Practice question

WOX2 and WOX8 are WUSCHEL-related homeobox transcription factors establishing apical and basal daughter lineages immediately after first asymmetric zygotic division. WOX2 marks apical cell promoting embryo proper development, protoderm specification, shoot identity, while WOX8 and WOX9 drive basal lineage suspensor development, auxin transport asymmetry via PIN7 polarity, and hypophysis specification. Complementary expression controls zygote elongation, division orientation, and downstream patterning cascades. Double mutants exhibit defective PIN1 distribution, misoriented divisions, abnormal apical-basal patterning, indicating these factors integrate transcriptional asymmetry with auxin transport to consolidate zygote polarity and early patterning events.