Please wait a minute...
J Integr Plant Biol, 1998, 40 (8): -, Research Article
Early Development and Ultrastructure of the Major Veins and Their Sheath Tissues in the Maize Leaves
OUYANG Xue-Zhi and XIE Shao-Ping
doi:
Abstract
The report described the ultrastructural changes that occurred in the major veins and their associated bundle sheaths (BS) of the maize ( Zea mays L. ) leaf blade in the process of their differentiation from three adjacent cells in the middle layer of the ground meristem, the minimal number of cells involved with the initiation of a procambial strand and the associated BS. The inner cell underwent two successive unequal periclinal divisions: a smaller cell that later differentiated into the adaxial BS cell precursor, and a larger one that divided once again periclinally yielding an abaxial BS cell precursor and a centrally located procambial initial cell. One of the two lateral cells immediately adjacent to either side of the inner cell also divided periclinally; these derivatives, along with another lateral cell of the original three-celled unit formed the precursor cells of the lateral BS. Prior to the initiation of protophlcem differentiation, all of the procambial cells showed ultrastructural characteristics basically similar to the procambial initial. They possessed a prominent nucleus with electron-dense aggregates of heterochromatin, a dense cytoplasm rich in ribosomes, proplastids and mitochondria; also a thin wall containing numerous plasmodesmata. In many cases, only short pieces of rough endoplasmic reticulum cistemae and a few small sized vacuoles were present. In adclifton, evidence of cytoplasmic disintegration leading to new vacuole formation was noted in the process of proeambium development. It was observed that certain endoplasmic reticulum was engaged in the sequestration and lysis of cytoplasm. No apparent uhrastmctuml difference was found between the BS cell precursors and the procambial initials, that was, the distinction between the procambium and the surrounding BS cells occurred gradually after vein initiation, The major ultrastmctural changes which occurred during the differentiation of the meristematic BS cells into the vacuolated cells were (1) a proplastid to chloroplast transformation going through a prolamellar body stage, and (2) the appearance of the multi-concentric membrane complex which might play a role in the degradation of some ribosomes and other cytoplasmic components during the differentiation of BS cells.
--------------------------------------------------------------------------------------------------------------------
   Online on:
This Article
   Full Text  
   Full Text (PDF) 
   Supporting information
Services
   E-mail Link to this Article
   Export Citation for this Article
Citing Articles
   Cited By
Google Scholar
   Articles by OUYANG Xue-Zhi
   Articles by XIE Shao-Ping
PubMed
   Articles by OUYANG Xue-Zhi
   Articles by XIE Shao-Ping
Editorial Office, Journal of Integrative Plant Biology, Institute of Botany, CAS
No. 20 Nanxincun, Xiangshan, Beijing 100093, China
Tel: +86 10 6283 6133 Fax: +86 10 8259 2636 E-mail: jipb@ibcas.ac.cn
Copyright © 2020 by the Institute of Botany, the Chinese Academy of Sciences
Online ISSN: 1744-7909 Print ISSN: 1672-9072 CN: 11-5067/Q
网站备案号:京ICP备16067583号-22