Ear Parts Research Articles

Presence and Correlation of Fusarium graminearum and Deoxynivalenol Accumulation in Silage Corn Plant Parts.

Corn silage, made from Zea mays, is a high-energy feed that is important for feeding dairy cows. Plant diseases, such as those caused by Fusarium graminearum, can decrease silage corn yields and quality. F. graminearum (teleomorph Gibberella zeae) is an ascomycete fungus that causes Gibberella ear and stalk rot in corn. F. graminearum produces deoxynivalenol (DON), a secondary metabolite toxic to humans and animals. An understanding of the distribution of DON and F. graminearum throughout the corn plant is important for determining the quality of corn silage. A partitioned sample experiment that included two brown midrib silage hybrids and three fungicide treatments was conducted in research plots located in Arlington, WI, U.S.A., in 2018 and 2019. At harvest, stalk and ear parts were physically separated, dried, and ground for analysis. DON concentration (in parts per million) was determined using an enzyme-linked immunosorbent assay, and F. graminearum DNA concentration (in picograms per nanogram) was determined using quantitative PCR. DON and F. graminearum DNA were detected in all samples, demonstrating accumulation of the fungus in stalks and ears of the plant. In 2018, DON contamination was as high as 30 ppm and varied drastically between stalks and ears. In 2019, DON concentrations were much lower (<5 ppm), but were consistently higher in stalk samples than ear samples. Across all samples, DON concentrations and F. graminearum accumulation were highly correlated within the separated stalk (r = 0.78) and ear portions (r = 0.87) but were not correlated between ears and stalks. Depending on the weather and planting conditions in a given year, stalk infections or ear infections may occur by F. graminearum, leading to subsequent DON increases in those respective parts that are independent of each other.

Invited Commentary RE: Correspondence to the Article: “Hyperbaric Oxygen Therapy for Large Composite Grafts: An Alternative in Pediatric Facial Reconstruction”

Thank you for your interest in our paper1 and for your letter2 describing this known alternative technique for the preservation of amputated ear parts. In our opinion and experience, the method you propose as described by Mladick et al. (dermabrading and burying the amputated ear cartilage with subsequent release from the pocket and split-thickness skin grafting) results, almost invariably, in a severely distorted ear over time with an ultimately unsatisfactory reconstruction. Interestingly, even Mladick et al.

Potential importance of the ear as a post‐anthesis carbon source to improve drought tolerance in spring wheat (Triticum aestivum L.)

AbstractIt is important to explore and propose a potential source for further improvements in drought tolerance in spring wheat (Triticum aestivum L.). The present study aimed to evaluate the significance of ear as a post‐anthesis carbon source under drought conditions in wheat genotypes with different sink–source balances. Field trials were conducted in 2017 and 2018 for four spring wheat genotypes (T. aestivum L.) with different sink–source balances in two different soil water conditions, irrigated and drought. The relative importance of a post‐anthesis carbon gain and dry matter remobilization as source functions for grain filling was evaluated in both environments. Digital infrared thermal imagery analysis was undertaken to analyse the contribution of the photosynthetic source to the leaf canopy and ear parts. In irrigated conditions, carbon assimilation was the major source for grain filling in all genotypes, whereas the contribution of dry matter remobilization was up to 20%. This was supported by a larger leaf area index (LAI) with a lower canopy temperature as the soil water stress alleviated. The ear temperature was always maintained below the canopy temperature, irrespective of irrigation treatment. When the drought intensity became more severe, very small leaf area was insufficient as the photosynthetic source organ for grain filling. Under severe drought condition, especially for genotypes with a larger sink capacity, carbon supply from ear itself appeared to play a significant role in grain filling. This study suggested that enhancing ear photosynthesis could be potential target for improving drought tolerance for high‐yielding modern wheat genotypes with larger sink and smaller biomass.

Ušní chirurgie v České republice

Surgical and outpatient care of a patient with ear disease is an integral part of otorhinolaryngology. It includes a wide range of procedures in the region of the external auditory canal, middle ear and other parts of the pyramid bone with various indications. The objective increase in the number of ear procedures at the department of the authors was the impulse to map the situation of ear surgery in the Czech Republic. Data were collected in the period from January 2020 to August 2020, using a questionnaire, which was sent to the heads of all ENT departments in the Czech Republic. The yield of the questionnaire was 100%. Overall 80% of all ENT departments perform ear surgeries, of which almost 85% perform pediatric ear surgeries too. The maximum of ear surgery proceeds in the university departments where an increase in the number of operated patients has been observed in the last 10 years. These departments also cover specialized procedures such as cochlear implantations and more extensive surgeries on the temporal bone. Keywords: ear surgery – ear diseases – hearing rehabilitation

On Distinctiveness and Symmetry in Ear Biometrics

Previous works show that human ears can be used for identification, gender classification, and kinship verification and have investigated whether there is a symmetry between a person's ears; however, the symmetry performances have been less than satisfactory. Our paper extends the analysis of gender classification on ear images and analyses bilateral symmetry of human ears, in both cases aiming to determine the ear parts from which recognition is derived. We use model-based analysis and deep learning methods to capitalize on structure and performance, respectively. We consider the rotation of ear images under an affine transformation, by modelling the ear as a flat plane attached to the head. We address the question as to whether it is possible that given an image of one ear, a person can then be recognized from their other ear. Such a symmetry-based strategy could reduce constraints on applications of ear biometrics. We show that it is possible to recognise the gender with a 90.9% success rate and that the ear rim (the upper helix and lobe) dominates performance. To investigate symmetry, we compare one ear with a mirrored version of the other ear and achieve 93.1% CCR, which is the current state-of-the-art, with important regions different from those determined for gender. To extend the analysis we construct two groups of images, one of which contains both ears from the same subject and the other contains two ears from different subjects. The 100% CCR confirms the existence of symmetry between a subject's ears. By these approaches we show that there is actually a high chance that there exists symmetry between a person's ears and that it would be prudent for recognition systems to concentrate on the inner ear rather than the outer ear.

Effects of Injectable Aminoglycosides on the Auditory Performance of Individuals with Drug Resistant Tuberculosis in Osun State, Nigeria

Ototoxicity caused by injectable aminoglycosides are capable of causing cochleotoxicity which is characterised as death of auditory hair cells (hearing loss) and vestibulotoxicity manifesting as balance disorders. Ototoxicity is always as a result of insidious effects of aminoglycosides on auditory system, with a kind of irreversible (permanent) hearing loss which is common among individuals being treated for Drug Resistant Tuberculosis (DRTB). Therefore, this study examined the effect of injectable aminoglycosides on the auditory performance of patients with DRTB in Osun state. Twenty (20) DRTB patients comprising of 14 males and 6 females were purposively selected to participate in this ex post facto research. Instruments used include Otoscope to diagnose infection of the middle ear and outer parts of the ear, Maico ST 20 portable diagnostic audiometer to determine the hearing threshold of the participants, and audiograms to record the test results. Baseline audiometry revealed that 35% of the participants had mild hearing loss before commencement of treatment with injectable aminoglycosides, while 70% of the participants had severe to profound hearing loss after completion of injectable aminoglycosides. 65% of the participants had tinnitus in addition to hearing loss, while 55% had high frequency loss only. Therefore, health workers should ensure that people with DRTB are well educated about the side effects of injectable aminoglycosides and be encouraged to access audiologic follow up and rehabilitation, while alternative injectable drugs with reduced or milder side effects are employed for treatment of Drug Resistant Tuberculosis.

Measurement of morphological parameters of internal acousticmeatus using thin-section CT

Objective: This study aimed to measure the morphological parameters of the internal acoustic meatus(IAM) and its adjacent structures using temporal-bone thin-section CT(computed tomography). Methods: CT images were obtained from 50 Chinese adult patients (25 males and 25 females, 100 sides) which had no visible lesion in the petrous part of the temporal bone and inner ear, the morphological parameters of all inner ear parts were sectionally measured on the specified plane using SPSS 22.0 software for statistical analysis. Results: The integral morphological characteristics of the IAM were observed. These results revealed that anterior-posterior diameter of the internal acoustic poer(IAP)(CD) was (6.93±1.85)mm, the superior-inferior diameter of the IAP(EF) was (4.40±0.86)mm, the length of the IAM(AB) was (9.30±1.60)mm, the superior-inferior diameter of the IAM(the intersection of inner 1/3 section and middle 1/3 section) was (4.13±0.83)mm, the superior-inferior diameter of the IAM(the intersection of middle 1/3 section and outer 1/3 section) was (4.61±1.02)mm, the anterior-posterior diameter of the IAM(the intersection of inner 1/3 section and middle 1/3 section) was (6.62±1.92)mm, the anterior-posterior diameter of the IAM(the intersection of middle 1/3 section and outer 1/3 section) was (6.28±1.65)mm, the depth of transverse crest (superior wall) was (3.10±0.75)mm, the depth of transverse crest (interior wall)the was (1.46±0.59)mm, the distance from transverse crest vertex A to the superior wall of the IAM was (2.05±0.42)mm, the distance from transverse crest vertex A to the interior wall of the IAM was (2.93±0.41)mm, the thickness of the superior bone wall of the IAM (the intersection of inner 1/3 section and middle 1/3 section) was (4.45±1.34)mm, the thickness of the superior bone wall of the IAM (the intersection of middle 1/3 section and outer 1/3 section) was (4.32±1.12)mm, the thickness of the superior bone wall of the IAM (the intersection of outer 1/3 section and transverse crest vertex) was (4.37±1.28)mm, and the appearance ratio of the cells in the whole IAM superior wall was 32%.The whole IAM assumed the shape of short cylinder, inclining about 1 cm outward, with the upper-lower diameter and anterior-posterior diameter about 5 mm. Conclusion: It is necessary for carrying out preoperative the temporal-bone thin-section CT to obtain the morphological parameters of the IAM, determine its basic morphology, and provide references to avoid damaging the other important structures during IAM surgeries.

The contribution of the awns of bread wheat (Triticum aestivum L.) to grain filling: Responses to water deficit and the effects of awns on ear temperature and hydraulic conductance

The awns of the ear have been reported as important sources of assimilates in wheat. However, their actual importance in grain filling is not well known. We examined several aspects of the awns and their role in the grain filling, and the objectives of this work were: (i) to study their photosynthetic activity during grain filling, comparing flag leaf, ear body and awns in two cultivars differing in ear contribution to grain filling, (ii) to estimate the influence of awns on the temperature and the hydraulic conductance of the ear, (iii) to analyze the response of the flag leaf versus awns to water deficit, particularly regarding relative water content and photosynthetic activity, (iv) to analyze if there is a correlation between awn size versus ear and awn contribution to the grain filling in six modern Argentinean cultivars, and, (v) to explore if awn size and awn contribution have changed during the past century, analyzing old and modern Argentinean cultivars. In this paper we show that: (1) during late grain filling, ear parts (particularly the body of the ear) maintained a higher photosynthetic activity than the flag leaf, (2) awns showed some ‘tolerance’ to water deficit, maintaining a higher relative water content and electron transport rate than the flag leaf under drought, (3) awns increase water conductance of the ear (particularly in the cv. K. Escudo), decrease the ear temperature during the morning, but increase ear temperature after midday (4) there is a moderately positive relationship between awn size and contribution of the ear to grain filling, and (5) in the retrospective analysis we did not find a clear tendency in awn size and awn contribution to grain filling along the years. However, in general terms modern cultivars seem to have a higher awn contribution (and higher awns size) than old ones.In summary, awns may have positive (increased photosynthetic area and activity, tolerance to drought) and negative (increased ear temperature) effects on grain filling, and their final impact on yield will depend on the interaction between these effects and prevailing environmental conditions.

Changes in the concentrations of fumonisin, deoxynivalenol and zearalenone in corn silage during ensilage

We assessed the production of the mycotoxins fumonisin, deoxynivalenol and zearalenone during the ensiling of corn. Corn was harvested at yellow-ripe or full-ripe stage and separated into the stem and leaf parts and the ear parts, including bracts. Each material was ensiled under five conditions: (1) no fungus added, anaerobic conditions; (2) no fungus added, aerobic conditions; (3) mycotoxin-producing fungus added, anaerobic conditions; (4) mycotoxin-producing fungus added, aerobic conditions; and (5) mycotoxin-producing fungus added to autoclaved material, aerobic conditions. After 40 days of ensilage, we analyzed the silage fermentative quality and mycotoxin concentration. The fermentative quality of all materials was good in treatments (1) and (3), because the pH < 4 increased the lactic acid content preventing mycotoxin levels from increasing. In treatments (2) and (4), fermentative quality of all materials was poor, and mycotoxin levels were slightly increased. In treatment (5), fermentative quality was poor, and mycotoxin levels were increased remarkably. These results indicate that mycotoxins are not produced under anaerobic conditions and are hardly produced under aerobic condition during the ensiling of corn. Our findings suggest that almost all mycotoxins in corn silage are produced pre-harvest.

Ramsay Hunt syndrome

Ramsay Hunt syndrome is defined as herpes zoster oticus associated with an acute peripheral facial nerve paresis and quite often with other cranial nerve lesions. The combination of motor, sensory and autonomic involvement leads to a variety of neurological damage patterns, i. e. facial muscle paresis, hearing and balance disorders, sensory problems and disturbances of taste as well as lacrimal and nasal secretion. Additional variability of the clinical picture of Ramsay Hunt syndrome is produced by varying patterns of skin involvement explained by individual anastomoses between cranial and cervical nerves. Knowledge of these findings and an early diagnosis of Ramsay Hunt syndrome are important as prognosis of cranial nerve damage depends on the time at which acyclovir-corticosteroid therapy is started.

History of arteficial deformation of the human body. IV. Mutalation of the ear, nose, lips, and other parts of human body

History of arteficial deformation of the human body. IV. Mutalation of the ear, nose, lips, and other parts of human body

Craniofacial measurements of full‐term neonates

PurposeThe purpose of this paper is to measure the craniofacial dimensions of 41 full‐term neonates nursed in the Special Care Baby Unit of Queen Mary Hospital in Hong Kong, so as to develop a good‐fitting and secure eye‐patch protector for protecting neonatal eyes from the strong light in phototherapy.Design/methodology/approachIn total, 14 craniofacial dimensions were measured using a new, safe and non‐intrusive method with a close‐range photogrammetric system and two dimensions of head circumference and facial arc were measured using manual method with a disposable paper tape in the hospital environment. Birth information of gestation, age, gender, present weight and present length has been recorded. A descriptive statistics was produced based on the measured data. Correlations between each pair of dimensions were investigated and factor analysis was conducted for application on an eye‐patch protector development.FindingsHead circumference was identified as the most desirable key dimension of a sizing system for an eye‐patch protector. Two head circumferences with the sizes of 310‐349 mm and 350‐389 mm, respectively, could effectively cover all full‐term neonates. Design guidelines were generated according to the measurement of the craniofacial dimensions.Originality/valueThis paper presents the craniofacial dimensions of head, eye, nose and ear parts of full‐term neonates.

High temperature effects on photosynthate partitioning and sugar metabolism during ear expansion in maize (Zea mays L.) genotypes

Short hot and dry spells before, or during, silking have an inordinately large effect on maize (Zea mays L.; corn) grain yield. New high yielding genotypes could be developed if the mechanism of yield loss were more fully understood and new assays developed. The aim here was to determine the effects of high temperature (35/27 degrees C) compared to cooler (25/18 degrees C) temperatures (day/night). Stress was applied for a 14 d-period during reproductive stages prior to silking. Effects on whole plant biomass, ear development, photosynthesis and carbohydrate metabolism were measured in both dent and sweet corn genotypes. Results showed that the whole plant biomass was increased by the high temperature. However, the response varied among plant parts; in leaves and culms weights were slightly increased or stable; cob weights decreased; and other ear parts of dent corn also decreased by high temperature. Photosynthetic activity was not affected by the treatments. The (13)C export rate from an ear leaf was decreased by the high temperature treatment. The amount of (13)C partitioning to the ears decreased more than to other plant parts by the high temperature. Within the ear decreases were greatest in the cob than the shank within an ear. Sugar concentrations in both hemicellulose and cellulose fractions of cobs in sweet corn were decreased by high temperature, and the hemicellulose fraction in the shank also decreased. In dent corn there was no reduction of sugar concentration except in the in cellulose fraction, suggesting that synthesis of cell-wall components is impaired by high temperatures. The high temperature treatment promoted the growth of vegetative plant parts but reduced ear expansion, particularly suppression of cob extensibility by impairing hemicellulose and cellulose synthesis through reduction of photosynthate supply. Therefore, plant biomass production was enhanced and grain yield reduced by the high temperature treatment due to effects on sink activity rather than source activity. Heat resistant ear development can be targeted for genetic improvement.

The Photosynthetic Role of Ears in C3 Cereals: Metabolism, Water Use Efficiency and Contribution to Grain Yield

This review concerns ear photosynthesis and its contribution to grain filling in C3 cereals. Ear photosynthesis is quantitatively important to grain filling, particularly in dry areas where source (i.e., assimilate) limitations can occur. Compared to the flag leaf, ear photosynthesis exhibits higher water stress tolerance. Several factors could be involved in the ear's “drought tolerance.” First, although degree of C4 metabolism in ear parts has been reported, current evidence supports only typical C3 metabolism. Second, recycling of respired CO2 (i.e., refixation) could have considerable impact on final crop yield by preventing loss of CO2. Because refixation of CO2 is independent of atmospheric conditions, water use efficiency (measured as total ear photosynthesis divided by transpiration) could be higher in the ear than in the flag leaf. Moreover, ear parts (in particular awns) show higher relative water content and better osmotic adjustment under water stress compared to the flag leaf. This capacity, in addition to persistence of photosynthetic components under drought (delayed senescence), might help the ear to continue to fix CO2 late in the grain filling period.

Ear of durum wheat under water stress: water relations and photosynthetic metabolism

The photosynthetic characteristics of the ear and flag leaf of well-watered (WW) and water-stressed (WS) durum wheat (Triticum turgidum L. var. durum) were studied in plants grown under greenhouse and Mediterranean field conditions. Gas exchange measurements simultaneously with modulated chlorophyll fluorescence were used to study the response of the ear and flag leaf to CO2 and O2 during photosynthesis. C4 metabolism was identified by assessing the sensitivity of photosynthetic rate and electron transport to oxygen. The presence of CAM metabolism was assessed by measuring daily patterns of stomatal conductance and net CO2 assimilation. In addition, the histological distribution of Rubisco protein in the ear parts was studied by immunocytochemical localisation. Relative water content (RWC) and osmotic adjustment (osmotic potential at full turgor) were also measured in these organs. Oxygen sensitivity of the assimilation rate and electron transport, the lack of Rubisco compartmentalisation in the mesophyll tissues and the gas-exchange pattern at night indicated that neither C4 nor CAM metabolism occurs in the ear of WW or WS plants. Nevertheless, photosynthetic activity of the flag leaf was more affected by WS conditions than that of the ear, under both growing conditions. The lower sensitivity under water stress of the ear than of the flag leaf was linked to higher RWC and osmotic adjustment in the ear bracts and awns. We demonstrate that the better performance of the ear under water stress (compared to the flag leaf) is not related to C4 or CAM photosynthesis. Rather, drought tolerance of the ear is explained by its higher RWC in drought. Osmotic adjustment and xeromorphic traits of ear parts may be responsible.

Photosynthetic pigment composition and photosystem II photochemistry of wheat ears

The characteristics of pigment composition and photosystem II (PSII) photochemistry in the flag leaf and ear parts of wheat ( Triticum aestivum L.) grown in the field was compared. At the early stage of flowering, awns and the flag leaf showed the highest values in the maximal efficiency of PSII photochemistry ( F v/ F m), actual PSII efficiency (Φ PSII), photochemical quenching ( q P), and the efficiency of excitation capture by open PSII centres ( F ′ v / F ′ m ), followed by glumes, lemmas, and paleae, respectively except that no differences in F ′ v / F ′ m were observed among glumes, leamms, and paleae. With progressing grain filling, there was a change in the photosynthetic pigment stoichiometry. In the ear parts, neoxanthin and antheraxanthin decreased equally with chlorophyll levels. Lutein and zeaxanthin decreased less than chlorophyll levels while β-carotene and violaxanthin decreased faster than chlorophyll levels. No big differences in pigment composition were observed among different ear parts. For the flag leaf, neoxanthin and β-carotene decreased concomitantly with chlorophyll, whereas lutein and xanthophyll cycle pigment were less affected, leading to increases in lutein/chlorophyll and xanthophyll cycle pigment/chlorophyll ratios. F v/ F m, Φ PSII, q P, and F ′ v / F ′ m decreased gradually in the flag leaf and ear parts but to different extents. The largest changes were observed in awns, followed by the lemmas of floret 2, the lemmas of floret 1, glumes, and the flag leaf, respectively. The results suggest that during grain filling, a down-regulation of PSII associated with an increase of the de-epoxidation state of the xanthophyll cycle carotenoids occurred in the flag leaf but not in the ear parts.

Activity and distribution of carbonic anhydrase in leaf and ear parts of wheat ( Triticum aestivumL.)

The activity of carbonic anhydrase (CA; EC 4.2.1.1.) was examined in leaf and ear parts of wheat plants ( Triticum aestivum L.) using physiological measurement and histochemical staining. CA activity in leaves increased to the maximum at flag-leaf visible stage, and then decreased to a minimum before increasing at dough stage. From milk to dough stage, CA activities tended to decrease in both glumes and paleas, but increased in the lemmas and pericarps. CA activities in the tissues of ear parts at milk stage were higher than that in leaf tissue, and cv. Xiaoyan54 possessed higher activity of CA in flag-leaves, glumes, lemmas and pericarps than cv. Jing411 at dough stage. Histochemical staining indicates that CA was localized mainly in the chloroplasts of mesophyll cells in flag-leaves and glumes, and also in the xylem vessels of vascular bundles and cytosol of mesophyll cells in lemmas and paleas, but little CA activity was found in the bundle sheath cells (BSC) of both flag-leaf and ear parts. The results suggest that the presence of CA in the mesopyll chloroplasts of glumes, as well as in the xylem vessels of vascular bundles and cytosol of mesophyll cells in lemmas and paleas, might play a functional role for C 4 photosynthesis at dough stage of wheat plants, and cv. Xiaoyan54 had a higher rate of CO 2 delivery than cv. Jing411.

Photosynthetic Characteristics of Non-Leaf Organs of Winter Wheat Cultivars Differing in Ear Type and their Relationship with Grain Mass Per Ear

Chlorophyll content, photosystem 2 functioning (Fv/Fm, Fv/F0), activity of ribulose-1,5-bisphosphate carboxylase/oxygenase, and net photosynthetic rates (PN) of flag leaf blade, sheath, peduncle, and ear organs were assessed in large-ear type (Pin 7) and small-ear type (ND93) wheat cultivars. Some differences were found in photosynthetic properties between different green plant parts, the values of all studied parameters in ear parts being higher in Pin7 than in ND93. Furthermore, ear surface areas and ear PN in 26 wheat genotypes measured at anthesis showed highly significant positive correlation with grain mass per ear. Hence a greater capability of ear photosynthesis may result in a greater grain yield in large-ear type cultivars.

Lack of C4 photosynthetic metabolism in ears of C3 cereals

ABSTRACTThere is continuing controversy over whether a degree of C4 photosynthetic metabolism exists in ears of C3 cereals. In this context, CO2 exchange and the initial products of photosynthesis were examined in flag leaf blades and various ear parts of two durum wheat (Triticum durum Desf.) and two six‐rowed barley (Hordeum vulgare L.) cultivars. Three weeks after anthesis, the CO2 compensation concentration at 210 mmol mol−1 O2 in durum wheat and barley ear parts was similar to or greater than that in flag leaves. The O2 dependence of the CO2 compensation concentration in durum wheat ear parts, as well as in the flag leaf blade, was linear, as expected for C3 photosynthesis. In a complementary experiment, intact and attached ears and flag leaf blades of barley and durum wheat were radio‐labelled with 14CO2 during a 10s pulse, and the initial products of fixation were studied in various parts of the ears (awns, glumes, inner bracts and grains) and in the flag leaf blade. All tissues assimilated CO2 mainly by the Calvin (C3) cycle, with little fixation of 14CO2 into the C4 acids malate and aspartate (about 10% or less). These collective data support the conclusion that in the ear parts of these C3 cereals C4 photosynthetic metabolism is nil.

Immunocytochemical localization of phosphoenolpyruvate carboxylase and photosynthetic gas-exchange characteristics in ears of Triticum durum Desf.

The presence and distribution of phosphoenolpyruvate carboxylase (PEPCase) in the glumes and immature grains of durum wheat (Triticum durum Desf.) were studied by electron-microscopical immunolabeling of PEPCase with polyclonal antibodies followed by protein A-gold. Plants were grown under mediterranean field conditions and samples were obtained two weeks after anthesis. In the kernels, high gold label was associated with the unstained areas of the protein bodies of aleurone cells, whereas labeling in the cytoplasm and chloroplasts of the pericarp was slight, although significantly above the background. In the glumes, high gold label was only located in cytoplasmic granules (vesicles) of the mesophyll cells, although labeling in the cytoplasm and chloroplasts was also significantly above the background. These observations in immature kernels and glumes are in accordance with the anaplerotic role of this enzyme, as evidenced in C3 plants. Measurements of apparent photosynthesis and its O2 dependence and CO2 compensation concentration were made on ears and flag leaves of durum wheat. In addition, an analog of phosphoenolpyruvate, 3,3-dichloro-2-dihydroxy-phosphinoylmethyl-2-propenoate, was used to inhibit PEPCase and, thereby, to assess the contribution of the PEPCase to photosynthesis in detached ears. There was no effect of the inhibitor on the apparent photosynthesis of ears. Whereas inhibition of apparent photosynthesis by 210 mL · L−1 O2 in flag leaves was typical of C3 species, inhibition in ears was even greater. The CO2 compensation concentrations in different ear parts were similar to or higher than in flag leaves and the O2 dependence was also comparable (about 70%). Therefore, gas-exchange data give further support to the assumption that a C4 cycle is absent or limited to very low rates in ears of durum wheat.