scholarly journals Induction of Defense Responses in Cultured Parsley Cells by Plant Cell Wall Fragments

1987 ◽  
Vol 84 (4) ◽  
pp. 1286-1290 ◽  
Author(s):  
Keith R. Davis ◽  
Klaus Hahlbrock
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Defense Responses

Hydroxycinnamic acid amide metabolism: physiology and biochemistry

2002 ◽  
Vol 80 (6) ◽  
pp. 577-589 ◽  
Author(s):  
Peter J Facchini ◽  
Jillian Hagel ◽  
Katherine G Zulak
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Floral Induction ◽  
Defense Responses ◽  
Hydroxycinnamic Acid ◽  
Flower Formation ◽  
Physiology And Biochemistry ◽  
Hydroxycinnamic Acid Amides ◽  
Coa Thioesters

Hydroxycinnamic acid amides (HCAAs) are a widely distributed group of plant secondary metabolites purported to function in several growth and developmental processes including floral induction, flower formation, sexual differentiation, tuberization, cell division, and cytomorphogenesis. Although most of these putative physiological roles for HCAAs remain controversial, the biosynthesis of amides and their subsequent polymerization in the plant cell wall are generally accepted as integral components of plant defense responses to pathogen challenge and wounding. Tyramine-derived HCAAs are commonly associated with the cell wall of tissues near pathogen-infected or wound healing regions. Moreover, feruloyltyramine and feruloyloctapamine are covalent cell wall constituents of both natural and wound periderms of potato (Solanum tuberosum) tubers, and are putative components of the aromatic domain of suberin. The deposition of HCAAs is thought to create a barrier against pathogens by reducing cell wall digestibility. HCAAs are formed by the condensation of hydroxycinnamoyl-CoA thioesters with phenylethylamines such as tyramine, or polyamines such as putrescine. The ultimate step in tyramine-derived HCAA biosynthesis is catalyzed by hydro xycinnamoyl-CoA:tyramine N-(hydroxycinnamoyl)transferase (THT; E.C. 2.3.1.110). The enzyme has been isolated and purified from a variety of plants, and the corresponding cDNAs cloned from potato, tobacco (Nicotiana tabacum), and pepper (Capsicum annuum). THT exhibits homology with mammalian spermidine-spermine acetyl transferases and putative N-acetyltransferases from microorganisms. In this review, recent advances in our understanding of the physiology and biochemistry of HCAA biosynthesis in plants are discussed.Key words: hydroxycinnamic acid amides, hydroxycinnamoyl-CoA thioesters, metabolic engineering, phenylethylamines, plant cell wall, polyamines, secondary metabolism, tyramine.

scholarly journals A Meloidogyne graminicola Pectate Lyase Is Involved in Virulence and Activation of Host Defense Responses

2021 ◽  
Vol 12 ◽  
Author(s):  
Jiansong Chen ◽  
Zhiwen Li ◽  
Borong Lin ◽  
Jinling Liao ◽  
Kan Zhuo
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Signal Sequence ◽  
Expression System ◽  
Pectate Lyase ◽  
Defense Responses ◽  
Hydrolytic Activity ◽  
Parasitic Nematodes ◽  
Cell Wall Degrading Enzymes

Plant-parasitic nematodes secrete an array of cell-wall-degrading enzymes to overcome the physical barrier formed by the plant cell wall. Here, we describe a novel pectate lyase gene Mg-PEL1 from M. graminicola. Quantitative real-time PCR assay showed that the highest transcriptional expression level of Mg-PEL1 occurred in pre-parasitic second-stage juveniles, and it was still detected during the early parasitic stage. Using in situ hybridization, we showed that Mg-PEL1 was expressed exclusively within the subventral esophageal gland cells of M. graminicola. The yeast signal sequence trap system revealed that it possessed an N-terminal signal peptide with secretion function. Recombinant Mg-PEL1 exhibited hydrolytic activity toward polygalacturonic acid. Rice plants expressing RNA interference vectors targeting Mg-PEL1 showed an increased resistance to M. graminicola. In addition, using an Agrobacterium-mediated transient expression system and plant immune response assays, we demonstrated that the cell wall localization of Mg-PEL1 was required for the activation of plant defense responses, including programmed plant cell death, reactive oxygen species (ROS) accumulation and expression of defense-related genes. Taken together, our results indicated that Mg-PEL1 could enhance the pathogenicity of M. graminicola and induce plant immune responses during nematode invasion into plants or migration in plants. This provides a new insight into the function of pectate lyases in plants-nematodes interaction.

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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