Plant idioblasts: Remarkable examples of cell specialization

Catharanthus roseus (L.) G. Don is a medicinal plant well known for producing antitumor drugs such as vinblastine and vincristine, which are classified as terpenoid indole alkaloids (TIAs). The TIA metabolic pathway in C. roseus has been extensively studied. However, the localization of TIA intermediates at the cellular level has not been demonstrated directly. In the present study, the metabolic pathway of TIA in C. roseus was studied with two forefront metabolomic techniques, that is, Imaging mass spectrometry (MS) and live Single-cell MS, to elucidate cell-specific TIA localization in the stem tissue. Imaging MS indicated that most TIAs localize in the idioblast and laticifer cells, which emit blue fluorescence under UV excitation. Single-cell MS was applied to four different kinds of cells [idioblast (specialized parenchyma cell), laticifer, parenchyma, and epidermal cells] in the stem longitudinal section. Principal component analysis of Imaging MS and Single-cell MS spectra of these cells showed that similar alkaloids accumulate in both idioblast cell and laticifer cell. From MS/MS analysis of Single-cell MS spectra, catharanthine, ajmalicine, and strictosidine were found in both cell types in C. roseus stem tissue, where serpentine was also accumulated. Based on these data, we discuss the significance of TIA synthesis and accumulation in the idioblast and laticifer cells of C. roseus stem tissue. A lkaloids constitute one of the largest groups of specialized metabolites, many of which have biological functions that are indispensable, not only for plants themselves but also for human health. Approximately 20% of plant species are known to contain alkaloids (1). The significant value of alkaloids as medicines or luxury items in human life has attracted widespread interest from researchers in a range of scientific fields. These researchers have extensively studied how plant-specialized metabolites are produced at cellular and tissue levels (2). The reports indicate that biosynthetic pathways of plant specialized metabolites often involve multiple cell types that are biochemically and morphologically distinct (3,4

show abstract

“…2L and Fig. S1) (35). In C. roseus, IC and LC were classified as plant idioblasts using the broad definition of this cell type.…”

Section: Discussionmentioning

confidence: 99%

Cell-specific localization of alkaloids in Catharanthus roseus stem tissue measured with Imaging MS and Single-cell MS

Yamamoto

Takahashi

Mizuno

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

115

View full text Add to dashboard Cite

show abstract

“…This leaf anatomy is widespread and occurs in diverse species, from the scleromorphic leaves of Australian family Proteaceae (Rao et al 1985) and mediterranean Olea (Arzee 1953) to dry tropical Simaroubiaceae (Foster 1956;Franceschinelli and Yamamoto 1993) and mesic Thea (Zhang et al 2009). Even amongst gymnosperms there is a representative: the broad leaves of Gnetum known to produce dense, water conducting thread-like filiform fibres in the mesophyll (Tomlinson and Fisher 2005;Feild and Balun 2008).…”

Section: Isolated Scleriedsmentioning

confidence: 99%

Viewing leaf structure and evolution from a hydraulic perspective

Brodribb

Feild

Sack³

2010

Functional Plant Biol.

258

230

View full text Add to dashboard Cite

Abstract. More than 40 000 km 3 year -1 of water flows through the intricate hydraulic pathways inside leaves. This water not only sustains terrestrial productivity, but also constitutes nearly 70% of terrestrial evapotranspiration, thereby influencing both global and local climate (Chapin et al. 2002). Thus, the central role played by leaf vascular systems in terrestrial biology provides an important context for research into the function and evolution of water transport in leaves. Significant progress has been made recently towards understanding the linkages between anatomy and water transport efficiency in leaves, and these discoveries provide a novel perspective to view the evolution of land plants.

show abstract

“…They are classic examples of idioblasts (Foster, 1956), differing markedly in structure and content from surrounding cells. Accumulation of the intravacuolar organic matrix and crystals of calcium oxalate within that matrix are prominent features in their differentiation.…”

Section: Matrix Structure and Developmentmentioning

confidence: 99%

“…Crystals at various stages of formation are distributed in the interveinal regions, along the major veins, and at the leaf margin (Figure la). The crystals develop within idioblasts (Foster, 1956), specialized cells that differentiate in isolation from one another (Figure lb). In the leaf, crystal idioblasts are located within the mesophyll at the interface between the palisade and spongy mesophyll (Figures lb and c), or in the vascular parenchyma (not shown).…”

Section: Distribution Of Crystals In Relation To Leaf Anatomymentioning

confidence: 99%

The intravacuolar organic matrix associated with calcium oxalate crystals in leaves of Vitis

et al. 1995

View full text Add to dashboard Cite

Summaryin Vitis (grape) calcium oxalate crystals form in a needlelike morphology unique to plants, presenting an intriguing system of biological control over mineral formation. Crystals develop within an organic matrix which appears to provide control over the sites and forms of crystal deposition; however, little is known about the chemical nature of the matrix. A procedure has been developed to isolate crystals along with their associated intravecuolar matrix from leaves of grape, and studies have been initiated into the chemical composition of the matrix by characterizing elemental content, carbohydrates, and protein. The isolated matrix consisted of two structural phases, membrane chambers enclosing developing crystals, and a water-soluble phase surrounding the crystal chambers. Elemental analysis detected substantial calcium and potassium, as well as some iron in the water-soluble phase. Analysis of the water-soluble matrix by GC-MS showed that it contained an unusual polymer with novel glucuronic acid linkages. In addition, linkage analysis indicated 6-linked arabinans, arabinogalactan, and various mannosyl units typical of complex carbohydrates of Nlinked glycoproteins. SDS-PAGE analysis of the wetersoluble matrix and crystal chambers showed that each had distinct banding profiles in silver-stained gels, with prominent 60 and 70 kOa polypeptides in crystal chamber extracts. Demineralization studies provided direct evidence that the isolated matrix promotes crystal nucleation. The findings about the organic matrix associated with calcium oxalate crystals in grape are discussed in relation to crystal nucleation and growth and features shared with animal and microbial biomineralization systems.

show abstract

Plant idioblasts: Remarkable examples of cell specialization

Cited by 153 publications

References 17 publications

Cell-specific localization of alkaloids in Catharanthus roseus stem tissue measured with Imaging MS and Single-cell MS

Cell-specific localization of alkaloids in Catharanthus roseus stem tissue measured with Imaging MS and Single-cell MS

Viewing leaf structure and evolution from a hydraulic perspective

The intravacuolar organic matrix associated with calcium oxalate crystals in leaves of Vitis

Contact Info

Product

Resources

About