Solanum tuberosum Microtuber Development under Darkness Unveiled through RNAseq Transcriptomic Analysis.

Area of Science:

• Plant Biotechnology
• Molecular Biology
• Genomics

Background:

• In vitro potato microtuber (MT) development is crucial for high-quality plant propagation.
• MT formation is influenced by environmental and chemical factors like photoperiod, sucrose, hormones, and osmotic stress.
• Previous research established a protocol for MT induction using sucrose, gelrite, and cytokinin (2iP) in darkness.

Purpose of the Study:

• To elucidate the molecular mechanisms underlying potato microtuber development.
• To identify key genes and pathways involved in MT formation through transcriptome-wide analysis.

Main Methods:

• Transcriptome-wide analysis was conducted to identify differentially expressed genes during MT development.
• Protein-protein interaction (PPI) network analyses were performed using the STRING database (v11.5).
• Identification and clustering of up- and down-regulated genes and proteins involved in MT formation.

Main Results:

• A total of 1715 genes were up-regulated and 1624 genes were down-regulated during MT development.
• PPI network analysis revealed 299 genes in 14 clusters, with significant enrichment in ribosomal proteins (RPs) and cell cycle (CC) proteins among up-regulated genes.
• Key up-regulated transcription factors (TFs) potentially involved include MYB43, TSF, bZIP27, bZIP43, HAT4, and WOX9.
• Down-regulated genes were predominantly associated with light and photosynthesis, hormone response, hormone-mediated signaling, and aging pathways.

Conclusions:

• The study reveals significant molecular reprogramming during potato microtuber development, involving coordinated regulation of ribosomal proteins, cell cycle progression, and transcription factors.
• Down-regulation of photosynthesis and hormone-related pathways suggests a shift towards storage and dormancy mechanisms.
• These findings provide insights into the genetic basis of potato microtuberization, aiding in the optimization of propagation protocols.