Abstract Detail

Development and Structure

Gladish, Daniel K [1], Saito, Susumu [2], Niki, Teruo [2].

Metaxylem vessel collapse during early development in primary roots of Zea mays ssp. mexicana.

Root apical meristem histological organization in Zea mays has been carefully studied previously. Classical histology describes its system as having “closed organization” with three histogen layers, calyptrogen, dermatogen/periblem, and plerome, that produce the rootcap, the protoderm and ground meristem tissue, and the procambium tissue, respectively. The spacing and timing of differentiation events of the procambium have been determined for root tips of modern cultivars of Z. mays. We were interested in seeing if an anatomical analysis of primary root apical meristem organization among the subspecies of Z. mays known as teosinte could contribute to understanding how evolutionary processes and the domestication of modern maize varieties might have affected developmental patterns in the roots. Root tips of seedlings were prepared, embedded in appropriate resins, and sectioned for light and transmission electron microscopy. While evaluating the mexicana subspecies of Z. mays, we encountered a severe abnormality of xylem development among 4% of the 227 mexicana seedlings screened. We provide detailed data indicating that all metaxylem vessel elements in these abnormal roots collapsed and probably became non-functional shortly after differentiation began. We speculate that these seedlings suffered from a mutation that affected the timing of the cell death program that is required to produce functional xylem vessels.

1 - Miami University, Department of Biology, 1601 University Blvd, Hamilton, OH, 45011, USA
2 - Takushoku University, Department of Biotechnology, Tatemachi 815-1, Hachioji, Tokyo, 193-0985, Japan

Keywords:
teosinte root
vascular development
vessel collapse
programmed cell death mutation.

Presentation Type: Oral Paper
Session: 29, Development and Structure I
Location: 202/Savannah International Trade and Convention Center
Date: Tuesday, August 2nd, 2016
Time: 3:00 PM
Number: 29007
Abstract ID:874
Candidate for Awards:None