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Anatomy, Quiescent centre, and their function

The quiescent centre (QC) is a hemispherical region of inactive cells located between the root cap and the active meristematic region in plants such as Zea mays and Vicia faba. Cells in the QC exhibit low concentrations of DNA, RNA, and proteins, and altered mitochondrial function that reduces ATP production, impacting the establishment and maintenance of the QC. The QC serves as a reservoir of cells that can become active during root damage or the development of secondary roots.

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Topic- Quiescent centre DEPARTMENT OF BOTANY Submitted to-Dr. Rikky Rai Dr. Priyanka Mishra Submitted by- Jagriti Dubey
Quiescent Centre Introduction: Central cap like or hemispherical region of inactive cell. Present in between the Root cap and active meristematic region of root apex. observed by Clowes (1956, 58) in Root tips of Zea mays (Maize). Quiscent centre is also present in many plants like Vicia faba Features of cells of Quiscent centre cells: Low concentration of DNA, RNA and Proteins. Fewer number of mitochondria, less endoplasmic reticulum and small dictyosomes.
The physiology and cytological properties of cells in the QC have now studied in a number of species: Species QC Cells Zea mays 174 500-600 Vicia feba 292 1100 Sinapis alba 520 600 A QC arise twise in primary roots:  Embryogeny  Stage of seed germination TheQC variable in volume :  Thin roots smaller or entirely absent  Long roots distinctive centre  Short roots no QC  Seedless it lack QC Vascular plants
A Role for Mitochondria in the Establishment and Maintenance of the Maize Root Quiescent Center Mitochondria in the oxidizing environment of the maize (Zea mays) root quiescent center (QC) are altered in function, but otherwise structurally normal.  Compared to mitochondria in the adjacent, rapidly dividing cells of the proximal root tissues, mitochondria in the QC show marked reductions in the activities of tricarboxylic acid cycle enzymes.  Use of several mitochondrial membrane potential (ΔΨm) sensing probes indicated a depolarization of the mitochondrial membrane in the QC, which suggests a reduction in the capacity of QC mitochondria to generate ATP and NADH.  Modifications of mitochondrial function are central to the establishment and maintenance of the QC.
 Auxin and cytokinin play antagonistic roles in regulating QC activity. Cytokinin promotes cell division and can activate the QC when present in excess. Auxin helps counteract this effect by restricting cytokinin signaling and its downstream pathways. Ethylene interacts with auxin in complex ways, both promoting and inhibiting QC activity depending on the context. It can influence auxin distribution and signaling, adding another layer of control to the QC maintenance. Function of Quiescent centre: • Act as reservoir of cells. • Cells become active whenever the previously active initials get damaged. •Cells become active during development of secondary roots. NOTE: Normally cells of Quiescent centre do not divide and remains inactive.
REFERENCE:  SINGH PANDE JAIN – DIVERSITY OF ANGIOSPERM,RASTOGI PUBLICATION  Dr. B.P.PANDEY- A TEXT BOOK OF BOTANY ANGIOSPERM,S.Chand  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1400572/ Thank you
Topic- Quiescent centre DEPARTMENT OF BOTANY Submitted to-Dr. Rikky Rai Dr. Priyanka Mishra Submitted by- Jagriti Dubey
Quiescent Centre Introduction: Central cap like or hemispherical region of inactive cell. Present in between the Root cap and active meristematic region of root apex. observed by Clowes (1956, 58) in Root tips of Zea mays (Maize). Quiscent centre is also present in many plants like Vicia faba Features of cells of Quiscent centre cells: Low concentration of DNA, RNA and Proteins. Fewer number of mitochondria, less endoplasmic reticulum and small dictyosomes.
The physiology and cytological properties of cells in the QC have now studied in a number of species: Species QC Cells Zea mays 174 500-600 Vicia feba 292 1100 Sinapis alba 520 600 A QC arise twise in primary roots:  Embryogeny  Stage of seed germination TheQC variable in volume :  Thin roots smaller or entirely absent  Long roots distinctive centre  Short roots no QC  Seedless it lack QC Vascular plants
A Role for Mitochondria in the Establishment and Maintenance of the Maize Root Quiescent Center Mitochondria in the oxidizing environment of the maize (Zea mays) root quiescent center (QC) are altered in function, but otherwise structurally normal.  Compared to mitochondria in the adjacent, rapidly dividing cells of the proximal root tissues, mitochondria in the QC show marked reductions in the activities of tricarboxylic acid cycle enzymes.  Use of several mitochondrial membrane potential (ΔΨm) sensing probes indicated a depolarization of the mitochondrial membrane in the QC, which suggests a reduction in the capacity of QC mitochondria to generate ATP and NADH.  Modifications of mitochondrial function are central to the establishment and maintenance of the QC.