By -
Avinash Darsimbe
Assistant Professor
Department of Botany
Shri Shivaji Science College, Amravati
Physiology of Senescence and Abscission
B.Sc. III (Sem - V)
BOTANY : PLANT PHYSIOLOGY AND ECOLOGY
Sant Gadge Baba Amravati University,Amravati
Vascular Cambium & Seasonal activity & its Role in Stem & RootFatima Ramay
Vascular Cambium & Seasonal activity & its Role in Stem & Root:
The vascular cambium (pl. cambia or cambiums) is a lateral meristem in the vascular tissue of plants.
The vascular cambium is a cylindrical layer of cambium that runs through the stem of a plant that undergoes secondary growth.
In Dicots:
The vascular cambium is in dicot stems and roots, located between the xylem and the phloem in the stem and root of a vascular plant, and is the source of both the secondary xylem growth (inwards, towards the pith) and the secondary phloem growth (outwards).
In Monocots:
Monocot stems, such as corn, palms and bamboos, do not have a vascular cambium and do not exhibit secondary growth by the production of concentric annual rings. They cannot increase in girth by adding lateral layers of cells as in conifers and woody dicots.
Cambium of some plants remains active for the entire period of their life, i.e., cambial cells divide and resulting cells mature to form xylem and phloem elements.
This type of seasonal activity usually found in the plants present in the tropical regions, and not all plants show cambial activity.
Percentage of ringless trees in the rain forests of;India : 75%Amazon : 43%Malaysia : 15%
In regions with definite seasonal climate; seasonal activity of cambium ceased with onset of unfavorable conditions; In Autumn, it enters the dormant state and lasts for the end of summer; In Spring, cambium again becomes active.
Duration of cambial activity is also affected by day-length, e.g., In Robinia pseudoacacia, cambium is dormant under short-day condition.
The cambium cells formed in circular in cross section from the beginning onwards.
The cambial ring is partially primary (fascicular cambium) and partially secondary (interfascicular cambium).
Periderm originates from the cortical cells (extra stelar in origin).
In Dicot stem, for mechanical support xylem is with comparatively smaller vessels, greater fibers and less parenchyma.
More amount of cork is produces for protection.
Lenticels on periderm are very prominent.
The cambial ring formed is wavy in the beginning and later becomes circular.
The cambium ring is completely secondary in origin.
Periderm originates from the pericycle (intra stelar in origin).
In Dicot root, xylem is with big thin walled vessels with few fibers and more parenchyma.
Less amount of cork is produced as root is underground.
Lenticels on periderm are not very prominent.
Everything about photoperiodism from scratch to smart, from the oldest models to the latest models as well as proposed one, exclusive and elusive illustrations and models for proper understanding
intro-hostory and discovery-characteristics of phytochrome-chemical nature of phytochrome-mode of action-mechanism-phytochrome mediated physiological responses-phytochrome is a pigment system:some evidences-role of phytochrome
By -
Avinash Darsimbe
Assistant Professor
Department of Botany
Shri Shivaji Science College, Amravati
Physiology of Senescence and Abscission
B.Sc. III (Sem - V)
BOTANY : PLANT PHYSIOLOGY AND ECOLOGY
Sant Gadge Baba Amravati University,Amravati
Vascular Cambium & Seasonal activity & its Role in Stem & RootFatima Ramay
Vascular Cambium & Seasonal activity & its Role in Stem & Root:
The vascular cambium (pl. cambia or cambiums) is a lateral meristem in the vascular tissue of plants.
The vascular cambium is a cylindrical layer of cambium that runs through the stem of a plant that undergoes secondary growth.
In Dicots:
The vascular cambium is in dicot stems and roots, located between the xylem and the phloem in the stem and root of a vascular plant, and is the source of both the secondary xylem growth (inwards, towards the pith) and the secondary phloem growth (outwards).
In Monocots:
Monocot stems, such as corn, palms and bamboos, do not have a vascular cambium and do not exhibit secondary growth by the production of concentric annual rings. They cannot increase in girth by adding lateral layers of cells as in conifers and woody dicots.
Cambium of some plants remains active for the entire period of their life, i.e., cambial cells divide and resulting cells mature to form xylem and phloem elements.
This type of seasonal activity usually found in the plants present in the tropical regions, and not all plants show cambial activity.
Percentage of ringless trees in the rain forests of;India : 75%Amazon : 43%Malaysia : 15%
In regions with definite seasonal climate; seasonal activity of cambium ceased with onset of unfavorable conditions; In Autumn, it enters the dormant state and lasts for the end of summer; In Spring, cambium again becomes active.
Duration of cambial activity is also affected by day-length, e.g., In Robinia pseudoacacia, cambium is dormant under short-day condition.
The cambium cells formed in circular in cross section from the beginning onwards.
The cambial ring is partially primary (fascicular cambium) and partially secondary (interfascicular cambium).
Periderm originates from the cortical cells (extra stelar in origin).
In Dicot stem, for mechanical support xylem is with comparatively smaller vessels, greater fibers and less parenchyma.
More amount of cork is produces for protection.
Lenticels on periderm are very prominent.
The cambial ring formed is wavy in the beginning and later becomes circular.
The cambium ring is completely secondary in origin.
Periderm originates from the pericycle (intra stelar in origin).
In Dicot root, xylem is with big thin walled vessels with few fibers and more parenchyma.
Less amount of cork is produced as root is underground.
Lenticels on periderm are not very prominent.
Everything about photoperiodism from scratch to smart, from the oldest models to the latest models as well as proposed one, exclusive and elusive illustrations and models for proper understanding
intro-hostory and discovery-characteristics of phytochrome-chemical nature of phytochrome-mode of action-mechanism-phytochrome mediated physiological responses-phytochrome is a pigment system:some evidences-role of phytochrome
Students able to understand that who helps to transport in plants, Mechanism of transport in plants, physical forces involved in transport, Behavior with different solutions.
Dear Students, this is the PPT to get the idea on Parts of Garden. The parts of garden are really very nice to read and know. You can built your garden with your own interest.
Dear students, how are you all?!. This PPT will give a basic idea for planning, designing and principles of Garden. You all can use this PPT as notes for your exams.
Dear students, in this ppt you will able to understand about the Incomplete dominance. Incomplete dominance is an allelic interaction. In incomplete dominance, both alleles of a character express their character in the F1 generation.
Prokaryotic and Eukaryotic Algal cell structuregkumarimahesh
Every science student must be aware of the Prokaryotic and Eukaryotic algal cell structure when they start their studies. This slide will be very helpful for knowing about the pro and Eu characteristics.
Chemotaxonomy is a little bit difficult task for the students to learn and understand. This slide helps the teachers and students to take class and understood it in a liable way
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
The increased availability of biomedical data, particularly in the public domain, offers the opportunity to better understand human health and to develop effective therapeutics for a wide range of unmet medical needs. However, data scientists remain stymied by the fact that data remain hard to find and to productively reuse because data and their metadata i) are wholly inaccessible, ii) are in non-standard or incompatible representations, iii) do not conform to community standards, and iv) have unclear or highly restricted terms and conditions that preclude legitimate reuse. These limitations require a rethink on data can be made machine and AI-ready - the key motivation behind the FAIR Guiding Principles. Concurrently, while recent efforts have explored the use of deep learning to fuse disparate data into predictive models for a wide range of biomedical applications, these models often fail even when the correct answer is already known, and fail to explain individual predictions in terms that data scientists can appreciate. These limitations suggest that new methods to produce practical artificial intelligence are still needed.
In this talk, I will discuss our work in (1) building an integrative knowledge infrastructure to prepare FAIR and "AI-ready" data and services along with (2) neurosymbolic AI methods to improve the quality of predictions and to generate plausible explanations. Attention is given to standards, platforms, and methods to wrangle knowledge into simple, but effective semantic and latent representations, and to make these available into standards-compliant and discoverable interfaces that can be used in model building, validation, and explanation. Our work, and those of others in the field, creates a baseline for building trustworthy and easy to deploy AI models in biomedicine.
Bio
Dr. Michel Dumontier is the Distinguished Professor of Data Science at Maastricht University, founder and executive director of the Institute of Data Science, and co-founder of the FAIR (Findable, Accessible, Interoperable and Reusable) data principles. His research explores socio-technological approaches for responsible discovery science, which includes collaborative multi-modal knowledge graphs, privacy-preserving distributed data mining, and AI methods for drug discovery and personalized medicine. His work is supported through the Dutch National Research Agenda, the Netherlands Organisation for Scientific Research, Horizon Europe, the European Open Science Cloud, the US National Institutes of Health, and a Marie-Curie Innovative Training Network. He is the editor-in-chief for the journal Data Science and is internationally recognized for his contributions in bioinformatics, biomedical informatics, and semantic technologies including ontologies and linked data.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
1. ASCENT OF SAP
Dr. K. GANESH KUMARI
ASSISTANT PROFESSOR
DEPARTMENT OF PLANT SCIENCE
SRIMAD ANDAVAN ARTS AND SCIENCE COLLEGE (AUTONOMOUS)
TRICHY - 5
2. Introduction
• The upward movement of sap from the root system to the
aerial parts of the plant through the xylem is known as
ascent of sap
• It distributes water and minerals to stem and leaves.
• This is also known as water conduction or translocation of
water
• Sap is an aqueous solution of water, dissolved mineral salts
and some organic solutes present in the xylem
• Hence, it is often known as xylem sap.
3. Rate of movement of Sap
• The rate of movement of sap varies with diameter of the
conducting vessels.
• Wide vessels – radii of 100 to 200 µM
- water rises up to the rate of 16 to 45 mh-1
• Small vessels – radii of 25 to 75 µM
- Water rises up to the rate of 1 to 6 mh-1
4. Path of Ascent of sap
• In plants, ascent of sap takes
place from roots to leaves only
through xylem.
• Water enters the xylem vessels or
tracheid of the root through the
cortical cells
• Xylem terminates as small
branches in the mesophyll tissue
• It forms a continuous column for
the ascent of sap to the leaves
5. • Means xylon in greek – wood
• Mostly dead cells
• Made up of no. of elements
Xylem Vessels
• Elongated or drum shaped structures
• Conducts water and minerals vertically
• Have perforation plate
Tracheids
• Elongated cells with tapering ends
• No perforation at the end walls but have
pores on lateral walls
Xylem Parenchyma
• It does not help in conducting
• Living cell
Xylem fibres
• Support
• Store starch Fibre Tracheid Vessel Xylem parenchyma
6. Xylem is the principal water conducting tissue in plant. It can be
shown by an experiment
7. Experiment 1
Balsam Plant experiment
• A leafy twig of balsam plant is cut under
water to avoid air bubbles and the cut
end is placed in a beaker with eosin
water
• Coloured lines will be seen moving
upwards in the stem as the stem is the
transparent in nature
• If the sections are cut at this stem, only
the xylem will be filled with coloured
water.
8. Experiment 2
Ringing experiment
• A leafy twig of woody plant is cut
under water to avoid the entry of air
bubbles and its bark is cut out of a ring
of 1inch length.
• Like wise another twig is cut from the
same plant and its wood element is
carefully removed from it for at least
1cm height with out damaging the
bark at that site.
• The cut ends of these two twigs are
kept dipped in water for 3 – 4 hours
9. Cont…
• While observing these twigs, the
leaves of debarked twig remain
fresh above the ringed portion
but those of wood eliminated
twig show the sign of wilting
• Therefore it is clear that in
debarked twig water is
continuously supplied to the
leaves through the xylem, so its
leaves remain fresh.
10. Transpiration pull and Cohesion theory
• According to this theory, the ascent of sap is due
to transpiration pull from the top of plant and the
cohesion and adhesion properties of water.
• It is a convincing theory for explaining the ascent
of sap in tall trees.
• This theory is now popularly known by various
names such as Dixons and Jolly’s theory, cohesion
theory, cohesion-tension theory and transpiration
pull theory.
• This theory is based on the cohesive and adhesive
properties of water and transpiration pull.
11. Cohesion
• Attraction between water molecules are
called cohesion.
• Water molecules remains joined to each
other due to the presence of H-bonds
between them.
• Although H-bond is very week, when
they are present in enormous numbers,
a very strong mutual force of attraction
or cohesive force develops between
water molecules.
• Hence, the water molecules form an
continuous water column in the xylem
12. Cont…
• Cohesive force provides a tensile
strength to the water column.
• The magnitude of cohesive force is
very high (260 bars) and hence the
water column cannot be broken by
the force of gravity.
• Further, this force is enough for
lifting water to a height of 120 m
and for overcoming the resistance
offered by barriers in the way of
water movement.
13. Adhesion
• The adhesion property (attraction between the
water molecules and the walls of xylem) further
ensures the continuity of water column in the xylem.
• Xylem vessels form continuous tubes extending from
roots to the top of the plants.
• One end of xylem tube is connected with the root
hairs (via pericycle, endodermis and cortex) and the
other end is connected with the substomatal cavity
in the leaves via mesophyll cells.
• This tube is filled with sap in the form a continuous
water column due to cohesion and adhesion
14. Transpiration pull
• The pulling force developed in the
water of xylem due to transpiration is
called transpiration pull.
• When transpiration takes place in
leaves at the upper parts of the plant,
water evaporates from the
intercellular spaces of the leaves and
goes to the outer atmosphere
through the stomata.
• As consequence, more water is
released into the intercellular spaces
from the mesophyll cells
15. Cont…
• The mesophyll in turn draw water
from the xylem of the leaf. Thus, a
water tension is created in the xylem
of leaves.
• This tension is transmitted downward
to water in the xylem of root through
xylem of stem.
• Because of this tension, water is
pulled upward to the leaves.
• Since sap exists as a continuous
column, it moves upward in the xylem
of stem and leaves to reach the
transpiring surfaces at the top of the
plant.
16. Cont…
• Thus transpiration at the leaf surfaces
pulls water from the roots to get it
into the leaves.
• The water column is just like a steel
rope which is extended from
substomatal cavities in the leaves to
the roots.
• If this rope is pulled from the top, the
entire rope will move upward.
• In plants, the pull is generated by the
process of transpiration and hence it
is known as transpiration pull.
17. Demonstration of water lifting power of transpiration Pull
• Cut a fresh leafy twig under water and fix
it in a long narrow glass tube which is
filled with water.
• Place the lower end of the tube in a beaker
containing mercury
• Make the joint between stem and glass tube
air tight.
• After sometime, due to transpiration pull,
the mercury will gradually rise in the glass
tube.
18. Objection to Cohesion theory
• Due to the variation of temperature, the xylem vessels enlarges
during the day time and shrinks in the night.
• While the vessel size is increasing, there are fair chances for the entry
of gas bubbles in the water column.
• The air bubbles in the conducting channels will break the continuity
of the water column.
• This phenomenon is known as Cavitation.
• It was demonstrated by Milburn and Johnson (1966)
19. Cavitation overcomes
• The impact of cavitation is overcome by the presence of
many columns of vessels side by side; it eliminates the
injurious effect of temporary cavitation.
• When the tension is relieved by rain or simply at night, the
gases are dissolved in the solution forming a continuous
column.