Analysis of Gametophytic Apomixis Using Confocal Microscopy.

Area of Science:

• Plant reproductive biology
• Cellular and molecular biology
• Genetics

Background:

• Apomixis is an asexual reproduction method occurring within plant ovules and seeds.
• Gametophytic apomixis involves producing an unreduced female gametophyte via modified meiosis or somatic cells.
• Parthenogenesis leads to embryo development from an unreduced egg cell, but studying these processes is difficult due to inaccessibility.

Purpose of the Study:

• To present a Feulgen staining protocol combined with confocal microscopy for studying apomixis.
• To obtain high-resolution images of female reproductive cells in whole-mount ovaries.
• To demonstrate the protocol's utility in analyzing mutants affecting apomixis.

Main Methods:

• Application of a Feulgen staining protocol.
• Utilizing confocal microscopy for high-resolution imaging.
• Whole-mount ovary preparations for rapid and simple analysis.

Main Results:

• Successfully obtained high-resolution images of nonreductional megasporogenesis and autonomous embryo formation.
• Visualized key cellular events in diplosporous (Taraxacum officinale) and aposporous (Pilosella piloselloides var. praealta) apomixis.
• Demonstrated the protocol's effectiveness for studying loss-of-diplospory and loss-of-parthenogenesis mutants.

Conclusions:

• The Feulgen staining and confocal microscopy method provides a powerful tool for high-definition imaging of plant reproductive processes.
• This technique simplifies the cyto-embryological study of apomixis, overcoming previous accessibility challenges.
• The protocol is valuable for investigating the genetic basis of apomixis and associated mutations.