Oxygen-depleted zones inside reproductive structures ofBrassicaceae: implications for oxygen control of seed development
作者:
D Marshall Porterfield,
Anxiu Kuang,
Peter JS Smith,
Mark L Crispi,
Mary E Musgrave,
期刊:
Canadian Journal of Botany
(NRC Available online 2000)
卷期:
Volume 77,
issue 10
页码: 1439-1446
ISSN:0008-4026
年代: 2000
DOI:10.1139/b99-098
出版商: NRC Research Press
数据来源: NRC
摘要:
Growth ofArabidopsis thaliana(L.) Heynh. in decreasing oxygen partial pressures revealed a linear decrease in seed production below 15 kPa, with a complete absence of seed production at 2.5 kPa oxygen. This control of plant reproduction by oxygen had previously been attributed to an oxygen effect on the partitioning between vegetative and reproductive growth. However, plants grown in a series of decreasing oxygen concentrations produced progressively smaller embryos that had stopped developing at progressively younger stages, suggesting instead that their growth is limited by oxygen. Internal oxygen concentrations of buds, pistils, and developing siliques ofBrassica rapaL. and siliques ofArabidopsiswere measured using a small-diameter glass electrode that was moved into the structures using a micromanipulator. Oxygen partial pressures were found to be lowest in the developing perianth (11.1 kPa) and pistils (15.2 kPa) of the unopened buds. Pollination reduced oxygen concentration inside the pistils by 3 kPa after just 24 h. InsideBrassicasilique locules, partial pressures of oxygen averaged 12.2 kPa in darkness, and increased linearly with increasing light levels to 16.2 kPa. Measurements insideArabidopsissiliques averaged 6.1 kPa in the dark and rose to 12.2 kPa with light. Hypoxia in these microenvironments is postulated to be the point of control of plant reproduction by oxygen.
点击下载:
PDF
(3741KB)
返 回