Development of structural and biochemical characteristics of C(4) photosynthesis in two types of Kranz anatomy in genus Suaeda (family Chenopodiaceae).

Genus Suaeda (family Chenopodiaceae, subfamily Suaedoideae) has two structural types of Kranz anatomy consisting of a single compound Kranz unit enclosing vascular tissue. One, represented by Suaeda taxifolia, has mesophyll (M) and bundle sheath (BS) cells distributed around the leaf periphery. The second, represented by Suaeda eltonica, has M and BS surrounding vascular bundles in the central plane.

Probing native lignin macromolecular configuration in Arabidopsis thaliana in specific cell wall types: further insights into limited substrate degeneracy and assembly of the lignins of ref8, fah 1-2 and C4H::F5H lines.

The interest in renewable, plant-derived, bioenergy/biofuels has resulted in a renaissance of plant cell-wall/lignin research. Herein, effects of modulating lignin monomeric compositions in a single plant species, Arabidopsis, are described. The earliest stage of putative "AcBr/Klason lignin" deposition was apparently unaffected by modulating p-coumarate 3-hydroxylase or ferulate 5-hydroxylase activities.

Winged bean chymotrypsin inhibitors retard growth of Helicoverpa armigera.

Two putative Kunitz-type chymotrypsin inhibitor genes (WCI2 and WCI5) were isolated from winged bean (Psophocarpus tetragonolobus (L.) DC). While WCI2 has previously been characterized, WCI5 represents a new member of the WCI family.

Structural, biochemical, and physiological characterization of photosynthesis in two C4 subspecies of Tecticornia indica and the C3 species Tecticornia pergranulata (Chenopodiaceae).

Among dicotyledon families, Chenopodiaceae has the most C(4) species and the greatest diversity in structural forms of C(4). In subfamily Salicornioideae, C(4) photosynthesis has, so far, only been found in the genus Halosarcia which is now included in the broadly circumscribed Tecticornia. Comparative anatomical, cytochemical, and physiological studies on these taxa, which have near-aphyllous photosynthetic shoots, show that T.

Diversity and plasticity of C photosynthesis in Eleocharis (Cyperaceae).

Eleocharis contains many amphibious species, and displays diversity of photosynthetic mechanism (C C or C-C intermediates). A unique feature of Eleocharis is the plasticity in the photosynthetic mechanism of some species in response to the environment. In this study, we have examined the culm anatomy and photosynthetic property of several Eleocharis species grown terrestrially and the changes in the newly produced culms over a short period time frame after switching from terrestrial to submerged condition.

Research note:Autoradiography utilising labelled ascorbic acid reveals biochemical and morphological details in diverse calcium oxalate crystal-forming species.

Many plant species accumulate calcium oxalate crystals in specialised cells called crystal idioblasts. In one species of crystal-forming plants (Pistia stratiotes L.; forming raphide crystals), it has been shown that ascorbic acid is the primary precursor of oxalic acid.

Flowers of Bienertia cycloptera and Suaeda aralocaspica (Chenopodiaceae) complete the life cycle performing single-cell C photosynthesis.

Leaves and cotyledons of the terrestrial C plants, Bienertia cycloptera Bunge ex Boiss. and Suaeda aralocaspica (Bunge) Freitag & Schütze (Chenopodiaceae), accomplish C photosynthesis within individual chlorenchyma cells: each species having a unique means of intracellular spatial partitioning of biochemistry and organelles. In this study the chlorenchyma tissue in flowers and stems of these species was investigated.

Expression of cinnamyl alcohol dehydrogenases and their putative homologues during Arabidopsis thaliana growth and development: lessons for database annotations?

A major goal currently in Arabidopsis research is determination of the (biochemical) function of each of its approximately 27,000 genes. To date, however, 12% of its genes actually have known biochemical roles. In this study, we considered it instructive to identify the gene expression patterns of nine (so-called AtCAD1-9) of 17 genes originally annotated by The Arabidopsis Information Resource (TAIR) as cinnamyl alcohol dehydrogenase (CAD, EC 1.

Aminocyclopropane carboxylic acid synthase is a regulated step in ethylene-dependent induced conifer defense. Full-length cDNA cloning of a multigene family, differential constitutive, and wound- and insect-induced expression, and cellular and subcellular localization in spruce and Douglas fir.

In conifer stems, formation of chemical defenses against insects or pathogens involves specialized anatomical structures of the phloem and xylem. Oleoresin terpenoids are formed in resin duct epithelial cells and phenolics accumulate in polyphenolic parenchyma cells. Ethylene signaling has been implicated in the induction of these chemical defenses.

The cytoskeleton maintains organelle partitioning required for single-cell C4 photosynthesis in Chenopodiaceae species.

Recently, three Chenopodiaceae species, Bienertia cycloptera, Bienertia sinuspersici, and Suaeda aralocaspica, were shown to possess novel C(4) photosynthesis mechanisms through the compartmentalization of organelles and photosynthetic enzymes into two distinct regions within a single chlorenchyma cell. Bienertia has peripheral and central compartments, whereas S. aralocaspica has distal and proximal compartments.

Beta-glucuronidase as reporter gene: advantages and limitations.

The beta-glucuronidase (GUS) gene is used extensively in plant biology studies; this analysis summarizes its advantages and limitations. With the advances in genomic sequencing and computational analyses (including bioinformatics), its application in the study of plant gene expression is now an integral component of modern day plant science. This chapter focuses on the detailed challenges of carrying out GUS studies for both qualitative and quantitative analyses, including the increasing employment of GUS from Bacillus strains, rather than E.

Ethylene in induced conifer defense: cDNA cloning, protein expression, and cellular and subcellular localization of 1-aminocyclopropane-1-carboxylate oxidase in resin duct and phenolic parenchyma cells.

Members of the Pinaceae family have complex chemical defense strategies. Conifer defenses associated with specialized cell types of the bark involve constitutive and inducible accumulation of phenolic compounds in polyphenolic phloem parenchyma cells and oleoresin terpenoids in resin ducts. These defenses can protect trees against insect herbivory and fungal colonization.

Functional characterization of phosphoenolpyruvate carboxykinase-type C4 leaf anatomy: immuno-, cytochemical and ultrastructural analyses.

Background And Aims: Species having C4 photosynthesis belonging to the phosphoenolpyruvate carboxykinase (PEP-CK) subtype, which are found only in family Poaceae, have the most complex biochemistry among the three C4 subtypes. In this study, biochemical (western blots and immunolocalization of some key photosynthetic enzymes) and structural analyses were made on several species to further understand the PEP-CK system. This included PEP-CK-type C4 species Urochloa texana (subfamily Panicoideae), Spartina alterniflora and S.

Differentiation of cellular and biochemical features of the single-cell C4 syndrome during leaf development in Bienertia cycloptera (Chenopodiaceae).

The terrestrial plant Bienertia cycloptera has been shown to accomplish C(4) photosynthesis within individual chlorenchyma cells by spatially separating the phases of carbon assimilation into distinct peripheral and central compartments. In this study, anatomical, physiological, and biochemical techniques were used to determine how this unique compartmentation develops. Western blots show ribulose-1,5-bisphosphate carboxylase (Rubisco) (chloroplastic) is present in the youngest leaves and increases during development, while levels of C(4) enzymes-pyruvate,Pi dikinase (chloroplastic), phosphoenolpyruvate carboxylase (PEPC) (cytosol), and NAD-malic enzyme (mitochondrial)-increase later in development.

Anatomical and chemical defenses of conifer bark against bark beetles and other pests.

Conifers are long-lived organisms, and part of their success is due to their potent defense mechanisms. This review focuses on bark defenses, a front line against organisms trying to reach the nutrient-rich phloem. A major breach of the bark can lead to tree death, as evidenced by the millions of trees killed every year by specialized bark-invading insects.

Calcium oxalate in plants: formation and function.

Calcium oxalate (CaOx) crystals are distributed among all taxonomic levels of photosynthetic organisms from small algae to angiosperms and giant gymnosperms. Accumulation of crystals by these organisms can be substantial. Major functions of CaOx crystal formation in plants include high-capacity calcium (Ca) regulation and protection against herbivory.

Sanguinarine biosynthesis is associated with the endoplasmic reticulum in cultured opium poppy cells after elicitor treatment.

Three key benzylisoquinoline alkaloid biosynthetic enzymes, (S)-N-methylcoclaurine-3'-hydroxylase (CYP80B1), berberine bridge enzyme (BBE), and codeinone reductase (COR), were localized in cultured opium poppy (Papaver somniferum) cells by sucrose density gradient fractionation and immunogold labeling. CYP80B1 catalyzes the second to last step in the formation of (S)-reticuline, the last common intermediate in sanguinarine and morphine biosynthesis. BBE converts (S)-reticuline to (S)-scoulerine as the first committed step in sanguinarine biosynthesis, and COR catalyzes the penultimate step in the branch pathway leading to morphine.

Functional compartmentation of C photosynthesis in the triple layered chlorenchyma of Aristida (Poaceae).

The genus Aristida (Poaceae), is composed of species that have Kranz anatomy and C photosynthesis. Kranz anatomy typically consists of two photosynthetic cell types: a layer of mesophyll cells where atmospheric CO is fixed into C acids, and an internal, chlorenchymatous vascular bundle sheath to which C acids are transferred and then decarboxylated to donate CO to the C cycle. The anatomy of Aristida species is unusual as it has three distinct layers of chlorenchyma cells surrounding the vascular tissue: an inner bundle sheath, an outer bundle sheath and the mesophyll cells.

Single-cell C(4) photosynthesis versus the dual-cell (Kranz) paradigm.

The efficiency of photosynthetic carbon assimilation in higher plants faces significant limitations due to the oxygenase activity of the enzyme Rubisco, particularly under warmer temperatures or water stress. A drop in atmospheric CO(2) and rise in O(2) as early as 300 mya provided selective pressure for the evolution of mechanisms to concentrate CO(2) around Rubisco in order to minimize oxygenase activity and the resultant loss of carbon through photorespiration. It is well established that a carbon-concentrating mechanism occurs in some terrestrial plants through the process of C(4) photosynthesis.

Methyl jasmonate-induced ethylene production is responsible for conifer phloem defense responses and reprogramming of stem cambial zone for traumatic resin duct formation.

Conifer stem pest resistance includes constitutive defenses that discourage invasion and inducible defenses, including phenolic and terpenoid resin synthesis. Recently, methyl jasmonate (MJ) was shown to induce conifer resin and phenolic defenses; however, it is not known if MJ is the direct effector or if there is a downstream signal. Exogenous applications of MJ, methyl salicylate, and ethylene were used to assess inducible defense signaling mechanisms in conifer stems.

Calcium channels are involved in calcium oxalate crystal formation in specialized cells of Pistia stratiotes L.

Background And Aims: Pistia stratiotes produces large amounts of calcium (Ca) oxalate crystals in specialized cells called crystal idioblasts. The potential involvement of Ca(2+) channels in Ca oxalate crystal formation by crystal idioblasts was investigated.

Methods: Anatomical, ultrastructural and physiological analyses were used on plants, fresh or fixed tissues, or protoplasts.

Calcium oxalate formation in Lemna minor: physiological and ultrastructural aspects of high capacity calcium sequestration.

•  The function of calcium oxalate (CaOx) raphide crystal formation, and structural features related to regulation of crystal formation, were studied in Lemna minor fronds using physiological and microscopy techniques. •  Specialized crystal-forming cells (crystal idioblasts) increased in number and size; CaOx, but not soluble oxalate, increased in response to increasing calcium in the growth medium. Size and number of idioblasts had a distinct upper limit.

Light-dependent development of single cell C4 photosynthesis in cotyledons of Borszczowia aralocaspica (Chenopodiaceae) during transformation from a storage to a photosynthetic organ.

Background And Aims: Previous work has shown that Borszczowia aralocaspica (Chenopodiaceae) accomplishes C4 photosynthesis in a unique, polarized single-cell system in leaves. Mature cotyledons have the same structure as leaves, with chlorenchyma cells having biochemical polarization of dimorphic chloroplasts and C4 functions at opposite ends of the cell.

Key Results: Development of the single-celled C4 syndrome in cotyledons was characterized.

Induction of anatomically based defense responses in stems of diverse conifers by methyl jasmonate: a phylogenetic perspective.

Conifers have evolved constitutive and inducible defense mechanisms to help in both wound healing and defense against attack by bark beetles and other organisms. These defenses include oleoresin, phenolics, and static structures in secondary phloem, such as lignified cells and calcium oxalate crystals, that create physical barriers. We used a phylogenetic approach to investigate the defense anatomy of conifer stems of 13 species from five families following treatment with methyl jasmonate (MJ), a compound that induces defense responses in stems of several Pinaceae species.

Development of biochemical specialization and organelle partitioning in the single-cell C4 system in leaves of Borszczowia aralocaspica (Chenopodiaceae).

The terrestrial plant Borszczowia aralocaspica (Chenopodiaceae) has recently been shown to contain the entire C(4) photosynthesis mechanism within individual, structurally and biochemically polarized chlorenchyma cells rather than in a dual cell system, as has been the paradigm for this type of carbon fixation (Nature 414: 543-546, 2001). Analysis of carbon isotope composition and (14)CO(2) fixation shows that photosynthesis and growth of B. aralocaspica occurs through carbon acquired by C(4) photosynthesis.