Increased glutamine in leaves of poplar transgenic with pine GS1a caused greater anthranilate synthetase a-subunit (ASA1) transcript and protein abundances: an auxin-related mechanism for enhanced growth in GS transgenics?

The initial reaction in the pathway leading to the production of indole-3-acetic acid (IAA) in plants is the reaction between chorismate and glutamine to produce anthranilate, catalysed by the enzyme anthranilate synthase (ASA; EC 4.1.3.27). Compared with non-transgenic controls, leaves of transgenic poplar with ectopic expression of the pine cytosolic glutamine synthetase (GS1a; EC 6.3.1.2) produced signi���cantly greater glutamine and signi���cantly enhanced ASA a-subunit (ASA1) transcript and protein (approximately 130% and 120% higher than in the untransformed controls, respectively). Similarly, tobacco leaves fed with 30 mM glutamine and 2 mM chorismate showed enhanced ASA1 transcript and protein (175% and 90% higher than controls, respectively). Furthermore, free IAA was signi���cantly elevated both in leaves of GS1a transgenic poplar and in tobacco leaves fed with 30 mM glutamine and 2 mM chorismate. These results indicated that enhanced cellular glutamine may account for the enhanced growth in GS transgenic poplars through the regulation of auxin biosynthesis

Examination of the quality of spinach leaves using hyperspectral imaging

The present research is focused on the application of hyperspectral images for the supervision of quality deterioration in ready to use leafy spinach during storage (Spinacia oleracea). Two sets of samples of packed leafy spinach were considered: (a) a first set of samples was stored at 20 ��C (E-20) in order to accelerate the degradation process, and these samples were measured the day of reception in the laboratory and after 2 days of storage; (b) a second set of samples was kept at 10 ��C (E-10), and the measurements were taken throughout storage, beginning the day of reception and repeating the acquisition of Images 3, 6 and 9 days later. Twenty leaves per test were analyzed. Hyperspectral images were acquired with a push-broom CCD camera equipped with a spectrograph VNIR (400���1000 nm). Calibration set of spectra was extracted from E-20 samples, containing three classes of degradation: class A (optimal quality), class B and class C (maximum deterioration). Reference average spectra were defined for each class. Three models, computed on the calibration set, with a decreasing degree of complexity were compared, according to their ability for segregating leaves at different quality stages (fresh, with incipient and non-visible symptoms of degradation, and degraded): spectral angle mapper distance (SAM), partial least squares discriminant analysis models (PLS-DA), and a non linear index (Leafy Vegetable Evolution, LEVE) combining five wavelengths were included among the previously selected by CovSel procedure. In sets E-10 and E-20, artificial images of the membership degree according to the distance of each pixel to the reference classes, were computed assigning each pixel to the closest reference class. The three methods were able to show the degradation of the leaves with storage time.

Objective optical classifier for tobacco leaves.

The main objective of the current research was to search the optimum method to segregate the most frequent color commercial quality classes of tobacco leaves (c.v. "Virginia"). These color classes cover the whole continuous color scale, between "Pale Lemon" and "Oxidated Brown". With the usual expert classification there exists a significant level of uncertainty . Within this research, several methods for data discrimination were tested, in order to solve uncertainty. Classification errors below 5% were obtained with this proposed classifier along two different seasons (1994&1995).

An elicitor isolated from smut teliospores (Sporisorium scitamineum) enhances lignin deposition on the cell wall on both sclerenchyma and xylem in sugarcane leaves

Sugarcane leaf shows the classical arrangement of cells which defines a C4 species. Vascular bundles consist of xylem, phloem and fibres, surrounded by an outer layer of sclereids and an inner ring of stone cells associated with the phloem. Some sclereids located below and above the vascular bundles act as docking cells and connect the vascular bundle to the internal surfaces of upper and lower layers of the epidermis. A compact mass of sclereids occupies the total internal volume of the leaf edge. Neither docking cells nor the internal mass of sclereids in the edge were markedly coloured by acriflavin or phloroglucinol, indicating the absence of lignin in their cell walls. However, such staining indicated that fibres of the vascular bundle and the external layer of sclereids were strongly lignified. Incubation of leaf discs with an elicitor produced by the pathogen Sporisorium scitamineum increased the thickness of the lignified cell walls of sclereids as well as the mid and small xylem vessels, as a possible mechanical defense response to the potential entry of the pathogen.

Wettability, polarity and water absorption of Quercus ilex leaves: effect of leaf side and age

Plant trichomes play important protective functions and may have a major influence on leaf surface wettability. With the aim of gaining insight into trichome structure, composition and function in relation to water-plant surface interactions, we analyzed the adaxial and abaxial leaf surface of Quercus ilex L. (holm oak) as model. By measuring the leaf water potential 24 h after the deposition of water drops on to abaxial and adaxial surfaces, evidence for water penetration through the upper leaf side was gained in young and mature leaves. The structure and chemical composition of the abaxial (always present) and adaxial (occurring only in young leaves) trichomes were analyzed by various microscopic and analytical procedures. The adaxial surfaces were wettable and had a high degree of water drop adhesion in contrast to the highly unwettable and water repellent abaxial holm oak leaf sides. The surface free energy, polarity and solubility parameter decreased with leaf age, with generally higher values determined for the abaxial sides. All holm oak leaf trichomes were covered with a cuticle. The abaxial trichomes were composed of 8% soluble waxes, 49% cutin, and 43% polysaccharides. For the adaxial side, it is concluded that trichomes and the scars after trichome shedding contribute to water uptake, while the abaxial leaf side is highly hydrophobic due to its high degree of pubescence and different trichome structure, composition and density. Results are interpreted in terms of water-plant surface interactions, plant surface physical-chemistry, and plant ecophysiology.

Detection and pattern recognition applied to leaves and chromosomes

The Project you are about to see it is based on the technologies used on object detection and recognition, especially on leaves and chromosomes. To do so, this document contains the typical parts of a scientific paper, as it is what it is. It is composed by an Abstract, an Introduction, points that have to do with the investigation area, future work, conclusions and references used for the elaboration of the document. The Abstract talks about what are we going to find in this paper, which is technologies employed on pattern detection and recognition for leaves and chromosomes and the jobs that are already made for cataloguing these objects. In the introduction detection and recognition meanings are explained. This is necessary as many papers get confused with these terms, specially the ones talking about chromosomes. Detecting an object is gathering the parts of the image that are useful and eliminating the useless parts. Summarizing, detection would be recognizing the objects borders. When talking about recognition, we are talking about the computers or the machines process, which says what kind of object we are handling. Afterwards we face a compilation of the most used technologies in object detection in general. There are two main groups on this category: Based on derivatives of images and based on ASIFT points. The ones that are based on derivatives of images have in common that convolving them with a previously created matrix does the treatment of them. This is done for detecting borders on the images, which are changes on the intensity of the pixels. Within these technologies we face two groups: Gradian based, which search for maximums and minimums on the pixels intensity as they only use the first derivative. The Laplacian based methods search for zeros on the pixels intensity as they use the second derivative. Depending on the level of details that we want to use on the final result, we will choose one option or the other, because, as its logic, if we used Gradian based methods, the computer will consume less resources and less time as there are less operations, but the quality will be worse. On the other hand, if we use the Laplacian based methods we will need more time and resources as they require more operations, but we will have a much better quality result. After explaining all the derivative based methods, we take a look on the different algorithms that are available for both groups. The other big group of technologies for object recognition is the one based on ASIFT points, which are based on 6 image parameters and compare them with another image taking under consideration these parameters. These methods disadvantage, for our future purposes, is that it is only valid for one single object. So if we are going to recognize two different leaves, even though if they refer to the same specie, we are not going to be able to recognize them with this method. It is important to mention these types of technologies as we are talking about recognition methods in general. At the end of the chapter we can see a comparison with pros and cons of all technologies that are employed. Firstly comparing them separately and then comparing them all together, based on our purposes. Recognition techniques, which are the next chapter, are not really vast as, even though there are general steps for doing object recognition, every single object that has to be recognized has its own method as the are different. This is why there is not a general method that we can specify on this chapter. We now move on into leaf detection techniques on computers. Now we will use the technique explained above based on the image derivatives. Next step will be to turn the leaf into several parameters. Depending on the document that you are referring to, there will be more or less parameters. Some papers recommend to divide the leaf into 3 main features (shape, dent and vein] and doing mathematical operations with them we can get up to 16 secondary features. Next proposition is dividing the leaf into 5 main features (Diameter, physiological length, physiological width, area and perimeter] and from those, extract 12 secondary features. This second alternative is the most used so it is the one that is going to be the reference. Following in to leaf recognition, we are based on a paper that provides a source code that, clicking on both leaf ends, it automatically tells to which specie belongs the leaf that we are trying to recognize. To do so, it only requires having a database. On the tests that have been made by the document, they assure us a 90.312% of accuracy over 320 total tests (32 plants on the database and 10 tests per specie]. Next chapter talks about chromosome detection, where we shall pass the metaphasis plate, where the chromosomes are disorganized, into the karyotype plate, which is the usual view of the 23 chromosomes ordered by number. There are two types of techniques to do this step: the skeletonization process and swiping angles. Skeletonization progress consists on suppressing the inside pixels of the chromosome to just stay with the silhouette. This method is really similar to the ones based on the derivatives of the image but the difference is that it doesnt detect the borders but the interior of the chromosome. Second technique consists of swiping angles from the beginning of the chromosome and, taking under consideration, that on a single chromosome we cannot have more than an X angle, it detects the various regions of the chromosomes. Once the karyotype plate is defined, we continue with chromosome recognition. To do so, there is a technique based on the banding that chromosomes have (grey scale bands] that make them unique. The program then detects the longitudinal axis of the chromosome and reconstructs the band profiles. Then the computer is able to recognize this chromosome. Concerning the future work, we generally have to independent techniques that dont reunite detection and recognition, so our main focus would be to prepare a program that gathers both techniques. On the leaf matter we have seen that, detection and recognition, have a link as both share the option of dividing the leaf into 5 main features. The work that would have to be done is to create an algorithm that linked both methods, as in the program, which recognizes leaves, it has to be clicked both leaf ends so it is not an automatic algorithm. On the chromosome side, we should create an algorithm that searches for the beginning of the chromosome and then start to swipe angles, to later give the parameters to the program that searches for the band profiles. Finally, on the summary, we explain why this type of investigation is needed, and that is because with global warming, lots of species (animals and plants] are beginning to extinguish. That is the reason why a big database, which gathers all the possible species, is needed. For recognizing animal species, we just only have to have the 23 chromosomes. While recognizing a plant, there are several ways of doing it, but the easiest way to input a computer is to scan the leaf of the plant. RESUMEN. El proyecto que se puede ver a continuaci��n trata sobre las tecnolog��as empleadas en la detecci��n y reconocimiento de objetos, especialmente de hojas y cromosomas. Para ello, este documento contiene las partes t��picas de un paper de investigaci��n, puesto que es de lo que se trata. As��, estar�� compuesto de Abstract, Introducci��n, diversos puntos que tengan que ver con el ��rea a investigar, trabajo futuro, conclusiones y biograf��a utilizada para la realizaci��n del documento. As��, el Abstract nos cuenta qu�� vamos a poder encontrar en este paper, que no es ni m��s ni menos que las tecnolog��as empleadas en el reconocimiento y detecci��n de patrones en hojas y cromosomas y qu�� trabajos hay existentes para catalogar a estos objetos. En la introducci��n se explican los conceptos de qu�� es la detecci��n y qu�� es el reconocimiento. Esto es necesario ya que muchos papers cient��ficos, especialmente los que hablan de cromosomas, confunden estos dos t��rminos que no pod��an ser m��s sencillos. Por un lado tendr��amos la detecci��n del objeto, que ser��a simplemente coger las partes que nos interesasen de la imagen y eliminar aquellas partes que no nos fueran ��tiles para un futuro. Resumiendo, ser��a reconocer los bordes del objeto de estudio. Cuando hablamos de reconocimiento, estamos refiri��ndonos al proceso que tiene el ordenador, o la m��quina, para decir qu�� clase de objeto estamos tratando. Seguidamente nos encontramos con un recopilatorio de las tecnolog��as m��s utilizadas para la detecci��n de objetos, en general. Aqu�� nos encontrar��amos con dos grandes grupos de tecnolog��as: Las basadas en las derivadas de im��genes y las basadas en los puntos ASIFT. El grupo de tecnolog��as basadas en derivadas de im��genes tienen en com��n que hay que tratar a las im��genes mediante una convoluci��n con una matriz creada previamente. Esto se hace para detectar bordes en las im��genes que son b��sicamente cambios en la intensidad de los p��xeles. Dentro de estas tecnolog��as nos encontramos con dos grupos: Los basados en gradientes, los cuales buscan m��ximos y m��nimos de intensidad en la imagen puesto que s��lo utilizan la primera derivada; y los Laplacianos, los cuales buscan ceros en la intensidad de los p��xeles puesto que estos utilizan la segunda derivada de la imagen. Dependiendo del nivel de detalles que queramos utilizar en el resultado final nos decantaremos por un m��todo u otro puesto que, como es l��gico, si utilizamos los basados en el gradiente habr�� menos operaciones por lo que consumir�� m��s tiempo y recursos pero por la contra tendremos menos calidad de imagen. Y al rev��s pasa con los Laplacianos, puesto que necesitan m��s operaciones y recursos pero tendr��n un resultado final con mejor calidad. Despu��s de explicar los tipos de operadores que hay, se hace un recorrido explicando los distintos tipos de algoritmos que hay en cada uno de los grupos. El otro gran grupo de tecnolog��as para el reconocimiento de objetos son los basados en puntos ASIFT, los cuales se basan en 6 par��metros de la imagen y la comparan con otra imagen teniendo en cuenta dichos par��metros. La desventaja de este m��todo, para nuestros prop��sitos futuros, es que s��lo es valido para un objeto en concreto. Por lo que si vamos a reconocer dos hojas diferentes, aunque sean de la misma especie, no vamos a poder reconocerlas mediante este m��todo. A��n as�� es importante explicar este tipo de tecnolog��as puesto que estamos hablando de t��cnicas de reconocimiento en general. Al final del cap��tulo podremos ver una comparaci��n con los pros y las contras de todas las tecnolog��as empleadas. Primeramente compar��ndolas de forma separada y, finalmente, compararemos todos los m��todos existentes en base a nuestros prop��sitos. Las t��cnicas de reconocimiento, el siguiente apartado, no es muy extenso puesto que, aunque haya pasos generales para el reconocimiento de objetos, cada objeto a reconocer es distinto por lo que no hay un m��todo espec��fico que se pueda generalizar. Pasamos ahora a las t��cnicas de detecci��n de hojas mediante ordenador. Aqu�� usaremos la t��cnica explicada previamente explicada basada en las derivadas de las im��genes. La continuaci��n de este paso ser��a diseccionar la hoja en diversos par��metros. Dependiendo de la fuente a la que se consulte pueden haber m��s o menos par��metros. Unos documentos aconsejan dividir la morfolog��a de la hoja en 3 par��metros principales (Forma, Dentina y ramificaci��n] y derivando de dichos par��metros convertirlos a 16 par��metros secundarios. La otra propuesta es dividir la morfolog��a de la hoja en 5 par��metros principales (Di��metro, longitud fisiol��gica, anchura fisiol��gica, ��rea y per��metro] y de ah�� extraer 12 par��metros secundarios. Esta segunda propuesta es la m��s utilizada de todas por lo que es la que se utilizar��. Pasamos al reconocimiento de hojas, en la cual nos hemos basado en un documento que provee un c��digo fuente que cucando en los dos extremos de la hoja autom��ticamente nos dice a qu�� especie pertenece la hoja que estamos intentando reconocer. Para ello s��lo hay que formar una base de datos. En los test realizados por el citado documento, nos aseguran que tiene un ��ndice de acierto del 90.312% en 320 test en total (32 plantas insertadas en la base de datos por 10 test que se han realizado por cada una de las especies]. El siguiente apartado trata de la detecci��n de cromosomas, en el cual se debe de pasar de la c��lula metaf��sica, donde los cromosomas est��n desorganizados, al cariotipo, que es como solemos ver los 23 cromosomas de forma ordenada. Hay dos tipos de t��cnicas para realizar este paso: Por el proceso de esquelotonizaci��n y barriendo ��ngulos. El proceso de esqueletonizaci��n consiste en eliminar los p��xeles del interior del cromosoma para quedarse con su silueta; Este proceso es similar a los m��todos de derivaci��n de los p��xeles pero se diferencia en que no detecta bordes si no que detecta el interior de los cromosomas. La segunda t��cnica consiste en ir barriendo ��ngulos desde el principio del cromosoma y teniendo en cuenta que un cromosoma no puede doblarse m��s de X grados detecta las diversas regiones de los cromosomas. Una vez tengamos el cariotipo, se continua con el reconocimiento de cromosomas. Para ello existe una t��cnica basada en las bandas de blancos y negros que tienen los cromosomas y que son las que los hacen ��nicos. Para ello el programa detecta los ejes longitudinales del cromosoma y reconstruye los perfiles de las bandas que posee el cromosoma y que lo identifican como ��nico. En cuanto al trabajo que se podr��a desempe��ar en el futuro, tenemos por lo general dos t��cnicas independientes que no unen la detecci��n con el reconocimiento por lo que se habr��a de preparar un programa que uniese estas dos t��cnicas. Respecto a las hojas hemos visto que ambos m��todos, detecci��n y reconocimiento, est��n vinculados debido a que ambos comparten la opini��n de dividir las hojas en 5 par��metros principales. El trabajo que habr��a que realizar ser��a el de crear un algoritmo que conectase a ambos ya que en el programa de reconocimiento se debe clicar a los dos extremos de la hoja por lo que no es una tarea autom��tica. En cuanto a los cromosomas, se deber��a de crear un algoritmo que busque el inicio del cromosoma y entonces empiece a barrer ��ngulos para despu��s poder d��rselo al programa que busca los perfiles de bandas de los cromosomas. Finalmente, en el resumen se explica el por qu�� hace falta este tipo de investigaci��n, esto es que con el calentamiento global, muchas de las especies (tanto animales como plantas] se est��n empezando a extinguir. Es por ello que se necesitar�� una base de datos que contemple todas las posibles especies tanto del reino animal como del reino vegetal. Para reconocer a una especie animal, simplemente bastar�� con tener sus 23 cromosomas; mientras que para reconocer a una especie vegetal, existen diversas formas. Aunque la m��s sencilla de todas es contar con la hoja de la especie puesto que es el elemento m��s f��cil de escanear e introducir en el ordenador.

Senescence-associated proteolysis induced by abiotic and biotic stresses in barley leaves

Leaf senescence is a recycling process characterized by a massive degradation of macromolecules to relocalize nutrients from leaves to growing or storage tissues. Our aim is to identify and analyze the C1A Cysteine ���Protease (CysProt) family members from barley (35 cathepsin L���,3B���,1Hand3F���like) involved in leaf senescence, to study their modulation by their specific inhibitors (cystatins) and to determine their roles mediated by abiotic (darkness and N starvation) and biotic (pathogens and pest) stresses.