K. Yamamoto, J. Z. Kiss. Oxford OH 45056.
Gravity is one of the stimuli that is important in plant growth and development.
The sites of gravity perception are the columella cells in roots and endodermal cells in hypocotyls and inflorescence stems. Since plastids likely play a role in these cells for graviperception, we investigated gravitropism in plastid mutants of Arabidopsis . Seedlings and inflorescence stems of both wild-type and arc6 were fixed and sectioned for anatomical studies. Plastid numbers per cell were examined in these sections with light microscopy. In the wild-type, an average of 5 plastids was observed per cell in columella and endodermal cells.