scholarly journals Localizatlon of expansin-like protein in apoplast of pea (Pisum sativum L.) root nodules during interaction with Rhizobium leguminosarum bv. viciae

2011 ◽  
Vol 76 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Marzena Sujkowska ◽  
Wojciech Borucki ◽  
Władysław Golinowski
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Rhizobium Leguminosarum ◽  
Plant Cell Wall ◽  
Root Nodules ◽  
Infection Thread ◽  
Nodule Development ◽  
Cell Enlargement ◽  
Pea Root ◽  
Pea Roots

During nodule development on pea roots, apoplast undergoes changes in activity of plant cell wall proteins such as expansins (EXPs). Because the accumulation of EXP protein has been correlated with the growth of various plant organs, we investigated using Western Blot and immunolocalization studies with antibody against PsEXP1, whether this protein was accumulated in the expanding cells of nodule. Immunoblot results indicated the presence of a 30-kDa band specific for pea root nodules. The EXP proteins content rose during growth of pea root nodules. Expansin(s) protein was localized in nodule apoplast as well as in the infection thread walls. The enhanced amount of expansin-like proteins in meristematic part of nodule, root and shoot was shown. The localization of this protein in the meristematic cell walls can be related to the loosening of plant cell wall before cell enlargement. Both, plant cell enlargement and infection thread growth require activity of expansin(s). Possible involvement of EXPs in the process of pea root nodule development is also discussed.

Frankia forms infection threads

1999 ◽  
Vol 77 (9) ◽  
pp. 1327-1333 ◽  
Author(s):  
R Howard Berg
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Infection Thread ◽  
Nodule Development ◽  
Wall Material ◽  
Cell Wall Material ◽  
Infection Threads ◽  
Nodule Symbiosis ◽  
Plant Control

Frankia forms symbioses with a great variety of plant hosts, and because nodule development is under plant control, this results in an interesting diversity in the structure of developing symbiotic cells. However, it is apparent that, in all these symbioses, the microsymbiont Frankia follows a similar pattern of development within symbiotic cells of the nodule: the cell is invaded by formation of an infection thread containing invasive hyphae sheathed in plant cell wall material, parasitic vegetative hyphae proliferate by branching from this infection thread, and N2-fixing symbiotic vesicles differentiate from tips of these vegetative hyphae. Infection threads are recognized by their ontogeny and morphology, being the cell-invasive structures in the case of the former and straight-growing hyphae in the case of the latter. Formation of infection threads is a feature shared in common with legumes. Unlike in legumes, the infection thread in actinorhizae is not defined by the presence of sheathing plant cell wall material; all forms of the bacterium have this. Rather than using the term "encapsulation," which suggests a bacterial origin, it is proposed the term "interfacial matrix" be used to describe this plant cell wall material separating Frankia from host cytoplasm.Key words: Frankia, infection thread, interfacial matrix, microsymbiont, nodule, symbiosis.

scholarly journals Development of Functional Symbiotic White Clover Root Hairs and Nodules Requires Tightly Regulated Production of Rhizobial Cellulase CelC2

2011 ◽  
Vol 24 (7) ◽  
pp. 798-807 ◽  
Author(s):  
Marta Robledo ◽  
José I. Jiménez-Zurdo ◽  
M. José Soto ◽  
Encarnación Velázquez ◽  
Frank Dazzo ◽  
...  
Keyword(s):  
Cell Wall ◽  
White Clover ◽  
Rhizobium Leguminosarum ◽  
Plant Cell Wall ◽  
Root Nodules ◽  
Root Hairs ◽  
Nitrogen Fixing ◽  
Plant Host ◽  
Root Cortex ◽  
Infection Threads

The establishment of rhizobia as nitrogen-fixing endosymbionts within legume root nodules requires the disruption of the plant cell wall to breach the host barrier at strategic infection sites in the root hair tip and at points of bacterial release from infection threads (IT) within the root cortex. We previously found that Rhizobium leguminosarum bv. trifolii uses its chromosomally encoded CelC2 cellulase to erode the noncrystalline wall at the apex of root hairs, thereby creating the primary portal of its entry into white clover roots. Here, we show that a recombinant derivative of R. leguminosarum bv. trifolii ANU843 that constitutively overproduces the CelC2 enzyme has increased competitiveness in occupying aberrant nodule-like root structures on clover that are inefficient in nitrogen fixation. This aberrant symbiotic phenotype involves an extensive uncontrolled degradation of the host cell walls restricted to the expected infection sites at tips of deformed root hairs and significantly enlarged infection droplets at termini of wider IT within the nodule infection zone. Furthermore, signs of elevated plant host defense as indicated by reactive oxygen species production in root tissues were more evident during infection by the recombinant strain than its wild-type parent. Our data further support the role of the rhizobial CelC2 cell wall–degrading enzyme in primary infection, and show evidence of its importance in secondary symbiotic infection and tight regulation of its production to establish an effective nitrogen-fixing root nodule symbiosis.

Ultrasound Assisted Solid-Liquid Extraction Devices - Harnessing Active Ingredients from Plant materials – Overview and Analysis

2020 ◽  
Vol 13 ◽  
Author(s):  
Venkatasubramanian Sivakumar
Keyword(s):  
Mass Transfer ◽  
Cell Wall ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Liquid Extraction ◽  
Active Ingredients ◽  
Plant Materials ◽  
Ultrasound Assisted ◽  
Solid Liquid Extraction ◽  
Solid Liquid

Background: In the growing environmental concern use of natural products, efficient processes and devices are necessary. Solid-Liquid extraction of active Ingredients from Plant materials is one of the important unit operations in Chemical Engineering and need to be enhanced. Objectives: Since, these active ingredients are firmly bound to the plant cell wall membrane, which pose mass-transfer resistance and need to get detached through the use of suitable process intensification tools such as ultrasound and suitable devices. Therefore, detailed analysis and review is essential on development made in this area through Publications and Patents. Hence, the present paper illustrates the development of ultrasound assisted device for solid-liquid extraction are presented in this paper. Methods: Advantages such as % Yield, Reduction in extraction time, use of ambient conditions, better process control, avoidance or minimizing multi stage extraction could be achieved due to the use of ultrasound in extraction as compared to conventional processes. Conclusions: Use of ultrasound to provide significant improvements in the extraction of Vegetable tannins, Natural dyes for application in Leather processing has been demonstrated and reported earlier. These enhancement could be possible through various effects of ultrasound such as better flow of solvents through micro-jet formation, mass transfer enhancement due to rupture of plant cell wall membranes through acoustic cavitation, better leaching due to micro-mixing and acoustic streaming effects. This approach would minimize material wastage; thereby, leading to eco-conservation of plant materials, which is very much essential for better environment. Hence, various methods and design for application of ultrasound assisted solid-liquid extractor device are necessary.

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