Pegging Stage Research Articles

Magnesium fertilizer application increases peanut growth and pod yield under reduced nitrogen application in southern China

This study investigated the effect of magnesium application on peanut growth and yield under two nitrogen (N) application rates in acidic soil in southern China. The chlorophyll content, net photosynthetic rate and dry matter accumulation of the N-sensitive cultivar decreased under reduced N treatments, whereas no effect was observed on the relevant indicators in the N-insensitive variety GH1026. Mg application increased the net photosynthetic rate by increasing the expression of genes involved in chlorophyll synthesis and Rubisco activity in the leaves during the pegging stage under 50%N treatment, while no effect on the net photosynthetic rate was observed under the 100%N treatment. The rate of dry matter accumulation at the early growth stage, total dry matter accumulation and pod yield at harvest increased after Mg application under 50%N treatment by increasing the transportation of assimilates from stems and leaves to pods in both peanut varieties, whereas no effect was found under 100%N treatment. Moreover, Mg application increased the NUE under 50%N treatment. No improvement of NUE in either peanut variety was found under 100%N treatment, while Mg application under the 50%N treatment can obtain a higher economic benefit than the 100%N treatment. In acidic soil, application of 307.5 kg ha−1 of Mg sulfate fertilizer under 50% reduced nitrogen application is a suitable fertilizer management measure for improving carbon assimilation, NUE and achieve high peanut yields in southern China.

Arbuscular Mycorrhizal Fungi Restored the Saline-Alkali Soil and Promoted the Growth of Peanut Roots.

Peanut (Arachis hypogaea L.) is an important oil and cash crop. An efficient utilization of saline-alkali soil resources, the development of peanut planting in saline-alkali soil, and obtaining high and stable yield have become urgent needs to ensure peanut production. Arbuscular mycorrhizal fungi (AMF) have been reported to develop the potential productivity of host plants and improve their salt resistance and tolerance. However, there is still limited research on promoting the growth and morphology of peanut roots. Therefore, in this study, seeds of salt-tolerant peanut variety "HY 25" were coated with commercial AMF inoculant before being planted in saline-alkali and normal soils to investigate the effects of AMF on peanut root growth and rhizosphere soil. The results showed that root morphological characteristics were significantly increased by the use of AMF at the podding stage in saline-alkali soil and from the flowering and pegging stage to the maturity stage in normal soil. Of note, the total root volume of peanut inoculated with AMF significantly increased by 31.57% during the podding stage in saline-alkali soil. Meanwhile, AMF significantly increased the phosphatase and invertase activities in the peanut rhizosphere of saline-alkali soil from the flowering stage to maturity stage and soil CAT activity at the maturity stage (41.16~48.82%). In normal soil, soil phosphatase and urease activities were enhanced by AMF at the flowering stage and the podding stage, respectively. AMF also increased the contents of soil organic matter, available phosphorus, and hydrolysable nitrogen, but decreased soil EC in saline-alkali soil. In addition to the significant increase in soil available phosphorus content, AMF had no significant effect on the physical and chemical properties of the soil and other soil nutrients in normal soil. AMF significantly increased pod biomass and yield in saline-alkali soil and normal soil, and improved their agronomic characteristics. In conclusion, peanut seeds coated with AMF improved the root morphological characteristics of peanuts and improved the physical and chemical properties in peanut rhizosphere, especially in saline-alkali soil. The process of rhizosphere soil nutrient transformation was also enhanced. Finally, AMF improved plant agronomic traits to increase the pod yield (16.5~21.9%). This study provides the theoretical basis and technical support for the application of AMF in peanut production in saline-alkali soil.

Optimizing sowing date and plant density improve peanut yield by mitigating heat and chilling stress

AbstractPeanut (Arachis hypogea L.) yield is dramatically declined by extreme weather stresses under climate change. Adjusting the sowing date and plant density are effective strategies to mitigate these stresses and improve peanut yield. However, a mechanistic understanding of the influence of environmental drivers and an optimized strategy have yet to be developed. Here, a 3‐year field experiment was conducted to evaluate the sowing date (April 25, early sowing; May 5, middle sowing; May 15, late sowing) and plant density (24, 30, and 36 plants m−2 as low, medium, and high) of peanut in the North China Plain. We found that higher pod yield was observed in the middle sowing (∼4492.4 kg ha−1) compared with the early and late sowing (∼3317.2 and 4088.1 kg ha−1, respectively). Meanwhile, the pod yield in high density (∼4162.5 kg ha−1) was 10.6% and 4.7% higher than low and medium density, respectively, mainly due to higher leaf area index. The relative peanut pod yield was positively correlated with the average minimum temperature 5 days before and after the flowering pegging stage, whilst it was negatively correlated with average maximum temperature 5 days before and after pod filling stage. Therefore, optimizing temperature conditions to improve the peanut yield can be achieved by adjusting the sowing date. In conclusion, sowing date and plant density manipulation constitute a useful method to mitigate heat and chilling stress and improve peanut yield.

Nestin is a marker of unipotent embryonic and adult progenitors differentiating into an epithelial cell lineage of the hair follicles

Nestin is an intermediate filament protein transiently expressed in neural stem/progenitor cells. We previously demonstrated that outer root sheath (ORS) keratinocytes of adult hair follicles (HFs) in mice descend from nestin-expressing cells, despite being an epithelial cell lineage. This study determined the exact stage when nestin-expressing ORS stem/precursor cells or their descendants appear during HF morphogenesis, and whether they are present in adult HFs. Using Nes-Cre/CAG-CAT-EGFP mice, in which enhanced green fluorescent protein (EGFP) is expressed following Cre-based recombination driven by the nestin promoter, we found that EGFP+ cells appeared in the epithelial layer of embryonic HFs as early as the peg stage. EGFP+ cells in hair pegs were positive for keratin 14 (K14) and K5, but not vimentin, SOX2, SOX10, or S100 alpha 6. Tracing of tamoxifen-induced EGFP+ cells in postnatal Nes-CreERT2/CAG-CAT-EGFP mice revealed labeling of some isthmus HF epithelial cells in the first anagen stage. EGFP+ cells in adult HFs were not immunolabeled for K15, an HF multipotent stem cell marker. However, when hairs were depilated in Nes-CreERT2/CAG-CAT-EGFP mice to induce the anagen stage after tamoxifen injection, the majority of ORS keratinocytes in depilation-induced anagen HFs were labeled for EGFP. Our findings indicate that nestin-expressing unipotent progenitor cells capable of differentiating into ORS keratinocytes are present in HF primordia and adult HFs.

Continuous regulated deficit irrigation enhances peanut water use efficiency and drought resistance

Regulated deficit irrigation (RDI) is an important means by which the water use efficiency (WUE) of peanut can be improved and facilitates the sustainable development of the peanut industry. However, most studies of RDI have only focused on single growth periods, which limits the water-saving potential. In this study, continuous regulated deficit irrigation (CRDI) was used to significantly improve the WUE of peanut through an experiment employing a split-plot design. Three levels of water deficit treatment, severe (H1/J1, 45% field capacity), moderate (H2/J2, 55% field capacity), and mild (H3/J3, 65% field capacity), were applied in the flower pegging stage (H) and the pod setting stage (J). Moderate CRDI (H2J2) stably improved the instantaneous water use efficiency of peanut leaves. Yield was not significantly decreased under the H2J2 treatment, and was only 4.47% lower than that of the H3J2 treatment, in which the yield was the highest. The highest WUE was observed in the H2J2 treatment (1.87 kg·m−3). The first time that the soil water content reached the lower limit in the pod setting stage, the proline content in the H1J1 treatment was 13.57 times higher than that in the H3J3, indicating that peanuts in the H1J1 treatment experienced substantial drought stress. The second time that the lower limit of soil water content was reached, the proline content in the H1J1 treatment was 7.14 times higher than that in the H3J3 treatment, indicating that the peanut drought resistance was improved by the drought-rehydration exercise at the flower pegging stage and drought stress was alleviated in the pod setting stage. We conclude that moderate CRDI is beneficial to peanut drought resistance for arid and semi-arid areas, and significantly promoted higher WUE.

Effect of Water Regimes on the Growth of and Yield of Rabi / Summer Groundnut Genotypes in Northern Transition Zone of Karnataka

Background: Groundnut crop grown during Rabi / summer experiences moisture stress, thus irrigation is must. However, water for irrigation gets scarce during summer month hence it becomes important to choose stress tolerant varieties and optimize irrigation schedule without compromising the yield.Methods: A field experiment with four rabi / summer groundnut genotypes (G1: Dh-86, G2: Dh-101, G3: K-9 and G4: G2-52) exposed to four irrigation regimes (I1: 7 irrigations at 15 days interval from sowing to 105 DAS as control, I2: withdrawal of one irrigation between 45 - 60 DAS i.e., pegging stage, I3: withdrawal of two irrigations between 45-75 DAS i.e., at pegging and pod filling stage, I4: withdrawal of four irrigations from 45-105 DAS i.e., at pegging, pod filling and kernel development stage) was carried out from December to April of 2016-17 on black cotton soils at AICRP on Groundnut UAS, Dharwad.Result: Among the genotypes tested, Dh-86 recorded significantly higher pod yield (2,376 kg ha-1) followed by Dh-101 (2,215 kg ha-1) and K-9 (2,048 kg ha-1), whereas G2-52 gave the lowest yield (1,880kg ha-1) and all of them performed well at I1 and I2 irrigation regimes. Among different water regimes, I1 (i.e., control) recorded significantly taller plants, higher LAI, more branches and higher dry matter at harvest as compared to other irrigation regimes, hence it also recorded significantly higher pod yield and haulm yield (2,870 and 4,691 kg ha-1, respectively), but was found at par with I2, i.e., crop stressed only at pegging stage (2,858 and 4,648 kg ha-1, respectively). This suggests that, at the most, one irrigation can be skipped at pegging stage without compromising on yield.

Effect of Moisture Regimes on Water use Efficiency of Rabi / Summer Groundnut Genotypes in Northern Transition Zone of Karnataka

Background: During rabi / summer irrigation water is a scarce resource, but crop needs more water due to non-rainy season and warmer climate. Hence, a field experiment was conducted during rabi / summer season of 2016-17 to study the effect of irrigation water regimes on water use efficiency (WUE) of groundnut genotypes in Northern Transition Zone of Karnataka. Methods: This field study comprised of four main plots as water regimes viz. I1: (control) seven irrigations at 15 days interval from sowing to 105 DAS, I2: Stress at pegging stage; withdrawal of one irrigation between 45 - 60 DAS, I3: Stress at pegging and pod filling stage; withdrawal of two irrigations between 45-75 DAS, I4: Stress at pegging, pod filling and kernel development stage; withdrawal of four irrigations from 45-105 DAS and four genotypes as sub plots viz. G1: Dh-86, G2: Dh-101, G3: K-9 and G4: G2-52. Treatments were replicated thrice and laid out in split plot design. Result: Among the water regime, I2 recorded significantly higher WUE (6.2 kg ha-1 mm-1) followed by I1 (control; 5.5 kg ha-1 mm-1). Water regime I2 also recorded significantly higher pod yield and haulm yield (2,857 kg ha-1 4,648 kg ha-1, respectively) along with other yield attributes, but was found at par with control (I1). This study showed that WUE as well as yield of rabi / summer groundnut can be enhanced if crop was exposed only to mild stress by skipping an irrigation at pegging stage out of total seven irrigations. Among the genotypes, Dh-86 with 2,375 kg ha-1 of pod yield performed significantly better over others like Dh-101 (2,215 kg ha-1), K-9 (2,048 kg ha-1) and G2-52 (1,880kg ha-1) suggesting differential response to moisture stress, thus choice of moisture stress tolerant genotypes is equally important to enhance WUE. Interaction between irrigation regime and genotypes showed that Dh-86 (G1) with I2 irrigation regime recorded significantly higher WUE (6.9 kg ha-1 mm-1), pod yield (3,168 kg ha-1) and net return (Rs. 95,655 ha-1) and was found at par with full irrigation regime (I1).

Effect of Waterlogging Stress on Dry Matter Accumulation, Photosynthesis Characteristics, Yield, and Yield Components in Three Different Ecotypes of Peanut (Arachis hypogaea L.)

Waterlogging has a negative effect on peanut production, but few studies have focused on the relationship between the geographical origin and waterlogging tolerance of peanut varieties. To explore this problem, three different peanut ecotypes (Zhanhong 2, Zhongkaihua 1, and Huayu 39) were waterlogged for 5, 10, and 15 days at seedling stage (S), flowering and pegging stage (F), and pod-filling stage (P), respectively. The relationship between the ecotype and waterlogging tolerance was determined by analyzing the effects of waterlogging on dry matter accumulation, photosynthetic characteristics, yield, and the yield components of peanut. The soil and plant analysis development (SPAD), net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), and intercellular CO2 concentration (Ci) values in leaves decreased under waterlogging stress, which led to a significant decrease in yield and yield components. The most noticeable effect of waterlogging stress appeared at the P stage and deleterious effects increased with an extension of the duration of waterlogging, where the yield loss was mainly attributed to the decrease in the number of total pods (TP) and the number of full pods (FP). Significant relationships were found between total dry weight (TDW), leaf dry weight (LDW), pod dry weight (PDW), TP, and FP, and the waterlogging stress tolerance index (WTI). Additionally, the waterlogging tolerance of peanut ecotypes is closely related to their geographic origin, where the most waterlogging-resistant ecotype was Zhanhong 2, followed by Zhongkaihua 1 and Huayu 39. Finally, breeding backgrounds and screening indices (SPAD, Pn, dry matter accumulation, and pod characteristics) beneficial to waterlogging tolerance breeding are suggested.

Metabolomics of groundnut (Arachis hypogaea L.) genotypes under varying temperature regimes

Various metabolites were analyzed in groundnut genotypes grown under varying temperature regimes (based on date of sowing). Four contrasting groundnut genotypes viz. ICGS44 (high-temperature tolerant), AK159 and GG7 (moderately-high-temperature tolerant), and DRG1 (high-temperature sensitive) were grown at three different temperature regimes i.e., low (early date of sowing), normal (normal date of sowing) and high temperature (late date of sowing) under field conditions. Untargeted metabolomic analysis of leaf tissue was performed by GC–MS, while targeted metabolite profiling was carried out by HPLC (polyamines) and UPLC-MS/MS (phenolics) at both the pegging and pod filling stages. Untargeted metabolomic profiling revealed exclusive expression/induction of beta-d-galactofuranoside, l-threonine, hexopyranose, d-glucopyranose, stearic acid, 4-ketoglucose, d-gulose, 2-o-glycerol-alpha-d-galactopyranoside and serine in ICGS44 during the pegging stage under high-temperature conditions. During the pod filling stage at higher temperature, alpha-d-galactoside, dodecanedioic acid, 1-nonadecene, 1-tetradecene and beta-d-galactofuranose were found to be higher in both ICGS44 and GG7. Moreover, almost all the metabolites detected by GC–MS were found to be higher in GG7, except beta-d-galactopyranoside, beta-d-glucopyranose, inositol and palmitic acid. Accumulation of putrescine was observed to be higher during low-temperature stress, while agmatine showed constitutive expression in all the genotypes, irrespective of temperature regime and crop growth stage. Interestingly, spermidine was observed only in the high-temperature tolerant genotype ICGS44. In our study, we found a higher accumulation of cinnamic acid, caffeic acid, salicylic acid and vanillic acid in ICGS44 compared to that of other genotypes at the pegging stage, whereas catechin and epicatechin were found during the pod filling stage in response to high-temperature stress, suggesting their probable roles in heat-stress tolerance in groundnut.

Effects of two phenolic acids on root zone soil nutrients, soil enzyme activities and pod yield of peanut

In order to investigate the relationship between the accumulation of phenolic acids in peanut continuous cropping soil and the continuous cropping obstacle of peanut, the effects of p-hydroxy benzoic acid and cinnamic acid on peanut root zone soil nutrients, soil enzyme activities and yield of peanut were studied by pot experiment at three stages of peanut, i.e. the pegging stage of peanut (45 days after seedling), the early podding (75 days after seedling) and the end of podding (105 days after seedling) stages. The results showed that the peanut root zone soil nutrients and enzyme activities changed obviously under the two phenolic acids treatment, especially at the pegging stage of peanut. The soil alkali-hydrolyzable nitrogen, available phosphorus, available potassium, and soil enzyme activities (urease, sucrose, neutral phosphatase) were decreased significantly. At the early and end of podding stages of peanut, the effects of the two phenolic acids on peanut root zone soil nutrients and soil enzyme activities were under a weakening trend. The allelopathy of cinnamic acid was stronger than that of p-hydroxy benzoic acid at the same initial content. The pod yield per pot was reduced by 45.9% and 52.8%, while the pod number of per plant was reduced by 46.2% and 48.9% at higher concentration (80 mg·kg-1 dry soil) of p-hydroxy benzoic acid and cinnamic acid treatments, respectively.

Physiological responses of peanut (Arachis hypogaea L.) cultivars to water deficit stress: status of oxidative stress and antioxidant enzyme activities

AbstractFrom a field experiment, the changes in oxidative stress and antioxidant enzyme activities were studied in six Spanish peanut cultivars subjected to 25−30 days of water deficit stress at two different stages: pegging and pod development stages. Imposition of water deficit stress significantly reduced relative water content, membrane stability and total carotenoid content in all the cultivars, whereas total chlorophyll content increased at pegging stage but decreased at pod developmental stage. Chlorophyll a/b ratio increased under water deficit stress in most of the cultivars suggesting a greater damage to chlorophyll b rather than an increase in chlorophyll a content. Oxidative stress measured in terms of H2O2, superoxide radical content and lipid peroxidation increased under water deficit stress, especially in susceptible cultivars such as DRG 1, AK 159 and ICGV 86031. Relationship among different physiological parameters showed that the level of oxidative stress, in terms of production of reactive oxygen species, was negatively correlated with activities of different antioxidant enzymes such as superoxide dismutase, catalase, peroxidase, ascorbate peroxidase and glutathione reductase. In conclusion, the study shows that water deficit stress at pod development stage proved to be more detrimental than at pegging stage. The higher activities of antioxidant enzymes in the tolerant cultivars like ICGS 44 and TAG 24 were responsible for protection of oxidative damage and thus provide better tolerance to water deficit stress.

Impact of Elevated CO2 on Growth and Physiological Parameters of Groundnut (Arachis hypogaea L.) Genotypes

Impact of Elevated CO2 on Growth and Physiological Parameters of Groundnut (Arachis hypogaea L.) Genotypes Five groundnut (Arachis hypogaea L.) genotypes- JL-24, ICGV 91114, Narayani, Abhaya, Dharani were evaluated at elevated (550 ppm) CO2 in OTCs during 2013 kharif to assess the variability in growth, biomass and physiological parameters. Elevated CO2 enhanced biomass and physiological parameters of all the selected groundnut genotypes, however the magnitude of response varied. Total biomass of genotypes was improved by 19% at 550 ppm and maximum response (34%) was recorded in ICGV 91114 and Narayani. The genotype ICGV 91114 recorded significant improvement of leaf and root biomass, total biomass and specific leaf weight with elevated CO2. Genotype Dharani recorded maximum root length, shoot length and leaf area at flowering stage and JL-24 at pegging stage. At elevated CO2, higher biomass was allocated to stem in JL-24, to roots in ICGV 91114, and no influence in Dharani as compared to other genotypes revealing its differential influence on biomass allocation. Increased Anet at enhanced CO2 was recorded in all the genotypes and it ranged from 18% (Abhaya) to 36% (Narayani), and the less efficient genotype at ambient condition recorded highest response and vice versa. The response of gs to elevated CO2 varied, whereas reduced Tr was recorded in all genotypes. At 550 ppm, groundnut genotypes showed 44% improvement in leaf level intrinsic WUE and maximum advantage (62%) was registered by Dharani. It is evident that the magnitude of groundnut crop response to elevated CO2 is cultivar, growth stage and component specific.

Effects of indole-3-acetic acid and auxin transport inhibitor on auxin distribution and development of peanut at pegging stage

This study was conducted to determine the effects of indole-3-acetic acid (IAA) and auxin polar transport inhibitor 2,3,5-triiodobenzoic acid (TIBA) on the growth, photosynthetic characteristics of leaves and IAA contents in different parts of peanut cv. Zhonghua 4 at pegging stage. It was found that spraying IAA resulted in an increase in IAA contents of different parts, the photosynthetic rate, and the growth of stem, peg and flower at pegging stage. Treatment with TIBA increased the first branch length and branch number per plant by 6.83% and 15.34%, while the stem height, peg length, flower number and peg number per plant were significantly inhibited by 25.08%, 29.52%, 33.18% and 30.14%. The average weights of single pod and the yield per pot with auxin and TIBA treatments were distinctly higher than the control. Pegging rate and net photosynthesis rate were enhanced by 4.56% and 12.67%, respectively, but intercellular CO2 concentration (Ci) was decreased than the control by 8.06% under 10μM TIBA treatment. The IAA contents of stems and leaves treated with 10μM TIBA were also significantly increased. These results suggest that auxin, along with its transport and distribution, control the growth of peanut at pegging stage, which may contribute to higher yield through enhanced pod development.

Long-term effects of fertilization and manuring on groundnut yield and nutrient balance of Alfisols under rainfed farming in India

Drought stress, uncertain and variable rainfall, low soil quality and nutrient deficiencies are among principal constraints for enhancing and sustaining agronomic productivity in rainfed farming in semiarid tropical regions of India. Therefore, long-term (1985–2004) effects of cropping, fertilization, manuring (groundnut shells, GNS; farmyard manure, FYM) and integrated nutrient management practices were assessed on pod yields, nutrient status and balances for a groundnut (Arachis hypogaea) monocropping system. The five nutrient management treatments were: control (no fertilizer); 100 % recommended dose of fertilizer (RDF) (20:40:40 N, P, K); 50 % RDF + 4 Mg ha−1 GNS; 50 % RDF + 4 Mg ha−1 FYM and 100 % organic (5 Mg ha−1 FYM). All treatments were replicated four times. The experiment was conducted at Anantapur district, Andhra Pradesh on an Alfisol using a Randomized Complete Block design. The gap in pod yields between control and different nutrient treatments widened with increase in duration of cultivation. Use of diverse fertilizer and manurial treatments produced significantly higher yields than control (P < 0.05). Amount and distribution of rainfall during critical growth stages was more important to agronomic yield than total and seasonal rainfall. Thus, the amount of rainfall received during pegging stage (r = 0.47; P < 0.05) and pod formation stage (r = 0.50; P < 0.05) was significantly correlated with the mean pod yields. Whereas, use of diverse fertility management practices improved nutrient status in soil profiles (N, P, K, S, Ca, Mg, Zn, Fe, Mn and B) after 20 years of cropping, yet soil available N, K and B remained below the critical limits. Long-term cultivation also caused deficiency of S, Zn and B, which limited the groundnut productivity. Crop removal of N, P and K during 20 years of cultivation was more in 50 % RDF + 4 Mg ha−1 GNS at 523, 210 and 598 kg ha−1, respectively. With the exception of control, there was a positive nutrient balance of NPK in all other treatments. Higher positive balance of N and K were observed in 50 % RDF + 4 Mg ha−1 GNS (616 and 837 kg ha−1, respectively), and those of P in 100 % RDF (655 kg ha−1) treatment. There was also a net depletion of available S, Zn, Cu and Mn, but a buildup of available Ca, Mg and Fe. Application of equal amount of GNS was as effective as or even better than FYM in terms of pod yields and nutrient buildup in the soil.

P75 Neurotrophin receptor differentiates between morphoeic basal cell carcinoma and desmoplastic trichoepithelioma: insights into the histogenesis of adnexal tumours based on embryology and hair follicle biology

Tumour development is frequently described in the basic pathology literature as a recapitulation of embryogenesis. However, a link between the embryology of the skin and the histogenesis of adnexal tumours has been largely overlooked. The low-affinity p75 neurotrophin receptor (p75NTR) has a profound role in hair follicle biology. We therefore speculated that it is involved in the histogenesis of follicular adnexal tumours. One of the most challenging diagnoses in dermatopathology is differentiating morphoeic basal cell carcinoma from desmoplastic trichoepithelioma. To describe the expression pattern of p75NTR during cutaneous embryogenesis, in the adult hair follicle and in morphoeic basal cell carcinoma and desmoplastic trichoepithelioma. Evaluation of the staining pattern for p75NTR was performed using standard immunohistochemical techniques. For comparison, we examined staining for cytokeratin 20 which highlights Merkel cells. All 17 desmoplastic trichoepitheliomas were immunoreactive with > 80% of the cells stained, whereas 12 of the 14 (86%) morphoeic basal cell carcinomas were p75NTR negative. In the two positive cases of morphoeic basal cell carcinoma < 30% of cells were labelled. In the late bulbous hair peg stage and in the postnatal anagen hair follicle p75NTR highlights the outer root sheath. Our results support the classification of desmoplastic trichoepithelioma as a follicular hamartoma mimicking the outer root sheath. In contrast, the lack of p75NTR expression in morphoeic basal cell carcinoma favours a concept of this tumour as a more primitive follicular lesion with the characteristics of a carcinoma and not a hamartoma. We suggest including p75NTR as a tool in the differential diagnosis between morphoeic basal cell carcinoma and desmoplastic trichoepithelioma.

Basal cell carcinoma and pilomatrixoma mirror human follicular embryogenesis as reflected by their differential expression patterns of SOX9 and β-catenin

The current classification schemes of adnexal tumours are predominantly based on morphological and immunophenotypical similarities to adult skin structures, whereas a link between the embryology of the skin and the histogenesis of adnexal tumours has been largely neglected. To describe the expression patterns of two proteins with proven relevance for hair follicle homeostasis (SOX9 and β-catenin) during human cutaneous embryogenesis and to compare the findings with their expression in basal cell carcinoma (BCC) and pilomatrixoma. Immunohistochemical evaluation with monoclonal antibodies against SOX9 and β-catenin was carried out in embryonic and adult human scalp skin, and BCC and pilomatrixoma samples. We found that the expression patterns of SOX9 and β-catenin during human hair follicle embryogenesis mirror the patterns in BCC and pilomatrixoma in spatial distribution within the various follicular subcompartments. Beginning with the hair peg stage, nucleocytoplasmic immunoreactivity of β-catenin is exclusively confined to the emerging matrix (comparable to pilomatrixoma), whereas SOX9 is restricted to the primordial outer root sheath (comparable to BCC). An appropriate immunophenotyping validated within the conceptual framework of cutaneous developmental biology allows a logical classification of adnexal neoplasms. Expanding this approach further has the potential to revise the current classification schemes so that not only BCC and pilomatrixoma but all adnexal tumours can be categorized logically.

Iron and Calcium Availability to Groundnut Plants as Affected by Calcium Carbonate and Water Levels in Calcareous Soil

ABSTRACT To assess possible causes of soil and plant iron deficiency and chlorosis in groundnut (Arachis hypogaea L.) on calcareous clay loam soils of Karnataka, India, a pot experiment was conducted to evaluate the availability of iron and calcium at varying levels of CaCO3 and soil water and their influence on pod yield. The CaCO3 levels of the soil achieved by liming were: 5% (C1), 7% (C2), 10% (C3), 15% (C4), and 20% (C5) (on mass basis). Three soil water levels, i.e., 75% (M1), 150% (M2), and 200% (M3) of field capacity, were imposed for one week each at flowering and pegging stages. Amorphous iron oxide-occluded iron, free iron oxide, and water-soluble calcium increased significantly with increasing levels of soil water. The diethyl triamine pentaacetic acid salt (DTPA)-extractable Fe, however, decreased at higher levels of CaCO3 and soil moisture. Conversely, the concentration of bicarbonate ions increased at higher levels of CaCO3 and soil water. The pod yield of groundnut, which was highest under M2C2, decreased at higher levels of CaCO3. This decrease in groundnut yield at higher levels of CaCO3 was attributed to deficiency of available Fe, DTPA-Fe, as caused by the increased concentration of bicarbonate ions.

Epithelium-Mesenchyme Interactions Control the Activity of Peroxisome Proliferator-Activated Receptor β/δ during Hair Follicle Development

Hair follicle morphogenesis depends on a delicate balance between cell proliferation and apoptosis, which involves epithelium-mesenchyme interactions. We show that peroxisome proliferator-activated receptor beta/delta (PPARbeta/delta) and Akt1 are highly expressed in follicular keratinocytes throughout hair follicle development. Interestingly, PPARbeta/delta- and Akt1-deficient mice exhibit similar retardation of postnatal hair follicle morphogenesis, particularly at the hair peg stage, revealing a new important function for both factors in the growth of early hair follicles. We demonstrate that a time-regulated activation of the PPARbeta/delta protein in follicular keratinocytes involves the up-regulation of the cyclooxygenase 2 enzyme by a mesenchymal paracrine factor, the hepatocyte growth factor. Subsequent PPARbeta/delta-mediated temporal activation of the antiapoptotic Akt1 pathway in vivo protects keratinocytes from hair pegs against apoptosis, which is required for normal hair follicle development. Together, these results demonstrate that epithelium-mesenchyme interactions in the skin regulate the activity of PPARbeta/delta during hair follicle development via the control of ligand production and provide important new insights into the molecular biology of hair growth.

The marginal band, a new structural component of the developing angiosperm leaf

The marginal band, a newly described structure of the dicot leaf, plays an essential role in the formation of this organ. It arises along the two edges of a leaf as several files of adaxial epidermal cells during the peg stage of ontogeny. Functionally, it appears to serve as the prepattern for a number of secondary features including (i) the marginal growth meristem present in all leaves as seen in mountain laurel, (ii) rows of lobes and spines as in Salvia and Ilex, (iii) pigmentation as in some cultivars of Hydrangea, (iv) propagation as in the plantlets of Kalanchoe pinnata, (v) marginal ridges for support in a few varieties of Viburnum and Ilex, and (vi) marginal necrosis as in Strelitzia for blade partitioning. © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society, 2003, 143, 21–28.

Formation of cornified cell envelope in human hair follicle development.

Cornified cell envelope (CCE) formation is an important step in the final stage of keratinization, in which CCE precursor proteins including involucrin and loricrin are cross-linked by keratinocyte transglutaminases (TGases) to the inner surface of the plasma membrane of cornified cells, while the outer surface is coated with material derived from secreted lamellar granules. Skin samples from human fetuses of a series of estimated gestational age (EGA) (49-163 days) were studied for the prescence of precursor proteins. Methods TGase activity was studied by in situ TGase activity assay, and ultrastructural features of CCE formation were observed at each stage of hair follicle development. We used immunofluorescent labelling to investigate the time and site of expression of CCE precursor proteins involucrin and loricrin, TGases 1, 2 and 3, and a 25-kDa lamellar granule-associated protein (LGP) in developing human hair follicles. In the hair germ (65-84 days EGA) (corresponding to the stages 1-2 of murine hair follicle morphogenesis), only TGase 2 was observed in the entire hair germ, where in situ TGase activity was weakly positive, although thickening of cell membrane was not seen ultrastructurally. In the hair peg (85-104 days EGA) (corresponding to the stage 3 of murine hair follicle morphogenesis), loricrin and TGase 2 were seen in cells of the upper part of the hair peg while TGase 1, 3 and LGP were observed in the inner cells of the hair peg. In situ TGase activity was weakly positive in the upper part and inner cells of the hair peg. In the bulbous hair peg (105-135 days EGA) (corresponding to the stages 4-6 of murine hair follicle morphogenesis) and differentiated lanugo hair follicle (> 135 days EGA) (corresponding to the stages 7-8 of murine hair follicle morphogenesis), immunoreactivities of involucrin, loricrin, TGase 1, 2, 3, in situ TGase activity and LGP were detected in the inner root sheath cells, hair canals and inner cells of the outer root sheath in the region of the isthmus. Ultrastructurally, thickening of cell membrane was already seen in the inner root sheath cells of the bulbous hair peg and electron-dense, thick CCE was observed in the hair cuticle and hair canal of differentiated lanugo hair follicle. These data indicate that, in terms of CCE formation, certain portions of the developing human hair follicle have already been determined in differentiation of the hair canal and cuticle at the hair peg stage.