Stability of the determined state

Area of Science:

• Plant Biology
• Developmental Biology
• Epigenetics

Background:

• Plant development involves cell fate determination, traditionally viewed as supracellular.
• The inheritance of determined states at the cellular level remains an area of investigation.

Purpose of the Study:

• To investigate the cellular inheritance of determined states in plant cells.
• To explore the role of cytokinin requirement in cellular determination.
• To examine the genetic and epigenetic mechanisms underlying cell fate stability.

Main Methods:

• Culturing tobacco cells from leaf lamina and stem cortex.
• Plant regeneration experiments to assess cell state inheritance.
• Analysis of cytokinin requirement (C- and C+ states) and habituation.
• Genetic analysis involving a dominant Mendelian gene (H1-2).

Main Results:

• Cultured leaf and cortex cells exhibit distinct, inheritable states of cytokinin requirement (C- and C+).
• These states are stable but not permanent, with progeny capable of forming complete plants.
• Pith cells can habituate from C- to C+ state, suggesting epigenetic plasticity.
• Evidence indicates a positive-feedback mechanism stabilizing epigenetic changes and a gene (H1-2) controlling phenotypes.

Conclusions:

• Plant cell determination can be inherited at the cellular level, not solely supracellularly.
• Cytokinin requirement states are stable epigenetic traits influenced by cellular memory.
• Both epigenetic mechanisms (habituation, feedback) and genetic factors (H1-2 gene) stabilize cell states.