and four C 4 plants to assess whether consistent anatomical patterns that may reflect functional constraints are present. CAM plants exhibited increased cell size and increased leaf and mesophyll thickness relative to C 3 and C 4 species.

Both C3 and C4 are types of dark reactions of photosynthesis. Both C3 and C4 plants fix energy from sunlight. Both C3 and C4 plants synthesize carbohydrates. Both C3 and C4 plants require 6 molecules of CO2 and 12 molecules of water to synthesis one molecule of glucose. The carbohydrate product of both C3 and C4 cycle is a three-carbon sugar phosphate molecules called Glyceraldehyde 3 phosphate G3P.

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