we launched imbibed seeds and seedlings of zea mays into outer space aboard the space shuttle columbia to determine the influence of microgravity on 1 ) root-cap regeneration , and 2 ) the distribution of amyloplasts and endoplasmic reticulum ( er ) in the putative statocytes ( i.e. , columella cells ) of roots .
C0014239
endoplasmic reticulum
C0007634
cells