• Background and Aims Pea (Pisum sativum) primary roots form long vascular cavities when grown under wet or flooded conditions at 25 °C. It is thought that the are a of aerenchyma. At °C short continue to grow after flooding. After reach 10 cm flooding causes rapid cessation growth, root tips often become curled. In longer do not extend into base roots, perhaps rendering them ineffective as was hypothesized resulting growth arrest due programmed cell death (PCD) rather than necrosis. Methods...

Premise Fluorescence microscopy is an effective tool for viewing plant internal anatomy. However, using fluorescent antibodies or labels hinders throughput. We present a minimal protocol that takes advantage of inherent autofluorescence and aldehyde‐induced fluorescence in cellular subcellular structures to markedly increase throughput ultrastructural visualization. Methods Results Twelve species distributed across the phylogeny were each subjected five fixative treatments: 1%...

Understanding plant adaptation mechanisms to prolonged water immersion provides options for genetic modification of existing crops create cultivars more tolerant periodic flooding. An important advancement in understanding flooding would be elucidate mechanisms, such as aerenchyma air-space formation induced by hypoxic conditions, consistent with immersion. Lysigenous occurs through programmed cell death (PCD), which may entail the chemical polysaccharides root tissue walls. We investigated...

Flooding at warm temperatures induces hypoxic stress in Pisum sativum seedling roots. In response, some undifferentiated cells the primary root vascular cylinder start degenerating and form a longitudinal cavity. Changes cellular morphology cell wall ultrastructure detected previously late stages of cavity formation suggest possible involvement programmed death (PCD). this study, cytological events occurring early were investigated. Systematic DNA fragmentation, feature many PCD pathways,...

Pea (Pisum sativum L. cv. Alaska) primary roots were exposed to flooding after growth for 4 or 5 d at 25°C under relatively dry conditions. Flooding reduced, but did not stop, root growth, and cavities caused by degradation of central vascular cells typically found from 10–60 mm the tips. stopped cell death in tips, formed that 20–60 tips roots. Degradation tip 5-day-roots was very rapid began elongation zone later apical zone. Root discolored, narrowed curled before arrest. The mitotic...

Cellular degeneration is essential for many developmental and stress acclimation processes. Undifferentiated parenchymatous cells in the central vascular cylinder of pea primary roots degenerate under hypoxic conditions created by flooding at temperatures >15°C, forming a long cavity that seems to provide conduit longitudinal oxygen transport roots. We show specific changes cell wall ultrastructure accompanied previously detected cytoplasmic organellar degradation cavity-forming The...

Pea seeds ( Pisum sativum L.) of six cultivars were planted in the field, greenhouse, or growth chambers, five different media, light dark, and at various temperatures (10–32 C). Under all conditions above 15 C central portion vascular cylinder, except “Ageotropum,” tended to form cavities almost every primary root examined. These then became filled by ingrowth specialized parenchyma cells (SP cells). The formation SP was temperature dependent since roots grown below always formed metaxylem...

The anatomy of the vascular cylinders 150-mm-long pea primary roots (Pisum sativum cv Alaska) grown at 10° and 25°C was examined by light electron microscopy. Root cylinder diameters were greater 10°C. At maturity cells longer 10°C than 25°C, but did not differ in mean diameter (11-16 μm). This effect most pronounced xylem sectors (626 vs. 429 Observation cell ultrastructure showed cellular degeneration some central both temperatures region 20-24 mm from root tip, more extensive 25°C....

Abstract The seeds of 20 legume species were grown in the greenhouse or growth chambers at different temperatures. Under warm temperature conditions (above 15 °C), six species, pea ( Pisum sativum ), broadbean Vicia faba chickpea Cicer arietinum lentil Lens culinaris wild lupine Lupinus latifolius and soybean Glycine max formed cavities vascular cylinder their primary roots, which turn became filled by ingrowth specialized parenchyma cells (SP cells). When these low (below however, a...

A lengthy cavity usually forms in the vascular cylinders of pea (Pisum sativum) primary roots response to sudden flooding at 25oC. This is thought be a form aerenchyma. Ethylene has been shown mediate inducible aerenchyma maize, therefore role ethylene formation cavities was examined. Pea seedlings grown for 4 d 2 L beakers vermiculite moistened below field capacity - conditions that do not favor were flooded with solutions containing inhibitors (AOA, EGTA, and STS). seeds germinated...

Classical histology describes the histological organization in Zea mays as having a "closed organization" that differs from Arabidopsis with development of xylem conforming to predictable rules. We speculated root apical meristem wild subspecies Z. (a teosinte) would differ domestic sweetcorn cultivar ('Honey Bantam'). Careful comparison could contribute understanding how evolutionary processes and domestication maize have affected development. Root tips seedlings were prepared sectioned for...

Young plant roots share a common architecture: central vascular cylinder surrounded by enveloping cylinders of ground and dermal tissue produced an apical promeristem. Roots with closed organization can be studied to explore how ontogeny is managed. The analysis transverse longitudinal sections has been the most useful approach for this, but suffers from limitations. We developed new method that utilizes digital photography three-dimensional (3D) computer virtual reconstructions overcome...

Premise of research. Vascular cavities (VCs) form in the primary roots many species cool-season herbaceous legumes when growing medium is saturated and relatively warm (>15°–20°C). Circumstantial evidence has suggested that VCs rapidly following flooding these are a inducible aerenchyma confers tolerance to waterlogging. This study was undertaken directly confirm that, once formed, improve internal rhizosphere oxygen levels around tips which they occur.Methodology. Seedlings Phaseolus...

Pea seeds (Pisum sativum L.) of six cultivars were planted in the field, greenhouse, or growth chambers, five different media, light dark, and at various temperatures (10–32 C). Under all conditions above 15 C central portion vascular cylinder, except “Ageotropum,” tended to form cavities almost every primary root examined. These then became filled by ingrowth specialized parenchyma cells (SP cells). The formation SP was temperature dependent since roots grown below always formed metaxylem...

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Serial sectioning and 3D image reconstruction methods were applied to elucidate the structures of apices root vascular cylinders (VCs) in taxa Poaceae: Zea mays “Honey Bantam”, Z. ssp. mexicana, Hordeum vulgare Oryza sativa. The primary nodal roots investigated. Observations performed using high-quality image-processing techniques improved developed by authors. We found that a quiescent uniseriate plerome was located at most distal part each VC. Vascular initials immediately basipetally as...

The reorganization of vascular cylinders pea ( Pisum sativum, cv. Alaska) primary roots following the formation cavities was examined by light and electron microscopy. Cavities usually began forming ~20 mm from root tip were continuous to ~90 tips in 150 long, where they filling with specialized parenchyma cells (SP cells). SP produced enlargement parenchymous xylem at cavity margins. Depending on extent shape cavity, also sometimes phloem early derivatives cambium. Enlargement some...

We developed a novel sectioning and staining method to make high contrast, resolution sections of plant tissue for light microscopy. Specimens teosinte (Zea mays L., ssp. mexicana) root tips were fixed embedded in Technovit 7100™ plastic resin. Thin sections, 1-2.5 μm, cut mounted on glass slides. The either treated with RNase or not, then stained 0.1% toluidine blue O observed through ∞/0 objective lenses. For microscopy, the enzyme procedure increased contrast. High magnification lenses...

Flooding reduces soil oxygen necessary for root growth. In some mesophytes low levels of are mitigated by the formation aerenchyma or expansion intercellular spaces. But immersion in water may have effects on roots addition to reducing levels. At temperatures >15°C Pisum sativum primary develop cavities centers their vascular cylinders response saturated flooded conditions. present study we compared pea hypoxia without flooding using an innovative system that allows separation gas...