The chloroplasts appear reduced or absent from the provascular and columella cells of walking-stick stage embryos.
RICARDO I TEJOS, ANA V MERCADO, LEE A MEISEL 2010, 'Analysis of chlorophyll fluorescence reveals stage specific patterns of chloroplast-containingcells during Arabidopsis embryogenesis', Biological Researchhttp://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602010000100012. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)