Search results for "plant cell"

How to Make a Vesicle: Coat Protein-Membrane Interactions

2018

Revisiting the cysteine-rich proteins encoded in the 3’-proximal open reading frame of the positive-sense single-stranded RNA of some monopartite fil…

2020

A reexamination of proteins with conserved cysteines and basic amino acids encoded by the 3 '-proximal gene of the positive-sense single-stranded RNA of some monopartite filamentous plant viruses has been carried out. The cysteines are involved in a putative Zn-finger domain, which, together with the basic amino acids, form part of the nuclear or nucleolar localization signals. An in-depth study of one of these proteins, p15 from grapevine B virus (GVB), has shown: (i) a three-dimensional structure with four alpha-helices predicted by two independent in silico approaches, (ii) the nucleolus as the main accumulation site by applying confocal laser microscopy to a fusion between p15 and the g…

Melatonin and phytomelatonin: Chemistry, biosynthesis, metabolism, distribution and bioactivity in plants and animals—an overview

2021

Melatonin is a ubiquitous indolamine, largely investigated for its key role in the regulation of several physiological processes in both animals and plants. In the last century, it was reported that this molecule may be produced in high concentrations by several species belonging to the plant kingdom and stored in specialized tissues. In this review, the main information related to the chemistry of melatonin and its metabolism has been summarized. Furthermore, the biosynthetic pathway characteristics of animal and plant cells have been compared, and the main differences between the two systems highlighted. Additionally, in order to investigate the distribution of this indolamine in the plan…

Routes to cell death in animal and plant kingdoms: from classic apoptosis to alternative ways to die—a review

2018

Programmed cell death is fundamental for multicellular organisms either in animal or plant kingdom. Classic apoptosis, which represents the best studied form of cell death, is dependent on caspase protease activity in animals. These proteases are not present in plants, where caspase-like activities, including metacaspases, are involved in the execution of plant cell death. Beyond apoptosis, various non-apoptotic forms of cell death also exist, including autophagy, necroptosis, pyroptosis, and ferroptosis. These types of cell death can be activated independently of apoptosis and sometimes occur when apoptosis is inhibited. Non-apoptotic forms of cell death are best characterized in animals, …

Tonoplast intrinsic proteins from cauliflower (Brassica oleracea L. var. botrytis): immunological analysis, cDNA cloning and evidence for expression …

1998

The vacuolar membrane (tonoplast) of plant cells contains aquaporins, protein channels that facilitate the selective transport of water. These tonoplast intrinsic proteins (TIPs) of 23-29 kDa belong to the ancient major intrinsic protein (MIP) family. A monospecific polyclonal antiserum directed against a 26 kDa intrinsic protein from the tonoplast of meristematic cells from cauliflower (Brassica oleracea L. var. botrytis) was used to screen a cDNA library. Two distinct cDNAs have been isolated. Both clones, c26-1 and c26-2, encode closely related TIPs. The c26-1 insert, consisting of 933 bp upstream of the poly(A) tail, is a full-length cDNA with an open reading frame encoding a protein of…

Calcium signaling in plant cell organelles delimited by a double membrane.

2006

AbstractIncreases in the concentration of free calcium in the cytosol are one of the general events that relay an external stimulus to the internal cellular machinery and allow eukaryotic organisms, including plants, to mount a specific biological response. Different lines of evidence have shown that other intracellular organelles contribute to the regulation of free calcium homeostasis in the cytosol. The vacuoles, the endoplasmic reticulum and the cell wall constitute storage compartments for mobilizable calcium. In contrast, the role of organelles surrounded by a double membrane (e.g. mitochondria, chloroplasts and nuclei) is more complex. Here, we review experimental data showing that t…

Vesicle formation in the membrane of onion cells (Allium cepa) during rapid osmotic dehydration

2009

BACKGROUND AND AIMS Optimization of osmotic dehydration in different plant cells has been investigated through the variation of parameters such as the nature of the sugar used, the concentration of osmotic solutions and the processing time. In micro-organisms such as the yeast, Saccharomyces cerevisiae, the exposure of a cell to a slow increase in osmotic pressure preserves cell viability after rehydration, while sudden dehydration involves a lower rate of cell viability, which could be due to membrane vesiculation. The aim of this work is to study cytoplasmic vesicle formation in onion epidermal cells (Allium cepa) as a function of the kinetics of osmotic pressure variation in the external…

Uptake of an Endocytic Marker by Rice Cells: Variations Related to Osmotic and Saline Stress

2003

Saline and osmotic stress are the main abiotic factors limiting the productivity of rice and other crop plants. Although both coincide in generating water deficit and affect many aspects of plant growth and development similarly, some effects of salinity are distinctively related to the ionic component of salt stress. At the cellular level, dessication tolerance is largely dependent on the cell's ability for osmotic adjustment. Here, we have studied the effects of saline and osmotic stress on endocytosis by rice cells, to investigate the common and distinctive effects of saline-generated stress and osmotically generated stress, and the possible involvement of endocytosis in tolerance mechan…

Early signaling network in tobacco cells elicited with methyl jasmonate and cyclodextrins.

2012

We analyze, for the first time, the early signal transduction pathways triggered by methyl jasmonate (MJ) and cyclodextrins (CDs) in tobacco (Nicotiana tabacum) cell cultures, paying particular attention to changes in cytosolic free Ca(2+) concentration ([Ca(2+)](cyt)), the production of hydrogen peroxide (H(2)O(2)) and nitric oxide (NO), and late events like the induction of capsidiol. Our data indicate that MJ and CDs trigger a [Ca(2+)](cyt) rise promoted by Ca(2+) influx through Ca(2+)-permeable channels. The joint presence of MJ and CDs provokes a first increase in [Ca(2+)](cyt) similar to that observed in MJ-treated cells, followed by a second peak similar to that found in the presence…

Modification of Plasma Membrane Organization in Tobacco Cells Elicited by Cryptogein

2014

Abstract Lipid mixtures within artificial membranes undergo a separation into liquid-disordered and liquid-ordered phases. However, the existence of this segregation into microscopic liquid-ordered phases has been difficult to prove in living cells, and the precise organization of the plasma membrane into such phases has not been elucidated in plant cells. We developed a multispectral confocal microscopy approach to generate ratiometric images of the plasma membrane surface of Bright Yellow 2 tobacco (Nicotiana tabacum) suspension cells labeled with an environment sensitive fluorescent probe. This allowed the in vivo characterization of the global level of order of this membrane, by which w…