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Regrowth via production of epicormic shoots is an important strategy for many woody plants after environmental disturbances such as fire, drought, and herbivory. Populations spreading across a broad latitudinal gradient offer opportunities to investigate if essential traits vary with heterogenous environmental conditions, such as in savanna ecosystems. This information can help us predict plant responses to climate change. Here, we evaluated if epicormic bud protection traits varied among populations of three focal savanna species (Miconia albicans, Solanum lycocarpum, and Zeyheria montana) that have a wide distribution and grow under variable climatic conditions. We randomly sampled 225 individuals over five spatially independent sites (7°, 10°, 15°, 18°, and 24° S) in Brazil, totaling 15 individuals per species per area. We analyzed anatomical transverse sections of five buds per species per area to assess the relative area occupied by crystal and phenolic idioblasts, the thickness of the trichome boundary layer, and to test if these traits were associated with climatic conditions. The buds were protected by cataphylls and composed of a variable number of undeveloped leaves enveloping the shoot apex. For M. albicans, we found an association between maximum temperature and both phenolic idioblasts and trichome boundary layer, but no association with crystal idioblasts. In S. lycocarpum, only the trichome boundary layer was associated with maximum temperature plus high radiation. Z. montana showed no variation. Combination of two or more traits can lead to the development of adaptative strategies to different climatic conditions. We present for the first time an analysis of epicormic bud traits in plant populations occurring in an extensive latitudinal gradient and shed light on how maximum temperature is associated with these traits, contributing to a better understanding of plant resprouting capabilities in widespread savanna plant species. [ABSTRACT FROM AUTHOR]

The presence of calcium oxalate (CaOx) crystals has been widely reported in the plant kingdom. These structures play a central role in various physiological functions, including calcium regulation, metal detoxification, and photosynthesis. However, precise knowledge about their possible roles and functions in plants is still limited. Therefore, the present work aims to study the ecotypic variability of Colobanthus quitensis, an extremophile species, concerning CaOx crystal accumulation. The CaOx crystals were studied in leaves of C. quitensis collected from different provenances within a latitudinal gradient (From Andes mountains in central Chile to Antarctica) and grown under common garden conditions. Polarized light microscopy, digital image analysis, and electron microscopy were used to characterize CaOx crystals. The presence of CaOx crystals was confirmed in the four provenances of C. quitensis, with significant differences in the accumulation among them. The Andean populations presented the highest accumulation of crystals and the Antarctic population the lowest. Electron microscopy showed that CaOx crystals in C. quitensis are classified as druses based on their morphology. The differences found could be linked to processes of ecotypic differentiation and plant adaptation to harsh environments.

Introduction: Centella asiatica (Linn.) Urban is an important medicinal plant with rejuvenate properties, used in Ayurveda for promoting vitality and life. The plant is often considered as a 'panacea' for several human ailments and the biological actions often has been ascribed to its pentacyclic triterpene compounds, mainly asiatic acid, madecassic acid and triterpene saponin-asiaticoside, madecassoside. The plant is also highly specialized for the richness of several micronutrients, iron, phosphorus, sodium, vitamin C, vitamin A, carotene and dietary fibers. Objectives: The present study was performed with the objectives of elaborating the macroscopic and histo-morpho diagnostic profile of Centella asiatica and to analyze the quantitative, and powder microscopic peculiarities to support its pharmacognostic characterization. Materials and Methods: Microscopic evaluation, quantitative standards and powder microscopy were carried out using the root, stolon, petiole and leaves. Results: Distribution of slightly lobed leaf margin with actinodromous major venation pattern, amphistomatic epidermis with animocytic stomata, distinctive contour of the midrib and petiole, occurrence of crystals in the idioblasts of the cortical parenchyma of root, stem, stolon, palisade and mesophyll. Vascular system with several free collateral bundles in the stem were features characteristic of the species. These findings in conjunction with reduction in lignified elements, arenchyma lacunae, sclerenchymatous netting in root, periphloematic sclereids in petiole, and stolon could be remarkable features diagnostic of the taxon. Conclusion: The present macroscopic and histo-anatomical observations of stem, root, stolon, petiole and leaves of Centella asiatica and powder microscopic, quantitative standards put forth could provide useful information for the regulatory aspects of the quality control measures of the crude drugs. [ABSTRACT FROM AUTHOR]

As a precursor to a large variety of compounds, myo-inositol is a central molecule required for cell metabolism and plant growth. The de novo synthesis of myo-inositol requires the activity of the enzyme D-myo-inositol-3-phosphate synthase (MIPS). MIPS cDNAs encoding one or more isoforms have been cloned from a number of species, nevertheless, little is known about the regulation of MIPS expression in developing seed. Seed-specific expression of a soybean isoform (GmMIPS-1) has been demonstrated, but tissue-specific localization during embryo development has not been reported. Using immunolocalization techniques, a specialized area of GmMIPS-1 expression was identified in the outer integumentary layer during early soybean seed development. In addition, localization data provided evidence that MIPS was associated with oxalate crystal idioblasts. [ABSTRACT FROM PUBLISHER]

Recent studies of calcium oxalate (Caox) crystal producing plant species have revealed that ascorbic acid is likely the primary precursor of the oxalic acid (OxA) used in crystal formation. Thus far, the evidence is based on pulse-chase labeling studies coupled with microautoradiography. In addition, some studies have used the same methods to investigate the biosynthetic pathway giving rise to the ascorbic acid being used to produce OxA. Strong evidence indicates that ascorbic acid is being produced via the pathway proposed by Wheeler and Smirnoff. Further evidence in support of this biosynthetic pathway is now being pursued in the form of identification and purification of key enzymes involved in the catalysis. The final enzyme in the synthesis, L-galactono-γ-lactone dehydrogenase (EC 1.3.2.3) has been isolated and purified from two plant species, cauliflower and sweet potato. Antibodies have been raised against the purified protein from sweet potato. In this study, we employed this antibody to gather further evidence that ascorbic acid is being produced in crystal idioblasts cells via the Wheeler-Smirnoff pathway by localization of this key enzyme. We used two Caox crystal producing species, Pistia stratiotes L. and Medicago truncatula Gaertn. as model systems. [Copyright &y& Elsevier]

The presence of calcium oxalate (CaOx) crystals has been widely reported in the plant kingdom. These structures play a central role in various physiological functions, including calcium regulation, metal detoxification, and photosynthesis. However, precise knowledge about their possible roles and functions in plants is still limited. Therefore, the present work aims to study the ecotypic variability of Colobanthus quitensis, an extremophile species, concerning CaOx crystal accumulation. The CaOx crystals were studied in leaves of C. quitensis collected from different provenances within a latitudinal gradient (From Andes mountains in central Chile to Antarctica) and grown under common garden conditions. Polarized light microscopy, digital image analysis, and electron microscopy were used to characterize CaOx crystals. The presence of CaOx crystals was confirmed in the four provenances of C. quitensis, with significant differences in the accumulation among them. The Andean populations presented the highest accumulation of crystals and the Antarctic population the lowest. Electron microscopy showed that CaOx crystals in C. quitensis are classified as druses based on their morphology. The differences found could be linked to processes of ecotypic differentiation and plant adaptation to harsh environments. [ABSTRACT FROM AUTHOR]