DEVBIO EMBRYOGENESIS

• stage of development that produces photosynthetic structures of the plant

  Vegetative development
• stage of development that focuses only in proliferation

  reproductive development
• how plants perceive where to grow

  polarity
• transformation of a single-celled zygote into a considerably more complex individual contained in the mature seed

  Embryogenesis
• process wherein the basic architecture of the plant is established, including the elaboration of forms

  morphogenesis
• process wherein there is an associated formation of functionally organized structures

  organogenesis
• process wherein there is a differentiation of cells to produce anatomically and functionally distinct tissues

  histogenesis
• changes in physiology that enables the embryo to withstand prolonged periods of inactivity

  dormancy
• enables the embryo to recognize and interpret environmental cues that signal the plant to resume growth

  germination
• division in the RAM and SAM signals the start of germination
• axis responsible for primary growth (RAM and SAM)

  Apical-basal axis
• axis responsible for secondary growth

  radial axis
• the first precursor cells

  apical and basal cell
• Small proteins appear to move readily in all stages of embryogenesis
• mobility of larger proteins is lower and becomes more restricted in older embryos
• mutation in this gene inhibits apical growth

  gurke
• mutation in this gene inhibits central growth

  fackel
• mutation in this gene inhibits basal growth

  monopteros
• mutation in this gene inhibits terminal growth

  gnom
• this is the starting point of RAM

  hypophysis
• suspends plant embryo from mother cell and acts like the umbilical cord

  suspensor cell
• signals the start for secondary growth; xylem and phloem

  eight-cell embryo
• gated channels present in one plant cell connecting it to its adjacent cell

  plasmolemma
• as the embryo increases in age, the smaller the molecules that can pass through the plasmolemma
• gene required for normal phloem development

  wol gene
• mutation in this gene leads to failure in the separation of the cortex and endodermis

  scr gene
• mutation in this gene leads to the failure of endodermic differentiation

  shr gene
• the five meristematic tissues are:

  RAM, SAM, intercalary meristem, marginal meristem, meristemoids
• this meristematic tissue gives the vascular cambium

  intercalary meristem
• this meristematic tissue are found in the edges of developing organs

  marginal meristem
• this meristematic tissue gives rise to trichomes & stomata

  meristemoids
• gives rise to columella of root cap

  Columella cells
• divide anticlinally to create daughter cells that divide periclinally to form two files of cells that mature into lateral root cap and epidermis

  Epidermal-lateral root cap initials
• divide anticlinally to create daughter cells that divide periclinally to form two cortical and endodermal cell layers

  Cortical-endodermal initials
• gives rise to vascular system and pericycle

  Stele initials
• zone of the RAM with completed differentiation and produces mature root structure

  Maturation zone
• zone of the RAM wherein the cells are actively dividing

  Elongation zone
• zone of the RAM wherein there is root elongation & growth

  Meristematic zone
• zone of the RAM wherein division is slow; reservoir

  Quiescent center
• zone in the RAM composed of columella cells + statoliths

  Root cap