10 Seed Development in Arabidopsis thaliana

Abstract

Seed production is perhaps the most impressive feature of the life cycle in Arabidopsis thaliana. Anyone who has ventured into an Arabidopsis growth room or transported mature plants from one place to another has observed the large number of seeds scattered everywhere. A single plant under optimal conditions can produce over 20,000 seeds within a few weeks. This remarkable efficiency in seed production was one of the features that first attracted scientists to Arabidopsis as a model system for genetic analysis (Rédei 1970). However, the view that Arabidopsis might serve as a model system for genetic and molecular analysis of seed development (Meinke and Sussex 1979a) was initially greeted with skepticism. With so many crop plants and large seeds to choose from, it seemed unnecessary for plant biologists to divert attention to a laboratory organism with small seeds. The amount of effort required to isolate sufficient material for biochemical assays seemed to discourage even Arabidopsis enthusiasts.

Fortunately, there were also several attractive features of seed development in Arabidopsis that eventually became apparent to plant biologists. Classical botanists had long recognized that in crucifers, the arrangement of fruits (siliques) in a developmental progression along the length of the stem simplified the identification of seeds at desired stages of development. They also valued small seeds because relatively few sections were required to visualize internal structures. The translucent nature of the seed coat prior to desiccation allowed direct observation of many basic features of embryo development, and the ability to distinguish unfertilized ovules,...