Living cells need to be more or less saturated with water to function normally, but they are usually incomplete in this desirable condition. The two basic parameters which describe the degree of unsaturation, i.e. the plant water deficit are (i) the water content and (ii) the energy status of the water in the cell. The water content is usually expressed as relative to that at full saturation, i.e. the relative water content or water saturation deficit, and the energy status of the water is usually expressed as the total water protential. Although the two parameters are linked in such a way that the total water potential decreases as the water content decreases, the relationship between the two, variously known as the moisture release curve, water potential isotherm or water retention characteristic, is not unique but varies with species, growth conditions and stress history (Slatyer, 1960; Jarvis and Jarvis, 1963; Altmann and Dittmer, 1966; Noy Meir and Ginzburg, 1969; Ludlow, 1976; Jones and Turner, 1978). Thus for completeness, both the water content and energy status of the water in plant tissue need to be measured. The total water potential (7') at any point in the plant can be partitioned into its components: the osmotic potential (re), turgor pressure (P), matric potential (z) and gravitational potential. As the gravitational component of the total water potential is only 0.01 MPa m- 1 (0.1 MPa = 1 bar), it can be neglected, except in very tall trees (Conner et al., 1977). For cells in equilibrium with their surroundings the total water potential is the same throughout the system, i.e. in the wall, cytoplasm, organelles and vacuole. However, the components of the total water potential may be quite different: in the vacuole the total water potential arises largely from osmotic and turgor forces, whereas in the wall, it arises largely from matric forces and to a small degree from osmotic forces. Thus the total water potential of a plant cell is given

Techniques and experimental approaches for the measurement of plant water status

Biochemical properties and chloroplast fine-structure of a viridis mutant of Gateway barley are described. The mutant was deficient in chlorophyll and carotenoids when young but developed nearly no...

Plastid structure, chlorophyll concentration, and free amino acid composition of a chlorophyll mutant of barley

In mammals, cadmium is widely considered as a non-genotoxic carcinogen acting through a methylation-dependent epigenetic mechanism. Here, the effects of Cd treatment on the DNA methylation patten are examined together with its effect on chromatin reconfiguration in Posidonia oceanica. DNA methylation level and pattern were analysed in actively growing organs, under short- (6 h) and long- (2 d or 4 d) term and low (10 mM) and high (50 mM) doses of Cd, through a Methylation-Sensitive Amplification Polymorphism technique and an immunocytological approach, respectively. The expression of one member of the CHROMOMETHYLASE (CMT) family, a DNA methyltransferase, was also assessed by qRT-PCR. Nuclear chromatin ultrastructure was investigated by transmission electron microscopy. Cd treatment induced a DNA hypermethylation, as well as an up-regulation of CMT, indicating that de novo methylation did indeed occur. Moreover, a high dose of Cd led to a progressive heterochromatinization of interphase nuclei and apoptotic figures were also observed after long-term treatment. The data demonstrate that Cd perturbs the DNA methylation status through the involvement of a specific methyltransferase. Such changes are linked to nuclear chromatin reconfiguration likely to establish a new balance of expressed/repressed chromatin. Overall, the data show an epigenetic basis to the mechanism underlying Cd toxicity in plants.

/pdf/in-posidonia-oceanica-cadmium-induces-changes-in-dna-3cu7uj83mr.pdf

In Posidonia oceanica cadmium induces changes in DNA methylation and chromatin patterning

The advent of user-friendly instruments for measuring force/deflection curves of plant surfaces at high spatial resolution has resulted in a recent outpouring of reports of the 'Young's modulus' of plant cell walls. The stimulus for these mechanical measurements comes from biomechanical models of morphogenesis of meristems and other tissues, as well as single cells, in which cell wall stress feeds back to regulate microtubule organization, auxin transport, cellulose deposition, and future growth directionality. In this article I review the differences between elastic modulus and wall extensibility in the context of cell growth. Some of the inherent complexities, assumptions, and potential pitfalls in the interpretation of indentation force/deflection curves are discussed. Reported values of elastic moduli from surface indentation measurements appear to be 10- to >1000-fold smaller than realistic tensile elastic moduli in the plane of plant cell walls. Potential reasons for this disparity are discussed, but further work is needed to make sense of the huge range in reported values. The significance of wall stress relaxation for growth is reviewed and connected to recent advances and remaining enigmas in our concepts of how cellulose, hemicellulose, and pectins are assembled to make an extensible cell wall. A comparison of the loosening action of α-expansin and Cel12A endoglucanase is used to illustrate two different ways in which cell walls may be made more extensible and the divergent effects on wall mechanics.

/pdf/plant-cell-wall-extensibility-connecting-plant-cell-growth-3egq0hkpe8.pdf

Plant cell wall extensibility: connecting plant cell growth with cell wall structure, mechanics, and the action of wall-modifying enzymes

There are many good treatments of water relations of plants, plant cells and plant tissues such as those by Dainty (1963 a), Slatyer (1967), Briggs (1967), Weatherley (1970) and, most recently, the excellent general book by House (1974) covering both plant and animal cells and tissues. There are also many articles in the old Encyclopedia of Plant Physiology, and there is the collection of articles in the three volumes edited by Kozlowski (1968 a, b; 1972).

Water Relations of Plant Cells

On the Relation between Turgor Pressure and Tissue Rigidity. I. Experiments on Resonance Frequency and Tissue Rigidity

Studies on the Formation of Protochlorophyll and Chlorophyll a under Varying Light Treatments

The Effect of Light on the Protoplasmic Viscosity

A New Method for the Determination of the Turgor of Plant Tissues

Pigment Transformations in Leaves of Wheat after Irradiation

Popular Tasks used by Researchers

How can I help with your research?

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

We encountered an error while loading the panel. Please try refreshing the page.

Something went wrong

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

Anyone with the link can view this chat. You can switch it back to private anytime.

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Hemming I. Virgin

Author Tools

Chat about Author