Trichomes control flower bud shape by linking together young petals

Area of Science:

• Plant biology
• Developmental biology
• Genetics

Background:

• Trichomes are plant surface outgrowths with diverse functions, including defense and insulation.
• Emerging evidence suggests trichomes play roles in regulating floral structure.
• The specific mechanism of trichome involvement in flower bud morphogenesis remained largely unexplored.

Discussion:

• Cotton petal trichomes mechanically entangle, forming a 'Velcro'-like structure that anchors adjacent petals.
• This physical association counteracts forces from asymmetric petal expansion, ensuring correct flower bud shape.
• Silencing GhMYBML10, a key petal trichome regulator, via RNA interference (RNAi) disrupts trichome development, leading to aberrant bud morphology.

Key Insights:

• Petal trichome entanglement is crucial for maintaining cotton flower bud shape and protecting reproductive organs.
• Disruption of this mechanism, as shown by GhMYBML10 silencing, results in corkscrew-shaped buds and desiccation damage.
• Artificial adhesion of petal edges partially restores normal bud shape and fertility, highlighting the importance of physical connections.

Outlook:

• The petal 'Velcro' mechanism may be conserved in other Malvaceae and potentially other plant families.
• This discovery offers a novel perspective on organ shape control, distinct from traditional cell-based signaling pathways.
• Further research could explore the genetic and evolutionary basis of this physical association mechanism in floral development.