Add Sugars, Impair Growth (IMAGE) Cold Spring Harbor Laboratory Caption The pistil of a flowering mustard plant Arabidopsis thaliana with a single HPAT gene mutation (left). The pollen tube (stained blue) penetrates deep enough to reach and fertilize local egg cells (arrows) -- the beginning of the process by which they become seeds. However, when two HPAT genes are mutated in Arabidopsis (right), the pollen tube is stunted. Without a proper "pollen pathway" to reach them, the plant's ovules are left barren. Curiously, then, HPAT mutations can have developmental consequences in both the simple moss (see accompanying image #2) and the more evolved mustard plant -- enhancing growth in the one, impairing it in the other. Credit Lippman lab, Cold Spring Harbor Laboratory Usage Restrictions give credit please License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.