scholarly journals Exodermis and Endodermis Respond to Nutrient Deficiency in Nutrient-Specific and Localized Manner

Plants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 201
Author(s):  
Jiří Namyslov ◽  
Zuzana Bauriedlová ◽  
Jana Janoušková ◽  
Aleš Soukup ◽  
Edita Tylová

The exodermis is a common apoplastic barrier of the outer root cortex, with high environmentally-driven plasticity and a protective function. This study focused on the trade-off between the protective advantages provided by the exodermis and its disadvantageous reduction of cortical membrane surface area accessible by apoplastic route, thus limiting nutrient acquisition from the rhizosphere. We analysed the effect of nutrient deficiency (N, P, K, Mg, Ca, K, Fe) on exodermal and endodermal differentiation in maize. To differentiate systemic and localized effects, nutrient deficiencies were applied in three different approaches: to the root system as a whole, locally to discrete parts, or on one side of a single root. Our study showed that the establishment of the exodermis was enhanced in low–N and low–P plants, but delayed in low-K plants. The split-root cultivation proved that the effect is non-systemic, but locally coordinated for individual roots. Within a single root, localized deficiencies didn’t result in an evenly differentiated exodermis, in contrast to other stress factors. The maturation of the endodermis responded in a similar way. In conclusion, N, P, and K deficiencies strongly modulated exodermal differentiation. The response was nutrient specific and integrated local signals of current nutrient availability from the rhizosphere.

2020 ◽  
Author(s):  
Raziye Kul ◽  
Melek Ekinci ◽  
Metin Turan ◽  
Selda Ors ◽  
Ertan Yildirim

Roots are generally subject to more abiotic stress than shoots. Therefore, they can be affected by such stresses as much as, or even more, than above ground parts of a plant. However, the effect of abiotic stresses on root structure and development has been significantly less studied than above ground parts of plants due to limited availability for root observations. Roots have functions such as connecting the plant to the environment in which it grows, uptaking water and nutrients and carrying them to the above-ground organs of the plant, secreting certain hormones and organic compounds, and thus ensuring the usefulness of nutrients in the nutrient solution. Roots also send some hormonal signals to the body in stress conditions such as drought, nutrient deficiencies, salinity, to prevent the plant from being damaged, and ensure that the above-ground part takes the necessary precautions to adapt to these adverse conditions. Salinity, drought, radiation, high and low temperatures, heavy metals, flood, and nutrient deficiency are abiotic stress factors and they negatively affect plant growth, productivity and quality. Given the fact that impending climate change increases the frequency, duration, and severity of stress conditions, these negative effects are estimated to increase. This book chapter reviews to show how abiotic stress conditions affect growth, physiological, biochemical and molecular characteristics of plant roots.


2021 ◽  
Vol 23 (06) ◽  
pp. 36-46
Author(s):  
Vrunda Kusanur ◽  
◽  
Veena S Chakravarthi ◽  

Soil temperature and humidity straight away influence plant growth and the availability of plant nutrients. In this work, we carried out experiments to identify the relationship between climatic parameters and plant nutrients. When the relative humidity was very high, deficiency symptoms were shown on plant leaves and fruits. But, recognizing and managing these plant nutrients manually would become difficult. However, no much research has been done in this field. The main objective of this research was to propose a machine learning model to manage nutrient deficiencies in the plant. There were two main phases in the proposed research. In the first phase, the humidity, temperature, and soil moisture in the greenhouse environment were collected using WSN and the influence of these parameters on the growth of plants was studied. During experimentation, it was investigated that the transpiration rate decreased significantly and the macronutrient contents in the plant leave decreased when the humidity was 95%. In the second phase, a machine learning model was developed to identify and classify nutrient deficiency symptoms in a tomato plant. A total of 880 images were collected from Bingo images to form a dataset. Among all these images, 80% (704 images) of the dataset were used to train the machine learning model and 20% (176 images) of the dataset were used for testing the model performance. In this study, we selected K-means Clustering for key points detection and SVM for classification and prediction of nutrient stress in the plant. SVM using linear kernel performed better with the accuracy rates of 89.77 % as compared to SVM using a polynomial kernel.


2021 ◽  
Vol 3 ◽  
Author(s):  
Michael Prabhu Inbaraj

Crop plants are continuously exposed to various abiotic stresses like drought, salinity, ultraviolet radiation, low and high temperatures, flooding, metal toxicities, nutrient deficiencies which act as limiting factors that hampers plant growth and low agricultural productivity. Climate change and intensive agricultural practices has further aggravated the impact of abiotic stresses leading to a substantial crop loss worldwide. Crop plants have to get acclimatized to various environmental abiotic stress factors. Though genetic engineering is applied to improve plants tolerance to abiotic stresses, these are long-term strategies, and many countries have not accepted them worldwide. Therefore, use of microbes can be an economical and ecofriendly tool to avoid the shortcomings of other strategies. The microbial community in close proximity to the plant roots is so diverse in nature and can play an important role in mitigating the abiotic stresses. Plant-associated microorganisms, such as endophytes, arbuscular mycorrhizal fungi (AMF), and plant growth-promoting rhizobacteria (PGPR), are well-documented for their role in promoting crop productivity and providing stress tolerance. This mini review highlights and discusses the current knowledge on the role of various microbes and it's tolerance mechanisms which helps the crop plants to mitigate and tolerate varied abiotic stresses.


Author(s):  
Robert E. White

The fertility of a soil refers to its nutrient supplying power. It is one of the most important soil factors affecting vineyard productivity, which is measured in tonnes of grapes per ha (or sometimes tons per acre). For viticulture, soil physical prop­erties, notably structure, aeration, and drainage are also very important determi­nants of productivity, as discussed in chapters 3, 6, and 7. Because vines are grown in permanent rows, and there are many cultural operations, soil physical prob­lems are often more difficult to ameliorate than problems of soil fertility. Soil fertility is assessed either by observing the condition of vines growing on a particular soil or by measuring the nutrient supplying power of the soil itself. The assessment should include recommendations on how to correct any problems identified. Thus, assessment of soil fertility can be made in two parts: 1. Diagnosis of nutrient deficiencies or excesses. The aim here is to identify which nutrients are deficient or in excess and the degree of deficiency or excess. An excess of a nutrient, which may create an imbalance with other nutrients, often leads to a nutrient toxicity. 2. Estimation of nutrient requirements. The goal here is to estimate how much of a limiting nutrient is required to achieve optimum growth or how to remedy a toxicity problem. Nutrient amendments can be made with fertilizers, manures, and composts, or by growing cover crops that include legumes. Visual symptoms are the signs that indicate a deficiency or excess of one or more essential elements in a plant. In the case of grapevines, such symptoms include chlorosis, stunted growth of shoots, necrosis of leaf margins, irregular fruit set, and small berries. Chlorosis is a generic term for leaf yellowing due to loss of chlorophyll. N deficiency typically causes an overall chlorosis of the leaves, but in other cases chlorosis occurs between the leaf veins (interveinal chlorosis). Some examples of visual symptoms are given in table 5.1 and figure 5.1.


2019 ◽  
Vol 11 (20) ◽  
pp. 5745 ◽  
Author(s):  
María del Carmen Pérez-Fuentes ◽  
María del Mar Molero Jurado ◽  
África Martos Martínez ◽  
José Jesús Gázquez Linares

Aims: Burnout syndrome is a phenomenon that is becoming ever more widespread, especially in workers such as nurses who have heavy workloads and time pressures. The progression of burnout syndrome has been shown to be related to both individual and work-related variables. The objective of this study is to examine the risk and protective roles played by work-related and personal variables, both sociodemographic and psychological, in the development of burnout in nurses. Method: The sample was composed of 1236 nurses aged between 21 and 57 years, with a mean age of 31.50 years (SD = 6.18). Women accounted for 84.5% (n = 1044), and the remaining 15.5% (n = 192) were men. Exploratory tests were performed to understand the relationships between burnout and other variables, and a binary logistic regression was conducted to understand the roles of these variables in the incidence of this syndrome. Lastly, a regression tree was constructed. Results: The results show that the sociodemographic variables examined are not related to the level of burnout in nurses. However, certain work-related variables, such as spending more time with colleagues and patients and reporting good-quality relationships, exhibit a negative relationship with the occurrence of burnout. Of the psychological variables, the stress factors conflict-social acceptance and irritability-tension-fatigue, as well as informative communication, are shown to be risk factors for the appearance of burnout in nurses. In contrast, the communication skills factor, empathy, and energy-joy exert a protective function. Conclusion: Identifying the variables that influence the occurrence of burnout syndrome and understanding the manner in which they exert their influence are key elements in the development of effective prevention and intervention of burnout in nursing.


1972 ◽  
Vol 25 (1) ◽  
pp. 77 ◽  
Author(s):  
RD Court ◽  
WT Williams ◽  
MP Hegarty

The effects of several single mineral nutrient deficiencies on the free amino acid composition of S. sphacelata, grown in water culture, have been examined. Most deficiencies result in an accumulation of the free amino acids. Severe copper deficiency causes a large increase in the alanine content of the leaf. Nitrogen deficiency causes decreases in almost all amino acids.


1999 ◽  
Vol 63 (4) ◽  
pp. 968-989 ◽  
Author(s):  
Hamdi Hussein Zahran

SUMMARY Biological N2 fixation represents the major source of N input in agricultural soils including those in arid regions. The major N2-fixing systems are the symbiotic systems, which can play a significant role in improving the fertility and productivity of low-N soils. The Rhizobium-legume symbioses have received most attention and have been examined extensively. The behavior of some N2-fixing systems under severe environmental conditions such as salt stress, drought stress, acidity, alkalinity, nutrient deficiency, fertilizers, heavy metals, and pesticides is reviewed. These major stress factors suppress the growth and symbiotic characteristics of most rhizobia; however, several strains, distributed among various species of rhizobia, are tolerant to stress effects. Some strains of rhizobia form effective (N2-fixing) symbioses with their host legumes under salt, heat, and acid stresses, and can sometimes do so under the effect of heavy metals. Reclamation and improvement of the fertility of arid lands by application of organic (manure and sewage sludge) and inorganic (synthetic) fertilizers are expensive and can be a source of pollution. The Rhizobium-legume (herb or tree) symbiosis is suggested to be the ideal solution to the improvement of soil fertility and the rehabilitation of arid lands and is an important direction for future research.


2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Gang Liang ◽  
Qin Ai ◽  
Diqiu Yu

Abstract Integrating carbon (C), nitrogen (N) and sulfur (S) metabolism is essential for the growth and development of living organisms. MicroRNAs (miRNAs) play key roles in regulating nutrient metabolism in plants. However, how plant miRNAs mediate crosstalk between different nutrient metabolic pathways is unclear. In this study, deep sequencing of Arabidopsis thaliana small RNAs was used to reveal miRNAs that were differentially expressed in response to C, N, or S deficiency. Comparative analysis revealed that the targets of the differentially expressed miRNAs are involved in different cellular responses and metabolic processes, including transcriptional regulation, auxin signal transduction, nutrient homeostasis and regulation of development. C, N and S deficiency specifically induced miR169b/c, miR826 and miR395, respectively. In contrast, miR167, miR172, miR397, miR398, miR399, miR408, miR775, miR827, miR841, miR857 and miR2111 are commonly suppressed by C, N and S deficiency. In particular, the miRNAs that are induced specifically by a certain nutrient deficiency are often suppressed by other nutrient deficiencies. Further investigation indicated that the modulation of nutrient-responsive miRNA abundance affects the adaptation of plants to nutrient starvation conditions. This study revealed that miRNAs function as important regulatory nodes of different nutrient metabolic pathways.


2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e14142-e14142
Author(s):  
Reid Christian Bowers ◽  
Michael A. Thompson ◽  
Sandra Tomany Korman ◽  
Sherjeel Sana ◽  
Manish Krishna Pant ◽  
...  

e14142 Background: An Anemia Clinic program was started Sept. 2016 as part of system wide implementation of Patient Blood Management (PBM) initiated in 2015. Methods: The Anemia Clinic accepted referrals for non-cancer anemia, predominantly preoperative cardiovascular surgery (CVS) Pts. Hgb thresholds were < 13 g/dL in men and < 12 g/dL in women. Non-anemia cytopenias triggered Hematology referral. All Pts were screened for iron, B12, folate, and reticulocyte. Nutrient deficiencies were supplemented. Pts with CKD or chronic disease were considered for erythropoiesis stimulating agents. Results: PBM implementation resulted in a drop in packed red blood cell (PRBC) usage (Table). Of CVS Pts pre-operatively anemic in 2019, 180 were referred to the Anemia Clinic and 301 were not. Anemia Clinic identified iron (N = 114), vitamin B12 (N = 24), and folate (N = 18) deficiencies. The percentage of Pts who received PRBCs after Anemia Clinic referral was not statistically different from those who were not referred (65.6% vs. 61.8% Chi-Square p = 0.44). Of preoperatively anemic Pts who were transfused in 2019, an average of 2.34 PRBCs were used in the referred group vs. an average of 2.21 PRBCs in those in the not referred group (Poisson Means p = 0.46). Length of stay (LOS) which was a median 10d ( P25= 7d, P75 =17d) in the referred group vs a median 12d ( P25= 7d, P75 =19d) in the non-referred group was not statistically different between groups (Smirnov p = 0.39). LOS analyses of observed-to-expected (O/E) ratios used the Premier Healthcare Providers Alliance Database (PHD) which contains data on approximately 45% of US hospital discharges. For 2019 through Nov. the referred group had an O/E = 1.03 (observed LOS μgeo = 11.58 days, expected LOS μgeo = 11.21 days, N = 167). The not referred group had an O/E = 1.06 (observed LOS μgeo = 12.24 days, expected LOS μgeo = 11.58 days, N = 272). Conclusions: PBM decreased PRBC use through systematization of best practices during the initial year. Subsequent addition of Anemia Clinic services has not decreased PRBC use further. There is a trend toward shorter LOS for patients referred to Anemia Clinic but it is not statistically significant. Our methods improved nutrient deficiency identification which may improve both later health outcomes not detected here and access to treatment for hematologic malignancies. [Table: see text]


HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 460d-460 ◽  
Author(s):  
Nicolas Tremblay ◽  
Léon-Étienne Parent

Celery (Apium graveolens var. Dulce) is a species particularly sensitive to nutritional balance. Seedlings in multicellular trays sometimes present problems that can be traced to nutritional causes. DRIS (Diagnosis and Recommendation Integrated System) and CND (Compositional Nutrient Diagnosis) are two recent concepts that can be implemented to diagnose nutritional imbalances from tissue analyses of any plant species. A data bank of 215 observations was used to elaborate DRIS and CND norms for celery transplants. The threshold yield for high yielders was set at 1600 g/plant (27% of the population). Both DRIS and CND systems were implemented and a validation process was undertaken. Nutrient deficiencies (N, P, K, Ca, Mg, Fe, B and Zn) were induced on celery seedlings in growing chambers. Tissues samples were given a balanced fertilization. The diagnosing methods (DRIS and CND) were compared on the basis of their ability to identify correctly the induced nutrient deficiencies.


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