root gravicurvature began by 15 min after reorientation , and did not involve significant changes in the ( i ) volume of individual columella cells or amyloplasts , ( ii ) relative volume of any cellular organelle , ( iii ) number of amyloplasts per columella cell , or ( iv ) surface area of cellular location of endoplasmic reticulum .
C0007634
cellular
C0014239
endoplasmic reticulum