Curso EXANI II 2024 Biología Biodiversidad: Estructura morfológica del reino fungí #16

Introduction to the Morphological Structure of Fungi

Overview of the Fungi Kingdom

• The fungi kingdom, also known as the kingdom of fungi, is one of the six kingdoms in biological classification.

• It includes eukaryotic organisms that are heterotrophic, meaning they obtain nutrients by absorbing them from their environment.

• Unlike plants, fungi do not have chlorophyll and cannot perform photosynthesis; they derive food from decomposing organic matter or symbiosis with other organisms.

Diversity and Size of Fungi

• Fungi exhibit a wide range of forms and sizes, from microscopic yeasts to macroscopic mushrooms.

• Yeasts are unicellular fungi found in aquatic environments and can only be seen under a microscope, while mushrooms are multicellular.

• The size of fungi varies significantly based on species and environmental conditions.

Structural Components of Fungi

Key Structures in Fungal Anatomy

• The structure of fungi consists of various parts that serve specific functions in their life cycle and interaction with the environment: mycelium, fruiting body (or fructiferous body), spores, etc.

• Mycelium is formed by a network of filaments called hyphae that absorb nutrients from the substrate.

Division into Two Main Parts

• The fungal structure can be divided into two fundamental parts:

• Fruiting Body: This is the visible part containing reproductive structures responsible for sexual reproduction and spore dispersal. It emerges above ground or substrate.

• Vegetative Body: This part is involved in nutrient absorption, growth, and expansion of mycelium but does not directly participate in reproduction.

Detailed Examination of Mycelium

Characteristics and Functions

• Mycelium is primarily composed of thin branched filaments called hyphae; it may constitute up to 90% or more of a fungus's total biomass depending on various factors like species and growth conditions.

• Hyphae develop from germinating spores and extend through substrates such as soil or host organisms to absorb nutrients effectively.

Comparison with Rhizoids

• Rhizoids are specialized structures similar to roots found in some fungi; they originate from hyphae but not all fungi possess them.

• In summary:

• Mycelium consists mainly of hyphae.

Micelio y su Estructura Molecular

Estructura del Micelio

• El micelio se presenta como una red tridimensional de hifas entrelazadas, compuesta principalmente por quitina.

• Las hifas son filamentos individuales que forman el micelio, encargándose de la absorción de nutrientes y agua del entorno.

• Las hifas tienen una estructura filamentosa que puede ramificarse, también están compuestas por quitina, proteínas y lípidos.

• Los rizoides son estructuras similares a raíces que fijan el hongo al sustrato y ayudan en la absorción de nutrientes; suelen ser más densamente empaquetados que las hifas.

Composición Molecular

• La composición molecular del micelio incluye quitina, proteínas y lípidos. Es importante enfocarse en estas características para estudios académicos.

• La vulva es una estructura membranosa o escamosa que rodea la base del cuerpo fructífero, compuesta por materiales orgánicos como proteínas y polisacáridos.

Funciones de las Estructuras Fúngicas

Funciones de la Vulva

• La vulva proporciona protección a las etapas tempranas del desarrollo del cuerpo fructífero, actuando como envoltura para el micelio joven.

Estipe: Soporte Estructural

• El estipe conecta el sombrero con el sustrato; su longitud y forma varían según la especie.

• Está compuesto por moléculas orgánicas como proteínas y polisacáridos, proporcionando fuerza estructural al cuerpo fructífero.

Estructuras Adicionales en Hongos

Anillo o Velo

• El anillo es una estructura en forma de anillo presente en algunos hongos; está compuesto principalmente por proteínas como queratina.

• Su función incluye proteger el himenio y participar en la dispersión de esporas durante el desarrollo.

Himenio: Producción de Esporas

• El himenio es la capa fértil donde se producen y liberan las esporas; contiene basidios responsables de esta producción.

• Está formado por componentes estructurales como quitina y polisacáridos que le confieren rigidez. Su principal función es proteger y liberar esporas.

Láminas y Laminillas

Structures and Functions of Fungi

Interlaminar Structures: Laminas and Laminillas

• The interlaminar structures, known as laminas, are small and narrow divisions found between the main laminae. They serve as secondary subdivisions composed mainly of hyphae, basidial cells, proteins, and polysaccharides.

• Basidial cells on the surface of these structures protect spores. The primary function of both laminas and laminillas is to produce and release spores essential for fungal reproduction and dispersal.

Pileus: The Cap of the Mushroom

• The pileus, or cap, is the visible upper part of a mushroom's fruiting body. It varies in shape (convex, flat, conical), size, color, and texture.

• This structure houses reproductive elements that eventually release spores. Its molecular composition typically includes a matrix of intertwined hyphae primarily made up of chitin and nitrogenous polysaccharides.

Functionality of the Pileus

• The main role of the pileus is to protect reproductive structures like laminas or pores where spores are produced and released.

Spores: Reproductive Cells

• Spores are specialized reproductive cells produced by fungi; they vary in shape and size depending on species. They are released from reproductive structures such as laminae.

• Composed mainly of nucleic acids (DNA/RNA), spores also contain macromolecules like lipids, proteins, and polysaccharides that provide structural protection against adverse conditions.

Summary Insights on Fungal Structures

• Spores play a crucial role in reproduction and dispersal within fungi. They are generated in various parts like laminae or pores.