There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.
Abstract
<p class="first" id="d10881961e58">Under stress, isolated microspores are reprogrammed
in vitro towards embryogenesis,
producing doubled haploid plants that are useful biotechnological tools in plant breeding
as a source of new genetic variability, fixed in homozygous plants in only one generation.
Stress-induced cell death and low rates of cell reprogramming are major factors that
reduce yield. Knowledge gained in recent years has revealed that initiation and progression
of microspore embryogenesis involve a complex network of factors, whose roles are
not yet well understood. Here, I review recent findings on the determinant factors
underlying stress-induced microspore embryogenesis, focusing on the role of autophagy,
cell death, auxin, chromatin modifications, and the cell wall. Autophagy and cell
death proteases are crucial players in the response to stress, while cell reprogramming
and acquisition of totipotency are regulated by hormonal and epigenetic mechanisms.
Auxin biosynthesis, transport, and action are required for microspore embryogenesis.
Initial stages involve DNA hypomethylation, H3K9 demethylation, and H3/H4 acetylation.
Cell wall remodelling, with pectin de-methylesterification and arabinogalactan protein
expression, is necessary for embryo development. Recent reports show that treatments
with small modulators of autophagy, proteases, and epigenetic marks reduce cell death
and enhance embryogenesis initiation in several crops, opening up new possibilities
for improving in vitro embryo production in breeding programmes.
</p>